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Oral Abstracts O1 Functionally Distinct HMGB1 Isoforms Correlate With Physiological Processes In Drug-Induced SJS/TEN. Daniel F Carr1, Wen-Hung Chung2, Rosalind E Jenkiins1, Mas Chaponda1, Gospel Nwikue1, Elena M Cornejo Castro1, Daniel J Antoine1, Munir Pirmohamed1 1. University of Liverpool, Liverpool, United Kingdom 2. Chang Gung Memorial Hospital, Taipei, Taiwan Keywords: Stevens Johnson Syndrome, HMGB1, Biomarker, Hypersensitivity Introduction Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are serious, life threatening severe immune-mediated cutaneous reactions with mortality ranging from 10-30%. The commonest causes are drugs. SJS/TEN is characterised by widespread epidermal detachment due to keratinocyte cell death. Increased concentrations of cytotoxic molecules may act as potential serum biomarkers of SJS/TEN. However, to date no mechanism based biomarker has been validated for diagnostic utility in this field. HMGB1 is a well-validated biomarker of cell death and inflammation. This study investigated whether HMGB1 represents a valid, utilisable biomarkers for drug-induced SJS/TEN. Method Serum samples from nevirapine-treated Malawian HIV patients (27 MPE, 12 DRESS, 12 SJS/TEN cases and matched tolerant controls) were analysed for total HMGB1 by ELISA. Novel mass-spectrometric protocols were also used to analyse post-translationally modified forms of HMGB1. In addition serum from 20 Taiwanese SJS patients (5 carbamazepine, 8 allopurinol, 5 phenytoin, 2 sulfamethoxazole) both during and post-reaction were analysed for HMGB1 isoforms. Results There was a significant elevation of mean total serum HMGB1at time of reaction in patinets with nevirapine-induced MPE (6.0ng/ml), HSS (6.3ng/ml) and SJS/TEN (15.9ng/ml) comapred to tolerant controls at weeks (1.3ng/ml) (p<0.001). Analysis of post-translationally modified isoforms of the HMGB1 in the different phenotypes (Fig. 1) showed patients with MPE and DRESS had elevation the acetylated form of HMGB1 which is a marker of innate immunity. By contrast, SJS/TEN patient sera contained comparable levels of acetylated HMGB1, but also had very high levels of the non-acetylated form, which is associated with cell death/ tissue injury. The tolerant control patients had low levels of the unacetylated form. This pattern of HMGB1 isoform elevation was replicated in the Taiwanese SJS cohort. As patients recovered, the total HMGB1 concentrations went down, although there was still significant elevation of the suphonyl (partially reduced) HMGB1 isoform which has no known immune function and may represent a marker of innate immunity returning to "steady state". Conclusion In conclusion, our data suggest that post-translationally modified HMGB1 may represent mechanism-based diagnostic and prognostic markers for drug-induced SJS/TEN. This needs to be studied in more patients. O2 Hypersensitivity Reactions To Beta-Lactams, Does The T Cell Recognition Pattern Influence The Clinical Picture? Natascha Wuillemin, Dolores Dina, Klara K Eriksson, Daniel Yerly University Hospital Bern, Bern, Switzerland Keywords: Hapten, PI, Amoxcillin Introduction Worldwide, beta-lactam antibiotics can commonly cause hypersensitivity reactions (HR) with various clinical pictures from minor affections like maculopapular exanthema (MPE) and urticaria to severe cutaneous adverse reactions (SCAR) and anaphylaxis. Currently, two different concepts provide rational explanations how a drug can initiate a drug HR by activating human T cells – the hapten concept and the pharmacological interaction with immune receptor (p-i) concept. In this study, we investigated the relationship between the reactivity pattern of drug-reacting T cells found in the peripheral blood of allergic patients and their clinical picture. Method We expanded beta-lactams reacting T cells from drug allergic individuals, including patients with typically IgE mediated hypersensitivity reactions such as urticaria or anaphylaxis as well as patients with T cell mediated reactions such as MPE and SCAR. The drug-reacting T cells were analyzed in terms of their phenotype (CD4+/CD8+) and the recognition pattern of AMX, e.g. hapten or p-i. Results From patients with type I HR to amoxicillin, T cell clones (TCC) could be generated and analysed. They showed amoxicillin reactivity according to the hapten mechanism: antigenic complexes were stably presented and antigen presentation machinery was essential for T cell activation. TCC from patients suffering from MPE showed similar features. Three patients with DRESS to amoxicillin or ceftriaxone could be included. Drug reacting T cells from those patients showed exclusively reactivity according to pi-concept. Stimulatory antigenic complexes were not stably presented for T cell activation and addition of drug to TCC in the presence of antigenic presenting cells lead to immediate activation, measured by calcium intake. Conclusion We conclude that T cells from type I HR and MPE patients recognize beta-lactams according to the hapten mechanism. In contrast, in patients with SCAR, the p-i concept might also be relevant for beta-lactams recognition. Consequently, the current preclinical risk evaluation of new drugs to cause severe HR, which is solely based on their ability to form haptens, might be insufficient. O3 Specific Binding Characteristics Of HLA Alleles Associated With Nevirapine Hypersensitivity Rebecca Pavlos1, Elizabeth Mckinnin1, David Ostrov2, Bjoern Peters3, Soren Buus4, David Koelle5, Abha Chopra1, Craig Rive1, Alec Redwood1, Susana Restrepo6, Austin Bracey6, Jing Yuan7, Silvana Gaudieri8, Mary Carrington9, David Haas10, Simon Mallal10, Elizabeth Phillips10 1. Murdoch University, Perth, Australia 2. University of Florida, Gainesville, United States 3. La Jolla Institute for Allergy and Immunology, La Jolla, United States 4. University of Copenhagen, Copenhagen, Denmark 5. University of Washington, Seattle, United States 6. Univesrity of Florida, Gainesville, United States 7. Boehringer Ingelheim Inc, Ridgefield, United States 8. Univesrity of Western Australia, Perth, Australia 9. Ragon Insitute, Cambridge, United States 10.Vanderbilt University, Nashville, United States Keywords: Nevirapine, HLA, Peptide Binding Groove Introduction Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) associated with a hypersensitivity syndrome (HSR) in approximately 5% of patients. Multiple class I/II HLA associations have been described in association with NVP hypersensitivity reaction (HSR) phenotypes. Based on the established models of drug HSR which highlight the significance of the HLA peptide binding groove for specific drug interactions, we compared NVP HSR-associated alleles across ethnic groups for similarities in peptide binding specificities and HLA binding pocket structure. Method HLA typing was performed on DNA from ClinicalTrials.gov NCT00310843. Univariate and multivariate analyses stratified for race were performed according to HLA class I/II alleles, MHCcluster groups and key HLA peptide binding groove amino acids. Results Examination of HLA allele peptide binding characteristics, together with structure of the B and F pockets in the peptide binding cleft identified a group of HLA-C alleles with common binding properties, and the same F pocket structure as HLAC*04:01 that were predictive of cutaneous NVP HSR (HLA-C*04:(03/06/07),C*05:(01/09),-C*18:01) (OR [95%CI] 2.9 [1.6-5.23], p=0.005). Similarly, a group of protective HLA-B alleles with a characteristic B pocket was identified (HLA-B*15:(01/12/24/25/27/32/35),-B*52:01)( OR [95%CI] =0.2 [0.07-0.5], p=0.0003). HLA-DRB1 alleles DRB1*01:(01/02/03), DRB1*04:(04/05/08/10),DRB1*14:02) which share the DRB1-P4 pocket were found to associate with cutaneous NVP HSR (OR [95%CI] 2.15 [1.23-3.24], p = 0.0013). Molecular docking suggests that NVP is able to bind to the B pocket in both HLA-B and HLA-C as well as the P4 residues in HLA-DRB1 Conclusion The cutaneous phenotypes of NVP HSR associates with different HLA-C, HLA-B and DR-alleles respectively that share peptide binding characteristics and binding pocket structure. Models suggest that NVP may bind directly to multiple HLA within the antigen binding cleft in the site normally occupied by peptide. The identified HLA-NVP interactions will have consequences for peptide binding and T cell receptor recognition in NVP HSR. O4 Do We Need To Measure Total IgE For The Interpretation Of Analytical Results Of ImmunoCAP And 3gAllergy Specific IgE? Douwe De Boer1, Paul Menheere1, Chris Nieuwhof2, Judith Bons1 1. Central Diagnostic Laboratory, MUMC+, Maastricht, Netherlands, The 2. Internal Medicine, MUMC+, Maastricht, Netherlands, The Keywords: Total IgE, Penicillin, Chlorhexidine, ImmunoCAP, 3gAllergy Introduction Non-specific binding of IgE in in-vitro IgE allergy tests contributes to falsepositive results. For ImmunoCAP it is stated that very low levels of allergen specific IgE (sIgE) should be evaluated with caution when total IgE (tIgE) > 1000 kU/L. For β-lactams and chlorhexidine sIgE the warning limit is 500 kU/L. For 3gAllergy no such alerts are known. These warnings imply to measure tIgE for an interpretation of analytical results of at least ImmunoCAP sIgE. Goal of this study is to verify such warning limits for ImmunoCAP as well as 3gAllergy. Method Relationship between sIgE and tIgE was investigated for ImmunoCAP (Thermo Fisher) and 3gAllergy (Siemens) penicillin V sIgE as well as for ImmunoCAP chlorhexidine sIgE. Ves v 5 sIgE was taken as the 1000 kU/L limit control. All tests were performed according the manufacturers’ instructions. Because ImmunoCAP and 3gAllergy tIgE have a very strong correlation (r = 0.995), sIgE of both tests were graphically plotted against ImmunoCAP tIgE only. An iterative polynomial regression procedure, which excluded outliers when those after fitting were outside the 95% confidence interval, was applied to check for the nature of a relationship. Results For ImmunoCAP penicillin V (r = 0.900) and chlorhexidine (r = 0.888) strong polynomial relations were observed, while for ImmunoCAP Ves v 5 only very weak relations (r < 0.500) were noticed. For tIgE > 500 kU/L most of the penicillin V and chlorhexidine sIgE values were > 0.10 kU/L and with increasing tIgE the number of sIgE values > 0.35 kU/L increased. For 3gAllergy some results were > 0.35 kU/L, but the majority of results was < 0.10 kU/L and consequently insufficient data points were obtained for adequate regression. ImmunoCAP is based on high-capacity binding cellulose and at relatively high concentrations of tIgE, the frequency of possible false-positive results increases, especially for penicillin V and chlorhexidine sIgE. 3gAllergy is based on non-specified polymers attached to a bead, which is also subjected to false-positive results for penicillin V sIgE, but only at lower levels and frequency. Conclusion The warning limit of 500 kU/L of tIgE for ImmunoCAP penicillin V and chlorhexidine sIgE is valid and above the limit false-positive results are likely. For 3gAllergy penicillin V sIgE a limit is also needed but at a higher level. Consequently, for the respective tests we do need to measure tIgE for any sIgE result > 0.10 kU/L. O5 Neutrophil Activation In Systemic Anaphylaxis: Results From The Multicentric NASA Study Friederike Jonsson1, Luc De Chaisemartin2, Vanessa Granger2, Caitlin Gillis1, Aurelie Gouel1, Catherine Neukirch2, Fadia Dib2, Pascale Roland Nicaise2, Dan Longrois2, Florence Tubach2, Sylvie Martin2, Pierre Bruhns1, NASA Study Group3 1. Institut Pasteur, France, France 2. Hopital Bichat, France, France 3. Institut Pasteur & Hopital Bichat, France, France Keywords: Anaphylaxis, Drug, Curare, IgG, Neutrophils Introduction Anaphylaxis is a severe systemic allergic reaction that can be life-threatening. In about 85% of cases evidence for the activation of the classical anaphylaxis pathway involving IgE and IgE receptors can be detected. Recently, an alternative pathway involving IgG and IgG receptors (FcγRs) on neutrophils has been suggested by animal models. We hypothesized that such a mechanism may also exist in humans and studied this possibility in a multicentric prospective cohort of patients suspected of perioperative anaphylaxis to neuromuscular blocking agents (NMBA). Method Consecutive patients suspected of perioperative anaphylaxis (n=86 cases) were recruited and paired with 86 control patients. Blood samples were collected for cases and controls promptly after anesthesia induction. Extensive allergological testing was performed 6-8 weeks after the reaction for cases. Circulating elastase, neutrophil extracellular traps (NETs), tryptase, histamine, and IgG and IgE anti-NMBA were measured by ELISA. FcγR expression on the major cell populations in the blood was analyzed by flow cytometry. Results We found higher circulating NETs and elastase levels during an anaphylactic reaction compared to controls. IgG anti-NMBA were found in both cases and controls, however for cases the IgG titer was associated with anaphylaxis severity. Finally, we show a significant decrease of FcγR expression specifically on neutrophils, pointing towards their engagement by immune complexes. This decrease not only correlated significantly with NET release but also with the severity of the anaphylactic reaction. Together, our results strongly suggest an activation of neutrophils by NBMA-IgG complexes during anaphylaxis. Conclusion We reveal for the first time the existence of an IgG-dependent neutrophil activation pathway during anaphylaxis in human. This additional mechanism opens potential applications in anaphylaxis diagnostics and treatment. O6 Purpuric Drug Eruptions Due To Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors (EGFR-TKIs) For Non-Small-Cell Lung Cancer (NSCLC): A Clinic-Pathological Study Of 32 Cases Kai-Lung Chen1, Shu-Ling Liao1, Yi-Shuan Sheen1, Yung-Tsu Cho1, Che-Wen Yang1, Jau-Yu Liau2, Chia-Yu Chu1 1. Department of Dermatology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, Taipei, Taiwan 2. Department of Pathology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, Taipei, Taiwan Keywords: EGFR-TKIs, Purpura, Vasculitis, Staphylococcus Introduction Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have been widely used to treat non-small-cell lung cancer (NSCLC). Skin toxicities related to EGFR-TKIs are common, such as acneiform eruptions, pruritus, xerosis, and paronychia. However, purpuric eruptions are rarely seen and only few cases reported. We conducted this study to classify the purpuric drug eruptions due to EGFR-TKIs (gefitinib, erlotinib, or afatinib) for NSCLC with clinicpathological correlations. Method During January 2012 to August 2015, 32 patients were included in this study. We recorded the characteristic, lag period, and also the peripheral platelet counts while biopsy. Skin biopsies with tissue culture were undertaken in every patients. DIF studies were performed in most of them. Results We classified the clinical presentations into four different types: purpura only (n=7, 21.9%), eczema craquelé-like (n=5, 15.6%), pustulosis (n=16, 50%), and necrolytic migratory erythema (NME)-like patches (n=8, 25%). Different types could be presented on the same patient concomitantly. 93% (15/16) of pustulosis type specimens grew Staphylococcus aureus, whereas only 25% (5/20) among other types. Most of the histopathology showed parakeratosis, hypogranulosis, perivascular lymphocytic and neutrophilic infiltration, endothelial cell swelling and RBC extravasation. Typical leukocytoclastic vasculitis (LCV) was found in 13-29% of patients. Most of the DIF showed negative finding. Most of the patients were responsive to one-week systemic cefazolin treatment with or without discontinuing the EGFR-TKI. Conclusion There are four types of the purpuric drug eruptions due to EGFR TKIs: purpura, eczema craquelé-like, pustulosis, and NME-like patches. No significant histopathological differences between each group, and less than one third of patients presented typical LCV. Staphylococcus aureus was the most common pathogen identified. Most of the patients showed dramatic improvement by the treatment of systemic antibiotics, especially those with pustulosis type. Poster presentations Poster Walk 1: Anaphylaxis (P01 – P09) P01 Anaphylactic Reactions During Anaesthesia And The Perioperative Period Rita Aguiar, Anabela Lopes, Natália Fernandes, Leonor Viegas, MA PereiraBarbosa Immunoallergology Department.Hospital de Santa Maria-Centro Hospitalar Lisboa Norte, Lisbon, Portugal Keywords: Anaphylatic Reactions, Anaesthesia Introduction Anaphylaxis incidence in the perioperative setting varies between 1:10000 and 1:20000. Although this value is yet to be determined in Portugal, an increase in the number of reactions has been reported. Clinical evaluation is important in order to identify risk factors and drugs that cause anaphylaxis, so that alternative options can be found. The aim of this study was to characterize the reactions of patients (pts) with perioperative anaphylaxis and for conducting medical techniques requiring sedation. Method Retrospective analysis of medical records of 57 pts with perioperative anaphylaxis and anaphylaxis undergoing medical procedures with sedation, observed in the immunoallergologic outpatient clinic (2009-2015). The diagnostic investigation was carried out 6-8 weeks after the reaction, included detailed medical history, specific IgE assay to betalactams and latex, skin tests (ST) with the culprit drug and evidence of provocation when necessary, according to the recommendations of the SFAR / ENDA. Results : We studied 56 pts (41 females) with mean age of 50 ± 18 years. Regarding the severity of anaphylaxis and according to Mertes classification, 24 cases (42.8%) had stage I reaction and 24 cases (42.8%) had II reaction, 7 cases (12.5%) grade III and 1 case (1.8%) grade IV. An IgE-mediated mechanism has been established in 34 pts (60.7%). The major etiologic agents causing IgE-mediated reactions were muscle relaxants in 7 pts (12.5%), antibiotics in 6 cases (10.7%; 4 cefazolin, 1 aminopenicillin, 1 ciprofloxacin), metamizole in 3 pts (5.4 %), 2 pts latex (3.6%), 7 pts (12.5%) reacted with less representative agents. On 10 pts (17,8%) drugs responsible for the reactions were associated with nonIgE-mediated mechanisms, anti-inflammatory (NSAIDs) are the most frequent agents (5 pts). In 14 pts (25%) it was not possible to determine a pharmacological aetiology of the reaction. Conclusion More than half of perioperative events (60.7%) have an IgE-mediated mechanism. Muscle relaxants, antibiotics and patent blue dye were the most frequently identified agents. In 17.8% of the reactions was involved a non-IgEmediated mechanism, namely NSAIDs. It is important to determine the aetiology of perioperative reactions for guidance in future surgery, either because the identified agents are often used outside the perioperative setting. P02 Anaphylaxis To Chlorhexidine: Is There A Cross-Reactivity To Alexidine? Antonia Bünter1, Nisha Gupta2, Tatjana Pecaric Petkovic1, Nicole Wirth1, Werner J Pichler1, Oliver Hausmann3 1. ADR-AC GmbH, Bern, Switzerland 2. Teleflex Incorporated, Bern, Switzerland 3. Dep. of Rheumatology, Immunology and Allergology, University Hospital and University of Bern, Bern, Switzerland Introduction Chlorhexidine (CHX) and its diacetate derivative (CHA) are two forms of the same disinfectant for skin and mucosal surfaces as well as medical devices. CHX/CHA are bivalent compounds with biguanide groups and chlorophenyl endings. CHX/CHA can cause IgE-mediated anaphylaxis. Alexidine (ALX), a related biguanide without aromatic end groups, has similar bactericidal properties and represents a potential substitute for CHX/CHA. The allergic potential of ALX is unknown. Method We investigated whether patients sensitized to CHX/CHA also react with ALX. We used blood of CHX/CHA-allergic donors for basophil activation testing (BAT for CD63 and CD203a as activation markers) with CHA and ALX. In addition, we performed inhibition assays with CHA, chlorguanide (CG) and ALX using a commercial IgE assay for CHX (ImmunoCAP, ThermoFisher Scientific, Uppsala). Results 13 patients from a single tertiary care center with allergic reactions to CHX within the last 8 years were included. 9/13 patients had still elevated CHX-specific IgE (>0.35 kU/l), although mostly substantially lower compared to the time of anaphylaxis. In 6/13 patients with CHX-specific IgE >0.7 kU/l CAP inhibition studies were performed. CG showed a strong inhibitory effect in 6/6 and CHA in 3/6 tested sera. ALX induced partial inhibition of CHX positivity in 2/6 sera but at much higher concentrations compared to CHA. 3/13 patients showed a positive BAT with CHA, one of them with additional positivity to ALX. Conclusion Both, CAP inhibition studies as well as BAT analysis show that patients with documented CHX/CHA allergy do not or only partially react with ALX in these IgE-based assays. Based on this limited cross-reactivity of CHX/CHA and ALX, ALX may be potential alternative for CHX-allergic patients. More patients need to be included to substantiate this assumption. An ALX-specific IgE assay would help to differentiate CHX/CHA- and ALX-specific sensitization. P03 Cefotaxime-Induced Severe Anaphylaxis In A Neonate Mehtap Yazicioglu1, Pinar G Ozdemir1, Gokce Ciplak2, Ozkan Kaya3 1. Trakya University Department of Pediatric Allergy, Edirne, Turkey 2. Trakya University Department of Pediatrics, Edirne, Turkey 3. Trakya Hospital, Edirne, Turkey Introduction Anaphylaxis is defined as a serious generalized allergic or hypersensitivity reaction that is rapid in onset and might cause death. It is very rare in infancy. In this case report, we present a neonate who developed anaphylaxis during infusion of first dose of cefotaxime. Case Description A-one month infant was referred to our Pediatric Emergency Department because of anaphylactic reaction with rash, cyanosis and respiratory arrest developed after first dose of cefotaxime treatment. She was intubated immediately, then extubated after 10 minutes. Pyhsical examination on admission showed prolonged expirium bilaterally, and rales at the right lung base. Other findings were unremarkable. She was hospitalized and treatment with salbutamol nebules (0,15mg/kg/dose, q 6hr) was started. Vital findings were observed closely. On the 4th day of admission, before discharge, she was consulted with our pediatric allergy department. She was born full term by Cesarean delivery, weighing 3,180 g. Her personal and family history was unremarkable, except her mother described rash and swelling of the lips and face after spraying cologne. Laboratory investigations on admission: CBC with white blood cell differential was within normal range; C-reactive protein (CRP): 1,35 mg/dl (0-0,34); serum total IgE:2,4 U/ml (0-170). Serum tryptase: 17,7ng/ml (on the 4th day of admission); serum tryptase 12,3ng/ml (after 2 months). Skin prick tests with cefotaxime (2 mg/ml), and cefotaxime (10 mg/ml) were both negative. We did not perform intradermal tests and drug provocation test with cefotaxime. The patient was discharged to be followed with prescription of epinephrine autoinjector to use in case of anaphylactic emergency, and the family was educated about about signs and symptoms of anaphylaxis and about when and how to use the EpiPen. How this report contributes to current knowledge Anaphylaxis in newborn period is very rare. Our case was interesting that to our knowledge this is the first case of anaphylaxis in a newborn induced by first dose of an antibiotic. We wished to attract attention that severe drug reactions can also be seen in early life. P04 Clinical Features And Diagnosis Of Anaphylaxis Resulting From Exposure To Chlorhexidine Peter John Cooke Auckland City Hospital, Auckland, New Zealand Keywords: Chlorhexidine, Skin Prick Testing, Specific IgE, Anaphylaxis Introduction The Auckland Anaesthetic Allergy Clinic is jointly provided by the Departments of Anaesthesia and Immunology. All patients referred following perioperative anaphylaxis are skin prick tested with chlorhexidine 2%. This review describes the clinical features of the cases in which a diagnosis of allergic anaphylaxis to chlorhexidine was made during the period January 2012 to December 2015. Method Patient data and clinic test results were archived on a simple Excel spreadsheet. These were reviewed by the author and a chart review of the chlorhexidine anaphylaxis cases was undertaken. Results A total of 14 patients were diagnosed with chlorhexidine allergy during the period. (11 male and 3 female). The following manifestations of anaphylaxis were documented: hypotension (12 patients), tachycardia (9), flushing (7), facial swelling (4), urticaria (3), bronchospasm (2), piloerection (2), agitation (1), generalized swelling (1). Four patients had CPR during their anaphylaxis, 9 patients had a grade 3 reaction and one patient had a grade 1 reaction. Twelve of the 14 patients received adrenaline. Anaphylaxis followed the insertion of a chlorhexidine impregnated central venous line in 7 cases, urethral catheterization with chlorhexidine containing gel in 3 and following topical exposure only in 4 cases. Skin testing was performed 30-130 days after the anaphylaxis event. All of the patients diagnosed with chlorhexidine allergy developed a wheal >3mm after a s prick test with 2% chlorhexidine (range 3-20mm). The specific IgE for Chlorhexidine was obtained in 11 of the 14 cases and in 10 of the 11 it was elevated. During the same period 219 other patients were seen at our clinic and all received skin prick tests for chlorhexidine 2%. All of these patients had completely negative tests with a no wheal and no flare. Conclusion This data shows that patients with chlorhexidine anaphylaxis demonstrate typical signs but that hypotension is the most common manifestation. Convincing skin testing results along with specific IgE testing and the clinical history provided the basis of the diagnosis. Chlorhexidine is used in our region for skin preparation prior to anaesthetic and surgical procedures and four anaphylaxis cases resulted from topical exposure to chlorhexidine. Our data also suggests that a skin prick test with 2% chlorhexidine in alcohol is a satisfactory method of skin testing. P05 Drug-Induced Anaphylaxis: Five-Year Single-Center Survey Inês Mota, Ângela Gaspar, Filipe Benito-Garcia, Marta Chambel, Mário MoraisAlmeida Immunoallergy Department, CUF Descobertas Hospital, Lisbon, Portugal Keywords: Anaphylaxis, Drug Allergy, NSAID, Antibiotics Introduction Drug-induced anaphylaxis (DIA) is the most common cause of fatal anaphylaxis. Anaphylaxis related to nonsteroidal anti-inflammatory drugs (NSAID) is typically drug-specific or class-specific, as well as with beta-lactams (BL) antibiotics (AB). Although skin testing and drug provocation tests (DPT) can confirm the diagnosis, in severe cases the diagnosis is mostly based on clinical history. The aim of this study was to characterize patients (pts) with DIA and their drug allergy work-up. Method Systematic review of all pts with clinical history compatible with DIA reported to our drug allergy center in the last five years. All pts were investigated according to ENDA/EAACI recommendations, through skin testing and in vitro tests (whether standardized tests available) and DPT (when indicated). Results A total of 114 pts were included: mean age 41.5 (SD±16.8) yrs, 10% <18 yrs, 68% female, 72% atopic and 23% had asthma. Median age of first anaphylactic episode was 36.5 yrs [1;74], and 19 pts had recurrent DIA. The main causes were NSAID (50 pts) [acetylsalicylic acid (15), ibuprofen (13), metamizol (13), diclofenac (9), paracetamol (3), etodolac, ketorolac and clonixin (1 each)] and AB (46 pts) [BL (37), quinolones (4), macrolides (3), fosfomycin (1) and minocycline (1)]. Other drug agents found: neuromuscular blocking drugs (5 pts), proton pump inhibitors (5 pts), carboplatin (3 pts), corticosteroids (2 pts), local anesthetics (2 pts), ranitidine, midazolam and patent blue (1pt each). There was a predominance of mucocutaneous manifestations (96%), followed by respiratory (80%) and cardiovascular (45%) symptoms. In 25% of pts the reaction occurred in hospital setting and 12% had intraoperative anaphylaxis. DIA was supported in 72 pts (63%), through skin tests in 62 and the remaining by in vitro tests or DPT. Considering the severity of reactions and the lack of standardized tests for some drugs, patients whose DIA was based on clinical history were successfully challenged with alternative drugs. Conclusion NSAID and AB were responsible for the majority of DIA. Anaphylactic reactions were reported at any age. The heterogeneity of mechanisms involved, the severity of clinical reactions and the lack of standardized in vivo and/or in vitro tests do not allow to confirm the diagnosis in all cases. Patients with DIA should be evaluated in specialized centers in order to perform accurate diagnosis, to prevent recurrence and to find safe alternatives. P06 Intraoperative Severe Anaphylactic Reaction Due To Patent Blue V Dye Luis Marques, Eva Alcoceba, Silvia Lara Hospitals Universitaris Santa Maria - Arnau de Vilanova, Lleida, Spain Introduction Intraoperative anaphylactic reactions are a diagnostic challenge. The chronology of the administration of the multiple drugs and the beginning of the reaction are important in identifying the culprit drug. Patent blue V is a well known cause of perioperative anaphylaxis This dye is a member of the triarylmethane family, which also includes isosulfan blue and methylene blue. Is used for staging breast cancer, identifying sentinel lymph nodes. The frequency of reactions is around 0,24 to 1,1%. It can be also found in food (food additive E-131) and cosmetics. Case Description We describe the case of a woman 65 years-old with a ductal carcinoma of the left breast, who suffered hypotension (85/60), bronchospasm with hypoxemia, urticaria, angioedema of the face, tongue and epiglottis after the administration through the nipple of colorant patent blue V. Anaesthetic induction was done with fentanyl, propofol and rocuronium. Adrenaline, bronchodilators, antihistamines, corticosteroids and vasopressive drugs were administered, being admitted in the ICU. The levels of tryptase were 8’5 µg/mL 20 min after the beginning of the reaction, 16’6 µg/mL at 2h and 3,23µg/mL at 48h. One month after the reaction cutaneous tests were done, being positive for patent blue V (intradermal reaction at 1/10) and negative for suxamethonium, cis-atracurium, rocuronium, fentanyl, propofol, midazolam, povidone-iodine and latex. It was the first time the patient received this dye or any similar dye as a drug. Intraoperative anaphylactic shock due to allergy to patent blue V was diagnosed. The future use of this dye was prohibited and an advise to avoid stuff which contains this product was given to the patient. A suspicion of sensitization through foods or cosmetics is possible as the patient reacted the first time she received this drug. How this report contributes to current knowledge This case confirms previous descriptions of reactions with patent blue V: reaction with the first exposition and severe allergic reactions, with hypotension and raise in tryptase levels. Cutaneous test are useful in the diagnostic and standardized concentrations have been described by ENDA. P07 Kounis Syndrome In The Setting Of Anaphylaxis To Diclofenac Leonor Carneiro-Leão, Carmen Botelho, Eunice Dias-Castro, Josefina Cernadas Serviço de Imunoalergologia, Centro Hospitalar de São João, Porto, Portugal Introduction Kounis Syndrome (KS), the occurrence of acute coronary events as consequence of allergic or hypersensitivity reactions has been described for years. It is still relatively unknown and consequently underdiagnosed, leading to inadequate treatment and subsequent morbidity. There are three subtypes of KS: type I which occurs in patients without predisposing cardiovascular factors; type II which occurs in patients with cardiovascular risk factors; and type III by stent thrombosis. Case Description A 55 year old man, a smoker with type II Diabetes, was admitted to our hospital for myocardial infarction (MI) after taking 2 pills of diclofenac 75mg for left leg pain. He complained of immediate generalized pruritus, malaise, constrictive radiating chest pain, dyspnea, dizziness and sweating. He was assessed by the mobile medical team on site as being agitated, hypotensive (BP: 96/74mmHg) and with generalized wheezing on chest auscultation. Aggressive fluid resuscitation, nebulized salbutamol and IV corticosteroids improved his status on route to the ER; he was also treated with acetylsalicylic acid 250mg and sublingual isosorbide dinitrate 5mg. Epinephrine was not given. ECG confirmed NSTEMI with an elevated troponin I (0.59ng/ml). Serum tryptase was not measured. He was admitted to the Coronary ICU and cardiac catheterization showed mild coronary artery disease. He recalled a previous reaction to diclofenac, with immediate generalized pruritus. The patient recovery was uneventful. He was then referred to our Drug Allergy Unit. Oral challenge with meloxicam 15mg was negative and he was instructed to avoid NSAID’s other than meloxicam. How this report contributes to current knowledge MI in the setting of anaphylaxis is underreported. Clinicians should be aware of this possible complication even in patients without cardiovascular risk factors in order to diagnose and treat it early. Also, the WAO Anaphylaxis guidelines recommend a minimum 4 hours observation period after anaphylaxis, 8-10 hours if there is respiratory or cardiovascular compromise during the reaction. This allows not only for detection and treatment of biphasic reactions, but also of secondary cardiovascular events. P08 Perioperative Anaphylaxis Audit: Royal Melbourne Hospital Katherine Nicholls1, William Lay2, Olivia Smith2, Christine Collins1, Gary Unglik1, Kymble Spriggs1, Priscilla Auyeung1, Jeremy McComish1, Jo A Douglass1 1. Department of Immunology and Allergy, The Royal Melbourne Hospital, Parkville, Australia 2. Department of Medicine, University of Melbourne, Parkville, Australia Introduction Perioperative anaphylaxis (PA) is a medical emergency, with potential for mortality. Skin testing (ST) of agents used in the perioperative period is considered the gold standard for the identification of likely causative agents1. Neuromuscular blocking agents (NMBA) (58%), antibiotics (12-15%) and latex (16-19%) are the most commonly implicated causative agents1,2. Chlorhexidine allergy is also described although its prevalence is not well established and likely underreported3,4. We conducted a retrospective audit of all patients who underwent ST and specific IgE testing (SpIgE) for investigation of a perioperative allergic event. We sought the proportion of patients who had a likely agent detected and the prevalence of likely causative agents in our cohort. Method Medical histories were reviewed for all patients referred for PA who underwent testing in our centre over a 2-year period from September 2013 to August 2015. Data collected included severity grading5, acute elevation in Mast cell tryptase (MCT) (>12ng/mL or >135% basal level), and causative agent indicated by the presence of a positive ST or SpIgE to NMBA, latex, antibiotics or chlorhexidine. Results are expressed as n (%) and comparisons performed by Fisher’s exact test. Results Of 47 patients identified during this period, ST was positive in 22 (47%), with NMBA and beta-lactam antibiotics accounting for 10 (42%) and 7 (29%) of positive results respectively. Of the 27 patients with MCT results, 14/19 (73%) patients with an acute MCT rise had positive skin or SpIgE tests, compared with only 1 (13%) of 8 patients with no reported MCT rise (P<0.01). Over the same period, 4 patients (18%) had positive SpIgE to chlorhexidine (range 0.4355.8kUa/L). Reactions graded as severe (Grade 3) were associated with an increased proportion of positive ST (16/31, 52%) compared with Grades 1 and 2 (6/16, 38%), however this result did not reach statistical significance. Conclusion The prevalence of causative agents reflects current literature, with an increased proportion of reactions to antibiotics, and decreased proportion to latex. Our audit indicated a significantly higher proportion of positive ST in those with acutely elevated MCT. In our cohort, chlorhexidine appeared to be a common allergen. References: 1 Mertes et al. JACI 2011;128:366-73, 2 Ebo et al. Allergy 2007;62:471-87, 3 Garvey et al. JACI 2007;120:409-415, 4 Calogiuri et al. J Allergy Ther. 2013;4, 5 Brown et al. JACI 2004;114:371-6 P09 Recurrent peri-operative anaphylaxis - a perfect storm Jonny G Peter, Paul Potter University of Cape Town, Cape Town, South Africa Introduction Allergy work-up to identify the causative agent in patients experiencing perioperative anaphylaxis is challenging. Patients have multiple exposures over a short time period; Paper-based records from remote hospitals are often unavailable to the allergist; and diagnostic testing for many drugs is either unavailable or sub-optimal. Case Description A 56-year-old man with debilitating osteoarthritis required hip replacements in order to work. He had no chronic medical co-morbidities, but labeled penicillin allergy following a childhood reaction during prolonged antibiotics for osteomyelitis. He was referred for testing after three operations in a remote private South African hospital. Peri-operative anaphylaxis, confirmed with serial tryptase measurement, occurred in the 1st and 3rd surgeries. Possible offending agents included: propofol, midazolam, bupivacaine, fentanyl, clindamycin and cyclokapron. Apparently, in the uneventful 2nd surgery, the drugs were the same except cyclokapron was omitted. Cleaning agents used were unknown. In vitro specific IgE testing was negative to latex but elevated (5.49kUA/l) for chlorhexidine; Skin testing was positive with chlorhexidine and intradermal testing generated systemic symptoms and required treatment. CAST ELISA testing was negative to propofol and bupivacaine. Clindamycin in vitro testing was unavailable and in vivo testing is not recommended. The likely offending agent was chlorhexidine, and the patient was anxious to return to work, thus, although each anesthetic chart was not available for detailed review, repeat surgery proceeded. Unfortunately, he experienced recurrent anaphylaxis despite a chlorhexidine free theatre. Several months later the anesthetic charts from all four operations were acquired, and it was clear that an additional offending agent was likely clindamycin. Avoidance of both clindamycin and chlorhexidine resulted in a safe surgery. Subsequent testing allowed the patient to be ‘de-labeled’ as penicillin allergic. How this report contributes to current knowledge Dual sensitivity is described in about 2% of peri-operative anaphylaxis cases. Thus, even if a possible causative agent is identified, it remains mandatory a conduct a detailed review of all anesthetic charts; however, this can pose a major challenge in countries were records remain paper-based. The use of alternative drugs in patients carrying a penicillin allergy label can carry significant morbidity. Poster Walk 2: DH regions and patient groups (P10 – P19) P10 A Rare Presentation Of Amoxicillin Allergy In A Young Child Fabrícia Carolino, Eunice Dias De Castro, Josefina R Cernadas Serviço de Imunoalergologia, Centro Hospitalar São João E.P.E., Porto, Portugal Introduction Fixed drug eruptions (FDE) are characterized by well-demarcated skin and/or mucosal lesions beginning a few minutes to several hours after drug exposure and that reappear at the exact location on re-exposure to the offending drug. Aminopenicillins are among those drugs most commonly associated with FDE. Non-pigmenting FDE (NPFDE) is an FDE type that leaves no residual pigmentation. Case Description The authors report the case of a non-atopic 5 years-old boy, presenting two reproducible episodes of cutaneous lesions (erythematous pruritic plaques) located to the genital area, occurring a few hours after medication with amoxicillin for upper airways infection. The antibiotic was changed to a non-betalactam drug with progressive symptoms resolution, leaving no residual skin pigmentation. There was a previous exposure to amoxicillin with tolerance. After the second episode, the child has already been medicated with a second generation cephalosporin (cefaclor) and tolerated this drug. Following the first evaluation in our Allergy Department, the child was assessed in the Drug Allergy Unit. No skin tests (intradermal with late reading) were performed due to agerelated constraints. A controlled re-challenge with oral amoxicillin in the agerecommended intake-dose was performed. Five hours after the end of oral challenge, the child began to develop a cutaneous exanthema and returned to the hospital for medical assessment as it was recommended. On physical examination, we observed swelling and erythematous plaques affecting the inferior part of penis, the scrotum and the perianal region; the child’s mother confirmed that the lesions presented the same location as that of the two previous episodes. Taking these findings into account, the final diagnosis was multiple fixed drug eruption. The child was treated with oral antihistamine and corticosteroid, with complete resolution in 3 days. How this report contributes to current knowledge To the authors’ knowledge, this is the third case reported of this type of drug eruption in the paediatric age. P11 Adverse Drug Reactions In Children: Antibiotics Or Virus? Ana Sofia Moreira1, Carmo Abreu2, Eva Gomes2 1. Centro Hospitalar Vila Nova Gaia e Espinho, Vila Nova Gaia, Portugal 2. Centro Hospitalar do Porto, Porto, Portugal Keywords: Children, Drug Reactions Introduction About 10% of portuguese children report to have had at least one adverse reaction to drugs and 6% to be allergic to at least one drug, being the antibiotics the most frequent medication implicated. The diagnostic investigation reveals that in 90% of cases drug hypersensitivity is not confirmed, what is thought to be related to the high prevalence of infectious/viral rashes in childhood. Our aim was to evaluate the main reasons for referral to our pediatric drug allergy clinic, characterize the reactions mentioned by patients, particularly with regard to their sazonality and to analyse the results of the diagnostic investigation performed. Method Retrospective analysis of medical records from the pediatric patients followed in our department, in the last 6 years, due to suspected drug hypersensitivity. Results We studied 364 children of whom 200 (55%) were male. The median age at the time of the suspected reaction was 3.5 years (6 months-17 years). Antibiotics were the suspected drug in 84% of cases (n=305). In 75% (n=274) of patients the symptoms reported were only cutaneous (maculopapular eruptions or urticaria) and in 72% (n=262) of cases the reaction was nonimmediate. Drug hypersensivity was confirmed in 10 patients (3%). The month in which the drug reaction occurred was identified by 51% (n=184) of patients. Sixty % of the reactions occurred during winter-spring months. Viral serologies were performed on 74 patients who reported a recent reaction and positive results for at least one of the viruses studied were obtained in 14 patients (19% - IgM) and 48 patients (65% - IgG). Conclusion The majority of children studied due to suspected drug hypersensitivity reported cutaneous symptoms and nonimmediate reactions. Most reactions occurred before 3 years of age, which according to the literature, concerns the age when infectious rashes are more frequent. We verified a seasonal pattern in the occurrence of the suspected drug reactions that is similar to that described for the most common viral infections in childhood, while the peak for antibiotic consumption has been reported in autumn. Confirmation of hypersentisitivity to the suspected drug was possible in 10 of 364 patients, while a possible viral etiology was documented in 14 of 74 patients. Our findings reinforce the idea that many of the cutaneous reactions which motivate the study in our department are probably caused by infections and not by drug hypersensitivity. P12 Allergic Reactions In Invasive Medical Procedures Bárbara Kong Cardoso, Elza Tomaz, Sara Correia, Filipe Inácio Hospital de S.Bernardo - Centro Hospitalar de Setúbal, Setúbal, Portugal Keywords: Perioperative Allergy, Invasive Medical Procedures, Drug Hypersensitivity Introduction Surgery associated allergic reactions have been extensively studied and culprit agents have been pointed on several reports. Nevertheless last decade changes in pharmacological protocols resulted in the increase of possible implicated drugs. In the other hand, other invasive procedures (diagnostic/therapeutic) have been increasing in frequency and are also related to allergic events. Our aim was to seek for new agents involved in perioperative allergy as well as characterize reactions occurring due to other invasive procedures Method We reviewed the medical records of 28 patients referred to our clinic for allergic reaction associated to an invasive procedure in the last two years regarding administered drugs, type of reaction and results of the allergological workup. Results In our study group, 21 were female and 7 male, mean age was 54.7 years (2 84). Fourteen were studied for procedures with general anesthesia related adverse events: 6 anaphylatic reactions, 6 urticaria/angioedema, 1 bronchospasm and 1 hypotension. Positive relevant results were obtained in 13 patients: 1 skin prick test (SPT) to metamizol, 2 intradermal skin tests (IDT) to midazolam, 1 to tramadol, 3 to ondansetron, 1 to rocuronium, 1 to atracurium, 2 to vecuronium, 2 to metamizol, 1 basophil activation test (BAT) to metamizol. One patient was positive to both to atracurium and vecuronium and one patient had no positive tests. In 9 patients reactions were associated to invasive procedures with local anesthesia. Positive results were one IDT and BAT to verapamil (anaphylaxis) and one patch test to iodixanol (maculopapular rash) in 2 patients submitted to coronary angiography. Six patients with adverse reactions during dental treatment and one during a carpal tunnel surgery had no positive tests. Five patients had been submitted to procedures without use of any anesthetic: 1 with local erythema after an esteroid intra-articular infiltration had a positive patch test to betamethasone dipropionate; 1 with an anaphylactic reaction during a colonoscopy had a positive BAT to metamizol used as analgesic; 1 with acute urticaria after contrast injection for a thyroid TC had IDT positive to iomeprol. Two patients had a negative workup. Conclusion Comparing to previous published series ondansetron seems to be emerging as an important agent in perioperative allergy. Invasive procedures other than major surgeries are associated to allergic reactions both immediate and non-immediate, some of them being severe. P13 Antibiotic Allergy In Children: Room For Improvement Annabelle Arnold1, Natasha Bear2, Kristina Rueter3, Grace Gong4, Michael O'Sullivan5, Saravanan Muthusamy1, Valerie Noble1, Michaela Lucas6 1. Department of Immunology, Princess Margaret Hospital, Perth, Australia 2. Telethon Kids Institute, Department of Clinical Research and Education, Princess Margaret Hospital, Perth, Australia 3. Department of Immunology, Department of Clinical Research and Education, Princess Margaret Hospital, Telethon Kids Institute, Perth, Australia 4. Department of Immunology, PathWest Laboratory Medicine WA, Princess Margaret Hospital, Perth, Australia 5. Department of Immunology, Princess Margaret Hospital, PathWest Laboratory Medicine WA, Fiona Stanley Hospital, School of Pathology and Laboratory Medicine, University of Western Australia, Perth, Australia 6. Department of Immunology, Princess Margaret Hospital, Sir Charles Gairdner Hospital, PathWest Laboratory Medicine WA, School of Medicine and Pharmacology, School of Pathology and Laboratory Medicine, University of Western Australia, Institute of Immunology and Infectious Diseases, Murdoch University, Perth, Australia Keywords: Allergy, Antibiotic, Anaphylaxis Introduction Beta-lactam antibiotics remain one of the most effective treatments of bacterial infections and are the most frequently prescribed antibiotic in children. Allergic reactions to these antibiotics are common. Nevertheless, strategies for peadiatric antibiotic allergy testing and management remain poorly defined, including issues around the need for skin testing prior to oral provocation challenges (OPC; 2dose) and the value of prolonged courses with the culprit antibiotic after the successful administration of an initial supervised dose. Method To address these issues, we performed a retrospective cross-sectional analysis of children (6m-16yrs) with an antibiotic allergy label who presented to a tertiary pediatric hospital in Western Australia from 2006 to 2015. Data collection included results of skin prick (SPT), intradermal testing (IDT) and OPCs, outcome of 5-day antibiotic courses, type of initial reaction, confounding illnesses and coexisting allergies. The data was analysed using Mann-Whitney U for continuous data and Fishers exact test for categorical data. Results We performed 207 beta lactam antibiotic tests in 172 children. In 82 (39.6%) cases OPCs were performed without preceding skin testing (Group 1); three OPCs (3.7%) were unsuccessful with 1 child with anaphylaxis. In 125 (60.4%) cases skin testing was performed (Group 2). Of these, 22 cases (17.6%) were positive by SPT or IDT; these children were deemed to have confirmed antibiotic allergy. The remaining 103 cases proceeded to OPC; 4 (3.8%) reacted to OPC, including 2 children with anaphylaxis. Finally, 152 cases (from Group 1 or 2) received a 5 day course with the culprit antibiotic. This resulted in a rash in 9 children (5.9%) during the course. In both groups confounding illnesses, initial reaction, gender and co-existing allergies did not predict testing outcome. Conclusion In our cohort, the rate of allergy confirmed by skin testing was significantly higher than for those who underwent a direct challenge (17.6% versus 3.7%). The rate of reactivity to OPC was comparable for Group 1 and 2. These data further supports that performing direct supervised OPC with the culprit drug in children may be safe and potentially may avoid the need for resource intensive skin testing. Extended courses with the culprit drug should be considered, allowing confirmation of non-immediate reactions such as cutaneous reactions. P14 Drug Hypersensitivity Reactions In Children And Results Of Diagnostic Evaluation Neringa Buterleviciute, Odilija Rudzeviciene Vilnius University Faculty of Medicine Centre of Children Pulmonology and Allergology, Vilnius, Lithuania Keywords: Drug Hypersensitivity, Chidren, Clinical Pattern, Diagnostics Introduction Patients or parents reported drug allergy in children is more common than the true drug allergy incidence. The aim of our study was to evaluate the clinical pattern of patient/parent reported drug hypersensitivity reactions and results of diagnostic evaluation. Method 15 children who were tested for drug allergy in 2015 were included in the study: 8 boys (53.3%) and 7 girls (46.7%), age range 1-15 years. We analysed causes, clinical pattern of reported drug hypersensitivity reactions and results of diagnostic evaluation. Results 26 drug hypersensitivity reactions were reported. Three drug hypersensitivity reactions were reported in 4 children, two reactions – in 3 children. The main suspected drugs were antibiotics 17 (65.4%), NSAIDs – 5 (19.2%) cases, local anaesthetics – 4 (15.4%) cases. Amoxicillin was the most frequently suspected drug (6 (23.1%) cases). 8 (30.8%) reactions appeared during 1 hour. Skin symptoms were reported in 24 (92.3%) cases: maculopapular rash – 20 (76.9%), angioedema – 5 (19.2%) cases. Respiratory and cardiovascular symptoms were reported in 2 cases (7.7%). Drug provocation test was positive only for 1 child, who experienced angioedema after nimesulide and ibuprofen intake, and drug provocation test was positive to ibuprofen. Conclusion The most common suspected drugs were antibiotics, especially amoxicillin. Skin was the most frequently affected and maculopapular rash was the most common symptom. Drug provocation test was positive only for 1 patient. P15 Nonimmediate Cutaneous Drug Reactions In Children: Are Skin Tests Required? Ana Sofia Moreira1, Carmo Abreu2, Eva Gomes2 1. Centro Hospitalar Vila Nova Gaia e Espinho, Vila Nova Gaia, Portugal 2. Centro Hospitalar do Porto, Porto, Portugal Keywords: Skin Tests, B-Lactams, Diagnosis Introduction Delayed urticaria and maculopapular eruptions associated with antibiotics are the most common reasons for referral to our pediatric drug allergy clinic. In this context, several studies point to the limited usefulness of skin tests, even to blactam antibiotics, with some authors advocating the use of drug provocation test without the need for other previous diagnostic procedures. Our aim was to describe the cases followed in our department in which this diagnostic approach was used (exclusive drug provocation test). Method Retrospective analysis of medical records from children referred to our drug allergy clinic due to suspected hypersensitivity to antibiotics, who reported nonimmediate cutaneous reactions (urticaria or maculopapular eruption) without signs of severity or systemic involvement. All children underwent provocation test with the suspected drug without conducting previous skin tests. The drug provocation test was extended to include the number of days of treatment reported at index reaction. Data was collected regarding gender of patients, age at the drug reaction, drug involved, symptoms reported on the reaction and results of the drug provocation test. Results We evaluated 213 children of which 50% (n= 107) were male, with a median age of 3 years (6 months-17 years) at the time of reaction. In 97% (n=206) of the cases the involved antibiotics were b-lactam (amoxicillin-clavulanic acid in 92 patients, amoxicillin in 89 and cephalosporins in 5 cases). Only 3 children had positive drug provocations tests. In all cases the symptoms were similar to those previously reported and easily controlled with oral antihistamine. Conclusion Performing an exclusive drug provocation test in children with suspected hypersensitivity to antibiotics, who present with nonimmediate cutaneous reactions without signs of severity, proved to be a safe and effective approach. P16 Pediatric Patients With A History Of Penicillin Allergy And A Positive Penicillin Skin Test May Not Be At An Increased Risk For Multiple Drug Allergies Sara May1, Thanai Pongdee2, Miguel Park3 1. University of Nebraska Medical Center, Omaha, United States 2. Mayo Clinic, Jacksonville, United States 3. Mayo Clinic, Rochester, United States Keywords: Penicillin Allergy, Multiple Drug Allergies, Risk Introduction Patients with a sulfonamide allergy or penicillins (PCN) may be at increased risk for reactions to other drugs. However, the studies were conducted in adults without PCN skin testing (PST) to confirm a PCN allergy. We conducted a study to determine if pediatric patients with a history of PCN allergy and a positive PST were at an increased risk for multiple drug allergies. Method Children (< 18 years) with a history of PCN allergy were evaluated with PST and reviewed for basic demographic, PST results, and other medication allergies listed in the allergy module in the electronic medical record. A univariate logistic regression analysis was employed to calculate the odds ratio (OR) and the 95% confidence interval (CI). P-value of 0.05 or less was considered statistically significant. The Institutional Review Board (IRB) approved the study. Results 778 children underwent penicillin skin test. 703 (90.4%) of 778 patients had a negative PST, 66 (8.5%) were positive, and 9 (1.1%) were equivocal. The overall mean ± standard deviation (SD) age of the study group was 5 ± 3.5 years. Three hundred and sixty seven (47.1%) were females. 703 children (90.4%) had a negative PST, 66 patients (8.5%) positive PST, and 9 (1.1%) equivocal PST. 181 (23%) of 778 patients reported a history of multiple drug allergies. Among the 181 patients reporting a history of multiple drug allergies, 81 (45%) were female and 100 (55%) were male. Males were 1.6 times (95% CI .8-1.6, p = 0.5) more likely than females to report multiple drug allergies, although not statistically significant. 14 (21%) of 66 patients with a positive PST reported multiple drug allergies compared to 167 (23%) of 712 (p = 0.76) patients with a negative PST. Those patients with multiple drug allergies and a history of PCN allergy, cephalosporin [15% (114 of 778)] was the most common medication listed in the allergy module. Other medication listed in the medication allergy modules were 10% (79) macrolide antibiotics, 9% (71) sulfonamides, 0.4% (3) quinolones, and 1% (9) nonsteroidal anti-inflammatory drug (NSAIDS). Conclusion PCN allergic pediatric patients may not be at an increased risk for multiple drug allergies. Among patients with a history of PCN allergy, cephalosporin, macrolide antibiotics and sulfonamide antibiotics were the most common drug allergies listed in the medication allergy module. P17 Proved Hypersensitivity To Drugs According Data Of Vilnius University Hospital Santariskiu Klinikos Linas Griguola1, Arturas Vinikovas1, Simona Kašinskaite2, Violeta Kvedariene2 1. Vilnius University, faculty of Medicine, Vilnius, Lithuania 2. Center of Pulmonology and Allergology, Clinic of Infectious, Chest diseases, Dermatology and Allergology, Vilnius University Hospital Santariskiu Klinikos, Vilnius, Lithuania Keywords: Drug, Hypersensitivity Introduction Adverse reactions to drugs are common problem, but true hypersensitivity to drug is rare. Aim of the study: to investigate true hypersensitivity reactions among female and male with suspicion of drug allergy. Method 755 patients with suspicion of allergic reactions to drugs were addressed to consultations in Pulmonology and Allergology center by general practitioners. Patients were divided into groups by sex and suspected drugs: I – Antibiotics (AB), II – NSAID, III – Other. Each category was divided into subcategories: IA beta-lactam AB, IB Other AB; IIA ASA, IIB acetaminophen, IIC other NSAID; IIIA local anesthetics (LA), IIIB iodine containing contrasts (ICC), IIIC Other. Results 755 patients with 980 cases of suspected drug allergy were investigated: 618(81.85%) females with average age 48.4(SD ± 15.2) and 137(18.15%) males with average age 47.6(SD ± 18). Female group had 821(83.8%) adverse reactions to drugs. 199(24.2%) reactions to I (AB): 151(75.9%) were to beta-lactams, from all tested 36(16.9%) were true hypersensitivity; 46(23.1%) reactions were to other-AB, from all tested reactions 4(9.1%) were proved. 2(1%) cases were not tested. Accordingly: II (NSAID) had 306(37.3%) reactions: to aspirin - 56(18.3%), 4(9.6%) were proved; to acetaminophen - 47(15.3%), 12(40%) were proved; IIC (Other-NSAID) – 203 (66.3%), 29(19.2%) were proved. III (Other) had 316(38.5%) reactions: IIIA (LA) – 99(31.3%), 1(1.5%) was proved; IIIB (ICC) – 20(6.3%), 2(15.5%) were proved; IIIC (Other) – 197(24%), proved - 19(15.4%). Male group had 159(16.2%) adverse reactions to drugs. I (AB) had 30(18.8%) reactions: IA (beta-lactam) - 25(83.3%), from all tested reactions 7(21.2%) were proved. Accordingly: IB (other-AB) – 5(16.6%), all negatives. II category had 77(48.4%) reactions: to aspirin - 17(22%), 2(16.6%) were proved; IIB (acetaminophen) – 18(23.4%), 2(11.8%) were proved; IIC (other-NSAID) – 42(54.5%), DPTs proved 2(6.9%). III category had 48(30.2%) reactions: IIIA (LA) – 16(33.3%), 1(7.7%) was proved; IIIB (ICC) – 6(12.5, all negatives; IIIC (Other) – 26(54.2%), DPTs proved 4(22.2%). NA - 4(2.5%). Conclusion Of all reactions true hypersensitivity were proved for: antibiotics – 15.6%, NSAIDs – 20.2%, other drugs - 11.1% in female group and 20% for AB, 10.3% for NSAIDs, 13.8% for other drugs in male group. P18 Self-Reported Prevalence Of Drug Hypersensitivity Reactions Among Students In Celal Bayar University, Turkey Ayse Aktas, Suheyla Rahman, Huseyin Elbi, Beyhan Cengiz Ozyurt celal bayar university, Manisa, Turkey Keywords: Drug Hypersensitivity, Prevalence, Introduction Drug hypersensitivity reactions (DHR) is defined "unwanted and harmful reactions occurring to drugs prescribed dose" by World Health Organization (WHO). DHR is an important health problem because of causing life-threatening condition, extending the length of stay in hospital and increasing the cost of treatment. The aim of this study was to determine the prevalence of self-reported DHR among students at the university. Method A structured questionnaire was carried out to students of Celal Bayar University in Manisa, Turkey. Results 2086 students have participated in our study. 1217 (58.3%) of them were women, 869 (41.7%) were male. The mean prevalance of self-reported DHR was 5.3% (111/2086). Drug allergy incidence of students (male / female) was 3.5% and 6.7%, respectively (p<0.001). The most common allergic reactions were rash 52.2%, cardiovascular reactions 12.6% and respiratory reactions 11.7%. Aforementioned two systems involvement were %23.4. The most frequently involved drugs were antibiotics 52.2% (n:58) and analgesics 24.3% (n:27). Conclusion The diagnosis of drug allergy is based on a detailed history of the onset of symptoms/signs’ relationship between the appearance of symptoms and drug use. Misinterpretations just based on the DHR story can effect the individual treatment options. A definitive diagnosis can be easily reachable with a complete clinical history, standardized skin tests and drug provocation tests. Therefore we can recommend that doctors should be more informed about the managements of DHR due to self-reported DHR is highly prevalant just like shown in this study. P19 Severe Drug Hypersensitivity Reactions In Pediatric Age Ozlem Cavkaytar, Betul Karaatmaca, Pinar Gur Cetinkaya, Saliha Esenboga, Umit M. Sahiner, Bulent E. Sekerel, Ozge Soyer Hacettepe University School of Medicine Department of Pediatric Allergy, Ankara, Turkey Keywords: Drug Hypersensitivity, Anaphylaxis, Child, Pediatric Introduction Epidemiologic data on drug induced anaphylaxis (DIA) in pediatric age is lacking. The aim of this study is to define the actual rate of drug induced anaphylactic reactions in childhood together with the severity and culprit drug patterns. Method Patients with a history of drug hypersensitivity reaction (DHR) referred between January 2012-December 2015 were included. After filling out an European Network for Drug Allergy (ENDA) questionnaire, initial skin tests and/or provocation tests were performed for the offending drug. The severity of anaphylactic reactions was determined as mild, moderate and severe according to EAACI guidelines on anaphylaxis in childhood. Results Among 627 children and adolescents referred due to a DHR, diagnostic work-up was completed in 532 patients. 103 (19.3%) of them [54.4% male, median age (interquartile range; 9.6 years (5.3-13.3)] had anaphylaxis in the history and diagnostic tests revealed that 75 (14.1% of all evaluated patients, 72.8% of all patients with a DIA) of them were actually hypersensitive to the offending drug. The culprit drugs responsible from actual DIA were antibiotics (36%), NSAIDs (22.7%), chemotherapeutics (20%), biologicals(6.7), anesthetic agents(5.3%), enzyme therapy(4%) and others. Majority of the patients with actual DIA reported moderate (38.7%) and severe (37.3%) drug induced anaphylactic reactions. History of chronic disease (44% vs. 17.9%, p=0.014), concomitant intake of other drugs regularly (40% vs. 7.1%, p=0.001), cyanosis (23% vs. 3.6%, p=0.022) and hospitalization (56.2 vs. 17.9, p=0.001) due to the suspected DIA and use of chemotherapeutics as the culprit drug (20% vs. 0, p=0.01) were more frequent, whereas use of antibiotics was less frequent (71.4% vs. 36%, p=0.001) in patients with actual DIA compared to nonhypersensitive patients. Atopic disease, atopy or family history of atopy or drug hypersensitivity did not have an impact on actual DIA. It is important to note that actual DIA was more frequent in children younger than 10 years of age compared to older adolescents (81.5% vs. 63.3%, p=0.038). Conclusion During childhood, any history of DIA reaction may not be an actual DHR, however young age, existence of chronic disease and use of chemotherapeutics might point out the actual drug induced anaphylaxis in children and adolescents. Poster Walk 3: Desensitisation (P20 – P28) P20 A Protocol For Desensitisation To Valaciclovir Celia Zubrinich, Bianca Tong, Mittal Patel, Michelle Giles, Robyn O'Hehir, Robert Puy Alfred Health, Melbourne, Australia Introduction We report a protocol for desensitisation to valaciclovir. Case Description A woman in her 40s developed generalised urticaria on the second or third day of her initial course of acyclovir (administered five times daily) for newly diagnosed genital herpes. The urticaria continued to cause distress despite substitution to valaciclovir for a further few days. Antiviral medication was ceased. The rash resolved over two weeks with the use of anti-histamines. For more than a decade since then, she has experienced frequent and prolonged confirmed herpetic recurrences, more often present than not. The attacks had a marked viral prodrome and significantly affected her lifestyle. Recurrent genital herpes may be treated with suppressive antiviral therapy if frequent. Supervised direct challenge to valaciclovir was an option but desensitisation was favoured because it required a single clinic visit and, of relevance to the patient, likely entailed less risk. We identified reports of desensitisation to acyclovir but not valaciclovir. The final treatment dose of acyclovir (usually 400 mg) differs from that of valaciclovir (500 mg). Acyclovir therapy requires multiple doses per day, whereas valaciclovir requires only a single daily dose. We developed and present a 14-dose oral desensitisation protocol that was administered over 3.5 hours (Figure 1). The first 10 doses were valaciclovir in suspension and the final four doses were prepared from a 500mg tablet. The patient tolerated the procedure with no ill effect. There has not been a single herpetic recurrence in the twelve months since the treatment commenced. How this report contributes to current knowledge Desensitisation to valaciclovir may be performed where suppressive therapy for herpes is indicated. P21 A Rare Case Of Desensitization To Modafinil Josefina Cernadas, Luís Amaral, Fabrícia Carolino Serviço de Imunoalergologia, Centro Hospitalar de São João E.P.E., Porto, Portugal Introduction Modafinil is a 2-benzhydrylsulfinylethanamide molecule, belonging to a class of medications called wakefulness promoting agents used to treat excessive sleepiness caused by narcolepsy (a condition that causes excessive daytime sleepiness) or shift work sleep disorder. Another use is to prevent excessive sleepiness caused by obstructive sleep apnea/hypopnea syndrome. It acts as a blocker of a type of molecule called the dopamine transporter. Rare occurrences including severe cutaneous adverse reactions, as erythema multiforme, SJS, TEN and DRESS, affecting adults and children and probably allergic, have been reported. Rare cases of angioedema and multi-organ hypersensitivity reactions have also been described. Case Description The authors describe a case of a 27 year-old male with the diagnosis of narcolepsy medicated with modafinil 100 mg in an increasing dosage. Four days after beginning the medication, he complained of generalized pruritus, maculopapular exanthema and angioedema of upper and lower limbs. No analytical changes were found in the acute phase. He was treated with intravenous corticosteroid and antihistamines and, four days after complete recovery, the drug was re-introduced with reproducible signs and symptoms arising twelve hours after the intake of 100 mg of modafinil. Because this was the only therapeutic option for the patient he was referred to our Allergy Department for desensitization. A suspension of 1mg/ml (100mg/100ml) was prepared and a “tailor made” desensitization protocol was started with an initial dose of 1 mg, followed by doubling doses, taken with one hour intervals. The cumulative dose reached on the first day was 15 mg, 85 mg on the second and 100 mg on the third and fourth days. For safety reasons, 100 mg/day were taken in the first week followed by an increase, to the intended doses (Neurology prescription) in the following weeks: 100+100 mg on the second week, 100+200 mg on the third week and 200+200 mg on the fourth and on, as chronic treatment. After we have achieved tolerance to a dose of 100 mg, the slowly increase to the targeted dose of 200 mg twice a day was well tolerated. The patient is still on the same therapeutic scheme with no further reactions. How this report contributes to current knowledge As far as we know this is the first case describing a desensitization protocol to modafinil. P22 A Sixteen-Day Desensitization Protocol In Delayed Type Hypersensitivity Reactions To Oral Drugs Semra Demir, Asli Gelincik, Muge Olgac, Raif Caskun, Derya Unal, Bahauddin Colakoglu, Suna Buyukozturk Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey Keywords: Delayed Type Hypersensitivity Reactions, Desensitization Introduction Although desensitization in immediate type hypersensitivity reactions due to chemotherapeutics is well described and standardized for many drugs, common protocols in delayed type hypersensitivity reactions (DHR) are not standardized. Our aim is to evaluate the usefulness of the 16-day desensitization protocol which we had recently described for capasitabine in DHRs caused by various oral chemotherapeutic drugs. Method We applied our slow desensitization protocol which started with 1/100 of the target dose and was completed in 16 days with slow incremental doses in patients who had experienced DHR due to various oral chemotherapeutic drugs. Results Four patients (2 female, 2 male) who were referred to our clinic for desensitization were included. The mean age was 55±22,25 years. The culprit drugs were pazopanib, nilotinib and lenalidomide. The mean reaction time after the initiation of the drug was 7,5±2,08 days and the reaction types were maculopapular rush (MPR) in 2 patients and generalized morbiliform rushes (GMR) in 2 patients. Two patients who had experienced MPR caused by lenalidomide completed the protocols without any reactions. However, the other two patients developed pruritus and rush on the 9th and the 15th days of the desensitization protocols. After the reactions were treated with methylprednisolone, the doses were decreased to the last tolerated doses and gradually increased afterwards. One of them completed the desensitization in 28 days. However, the second patient could tolerate almost the ¾ of the targeted dose. Conclusion This sixteen-day protocol seems to be a useful guide for the desensitization in delayed type hypersensitivity reactions especially in MPR in oral chemotherapeutics. However, the protocol can be modified in some patients. P23 Desensitization To Intravenous Etoposide Using A 12 And A 13-Step Protocol. Two Cases Report. Olga Vega Matute1, Amalia Bernad1, Gabriel Gastaminza1, Roselle Madamba1, Carlos Lacasa2, MJ Goikoetxea1, Carmen D'Amelio1, Jose Rifón3, Nicolas Martínez3, Marta Ferrer1 1. Departament of Allergy and Immunology Clínica Universidad de Navarra, Pamplona, Spain 2. Department of Pharmacy Clínica Universidad de Navarra, Pamplona, Spain 3. Departament of Hematology Clínica Universidad de Navarra, Pamplona, Spain Introduction Etoposide is a chemotherapy agent used to treat malignant conditions. Because of the repeated use of this drug in within time intervals for cancer treatment, there is a high chance as with any chemotherapeutic agent to induce hypersensitivity reactions (HSR). It is reported to induce HSR in 6% of the patients. Case Description We present two cases. First is a 7 year old female patient with acute myeloid leukemia (AML). She had previously received 2 courses of treatment with etoposide. In the second course, with the first administration she had a reaction consisted with facial erythema and severe dyspnea. When evaluated in our hospital, she needed treatment with etoposide for autologous stem-cell transplantation. The second patient was an 8 year old male with refractory acute lymphoid leukemia (ALL-B) that had received 6 doses of treatment with etoposide. In the last dose, he reported pharyngeal obstruction and chest erythema. When evaluated in our hospital, he needed salvage chemotherapy containing etoposide followed by allogenic stem-cell transplantation. We performed skin prick test with Etoposide, using commercially available drug solution for intravenous use. In both patients the test was negative. Because Etoposide was the most suitable chemotherapeutic option for both patients, we decided to administer the drug using a desensitization protocol. Castells (2) developed a protocol for desensitization to drugs with a 12 steps infusion of the target dose. In the first case we had to add 1 step to this protocol because of the dose needed. She received premedication treatment and 400mg of Etoposide in a 13 steps protocol, twice in consecutive days. She had no HSR, the transplantation went well and she is now in complete remission. In the second patient we followed the 12 step protocol with premedication treatment and the patient was able to receive the target dose (150mg). We did 3 desensitization protocols with the total dose, in 3 consecutive days. He had no HSR and he continues in follow up in our hospital. How this report contributes to current knowledge Patients with HSR to etoposide, in which this drug is the most adequate chemotherapeutic option for such a severe disease, the desensitization protocol is a treatment that proved to be effective in order to administer the treatment. P24 Drug Desensitisation In Oncology: The Experience Of An Immunoallergology Department For 5 Years Carmelita Ribeiro1, Emília Faria1, Cristina Frutuoso2, Anabela Barros2, Rosário Lebre2, Alice Pego2, Ana Todo Bom1 1. Allergy and Clinical Immunology Department, Coimbra University Hospital Center, Coimbra, Portugal 2. Oncology Department, Coimbra University Hospital Center, Coimbra, Portugal Keywords: Drug Desensitisation, Oncology,Chemotherapy Agents, Platins,Taxanes Introduction Any cancer drug can potentially trigger a hypersensitivity reaction (HSR), particularly chemotherapy agents and monoclonal antibodies. The more frequent drugs inducing HSR are the platins (IgE-mediated reactions) and taxanes (nonimmunological reactions). Desensitisation protocols must be considered when there is no valid and effective alternative treatment. This is especially relevant for cancer patients who are thus able to continue their first line treatment.The aim was to describe the experience of an Immunoallergology Department with desensitization to chemotherapy agents. Method Retrospective review of charts of oncology patients desensitized in the Immunoallergology Department of CHUC in the last 5 years. Results There were a total of 72 desensitisation procedures corresponding to 15 patients treated (11 female) during the period in question, with a mean age of 56 years (range: 28-73 years). The patients had ovarian cancer (8 patients), lung cancer (3 patients), colon cancer (2), rectal cancer (1) and breast cancer (1). The HSR were all with moderate to severe immediate reactions: rash, urticaria, laryngeal stridor, bronchospasm, syncope and anaphylaxis (6 patients). Eleven patients were desensitized to platins (carboplatin n=6, cisplatin=3, oxaliplatin n=2), three to taxanes (docetaxel n=2, nabpaclitaxel n=1) and one to monoclonal antibodies (panitumumab). In the total of 72 desensitisation procedures, the range of desensitisation procedures for patient was 17 (maximum) to 2 (minimum) treatmens with carboplatin. There were 5 desensitisation procedures in 2011, 12 in 2012, 19 in 2013, 18 in 2014 and also in 2015. In the 72 desensitisation did not have any reaction in 59 procedures (82%) and in the others, the reactions were milder than the initial HSR (only 1 patient had anaphylaxis in the third desensitization with cisplatin). All patients received their daily programmed dose. Five patients discontinued the desensitization programme (3 patients due to progression of the oncological disease, 1 patient due to neurological toxicity and another for anaphylaxis during de desensitization). Conclusion In the majority of patients, desensitization procedures allowed safe reintroduction of chemotherapy agents in Immunoallergology centers with experience. This approach must be considered by Oncologic doctors in the treatment of specific oncologic patients with previous history of HSR to these drugs. P25 Filgrastim Anaphylaxis: A Successful Desensitization Protocol Luis Amaral, Josefina Cernadas Serviço de Imunoalergologia, Centro Hospitalar de São João E.P.E., Porto, Portugal Introduction Filgrastim is a recombinant human granulocyte colony-stimulating factor (G-CSF) and is used to prevent or treat neutropenia that is generally associated with chemotherapy. Anaphylatic reactions to filgrastim are rarely reported and there is only one published successful desensitization protocol in a patient with immediate hypersensitivity to filgrastim. Case Description We describe a case of a 47-year-old woman with ductal breast carcinoma receiving chemotherapy with doxorubicin, cyclophosphamide and docetaxel. She developed chemotherapy induced neutropenia for which she was started on SC filgrastim [300mcg] days after the chemotherapy cycle, given once a day, for 4 consecutive days. Ten minutes after the 4th dose of filgrastim, she developed facial erythema, labial angioedema, dyspnea and colicky abdominal pain. These symptoms quickly reversed spontaneously in 48h. Subsequently, filgrastim was withdrawn and anaphylaxis work-up was done. A 5-step desensitization protocol was performed using sequential doses intravenously: 15, 30, 60, 80, 115 to a cumulative dose of 300 mcg diluted in 20mL of saline over approximately 3 hours. In the following day she received 300mcg in two steps with success and in 3rd day in one without any reaction. How this report contributes to current knowledge In summary, we present a successful desensitization protocol for filgrastim in a patient with a previous life-threatening immediate hypersensitivity reaction. P26 Galsulfase Hypersensitivity And Desensitization Of A Mucopolysaccharidosis VI Patient Luis Felipe Ensina, Carolina Aranda, Ines Camelo Nunes, Ana Maria Martins, Dirceu Solé Federal University of São Paulo, São Paulo, Brazil Keywords: Omalizumab, Desensitization Introduction Mucopolysaccharidosis VI or Maroteaux-Lamy Syndrome (MPS VI) is a lysosomal storage disorder caused by deficiency of arylsulfatase B. The enzyme replacement therapy (ERT) with galsulfase is so far the only specific treatment for MPS VI. Infusion-related reactions (IRR) to ERT can occur and can be severe, precluding further ERT. However, the interruption of ERT can accelerate the disease progression and precipitate earlier death. The aim of this study is to report IRR to galsulfase in a MPS VI Brazilian patient, and his treatment reestablishiment after desensitization. Method a 7y-old male started presenting symptoms such ias dyspnea and itch during his 44th infusion. No improvement was observed with premedication (corticosteroids and antihistamines) in the folowing infusion. ERT were stopped for four weeks and the patient underwent skin tests (prick and intradermal). Skin prick test was performed using the straight concentration of galsulfase and Intradermal tests with progressive dilutions. Skin tests were also performed in 10 healthy subjects and in a MPS VI patient without IRR, to rule out a skin irritant effect, since skin tests with galsulfase have not been standardized. Results Patient presented a positive skin prick test, suggesting an IgE-mediated reaction. Therefore, a rapid desensitization protocol was generated. Three solutions ( each 250 mL 0.9% sodium chloride – 1:100, 1:10 and 1:1 respectively) were delivered in 12 consecutive steps at an increasing infusion rate. Pre-medications were used to block different allergy pathways. This protocol has succeeded for six months, when during the 22th infusion he started to present wheals in the beginning of the third bag. A new protocol was developed (four bags -16 steps), but the patient still had symptoms. A 75mg omalizumab (Omab) monthly was introduced. Ten days after the Omab, a new infusion using the same desensitization protocol was performed with no reaction. Conclusion To our knowledge, we are the first group to use an adapted 12-step desensitization protocol to galsufase with omalizumab. The protocol has shown to be safe and effective for the patient receiving the enzyme in the recommended dose. Management of these reactions with desensitization can provide first line therapy and permit continued ERT. P27 RAPID DRUG DESENSITIZATION WITH BIOLOGICALS: ONE-CENTER EXPERIENCE WITH FOUR BIOLOGICALS Sevim Bavbek, Resat Kendirlinan, Pamir Çerçi, Seda Tutluer, Sadan Soyyigit, Zeynep Çelebi Sözener, Ömür Aydin, Reyhan Gümüsburun Ankara University, Ankara, Turkey Keywords: Biologicals, Rituximab, Infliximab, Rapid Drug Desensitization Introduction Rapid drug desensitization (RDD) induces a temporary tolerance to biological drugs inducing hypersensitivity reactions (HSRs) but data are limited regarding use of this outside of the USA.Therefore in this study we aimed to report our data with RDD to rituximab, infliximab, cetuximab and trastuzumab. Method The study was conducted as a retrospective chart review of patients with symptoms of HSRs to biological agents to which RDD have been performed between January 2012 and January 2016.. HSRs were classified as Grade I, II and III based on their severity. Skin prick/intradermal tests were performed with implicated biologicals. The 12-step RDD protocol developed at Brigham and Women Hospital was used Results Study group consisted of 11 female and four men ( mean age: 54, 21±11 years). Majority of the study subjects (66.6%) were using the biological agents for the treatment of malign diseases. Twelve subjects had experienced HSR to rituximab, three had HSR to cetuximab, infliximab and trastuzumab respectively. HSR to cetuximab, infliximab and trastuzumab occurred during first infusion and all were Grade III, 11 of 12 subjects with rituximab hypersensitivity had reaction during first infusion, nine had Grade II and three had Grade III. Of the 15 patients, 86,6% had respiratory symptoms, 66,6% had cardiovascular, 60% had cutaneous symptoms, and 40% had gastrointestinal symptoms. Skin tests with rituximab were done on eight patients, only three resulted in positive in 1/100 dilutions of intradermal tests, and skin tests were negative on either prick or intradermal tests with other biologicals. Of 88 RDD, 81 desensitizations with rituximab, five desensitizations with cetuximab, and one desensitization with infliximab and one desensitization with trastuzumab were done. There were nine breakthrough reactions (10.1 %) in seven subjects, which were all associated with rituximab and less severe than initial reactions. Of breakthrough reactions, 55.5% were cutaneous, followed by cardiovascular (33%), respiratory (22,2%), and gastrointestinal (11,1%) symptoms. Reactions mainly occurred at step 12, and all were successfully under-controlled and except single desensitization, all desensitization procedures were completed with full target dose. Conclusion We found RDD is safe and effective, to our knowledge, in the largest series of biological including Rituximab in our country. P28 Successful Desensitization To A High Dose Of Methotrexate In A Delayed Type Hypersensitivity Reaction Josefina Cernadas1, Leonor Carneiro-Leão1, Fabrícia Carolino1, Marta Almeida2 1. Serviço de Imunoalergologia, Centro Hospitalar de São João, Porto, Portugal 2. Serviço de Pediatria, Instituto Português de Oncologia do Porto Francisco Gentil, Porto, Portugal Introduction Delayed type hypersensitivity reactions are mediated by cells rather than by antibodies. They can be life-threatening and classically constitute a contraindication to desensitization (DZT). However, in selected cases of uncomplicated exanthemas, when the culprit drug is irreplaceable or more effective, this option might be considered. Methotrexate (MTX) is a folic acid antagonist with a major role in the treatment of B cell acute lymphoblastic leukemia (ALL). The authors describe a successful DZT to a high dose of IV MTX associated to inthrathecal administration, following a delayed-type hypersensitivity reaction. Case Description We report a case of a 12 year old boy under B cell ALL treatment. He was scheduled to receive 4 cycles of MTX 8000mg IV perfusion over 24h (10% on the 1st hour, 90% over the remaining 23h hours, with a constant concentration), followed by inthrathecal administration of MTX 12mg, cytarabine 30mg and prednisolone 10mg. He complained of an intensely pruritic morbilliform exanthema in his abdomen arising 72h after completion of the first treatment. The rash resolved with anti histamines and oral and topic corticosteroids, over a period of 10 days with severe residual hyperpigmentation. No renal or liver function analytical changes were found during this episode. Because no alternative treatment was available for his specific type of leukemia, a decision to perform DZT was made. The patient (60Kg) was pretreated with montelukaste 10mg, starting 2 days before chemotherapy (QT); prednisolone 60mg was started the day before QT and maintained over 4 days in decreasing doses. He was admitted and a 14 step DZT protocol to MTX was performed. The doses administered were doubled in each step until the 14th step, with a cumulative dose of 1671mg of MTX infused over a period of 4.5 hours. The remaining dose, until the target dose of 8000mg was infused at a small rate during 24.5h. This procedure was followed by triple inthrathecal treatment, including MTX. The patient was able to reach the target dose without any reaction. He has now completed 3 of the 4 scheduled cycles. How this report contributes to current knowledge To our knowledge this is the first description of a successful DZT to such a high dose of MTX in a delayed type reaction. The IV DZT protocol also made possible the administration of inthrathecal MTX. Our findings support that DZT protocols might be suitable in selected cases, allowing these patients to safely continue with first line therapy. Poster Walk 4: SJS (P29 – P38) P29 Assessment Of Impact Of Infection On Drug-Induced Severe Cutaneous Adverse Reactions And Rhabdomyolysis Using The Japanese Adverse Drug Event Report Database Kimie Sai1, Takuya Imatoh1, Ryosuke Nakamura1, Chisato Fukazawa2, Yasushi Hinomura2, Yoshiro Saito1 1. National Institute of Health Sciences, Tokyo, Japan 2. Japan Pharmaceutical Information Center, Tokyo, Japan Keywords: Severe Cutaneous Adverse Reactions, Rhabdomyolysis, Infection, Database Introduction Involvement of immune-mediated mechanism has been demonstrated in a certain type of serious adverse drug reactions (ADRs), such as severe cutaneous adverse reactions (SCAR) or rhabdomyolysis (RM), and thus, a possible potentiation of these ADRs by infection via activating immune reactions is postulated. In this study, to assess a role of infection in occurrence and severity of SCAR and RM in Japanese cases, we analyzed a relation of infection to reporting rates of these ADRs and severe outcomes or periods to onsets using the Japanese Adverse Drug Event Report database (JADER). Method A total of 302,641 reports regarding primary suspected drugs from 2009 to 2013 in JADER were used in our analysis. Of these, a total of 3,167 SCAR reports (Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN), or mucocutaneous ocular syndrome) and 1,847 RM reports were included. Infection-Positive (Infect-P) was defined if the individual case report included data on anti-infectious drugs or infection-related diseases, either as a primary suspected drug (PS) or concomitant drugs/diseases (CO). Rates of infections for SCAR or RM among total reports, and ratios of severe phenotype (TEN for SCAR) and severe outcomes (no recovery, permanent damage and death) and period to onset of SCAR or RM were compared between Infect-P and Infection-Negative (Infect-N). Results The reporting ratios for Infect–P (vs. Infect-N) were significantly higher in SCAR (adjusted odds ratio [95%CI]: 1.8 [1.7-2.0] for PS and 2.0 [1.8-2.2] for CO, respectively) and lower in RM (0.6 [0.5-0.7] for PS and 0.8 [0.7-0.9] for CO). The rate of TEN in SCAR was significantly higher in Infect-P (vs. Infect-N) (1.3[1.1-1.6] for PS and 2.2 [1.8-2.7] for CO). Higher rates of severe outcomes by Infect-P (vs. Infect-N) were observed for SCAR (1.6 [1.2-2.1] for PS and 1.9[1.4-2.5] for CO) and RM (1.3 [0.8-2.2] for PS and 1.7 [1.0-2.3] for CO). The mean period to onset of SCAR was shorter for PS (25 days) but marginal for CO (40 days) in Infect-P comparing with Infect-N (36 days), and earlier onset of RM was evident in Infect-P (47 days for PS and 191 days for CO) comparing with Infect-N (250 days). Conclusion This study indicated a substantial association between infection and occurrence/severity in SCAR as well as RM, showing much larger impacts on SCAR. P30 Characterization Of Erythema Multiforme And Severe Cutaneous Adverse Reactions Hospitalizations Bernardo Sousa-Pinto, Cláudia Correia, Lídia Gomes, Sara Gil-Mata, Luís Araújo, Luís Delgado Immunology Laboratory - Basic and Clinical Immunology. Faculty of Medicine, Porto, Portugal Keywords: Erythema Multiforme, Severe Cutaneous Adverse Reactions, Epidemiology, Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis Introduction Erythema multiforme (EM) and severe cutaneous adverse reactions (SCARs) are immunologically-mediated delayed hypersensitivity reactions triggered after exposition to external agents such as drugs. We aim to characterize hospitalizations occurring in Portuguese public hospitals with associated diagnosis of drug-related EM and SCARs concerning patients’ demographic and clinical characteristics, in-hospital mortality and most frequently associated drug classes. Method We used a database containing all hospitalizations occurred in mainland Portugal public hospitals and analyzed all episodes with associated diagnosis of drugrelated EM or SCARs - Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and SJS/TEN overlap syndrome. These hospitalizations were compared concerning patients’ demographic and clinical characteristics (gender, age and comorbidities), length of stay, and in-hospital mortality. We also evaluated the drug classes most frequently associated with these diagnoses, estimating the number of episodes per million drug packages sold. A logistic regression was performed to evaluate for factors significantly associated with inhospital mortality among SCARs. Results Between 2009 and 2014, there were 122 hospitalizations with associated diagnosis of EM and 132 with associated diagnosis of SCARs. Most EM (65%) and SCARs (55%) episodes occurred in women. The median age was 63 years old for both EM and SCARs. The frequency of HIV co-infection was higher among SCARs episodes (9% versus 2%; p=0.009). In-hospital mortality varied between 7% (EM) and 44% (TEN). Advanced age (OR=1.06; 95% CI: 1.02-1.45), heart failure (OR=4.93; 95% CI: 1.01-23.99), liver disease (OR=7.39; 95% CI: 1.0751.02) and TEN diagnosis (OR=14.66; 95% CI: 1.73-124.31) were all significantly associated with higher risk of in-hospital mortality among SCARs episodes. The highest numbers of EM and SCARs episodes per million drug packages sold concerned antiviral (1.5 and 8.7, respectively) and uric acid metabolism drugs (2.4 and 5.0, respectively). Conclusion SCARs are associated with higher mortality than EM. Advanced age, heart failure, liver disease and TEN diagnoses are associated with higher in-hospital mortality among SCARs episodes. Antiviral and uric acid metabolism drugs are the drug classes most frequently associated with SCARs hospitalizations. P31 Effects Of Infection On Incidence/Severity Of SJS/TEN And Myopathy In Japanese Cases Analyzed By Voluntary Case Reports Ryosuke Nakamura1, Kimie Sai1, Takuya Imatoh1, Yoshimi Okamoto-Uchida1, Koji Kajinami2, Kayoko Matsunaga3, Michiko Aihara4, Yoshiro Saito1 1. National Institute of Health Sciences, Tokyo, Japan 2. Kanazawa Medical University, Ishikawa, Japan 3. Fujita Health University, Aichi, Japan 4. Yokohama City University, Kanagawa, Japan Keywords: SJS, TEN, Myopathy, Infection, Adverse Reaction Introduction Immunological mechanisms are supposed to be involved in the pathogenesis of certain types of serious adverse reactions (ADRs), such as severe cutaneous adverse reactions or rhabdomyolysis. Therefore, infection which activates immune system may affect incidence and severity of ADRs. In this study, we analyzed an association of concomitant infectious diseases with incidence/severity of Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and myopathy, based on Japanese voluntary case reports. Method Patients who experienced SJS/TEN (259 cases) or myopathy (a total of 129 cases) were recruited through a nationwide blood sampling network in Japan operated by the National Institute of Health Sciences under a cooperation of the Ministry of Health, Labour and Welfare, Pharmaceuticals and Medical Devices Agency, and Federation of Pharmaceutical Manufacturers’ Association of Japan. Written informed consent was obtained from all recruited patients. Using the case report data, we analyzed rates for concomitant infectious disease (tuberculosis, hepatitis, AIDS, influenza infection, and herpes simplex infection, etc.), and compared the severity (severe phenotypes or outcomes) and the mean period to onset of the ADRs between patients with and without infectios diseases. Results For SJS/TEN cases, the rate of infectious diseases was 51%, of which 31% was the cases caused by a primary suspected drug. The rates of severe phenotype TEN, ocular involvement and permanent damage were significantly higher (p<0.05) and the mean period of onset of SJS/TEN was significantly shorter in the infectious patients’ group compared with non-infectious group. The rate of infectious diseases in myopathy was 23%, of which 12 % was the cases caused by a primary suspected drug. The rates of severe phenotype and permanent damage were higher and the mean period of onset of myopathy was shorter in the myopathy patients with infectious disease than those without infection, although these differences were not statistically significant. Conclusion This study indicated that the incidence and the severity of SJS/TEN and myopathy are associated with the concomitant infectious disease, especially in the cases of SJS/TEN, which might reflect a greater contribution of immune system as a mechanism of occurrence. P32 Efficacy Of Tumor Necrosis Factor–a Antagonists In StevensJohnson Syndrome And Toxic Epidermal Necrolysis: A Randomized Controlled Trial And Immunosuppressive Effects Evaluation Chuang-Wei Wang1, Shih-Chi Su1, Shuen-Iu Hung2, Hsin-Chun Ho1, Chih-Hsun Yang1, Wen-Hung Chung1 1. Department of Dermatology, Drug Hypersensitivity Clinical and Research Center, Chang Gung Memorial Hospital, Linkou And Keelung, Taiwan 2. Department and Institute of Pharmacology, School of Medicine, Infection and Immunity Research Center, National Yang-Ming University, Linkou, Taiwan Introduction Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare, but life-threatening adverse drug reactions. While the clinical manifestations of SJS/TEN are well-defined, the optimal treatment for these diseases remains unavailable. We aim to evaluate the efficacy and safety of etanercept (anti-TNF-α agent) in patients with SJS/TEN. Method We enrolled 98 patients with SJS/TEN to perform an open, prospective, doubleblind and randomized comparison trial of etanercept versus corticosteroid. We further investigated the immunologic effects of etanercept in SJS/TEN patients. Results This study demonstrated that etanercept had clinical improvements in patients with SJS/TEN. Etanercept revealed to be more decreased the SCORTEN-based predicted mortality rate (predicted rate=17.47%; observed rate=8.33%) than in corticosteroid use (predicted rate=20.13%; observed rate=15.91%). Compared with corticosteroid, etanercept also showed a shorter skin healing time (The median times are 14 days for etanercept and 17 days for corticosteroid; P<0.05*) and less side effect for gastrointestinal hemorrhage (0% after etanercept use and 11.8% after corticosteroid use; P <0.05*) in total SJS/TEN patients. For mechanism study, etanercept significantly decreased the granulysin and TNF-α expression in blister fluids and plasma (In blister fluids: granulysin=62.5% and TNF-α=50.0% decrease after 2 days treatment; in plasma: granulysin=54.7% and TNF-α=69.2% decrease after 15 days treatment, all P<0.05*) and increased Treg cells population (2-fold percentage increase after 15 days treatment, P<0.01**). Conclusion This study indicates that etanercept (anti-TNF-α agent) not only has immunosuppressive effects but also serves as an alternative medicine for SJS/TEN treatment. P33 Evolution Of Drug Causality In Stevens-Johnson Syndrome And Toxic Epidermal Necrolysis In Europe: Analysis Of 10 Years RegiSCARStudy Maren Paulmann1, Ariane Dunant2, Maja Mockenhaupt1, Peggy Sekula3, Martin Schumacher3, Sylvia Kardaun4, Luigi Naldi5, Teresa Bellón6, Daniel Creamer7, Cynthia Haddad8, Bruno Sassolas9, Bénédicte Lebrun-Vignes10, Laurence Valeyrie-Allanore8, Jean-Claude Roujeau8 1. Dokumentationszentrum schwerer Hautreaktionen, University Medical Center, Freiburg, Germany 2. Department of Biostatistics and Epidemiology Unit, Institut GustaveRoussy, Villejuif, France 3. Institute of Medical Biometry and Medical Informatics, University Medical Center, Freiburg, Germany 4. Reference Center for Cutaneous Adverse Reactions, University Medical Center, Groningen, Netherlands, The 5. Department of Dermatology, Papa Giovanni XXIII Hospital, Bergamo, Italy 6. Institute for Health Research, University Hospital La Paz–IdiPAZ, Madrid, Spain 7. Department of Dermatology, King's College Hospital, London, United Kingdom 8. Reference Center for Toxic and Autoimmune Blistering Diseases, Hopital Henri Modor, University Paris-Est, Créteil, France 9. Department of Internal medicine and Respiratory Diseases, Hôpital Cavale Blanche, Brest, France 10.Department of pharmacology, Hôpital Pitié-salpétrière, Paris, France Introduction Stevens-Johnson syndrome (SJS) / toxic epidermal necrolysis (TEN) is rare, but the most severe of all adverse drug reactions due to a high mortality, which is almost 50% in TEN. Good evaluation of risk factors is essential for efficient pharmacovigilance. Method From January 2003 to December 2012 the international Registry of Severe Cutaneous Adverse Reactions (RegiSCAR) included 1096 cases of SJS/TEN collected in seven countries (France, Germany, Israel, Italy, Netherlands, Spain, United Kingdom). The diagnoses and dates of onset were validated by an expert group, blinded for any information on exposures. Causality was established by using the specific algorithm ALDEN that had previously shown a good correlation with the results of a case-control analysis in an earlier systematic collection of several hundred cases. Results In terms of overall causality assessment, at least one medication was evaluated as the «probable» or «very probable» cause in 744/1096 cases (68 %). A medication cause was determined as «possible» in 209 cases (19%), as «unlikely» in 68 cases (6,2%) and “very unlikely” in 57 cases (5,2%). 18 patients (1.6%) denied any exposure to medications. The 5 medications most often incriminated («probable» or «very probable» causality) were allopurinol (n=187; 17%), sulfamethoxazole (n=80), lamotrigine (n=76), carbamazepine (n=51), phenytoin (n=42). There were substantial differences between reactions developing among hospitalized and community patients, e.g. older age, exposure to a substantially higher number of drugs and a noticeable role for metamizole among inhospital cases in Germany. In both groups (inhospital and community cases) we identified a signal for proton pump inhibitors. Conclusion In spite of prior warnings in medical journals and towards regulatory agencies, allopurinol is still the principal cause of SJS/TEN in Europe, as it was 10 years ago. Off-label prescription of allopurinol for asymptomatic hyperuricemia has not decreased. Sulfamethoxazole and other anti-infective sulfonamides are still frequent inducers of SJS/TEN. Lamotrigine is now the third cause and the first one among antiepileptic drugs, independent of new indications such as bipolar disorder. Finally, it is important to note that at least 13% of SJS/TEN-cases have no drug cause. Investigation of other possible causes of such «idiopathic cases», e.g. infections, should be a priority. P34 Long-Term Sequelae In Patients With Stevens-Johnson Syndrome And Toxic Epidermal Necrolysis: A 5-Year Analysis Maren Paulmann1, Carmen Kremmler1, Peggy Sekula2, Laurence ValeyrieAllanore3, Luigi Naldi4, Sylvia Kardaun5, Maja Mockenhaupt1 1. Dokumentationszentrum schwerer Hautreaktionen, University Medical Center, Freiburg, Germany 2. Institute of Medical Biometry and Medical Informatics, University Medical Center, Freiburg, Germany 3. Reference Center for Toxic and Autoimmune Blistering Diseases, Hopital Henri Modor, University Paris-Est, Créteil, France 4. Department of Dermatology, Papa Giovanni XXIII Hospital, Bergamo, Italy 5. Reference Center for Cutaneous Adverse Reactions, University Medical Center, Groningen, Netherlands, The Introduction Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare, but severe reactions with blisters and erosions of skin and mucosae. Most often SJS/TEN is induced by drugs, less frequently by infections, whereas some cases are “idiopathic”. Severity is determined by skin detachment related to the body surface area (BSA): SJS <10%, TEN >30%, and SJS/TEN-overlap 10-30% of BSA. The high mortality rate is due to severity as well as age of the patient. Survivors frequently suffer from long-term sequelae, particularly of the mucosae. Method In order to evaluate frequency and extent of late sequelae in patients with SJS/TEN, a cohort study was performed. Patients with a validated diagnosis of SJS/TEN, who were included in the international Registry of Severe Cutaneous Adverse Reactions (RegiSCAR) between 2003 and 2007, were asked to answer a follow-up questionnaire. Results 112/233 completed follow-up questionnaires could be analyzed. 62 patients were diagnosed with SJS, 35 with SJS/TEN-overlap, and 15 with TEN. The mean age is 44 years, and approx. 60% are women. More than 90% of the patients suffer from sequelae after 5 years, while the percentage increases with severity of the reaction. Less than 50% were able to completely return to their normal daily activities. Sequelae mainly affect skin (73%), mucosa (57%) and nails (52%). Chronic sequelae of the eyes (67%) are the main issue for the patients. They include increased photosensitivity, dry eyes, ingrowing eyelashes (trichiasis), excessive watery eyes (epiphora), inflammatory cicatrization up to blindness. Furthermore, patients describe sleep disturbances and nightmares (29%). In addition, they are afraid of drug use (65%), and 56% of the patients avoid taking drugs, which may have a negative impact on their health. Although many patients consider professional psychological support helpful (54%), only 9% had received it. Conclusion This evaluation shows that the majority of patients who survived SJS/TEN suffer from long-term sequelae. An interdisciplinary approach is not only important in the acute stage of the disease, but also after discharge from the hospital, including regular check-ups by specialists for these rare severe reactions. P35 Major Emotional Complications And Decreased Health Related Quality Of Life Among Survivors Of Stevens-Johnson Syndrome And Toxic Epidermal Necrolysis Roni P. Dodiuk-Gad1, Cristina Olteanu2, Anthony Feinstein3, Rena Hashimoto4, Raed Alhusayen4, Sonia Whyte-Croasdaile5, Yaron Finkelstein6, Marjorie Burnett7, Shachar Sade8, Robert Cartotto7, Marc Jeschke7, Neil H. Shear4 1. Department of Dermatology, Ha’emek Medical Center, Afula, Israel 2. Faculty of Medicine, University of Toronto, Toronto, Canada 3. Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, Canada 4. Division of Dermatology, Department of Medicine, Sunnybrook Health Sciences Centre, Toronto, Canada 5. SJS and TENS Group Canada-CAST International, Toronto, Canada 6. Paediatric Emergency Medicine, Clinical Pharmacology and Toxicology, The Hospital for Sick Children, Toronto, Canada 7. Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Canada 8. Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Canada Keywords: Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, Emotional Complications, SJS/TEN Introduction Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are lifethreatening mucocutaneous reactions, predominantly drug-induced. In addition to these high mortality rates, early and late physical complications are common. No studies were conducted on the emotional status or the general Health-Related Quality of Life among survivors of SJS/TEN. We aimed to characterize the longterm emotional complications and health-related quality of life among SJS/TEN survivors. Method Patients older than 18 years who survived SJS/TEN were assessed using various parameters. Emotional assessment was conducted by three validated questionnaires: Impact of Events Scale-Revised, General Health Questionnaire, and Hospital Anxiety and Depression Scale. Health-Related Quality of Life was assessed by three validated questionnaires: Dermatology Life Quality Index, EQ5D, Skindex-29 and one specially designed for the study. Results Our cohort consists of 17 patients with mean 51.6±74.7 months (median=9, range=1-228) following SJS/TEN. Eleven out of 17 (65%) were found to have symptoms of post-traumatic stress (Impact of Events Scale-Revised, mean=22.4±19.9) and 5 (29%) met the criteria for post-traumatic stress disorder, 12 (71%) had psychological distress (General Health Questionnaire, mean total score=4.6±4.2) and 11 (65%) had symptoms of a psychiatric clinical disorder (Hospital Anxiety and Depression Scale, mean total score=14.5±8.4). The Dermatology Life Quality Index indicated a moderate to extremely large effect on the lives of 9 (53%) participants (mean total score=6.9±7.6). Skindex29 indicated a mild-severe effect on Health-Related Quality of Life in 10 (59%) participants (mean=24.6±21.5). Participants rated their general health at a mean of 66.2/100±18.1 (EQ-5D VAS). Fourteen (82%) participants reported that SJS/TEN decreased their current quality of life. Twelve (71%) reported that SJS/TEN influenced their current emotional status. Eleven (65%) reported that SJS/TEN influenced their current everyday activities. Conclusion Survivors of SJS/TEN suffer from severe long-term emotional complications and decreased health-related quality of life. P36 Retrospective Analysis Of Stevens-Johnson Syndrome And Toxic Epidermal Necrolysis In Japanese Patients - Treatment And Outcome Naoko Takamura1, Yumiko Yamane1, Setsuko Matsukura2, Kazuko Nakamura2, Yuko Watanabe1, Yukie Yamaguchi1, Takeshi Kambara2, Zenro Ikezawa1, Michiko Aihara1 1. Department of Environmental Immuno-Dermatology## Yokohama City University, Yokohama, Japan 2. Department of Dermatology## Yokohama City University Medical Center, Yokohama, Japan Keywords: SJS, TEN Introduction Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but severe adverse drug reactions with high mortality. Method To present the clinical characteristics of SJS and TEN in Japan and evaluate the efficacy of treatments, we retrospectively analyzed cases of SJS and TEN treated in Yokohama City University Hospital and Yokohama City University Medical Center between January 2000 and December 2015. Results 60 cases of SJS (24 males and 36 females; average age, 54.2 years) and 40 cases of TEN (19 males and 21 females; average age, 56.2 years) were included in this study. 31 cases of SJS (51.6%) and all cases of TEN were caused by drugs. Hepatitis was the most common organ involvement in both SJS and TEN. Renal dysfunction, intestinal disorder, and respiratory disorder were also involved in some cases. The major complication was pneumonia and sepsis. All cases except for 4 cases were treated systemically with corticosteroids. In SJS 40 cases (66.6%) were treated with corticosteroid alone, Steroid pulse therapy was performed in 40% of SJS and 90% of TEN. Plasmapheresis and/or immunoglobulin therapy was combined with steroid therapy performed 17 cases in SJS (42%) and 26 cases in TEN (65%). Average SCORTEN score was 1.13 in SJS and 2.32 in TEN. The mortality rate was 6% and the rates for SJS and TEN were 1.7% and 12.5%, respectively. The mortality rate was 0% treated with combination of corticosteroid, plasmapheresis and immunoglobulin therapy in SJS and TEN. These were much lower than predicted mortality according to a severity-of-illness scoring system fot TEN prognosis (SCORTEN) socre. Conclusion Treatment with steroid pulse therapy in combination with plasmapheresis and/or immunoglobulin therapy seems to have contributed to prognostic improvement in SJS/TEN. P37 Severe Physical Complications Among Survivors Of Stevens-Johnson Syndrome And Toxic Epidermal Necrolysis Roni P. Dodiuk-Gad1, Cristina Olteanu2, Rena Hashimoto3, Hall Chew4, Raed Alhusayen3, Sonia Whyte-Croasdaile5, Yaron Finkelstein6, Marjorie Burnett7, Shachar Sade8, Robert Cartotto7, Marc Jeschke7, Neil H. Shear3 1. Department of Dermatology, Ha’emek Medical Center, Afula, Israel 2. Faculty of Medicine, University of Toronto, Toronto, Canada 3. Division of Dermatology, Department of Medicine, Sunnybrook Health Sciences Centre, Toronto, Canada 4. Department of Ophthalmology and Vision Sciences, Sunnybrook Health Sciences Centre, Toronto, Canada 5. SJS and TENS Group Canada-CAST International, Toronto, Canada 6. Paediatric Emergency Medicine, Clinical Pharmacology and Toxicology, The Hospital for Sick Children, Toronto, Canada 7. Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Canada 8. Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Canada Keywords: Physical Complications, Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, Long-Term Complications Introduction Stevens–Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are considered the most severe types of cutaneous adverse reactions to drugs, with high morbidity and mortality rates. We aimed to characterize the long-term physical complications among SJS/TEN survivors. Method Patients older than 18 years who survived SJS/TEN were assessed by an interview and by skin, oral mucous membrane and detailed ophthalmic exam. Results Our cohort consists of 17 patients with mean 51.6±74.7 months (median=9, range=1-228) following SJS/TEN. The most commonly reported symptom among survivors was chronic fatigue/weakness (76%). The most common cutaneous signs were post-inflammatory dyspigmentation in 77% of participants, scars (46%), and milia (15%). The most common cutaneous symptoms were pruritus (53%), photosensitivity (35%), and dry skin (24%). In the ophthalmic exam, dry eyes were the most common finding in 44%. Other identified signs were: lid adhesions/symblepharon (33%), chronic ocular surface inflammation (33%), loss of visual acuity (22%), chronic conjunctivitis (22%), keratinization of the tarsal conjunctiva (22%), lachrymal duct scarring (22%), blindness (11%), photophobia (11%), ectropian and trichiasis (11%), corneal abrasions/ulcers (11%), conjunctival synechiae (11%), and corneal neovascularization (11%). The most commonly reported ocular symptoms were dry eyes in 47% of participants; other symptoms included photophobia (35%), loss of visual acuity (35%), and ocular pain (24%). Hair loss and nail loss were reported in 53% and 35% of participants a few months after TEN, respectively. Other less common complications included genital synechiae in 18% of female survivors, lupus (12%), renal dysfunction (12%), and fibromyalgia (6%). Tinnitus, tenderness on soles of feet, abnormal ECG, and vocal cord dysfunction were each reported in 6% of participants. Conclusion Survivors of SJS/TEN suffer from severe, long-term physical complications and require ongoing longitudinal medical follow-up. P38 Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Combined With Haemophagocytic Lymphohistiocytosis: A Case Report Brittany Knezevic1, Una Nic Ionmhain1, Allison Barraclough1, Michaela Lucas2, Matthew Anstey1 1. Sir Charles Gairdner Hospital, Perth, Australia 2. Pathwest Laboratory Medicine, Queen Elizabeth II Medical Centre, Perth, Australia Introduction The combination of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) with haemophagocytic lymphohistiocytosis (HLH) is life-threatening and usually fatal in adults. We report a rare case of a 36 year old male who survived these concomitant illnesses. Case Description The patient presented with a one week history of fevers and flu-like symptoms, with onset of a mucocutaneous rash on day five. He was admitted to a tertiary intensive care unit (ICU) with a diagnosis of SJS/TEN (20-25% of total body surface area). The potentially implicated drugs (ibuprofen, codeine and amoxicillin) were promptly withdrawn, and he received immunosuppressive therapy with methylprednisolone, intravenous immunoglobulin and cyclosporin combined with supportive ICU care. He continued to systemically deteriorate at a time when his skin lesions stabilised. Recognition of hyperferritinemia (40900 ug/L), unremitting fevers and pancytopenia in a critically ill patient, clinched the diagnosis of HLH which was confirmed on bone marrow biopsy. He received treatment with the HLH-94 chemotherapy protocol (including etoposide and dexamethasone). Sequential skin patch tests to ibuprofen and amoxicillin, performed six months post-discharge, were negative (codeine patches were not available). The patient’s negative patch tests were interpreted with caution, due to previous chemotherapy and the unavoidable delays to testing, both of which may have led to T lymphocyte depletion and false negative patch test results. The patient was advised to strictly avoid all non-steroidal antiinflammatories, aspirin, codeine and amoxicillin (he had tolerated other opiates and beta-lactams in hospital). How this report contributes to current knowledge To our knowledge, this is the first report of an adult surviving a severe episode of HLH and SJS/TEN overlap (rather than SJS alone). This case highlights (i) the potential for HLH to coexist with SJS/TEN and the importance of early recognition and treatment, (ii) the difficulties in interpreting patch tests in patients who have received marrow ablative therapies, and (iii) the complexities of providing recommendations on drug avoidance to patients with severe cutaneous adverse drug reactions and negative patch test results. In vitro lymphocyte proliferation assays may be a useful alternative diagnostic tool in this clinical setting. Poster Walk 5: Other organs / Unexpected immune reactions (P39 – P47) P39 A Case Report Of Patient With Anti-Tuberculosis Drug-Related Severe Liver Failure Toru Usui1, Xiaoli Meng1, John Farrell1, Paul Whitaker2, John Watson2, Neil French1, Kevin Park1, Dean Naisbitt1 1. MRC Centre for Drug Safety Science, Dept Molecular & Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom 2. Regional Adult Cystic Fibrosis Unit, St James’s Hospital, Leeds, United Kingdom Keywords: Isoniazid, Drug-Induced Liver Injury Introduction Exposure to anti-tuberculosis drugs (ATDs) isoniazid (INH), ethambutol (ETB), pyrazinamide (PZA) and/or rifampicin (RIF) is associated with a mild elevation of liver enzymes that occasionally develops into severe liver injury. We have reported that INH-specific CD4+ T-cell clones circulate in patients with ATDrelated liver injury, which suggests that the adaptive immune system is involved in the disease pathogenesis. This study details the nature of the drug antigenspecific T-cell response that develops in a fatal case of ATD-related liver failure. Method Peripheral blood mononuclear cells were isolated from a patient who had a severe liver reaction to ATD medications, ALT 514 IU/L and Bilirubin 30 mg/dL. A lymphocyte transformation test (LTT) and IFNγ-ELISPOT assay using ATDs were performed and clones were generated from ATDs by serial dilution. Drug-specific clones were identified in terms of cross-reactivity and doseresponsiveness and then characterized in terms of CD phenotype and cytokine secretion. Results Positive LTT against multiple drugs (INH, ETB, PZA, RIF, and activated ester of isonicotinic acid which forms isonicotinic amide adducts in the cell culture system) was observed. Over 700 T-cell clones were generated from INH, ETB, PZA, RIF or activated ester of isonicotinic acid treated peripheral blood mononuclear cells. Antigen-specific proliferative responses of CD4+/CD8+ clones were identified with only ETB and RIF. Clones were highly specific and did not crossreact with other ATDs. Clones are activated to proliferate and secrete cytotoxic mediators (granzyme B, perforin) and effector cytokines (IFN-γ, Il-13). Conclusion In conclusion, cytotoxic ETB and RIF-specific T-cell clones have been identified in patient with ATD-related severe liver failure. P40 Acute Interstitial Nephritis Induced By Ibuprofen Ana Castro Neves, Susana Cadinha, Ana Moreira, JP Moreira Da Silva Centro Hospitalar de Vila Nova de Gaia/Espinho, Vila Nova De Gaia, Portugal Introduction Acute Interstitial Nephritis (AIN) is often drug induced and the most frequently implicated drugs are Non-steroidal anti-inflamatory drugs (NSAIDs) and antibiotics. We report the case of a patient with AIN induced by Ibuprofen. Case Description A 74 year-old-female was admitted at emergency department with a 10-day history of malaise, anorexia, nausea, diffuse myalgias, fever (38ºC) and flank pain, treated with Paracetamol, Ibuprofen and Ciprofloxacin for suspected Pyelonephritis, by her attending physician. At admission she was febrile (38ºC) and prostrated. Laboratory studies revealed: leukocytosis, acute kidney injury (serum creatinine 5,8 mg/dL, blood urea nitrogen 178 mg/dL) and positive Creactive Protein; urinalysis with leucocituria, proteinuria and hematuria; negative blood culture. Chest X-ray and ultra sound of kidneys were normal. Treatment with Paracetamol, Ibuprofen and Ciprofloxacin was discontinued and she started Meropenem and intravenous fluids. Renal function improved and she was discharged after 3 days. One year later she was admitted to hospital with similar clinical presentation and diagnosed with AIN. Ten days prior to this admission she was treated with Ciprofloxacin and Ibuprofen for Phlebitis. After these 2 episodes she was again treated with Ciprofloxacin with good tolerance. She was then referred to our Drug Allergy Clinic for suspected hypersensitivity to Ibuprofen. Lymphocyte transformation test (LTT) with Ibuprofen was positive (stimulation index of 13,4 at 10ug/mL). Drug provocation test (DPT) with the suspected drug was not performed. DPT and long-term challenge with alternative drugs (Paracetamol and Etoricoxib) were both negative. How this report contributes to current knowledge Renal biopsy is the only definitive method to establish the diagnosis of AIN. However, when diagnosis seems likely, a probable precipitating drug can be easily withdrawn or patient improves readily after withdrawal of the suspected drug, biopsy can be avoidable. Challenge with the suspected drug remains the gold standard for diagnosis of drug hypersensitivity. Since AIN is a severe hypersensitivity reaction, DPT with the suspected drug is contra-indicated. The obvious time relationship between Ibuprofen treatment and reaction development in both episodes, the reproducible clinical presentation and positive LTT, suggests Ibuprofen has been the culprit drug. In cases of severe reactions LTT seems to be a valuable diagnostic tool. P41 Cetuximab Induced Acneiform Rash – Two Case Reports Daniela Ledic Drvar1, Sandra Jerkovic Gulin2, Suzana Ljubojevic Hadzavdic1, Romana Ceovic1 1. Department of Dermatology and Venereology, University Hospital Center Zagreb and School of Medicine, Zagreb, Croatia 2. Department of Dermatology and Venereology, General Hospital Sibenik, Sibenik, Croatia Introduction Epidermal growth factor receptor inhibitors (EGFRIs) are used for treatment of advanced lung, pancreatic, colorectal, and head and neck cancers. Cetuximab is a monoclonal antibody that competitively binds to the extracellular domain of EGFR and blocks cytoplasmic-domain phosphorilation. It is characterized by frequent cutaneous adverse reactions (CARs) including acneiform rash (AR), desquamation, xerosis, pruritus, hair abnormalities, paronychia, changes in nails, mucositis, increased growth of facial hair and eyelashes, and teleangiectasias. AR usually appears between day 2 to week 6 after cetuximab introduction. According to the National Cancer Institute Common Toxicity Criteria, severity of toxicity of AR is graded into five grades, and according to EGFRI-induced AR severity score into mild, moderate and severe toxicity. Prophylactic antibiotic treatment with doxycycline 100 mg bid for the first 6 weeks is recommended. Therapeutic plan includes use of grade-based skin treatment algorithm: a) mild toxicity - local therapy with corticosteroids or antibiotics, b) moderate toxicity - local therapy with addition of oral antibiotic, and c) severe toxicity - cetuximab dose lowering and therapy for moderate toxicity with an addition of a methyprednisolone dose pack. If therapy is ineffective within 2-4 weeks, it is necessary to discontinue cetuximab treatment. Case Description We present two male patients with metastatic colorectal cancer who developed papulopustular lesions on the sebum-rich areas of the face, scalp and trunk accompanied by pruritus and burning sensations (grade 2/3 or moderate toxicity), one to three weeks after introduction of cetuximab. One patient developed desquamation of the palms. Comedones, primary acne lesions, were lacking. There was no sign of superinfection. Patients were treated with doxycycline 2x100 mg bid for two weeks, followed by 1x100 mg, until the end of cetuximab therapy. Local therapy included clindamycin lotion, hydrocortisone /oxytetracycline ointment, benzoyl peroxide suspension and emollients. After three weeks of treatment, significant improvement of AR severity was achieved and there was no need for cetuximab dose reduction. How this report contributes to current knowledge Studies have demonstrated positive correlation between treatment efficacy and CARs for EGFRI. Since frequency and severity of skin lesions are dosedependent, a gradual increase in dose until CARs develop might be a good strategy to maximize the efficacy of EGFRI. P42 Enteropathy Associated With Losartan Ana Montoro De Francisco, Talía De Vicente Jiménez, Amelia García Luque, Natalia Rosado David, José Mª Mateos Galván Hospital Central de la Defesa, IMIDEF, Madrid, Spain Introduction On August 2012 Rubio-Tapia et al reported an association of olmesartan therapy with an unexplained enteropathy symptomatically resembling celiac disease or sprue. Olmesartan is an Angiotensin II Receptor Antagonist (ARA II) widely used in high blood pressure, heart disease and diabetics. On July 2013 the Food Drug Administration (FDA) approves label changes to include intestinal problems, Severe Spruelike Enteropathy (SSE) linked to blood pressure medicine olmesartan. Losartan was the first ARA II commercialized in 1995 and it seems to produce similar Adverse Drug Reactions (ADR) that olmesartan. Case Description Method Desing: Case report of enteropathy associated with losartan Scope: Allergy Service, Hospital Central de la Defensa, Madrid. Period: May 2015 Main variables assessed: demographic and clinical variables, diagnostic criteria, treatment, evolution, causal relationship between drug and enteropathy according to the modified Karch Lasagna algorithm. The patient has given written informed consent for the publication research. Results A 81 years old woman, diagnosed of hypertension, treated for three years with losartan 100 mg/d. After starting treatment she refers chronic diarrhea and since two years ago worsening diarrhea, abdominal pain and weight loss. The patient was treated at the emergency service twice for 3-4 daily episodes of watery, nonbloody diarrhea associated with abdominal bloating. The patient failed conservative management including gluten-free diet, oral antibiotic and corticosteroid. Additionally to diarrheal syndrome, the patient showed hoarseness and cough. Allergologic study: immediate and delayed prick test and specific IgE were negative for food. A colonoscopy with colonic biopsies revealed evidence of microscopic colitis. Treatment: Losartan withdrawal, achieving complete remission in four weeks. The case has been reported to Spanish Postmarketing Surveillance System. How this report contributes to current knowledge The allergist should keep in mind this possible and rare ADR in patients treated with losartan (ARA II) showing enteropathy, as discontinuing losartan leads to clinical improvement. This enteropathy case is very similar to SSE described in 2012 related to olmesartan. P43 Granuloma Annulare After Therapy With Canakinumab Razvigor Darlenski Tokuda Hospital Sofia, Sofia, Bulgaria Introduction Granuloma annulare (GA) is a benign inflammatory dermatosis affecting predominantly females. The disease etiology and pathophysiology remain unclear. Trauma, association with diabetes mellitus and medicamentous genesis have been suspected. Pathogenic mechanisms include cell-mediated immunity (type IV), macrophage activation, and cytokine-mediated degradation of connective tissue. Case Description Herein we present a 56-years-old male Caucasian patient who developed skin lesions on the back of the hand 3 months after initiation of therapy with canakinumab as a part of a clinical trail for treatment of coronary artery disease. Upon admission the skin changes involved the dorsum of the hand and were presented by annular papules and plaques, the largest 3 cm in diameter with depressed center and elevated and infiltrated borders. The patient had no other relevant history of present or past disease beyond the coronary artery diseases and elevated serum cholesterol levels. He took no other medication prior or during the disease onset. Based on the clinical findings the diagnosis of GA was coined. Cryotherapy with liquid nitrogen was performed. Canakinumab was withdrawn. Skin lesions resolved within the 2 weeks later. No new lesions appeared during the 6 months follow up. How this report contributes to current knowledge Canakinumab is a IL-1 beta monoclonal antibody used in rheumatology and in the treatment of autoinflammatory syndrome. Recently it was tested in coronary artery disease, gout and COPD. As a new drug, its safety profile and unwanted adverse events are still to be challenged. In the described case we present the development of cutaneous reaction coinciding with the drug introduction. Druginduced GA has been described in the literature, e.g. after allopurinol, amlodipine, TNF-alpha inhibitors, gold, and interferon therapy. As far as we are aware no previous reports exist on the association between canakinumab therapy and GA. P44 Hypersensitivity Eosinophilic Myocarditis Or Acute Coronary Syndrome? – Case Report Dario Gulin1, Jozica Sikic1, Jasna Cerkez Habek1, Sandra Jerkovic Gulin2, Edvard Galic1 1. University Hospital Sveti Duh, Zagreb, Croatia 2. General Hospital Sibenik, Sibenik, Croatia Introduction Eosinophilic myocarditis (EM) is a potentially fatal disease if left untreated. There are numerous drugs that have been implicated in causing the hypersensitivity (HS) form of EM but frequently the cause of the disease remains unknown as it could have a delayed presentation for up to two years. In this case report we present an atypical clinical presentation of HS EM, possibly caused by hydrochlorothiazide (HCT), and significant coronary artery disease (CAD). Case Description A 63-year-old man presented to the emergency department with flu-like symptoms. He had a history of chronic bronchitis and arterial hypertension treated with budesonide/formoterol and HCT. His general physical examination was unremarkable, without any signs of heart failure. Complete blood count (CBC) revealed leucocytosis with slightly eosinophilia and elevated troponin and CRP. ECG showed no changes in ST/T segment. Echocardiography revealed minimal pericardial effusion for up to 4 mm. Initial right pneumonia was observed on X-ray. He was treated with amoxicillin/clavulanic acid, azithromycin and ibuprofen. Fifth day of hospitalization the signs of disease became more prominent: CBC revealed 19.2x10^9/L leucocytes with 11.2x10^9/L eosinophils and troponin level was doubled. Pulse doses of corticosteroids (CS) (methylprednisolone 500 mg i.v.) were started and other therapy was discontinued. Seven hours later patient was asymptomatic, leucocytes were normal with slightly eosinophilia. Pulse doses of CS were continued up to three days when converted to oral CS. Endomyocardial biopsy showed no inflammation. Coronarography revealed two-vessel CAD, treated with percutaneous coronary intervention. How this report contributes to current knowledge One of the most common cause of EM reported in literature is drug HS. In our patient HCT is a potential cause. Symptoms, levels of troponin, ECG and echocardiographic changes were more suggestive for EM than CAD. Endomyocardial biopsy revealed no EM but it was performed third day after pulse dosage of intra-venous CS, when symptoms completely vanished. It should be also noted that EM is a focal disease and biopsy doesn’t have to prove the diagnosis. It is more obvious that CAD was co-finding, as symptoms of CAD could not be resolved using CS, and troponin levels would not fall second day after initiating therapy. CBC with eosinophilic drop powers that hypothesis. Early administration of systemic CS is necessary regardless of underlying causes, as delayed treatment may result in fatal outcomes. P45 Piperacillin-Induced Immune Haemolytic Anaemia - A Severe And Frequent Complication Of Antibiotic Treatment In Patients With Cystic Fibrosis. Philip Specht1, Doris Staab1, Beate Mayer2, Jobst Roehmel1 1. Division of Cystic Fibrosis, Pediatric Pneumology and Immunology, Charité-Universitätsmedizin Berlin, Berlin, Germany 2. Institute for Transfusion Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany Keywords: Piperacillin, Autoimmune, Haemolysis, Cystic Fibrosis, Introduction Two mechanisms of drug-induced haemolysis have been described. Usually both, extravascular and intravascular haemolysis, are caused by drug dependent antibodies (ddAb). Extravascular haemolysis presents with mild and less severe clinical symptoms of anaemia, whereas intravascular haemolysis usually manifests with a rapid destruction of red blood cells caused by antibodymediated complement activation leading to acute clinical symptoms. Interestingly more than 50% of all piperacillin-induced immune haemolytic anaemia (PIHA) cases investigated at a reference laboratory in Germany were patients with cystic fibrosis (CF). Therefore the investigated hypothesis of this study is a higher prevalence for PIHA in patients with CF as for the general population. Additionally risk factors for PIHA are systematically assessed. Method Included were all patients with CF older than 12 years who were admitted to the hospital for antibiotic treatment. Past transplantation was an exclusion criterion. Blood samples were obtained in the beginning and at the end of a given intravenous treatment. Direct antiglobulin test (DAT) and indirect antiglobulin test (IAT) were performed using standard techniques. For positive samples an antibody differentiation was done. DdAb were investigated using gel technique. Thus we prepared a 1mg/mL drug solution or used ex-vivo antigens, respectively and incubated it for 30 minutes in presence of patients’ plasma and group O RBCs. The individual prior exposure to piperacillin and information concerning atopy and microbiology are documented. Results In the ongoing trial 2 out of 20 patients developed a PIHA. This is a high prevalence compared to the general expectation of approximately 1:1000000. Both had ddAb but no complement activation. This is typical for extravascular haemolysis. Clinical symptoms of haemolysis were mild but there was a drop of haemoglobin by 4 mg/dL. The study will be finished by April 2016. Conclusion These results suggest a higher prevalence of PIHA in patients with CF than expected in the general population. This is backed by several case reports. Possibly this is due to the exposure to piperacillin. Therefore PIHA should be considered when treating patients with CF. P46 Progesterone Triggered Pemphigus Foliaceus - Case Report Sandra Jerkovic Gulin1, Caius Solovan2, Anca Chiriac3 1. Department of Dermatology and Venereology, General Hospital Sibenik, Sibenik, Croatia 2. Department of Dermatology, University of Medicine and Pharmacy, Tamisoara, Romania 3. Dermatology Department, Nicolina Medical Centre, Apollonia University, „P.Poni“ Research Institute of Macromolecular Chemistry, Iasi, Romania Introduction Pemphigus foliaceus (PF) is a benign variety of pemphigus (P) characterized by acantholysis in the upper part of epidermis, induced by immunoglobulin G (IgG) autoantibodies (mainly IgG4 subclass) targeting desmoglein -1 (dsg-1). Clinical expression of PF is based on the presence of scaly and crusted erosions on an erythematous base, flaccid blisters, minor or no involvement of mucous membranes and with seborrheic distribution and aspect of the lesions in early stages of the disease. PF is classified into four types: endemic (fogo selvagem), idiopathic, erythematosus (Senear-Usher syndrome) and drug-induced. Drugs triggering or inducing PF reported in literature are penicillamine, bucilamine, captopril, lisinopril, enalapril, fosinopril, candesartan, tipronin and rifampicin. Case Description A 45-year-old woman presented with facial erythema, multiple erythematous papules and plaques, few scaly plaques, shallow erosions and superficial blisters on an erythematous base localized on the upper chest and upper back in „V“ distribution, acompanied by pain and burning sensation. Mucous membranes were spared. Lesions appeared two months after initiating systemic therapy with medroxyprogesterone acetate 10mg daily for 14 days per month for metrorrhagia. Biopsy revealed subcorneal cleft within the upper epidermis with acantholytic keratynocytes. Direct immunofluorescence (DIF) of perilesional skin showed intercellular, intraepithelial IgG. Indirect immunofluorescence (IIF) showed intercellular, intraepithelial IgG, with higher fluorescent intensity in the upper dermis. The diagnosis of possible drug induced PF was presumed based on clinical, histological and immunological grounds. The suspected culprit drug – progesterone was discontinued. Treatment with high-potency topical corticosteroid (betamethasone) in combination with gentamicin ointment twice daily was started. After 4 weeks of treatment, lesions resolved almost completely. Close follow-up was recommended. How this report contributes to current knowledge Although PF often occurs spontaneously, it may be triggered by certain medications. A case of localized PF induced by topical imiquimod treatment has been recently reported, based on an unknown mechanism of acantholysis, probably due to antibodies to dsg-1. Drug as a trigger must be suspected in every newly diagnosed P. Indentification and elimination of triggering drug may soothe the clinical symptoms and shorten the treatment. P47 Ramipril - Triggered Generalized Pustular Psoriasis Paola Djurinec1, Kresimir Kostovic1, Mirna Bradamante1, Sandra Jerkovic Gulin2, Romana Ceovic1 1. Department of Dermatology and Venereology, University Hospital Center Zagreb and School of Medicine Zagreb, Zagreb, Croatia 2. Department of Dermatology and Venereology, General Hospital Sibenik, Sibenik, Croatia Introduction Generalized pustular psoriasis (GPP) is an extreme and serious form of psoriasis (P) with tiny, sterile, yellow pustules on an erythematous base. The clinical presentation of drug-provoked P include more often generalized plaque P and erythroderma, and rarely palmoplantar pustulosis or GGP. Drugs can cause a) precipitation of P de novo in predisposed or nonpredisposed individuals; b) exacerbation of pre-existing psoriatic lesions; c) induction of lesions in clinically normal skin in patients with P; and d) development of treatment-resistant P. Angiotensin-converting enzyme inhibitors (ACEIs) are widely used to control hypertension and are considered to be possible triggering, exacerbating or inducing agents of P. Rarely, ACEIs have been reported in the literature as inductors of GPP. We present our first case of ramipril-triggered GPP. Case Description 46-year-old women presented with low-grade fever, erythema, small pustules 12 mm in size and exfoliation involving skin on trunk, extremities, palms and soles. She had no previous history of P or family history of P. She began taking the new antihypertensive – ramipril two months before the onset of symptoms. Laboratory findings showed elevated erythrocyte sedimentation rate and Creactive peptide with other biochemical findings within normal limits. Gram stained smear examination of pustules were negative and the pus culture was sterile. We set up a working diagnosis of GPP based on history, laboratory findings and clinical picture and the main differential diagnosis was acute generalized exanthematous pustulosis. Biopsy was performed. Ramipril as suspected culprit drug was discontinued and replaced with valsartan. We started the treatment with acitretin 50mg/day which resulted in good initial therapeutic response. On the basis of clinical picture, biopsy and satisfactory therapeutic outcome, the diagnosis of GPP was confirmed. How this report contributes to current knowledge Only one case of ramipril-induced GPP in patient with psoriatic arthritis has been published in the literature. According to our knowledge, we present a first case of ramipril-triggered GPP in an individual without personal and family history of P. As P is a common skin disorder, knowledge of the factors that are inducers, triggers, or aggravators of the disease is of utmost importance for clinicians. Drug cessation or replacement may play a crucial role in the treatment outcome so taking a detailed history is decisive. Poster Walk 6: NSAIDs (P48 – P56) P48 Aspirin Desensitization In Cardiovascular Disease – Portuguese Experience Jose Pedro Almeida1, Joana Caiado1, Elisa Pedro1, Pedro Canas Da Silva2, Manuel Pereira Barbosa1 1. Immunoallergology Department, Centro Hospitalar Lisboa Norte/Hospital Santa Maria, Lisbon, Portugal 2. Cardiology Department, Centro Hospitalar Lisboa Norte/Hospital Santa Maria, Lisbon, Portugal Keywords: Aspirin Hypersensitivity, Drug Desensitization, Anaphylaxis Introduction Several studies have demonstrated a reduction in adverse cardiovascular events with the administration of dual antiplatelet therapy (aspirin and clopidogrel) to patients (pts) with coronary artery disease, especially in the prevention of thrombosis after implantation of bare-metal and drug-eluting stents. However, when pts have aspirin hypersensitivity (AH) this treatment is limited, and they are maintained on monotherapy with clopidogrel. Aspirin desensitization (AD) is the alternative for these individuals. The aim is to describe the experience of a Portuguese Allergy Department in AD on cardiovascular pts, between April 2006 and January 2016. Method Thirty pts with previous history of AH who needed dual antiplatelet therapy due to cardiovascular disease (female-14;male-16), mean age 64 years-old, were desensitized to aspirin. The clinical presentation of AH was asthma (6 pts), anaphylaxis (4 pts), cutaneous rash (7 pts), angioedema (13 pts), in some cases with very remote reactions (>20 years ago). In most pts (22 out of 30), AD was performed immediately after percutaneous coronary intervention (PCI). Most AD were performed in Cardiology Department (27); 3 pts with planned AD were desensitized at the Allergy Day-Care Unit ; oral doses were increased every 3060 minutes (target dose 152.5mg) under a 4.5-hour protocol. Pre-medication was not administered. Results All pts successfully completed AD, although there were 2 reactions 30 minutes after the procedure: a 63 year-old man who developed acute rhinitis and conjuntivitis, eyelid angioedema and dry cough; and a 75 year-old man who developed acute generalized urticaria. All pts were monitored after AD, and are still on daily aspirin 100 mg (there were neither hypersensitivity reactions nor drop-outs). Conclusion Despite positive clinical history of AH, some pts had a remote reaction, and due to the emergency of the procedure we were not able to confirm their AH. This fact could in part explain the low incidence of reactions during AD; another reason could be the smaller dose of aspirin used as antiplatelet (100-150mg) compared with the dose to which they previously reacted (>500mg). Some authors advocate that AD should be performed before PCI, but PCI could provide greater hemodynamic stability and therefore allow a safer AD. Based on our experience, AD is safe and efficacious, even when performed after PCI, with all pts responding to the desensitization procedure. P49 Astma And/Or Rhinitis To NSAIDs With Good Tolerance To ASA. Gador Bogas1, Natalia Blanca-López2, Diana Pérez-Alzate2, Inmaculada Doña1, José Augusto Agúndez3, Elena García-Martín3, José Antonio Cornejo-García4, Cristobalina Mayorga4, María José Torres1, Gabriela Canto2, Miguel Blanca5 1. Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 2. Allergy Service, Infanta Leonor University Hospital, Madrid, Spain 3. Department of Pharmacology, University of Extremadura, Caceres, Spain 4. Research Laboratory and Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 5. Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA,, Malaga, Spain Introduction Subjects with hypersensitivity reactions to NSAIDs with airways involvement can develop rhinitis and or asthma after the intake of ASA and other NSAIDs that are strong COX-1 inhibitors. Some cases may also respond to weak COX-1 and selective COX-2 inhibitors. The hallmark characteristic is that symptoms are triggered by asthma and that in most instances subjects have a pre-existing respiratory disease. We studied if subjects can be selective responders to some NSAIDs including weak COX-1 or selective COX-2 inhibitors having good tolerance to ASA. Method Subjects reporting rhinitis and/or asthma to a single NSAID with good tolerance to ASA were evaluated. An allergological evaluation was carried out plus a controlled challenge with ASA for verifying tolerance. In a second step we proceed to a controlled challenge with the culprit drug involved. FEV1 and acoustic nasal rhynomanometry were measured with values lower that 12% and 30% respectively considered as a positive response. Also nasal and bronchial symptoms were recorded. Results We confirmed in 21 cases the appearance of nasal and/or bronchial symptoms by objective parameters (decrease in FEV1 and/or decrease in nasal volume cavity) after the administration of the drug. The drugs involved were ibuprofen in 4 cases, paracetamol in 4 cases, desketoprofen in 1 and etoricoxib in another. Conclusion Selective respiratory responses to a single NSAID with good tolerance to ASA occur. Although the underlying mechanism is not known, the classical involvement of the leukotriene’s pathway occurring is aspirin exacerbated respiratory disease seems to be discarded. This constitutes a new phenotype within the category of hypersensitivity reactions to NSAIDs. P50 Clinical Characteristics Of 196 Patients With Non-Steroidal AntiInflammatory Drug (NSAIDs) Hypersensitivity Sengül Aksakal1, Aytül Zerrin Sin2, Zeynep Peker Koç2, Fatma Düsünür Günsen2, Ömür Ardeniz2, Emine Nihal Mete Gökmen2, Okan Gülbahar2, Ali Kokuludag2 1. Karadeniz Technical University Medical Faculty Department of Clinical Immunology, Trabzon, Turkey 2. Ege University Medical Faculty Department of Allergy and Clinical Immunology, Izmir, Turkey Keywords: Non-Steroidal Anti-Inflammatory Drug Hypersensitivity Introduction Nonsteroidal antiinflammatory drugs (NSAIDs) as the most frequently prescribed classes of drugs have been reported to be the second most common cause of drug hypersensitivity reactions after beta-lactam antibiotics. In this study we aimed to evaluate the clinical characteristics of NSAID hypersensitivity based on European Network for Drug Allergy (ENDA)’s classification. Method 196 patients diagnosed as NSAIDs hypersensitivity between the years of 20132014 were enrolled to the study. The patients were questioned about the other allergic diseases (rhinitis, asthma, urticarial, personal and familial drug allergy) besides the demographic features. NSAID reactions were classified as follow : NSAID induced urticaria/ angioedema (NIUA), single NSAID induced urticaria/angioedema, anaphylaxis or both (SNIUAA), NSAID exacerbated cutaneous disease (NECD), NSAIDs exacerbated respiratory disease (NERD), single NSAID induced delayed hypersensitivity reactions (SNIDR). Acetylsalicylic acid, diclofenac, paracetamol and meloxicam were the most frequently preferred drugs for oral provocation test to distinguish of cross-reactive and IgE-mediated reactions. Results Hypersensitivity to NSAIDs was 3 times common in female (%77) than male (%23). The patients with NERD had atopic history the most frequently (%50). % 6.6 of patients have drug allergy in their family. The frequency of hypersensitivities was found respectively as follows: NIUA (%46), SNIUAA (%24), NECD (%15), NERD (%8), SNIRD (%7). The patients who had crossreactive hypersensitivity to many of NSAIDs could be tolerated paracetamol, meloxicam and nimesulid. Diclofenac (11 cases %23), Flurbiprofen (7 cases % 15), Metamizol (7 cases %15) were induced SNIUAA respectively, But according to their chemical structure propionic acid derivatives had been caused severe anaphylaxis mostly. Commonly seen delayed reactions due to NSAIDs are maculopapular eruptions and fixed drug eruption. Conclusion NSAIDs were caused NIUA, SNIUAA and NECD most frequently (%85) although NERD and delayed reactions were quite rare. There are still unexplained points in these cases. Therefore there are needed more clinical studies. P51 Development Of Immediate Hypersensitivity To Several NSAIDs Maintaining Good Tolerance To ASA Natalia Pérez-Sánchez1, Natalia Blanca-López2, Diana Pérez-Alzate2, Gador Bogas1, Inmaculada Doña1, María Salas1, María José Torres1, Miguel Blanca1, Gabriela Canto2 1. Allergy Unit, Malaga Regional University Hospital-IBIMA, Malaga, Spain 2. Allergy Service, Infanta Leonor Hospital, Madrid, Spain Introduction Subjects responding to several NSAIDs including ASA are considered crosshypersensitive, whereas those responding to only one NSAID with tolerance to other chemically unrelated NSAIDs are considered selective responders. However, in some cases, patients that develop immediate reactions to several NSAIDs are classified as cross-hypersensitive without assessing ASA tolerance. Case Description A 70 year-old woman, without allergic history, referred that in 1996 she developed two episodes of urticaria less than an hour after paracetamol intake. Three years after, she had developed three episodes of urticaria 90 minutes after dipyrone intake. At that time she was allergologically evaluated: intradermal test (ID) with dipyrone (2 mg/ml) and paracetamol (0.1 mg/ml) were positive. She was challenged with ASA showing tolerance at full therapeutic doses (500 mg). In 2012, she suffered from an episode of facial angioedema and pruritus in the tongue after celecoxib intake. She reported previous tolerance to this drug on many occasions. In September 2014, she was re-evaluated: ID to paracetamol was negative (0.1 mg/ml), and ID and basophil activation test (BAT) to dipyrone were positive. Drug challenges: 60 minutes after achieving a cumulative dose of paracetamol 300 mg, she developed generalized pruritus and urticaria. Two weeks later, she presented pruritus in the tongue and ears, nasal itching and obstruction, and wheals in the neck after provocation with a cumulative dose of 100 mg of celecoxib, with no changes in FEV1 values. After another interval of two weeks tolerance to etoricoxib was observed at full therapeutic doses. Two weeks later the patient tolerated ASA and ibuprofen during controlled challenge until therapeutic doses. In addition, around two months later the patient received two independent two day treatment courses with these drugs, separated by a two week time interval. How this report contributes to current knowledge Subjects may develop an immediate response to a number of different NSAIDs, including some COX-1 and/or selective COX-2 inhibitors but tolerate strong COX1 inhibitors. This case shows the importance of testing for ASA tolerance when confronted by a patient who responds to several chemically unrelated NSAIDs. P52 Diagnosis Of Hypersensitivity Reactions To Paracetamol In A Large Serie Of Cases Inmaculada Doña1, Maria Salas1, Francisca Gomez1, Natalia Blanca-Lopez2, Diana Perez-Alzate2, Gador Bogas3, Esther Barrionuevo1, Maria Jose Torres1, Inmaculada Andreu4, Miguel Ángel Miranda4, Gabriela Canto2, Miguel Blanca1 1. Regional Hospital of Málaga-IBIMA, Málaga, Spain 2. Infanta Leonor Hospital, Madrid, Spain 3. Regional Hospital of Málaga, Málaga, Spain 4. Dpto. Química /Instituto de Tecnología Química –UPV-CSIC, Valencia, Spain Introduction The most important drug involved in hypersensitivity drug reactions (HDR) are NSAIDs. Two mechanisms are involved: immunological sensitization (specific IgE or T-cell) and pharmacological (COX-1 inhibition). Paracetamol, one of the drug most highly consumed all over the world, has been implicated in HDR. The contribution these mechanisms in HDR to paracetamol is not well known. We studied a large group of patients who developed one/several episodes indicative HDR to paracetamol. Method Patients with reactions to paracetamol were classified as cross-hypersensitivity (CH) if they responded to two others NSAIDS not chemically related including ASA. If only paracetamol was implicated, drug provocation test (DPT) with ASA was required: if positive, they were included as CH and if negative, as selective responders (SR). In cases who reported respiratory symptoms, nasal provocation test with L-ASA were performed. Atopy status was also assessed with prick test to inhalant allergens. Results A total of 350 patients with confirmed diagnosis of HDR to paracetamol were included: 288 (82.28%) resulted to be CH and 62 SR (17.71%). Within the CH group, following the ENDA classification, 181 (62.84%) were NIUA, 25 (8.68%) NERD, 16 (5.55%) NECD, and in 60 (20.83%) blended reactions. A total of 46 (25.41%) patients required a positive DPT for diagnosis. Nasal challenge with LASA was positive in 19 (82.6%) patients with clinical history suggestive of NERD. Within SR group, 56 cases (90.32%) were SNIUAA ( reaction less than 24), being anaphylaxis the most frequent clinical entity (29 (51.78%), followed by urticaria/angioedema (16; 28.57%), angioedema (6; 10.71%), urticaria (4; 7.14%) and fixed drug eruption (1; 1.78%). A total of 18 (32.14%) patients required a positive DPT to paracetamol for diagnosis. The remaining 6 (9.67%) cases were SNIDHR as they had the reaction more than 24 hours after paracetamol administration: 4 (66.66%) maculopapular exanthema and 2 (33.33%) exanthema with desquamation. One patient had respiratory symptoms and was confirmed as SR. Conclusion These data indicate that when patients develop a HDR to paracetamol after carried out the allergological work-up, the 80% of patients who developed a positive response were CH with a lower proportion being SR. DPT was needed in more than 20% of cases to achieve the diagnosis. P53 Hypersensitivity To Paracetamol According To The New Classification Of Hypersensitivity To NSAIDs Gabija Didžiokaite1, Olesia Gaidej2, Simona Kašinskaite3, Violeta Kvedariene3 1. Vilnius University, Faculty of Medicine, Vilnius, Lithuania 2. Vilnius University Hospital Santariskiu Klinikos, Centre of Internal Medicine, Vilnius, Lithuania 3. Center of Pulmonology and Allergology, Clinic of Infectious, Chest diseases, Dermatology and Allergology, Vilnius University Hospital Santariskiu Klinikos, Vilnius, Lithuania Keywords: Paracetamol, Diagnostics, Provocation Tests, Drug Hypersensitivity Introduction Paracetamol is often proposed as a safe alternative to the patients with hypersensitivity to NSAIDs. However, reactions induced by this drug can manifest in a wide variety of symptoms. Aim: To evaluate hypersensitivity to paracetamol in Lithuanian adult population according to the new classification of hypersensitivity to NSAIDS. Method We followed 183 adult patients (211 clinical histories) of suspected hypersensitivity to paracetamol in the Pulmonology and Allergology Centre of Vilnius University Hospital Santariskiu Klinikos. The median age of patients was 42.5 [32.75 – 53.25] years. Most of the patients were females 144 (78.7%). 14 medications containing paracetamol were reported. ENDA questionnaires were completed, patch and drug provocation tests (DPTs) were performed to confirm the diagnosis. Results We adapted our clinical cases to the new classification of hypersensitivity to NSAIDs and divided our patients into 5 categories. 53 cases (47 patients) were nonimmunologically mediated (cross-reactive) hypersensitivity reactions to NSAIDs: 4 cases of “NSAIDs-exacerbated respiratory disease”, 4 cases of “NSAIDs-exacerbated cutaneous disease” and other 45 cases (39 patients) of “NSAIDs-induced urticaria/angioedema (NIUA)”. 86 cases (75 patients) were immunologically mediated (non-cross-reactive) hypersensitivity reactions to NSAIDs: 63 cases (55 patients) of “Single-NSAID-induced urticaria/angioedema or anaphylaxis (SNIUAA)” and 23 cases (20 patients) of “Single-NSAID-induced delayed hypersensitivity reactions (SNIRD)”. 10 cases of bronchospasm without underlying chronic airway respiratory diseases and 62 cases of anaphylaxis, maculopapular rash and other hypersensitivity reactions induced not only by paracetamol but also by other NSAIDs could not be classified according to the criteria of this classification. Only 25 (13,7%) patients (mostly SNIUAA (10 patients) and SNIRD (7 patients)) underwent further allergological work-up with suspected causative drug. Only 7 (28 %) of them (3 SNIUAA, 2 NIUA and 2 SNIRD), had true paracetamol hypersensitivity. For 1 patient hypersensitivity was demonstrated by patch test, and for 6 by DPTs. 6 out of 7 positive test results occurred as skin reactions. Conclusion True hypersensitivity to paracetamol is rare. In our research, only patients with skin reactions in their clinical history, mostly SNIUAA, were confirmed to be hypersensitive to this drug. P54 Ibuprofen And Other Aryl Propionic Derivates Can Induce Immediate Selective Hypersensitivity Responses. Diana Perez-Alzate1, Natalia Blanca-López1, Maria Isabel Garcimartin1, Inmaculada Doña2, Maria Luisa Somoza1, Cristobalina Mayorga3, Maria Jose Torres4, Gador Bojas2, Jose Antonio Cornejo-Garcia3, Maria Gabriela Canto1, Miguel Blanca5 1. Allergy Unit, Infanta Leonor University Hospital, Madrid, Spain 2. Allergy Unit, Regional University Hospital of Malaga, Malaga, Spain 3. Research Laboratory and Allergy Unit, IBIMA, Regional University Hospital of Malaga, Malaga, Spain 4. Allergy Unit, Regional University Hospital of Malaga, Madrid, Spain 5. Allergy Unit, Regional University Hospital of Malaga, Malaga, Spain, Malaga, Spain Keywords: Aryl-Propionic Derivates, Ibuprofen, Immediate Selective Responses Introduction Arylpropionic acid derivatives are the most commonly prescribed and consumed NSAIDs and very often obtained without medical prescription. From these the most common is ibuprofen. Within the group of hypersensitivity reactons to NSAIDs, these drugs are progressivelly involved and include those mediated by specific immunological mechansims and those classically classified as crossintolerance reactions. Within the first category, IgE mediates or T cell specific responses may occur. We present a serie of cases with an immediate selective response to ibuprofen and other arylpropionic derivatives confirmed by drug provocation tests (DPT). In addition to demostrate selectivity of the response to these drugs we assesed cross-reactivity between them. Method Subjects who reported symptoms indicative of an hypersensitivity reaction to an NSAIDs were evalauted. A DPT with ASA was carried out to rule out crossintolerance (non allergic hypersensitivity). Imputability of the different aryl propionic derivatives and assesement of cross-reactivity was carried out by drug provocation tests. Serum tryptase was quantized in peripheral blood at 2 and 24 hours post episode and in the affected skin by immunohistochemistry at the momment of the appearance of the reaction. Results All subjects included had good tolerance to ASA. After proceeding with the aryl propionic acid derivative challenge, 42 cases were classified as selective immediate responders. Ibuprofen was the drug most frequently involved, followed by naproxen and desketoprofen. We found cases than only responded to one sngle drug and others who responded to several, confirming crossreactivity. Quantitation of tryptase levels in peripheral blood and skin biopsies were indicative of an immediate selective response with the involvement of mast cell activation. Conclusion Ibuprofen and other aryl propionic acid derivatives can induce selective responses in subjects with NSAIDs hypersensitivity. Further studies are in progress for identifiyng the possible adducts (hapten-carrier complexes) implicated and the existence of cross-reactivity. P55 Subjects Developing Immediate Responses To Several NSAIDs Can Be Selective With Good Tolerance To ASA. Natalia Blanca-Lopez1, Diana Pérez-Alzate1, Francisco Javier Ruano Perez1, Inmaculada Doña2, Maria Luisa Somoza1, Inmaculada Andreu3, Miguel Angel Miranda3, Cristobalina Mayorga4, Maria Jose Torres2, Jose Antonio CornejoGarcia4, Miguel Blanca2, Maria Gabriela Canto1 1. Allergy Unit, Infanta Leonor University Hospital, Madrid, Spain 2. Allergy Unit, Regional University Hospital of Malaga, Malaga, Spain 3. Universidad Politécnica de Valencia, Valencia, Spain 4. Research Laboratory and Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA,, Malaga, Spain Keywords: NSAIDs, Immediate Reactions, Selective Response Introduction Hypersensitivity reactions to NSAIDs can be classified as cross-intolerance where vasoactive mediators are released by nonspecific immunological mechanisms, and selective responders mediated by IgE antibodies or T cells. Those responding to several no chemically-related NSAIDs are considered cross-intolerants. The existence of responders to several NSAIDs with good tolerance to ASA was studied Method We searched in the dabase of the National Spanish Network for the Study of Adverse Reactions to Drugs and Allergens the possible existence of cases with immediate reactions to different NSAIDs and good tolerance to ASA confirmed by drug provocation tests (DPT). In these the selective response to the culprit NSAIDs was confirmed. Results We found 20 cases that acomplished these criteria. The higher number of episodes occurred with a pyrazolone derivative (dipyrone) followed by ibuprofen and other arylpropionic acid derivatives (ketoprofen and naproxen), diclofenac, paracetamol and COX-2 inhibitors. A total of 60 episodes were reported, being 3 NSAIDs involved in 15 cases, and more than 3 drugs in 5 patients. Conclusion Subjects with reactions to different NSAIDs but good tolerance to ASA exist. In patients with multiple responses to NSAIDs if tolerance to ASA is not known it should be assessed before being considered as cross-intolerants. This study adds a new phenotype to hypersensitivity reactions to NSAIDs. Further studies are in progress to determine how many cases with NSAIDs hypersensitivity belong to these category. P56 Utility Of Low-Dose Oral Aspirin Challenges For Diagnosis Of Aspirin Exacerbated Respiratory Disease Elina Jerschow1, Teresa Pelletier2, Zhen Ren3, Golda Hudes4, Marek Sanak5, Esperanza Morales6, Victor Schuster1, Simon D Spivack4, David Rosenstreich7 1. Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, United States 2. Albert Einstein College of Medicine, Bronx, United States 3. Jacobi Medical Center, Ny, United States 4. Albert Einstein College of Medicine/Montefiore Medical Center, Ny, United States 5. Jagiellonian University Medical College, Bronx, Poland 6. Ferkauf Graduate School of Psychology at Yeshiva University, Ny, United States 7. Albert Einstein College of Medicine/Montefiore Medical Center, Krakow, United States Keywords: Aspirin Exacerbated Respiratory Disease, Fraction Of Exhaled Nitric Oxide, Leukotriene E4, Oral Graded Aspirin Challenge, Prostaglandin D2 Introduction Aspirin exacerbated respiratory disease (AERD) is diagnosed through graded aspirin challenges that induce hypersensitivity reactions and eicosanoid level changes. It is not known whether diagnostically useful changes also occur after low dose aspirin challenges that do not induce hypersensitivity reactions. We investigated the utility of low dose oral aspirin challenges for diagnosing AERD by measuring different clinical parameters and eicosanoid changes. Method Sixteen AERD and thirteen aspirin-tolerant asthma patients (ATA) underwent oral challenges with low dose (20, 40 mg) aspirin, and diagnostic oral graded aspirin challenges (up to 325 mg aspirin). Forced expiratory volume in 1 second (FEV1), nasal peak flow (NPF), the fraction of exhaled nitric oxide (FeNO), and eicosanoid levels in plasma and urine were analyzed. Results In AERD but not in ATA subjects, 40 mg aspirin challenges induced a significant decrease from baseline in FeNO (19% (±5.1), p=0.001) without causing any hypersensitivity reaction. The FeNO decrease also occurred after higher dose aspirin challenges (27.8% (±4.9) (p<0.001)). The sensitivity and specificity of 40-mg-aspirin-induced FeNO changes for identifying AERD were 90% and 100% with an area under the curve (AUC) of 0.98 (95%CI 0.92-1.00). The low dose challenge also induced a significant leukotriene E4 urine increase in AERD patients (from 6.32 (±0.08) to 6.91 (±0.15) log-pg/mg creatinine (p<0.001)) but the sensitivity and specificity of these changes were less than for the FeNO changes. Conclusion The low dose aspirin-induced decrease in FeNO in AERD patients may be useful for the diagnosis of aspirin allergy without inducing a hypersensitivity reaction. Poster Walk 7: NSAID 2 (P57 – 65) P57 Alternate Regulation Of Cyclooxygenase-2 (COX-2) MRNA Expression May Predispose Patients To Aspirin-Induced Exacerbations Renato Erzen, Mira Silar, Nissera Bajrovic, Matija Rijavec, Mihaela Zidarn, Peter Korosec University hospital for respiratory diseases and allergy Golnik, Golnik, Slovenia Keywords: Asthma/Rhinitis, Hypersensitivity To Acetylsalicylic Acid, COX-2 MRNA Expression Introduction Exposure to acetylsalicylic acid (ASA) and other nonsteroidal anti-inflammatory drugs (NSAID) may exacerbate respiratory disease (asthma, rhinitis), cutaneous diseases (urticaria and angioedema in patients with chronic urticaria, trigger urticaria, angioedema and anaphylaxis in patients without underlying diseases. We made a hypothesis that alternate regulation of cyclooxigenase-2 (COX-2) mRNA expression may predispose patients to ASA-induced exacerbations. Method We performed a prospective study of 40 subjects (mean age 49 years, 27 women) who had suspected hypersensitivity to ASA or other NSAID. 20 subjects had asthma (10 of them also nasal polyposis). We performed provocation tests (nasal and/or oral) with ASA in all of them. In 14 subjects tests were positive (8 nasal). Gene expression was analyzed in whole blood sample using real-time RT PCR just before ASA provocation and 4 hours after provocation. We also included 6 Hymenoptera venom allergic patients which were followed after systemic reaction (SR) during VIT failure and 4 healthy control subjects. Results We found significantly important increase of COX-2 mRNA expression in patients with ASA provocation test (p=0.004). There was no difference in ASA tolerant patients. COX-1 expression was comparable between ASA tolerant and hypersensitive patients and showed no dynamic during provocation. There were no changes in COX-2 expression in subjects with SR during VIT or in healthy control subjects. Conclusion Main findings in our study are: (1) after provocation with ASA COX-2 expression is increased in subjects with Aspirin intolerance in comparison with subjects who tolerate Aspirin; (2) during allergic reaction like SR in VIT failure we found no differnce in COX-2 expression; (3) all subjects that were positive on ASA provocation test had asthma and/or nasal polyposis. P58 Anaphylaxis To Diclofenac: What About The Underlying Mechanism? Leonor Carneiro-Leão, Fabrícia Carolino, Luís Amaral, Carmen Botelho, Eunice Dias-Castro, Josefina Cernadas Serviço de Imunoalergologia, Centro Hospitalar de São João, Porto, Portugal Keywords: Diclofenac Anaphylaxis Mechanism Introduction Diclofenac is a phenylacetic acid derivative belonging to the group of arylcarboxylic acids. NSAIDs have been reported as the 2nd most frequent cause of drug-induced anaphylaxis and diclofenac was the only NSAID significantly associated with anaphylaxis. However, some doubts remain about the pathophysiology of these reactions. Here we describe a case series of anaphylaxis probably induced by diclofenac. Method Retrospective analysis of patients with suspected anaphylaxis to diclofenac studied in our DAU, who underwent skin tests (ST). Records were analyzed for clinical signs and symptoms, severity of reactions, ST and oral challenges (OC). ST were performed with commercially available IV formulation of diclofenac, in a concentration of 25 mg/ml, diluted from 1x10-4 to 1/1 for IDT and 1/1 for SPT. Results A total of 33 patients were enrolled in the final analysis. Mean age was 50(± 12.75) years, 22(68.8%) were women, 6(18.2%) were atopic. The time elapsed until the reaction was less than 1 hour in 26(83.2%) cases. Seventeen patients had grade 4 anaphylaxis and 10 had history of re-exposure with reproducible symptoms. Nineteen patients (62.7%) reported reactions only to diclofenac (single-reactors) and 12 to other NSAIDs (multiple reactors) (8 to acetylsalicylic acid, 2 to aceclofenac). Twelve single-reactors (63.2%) had positive ST (two with systemic symptoms during the procedure). Only 4 multiple reactors (33.3%) had positive tests. Only 1 diagnostic OC was performed in order to clarify a doubtful history and it was positive. OC with alternative drugs were performed in 29 patients, with meloxicam in 17 and etoricoxib in 9. Two patients had skin symptoms during the alternative OC and both were from the multiple reactors group. Conclusion We report a large series of anaphylaxis to diclofenac assessed by skin tests. As the majority of NSAIDs hypersensitivity reactions are considered to be due to a non-immunologic mechanism, non-irritative concentrations to IDT and specific IgE’s are not available. Characteristics such as the severity and time of reaction, single-reactor status and systemic symptoms during skin tests suggest IgEdependent hypersensitivity in this sudy. The value of intradermal tests and their non-irritative concentrations remain to be determined.doubtful history and it was positive. P59 COX-2 Inhibitors - Are They Always A Safe Alternative In Hypersensitivity To Nonsteroidal Anti-Inflammatory Drugs? Luis Amaral, Fabricia Carolino, Eunice Castro, Josefina Cernadas Serviço de Imunoalergologia, Centro Hospitalar de São João E.P.E., Porto, Portugal Introduction Nonsteroidal anti-inflammatory drugs (NSAID) are one of the most frequent causes of drug-induced hypersensitivity reactions worldwide. It is generally assumed that inhibition of cycloxygenase 1 (COX-1) enzyme by the offending drugs plays a relevant pathogenic role in multiple NSAID reactors. It is generally expected tolerability to preferential/selective COX-2 inhibitors among patients with NSAIDs hypersensitivity. Method We reviewed the medical records and selected patients referred to our drug allergy unit in the past five years, with history of reproducible hypersensitivity reactions to NSAIDs COX-1 inhibitors and positive oral challenge (OC) with etoricoxib, a selective COX-2 inhibitor, and/or to meloxicam, a preferential COX2 inhibitor. Results Inclusion criteria were met in 15 patients, aged 28 to 68 (47±13 years-old), 12 females. Seven patients were atopic. Eight patients had asthma, 5 chronic rhinosinusitis and nasal polyposis and 3 patients had chronic urticaria. The primary NSAIDs hypersensitivity reactions were: 8 urticaria and angioedema; 4 anaphylaxis and 3 asthma exacerbation. Eight patients presented a positive OC with meloxicam: 4 with immediate urticaria and angioedema; 3 with late-onset of angioedema and 1 with asthma exacerbation. One patient with late-onset angioedema to meloxicam also had a late-onset of angioedema with etoricoxib. Eight subjects had positive OC with etoricoxib: 5 with immediate urticarial, 2 with late-onset angioedema and 1 with anaphylactic reaction. Conclusion Based on the results of previous studies, it could be tempting to prescribe COX-2 inhibitors in cases of multiple reactors to NSAIDs COX-1 inhibitors, without establishing its tolerance in a proper setting. However, these data strongly suggest that, before prescribing an alternative NSAIDs, a provocation test should always be performed. P60 Management Of Patients With History Of NSAIDs Reactions Prior To Coronary Angioplasty Mona Al-Ahmad1, Tito Rodriguez2 1. Microbiology Department, Faculty of Medicine, Kuwait University, Kuwait, Kuwait 2. Al Rashed Allergy Center, Kuwait, Kuwait Keywords: Aspirin , Desensitization , Coronary , Introduction History of NSAIDs hypersensitivity is common in some patients with coronary artery disease who are in need for coronary angioplasty. These patients require dual antiplatelet therapy to avoid in-stent thrombosis, and full evaluation of NSAIDs allergy. We present a cohort of patients with acute coronary syndrome undergoing aspirin desensitization to evaluate the short- and long-term efficacy and safety Method We developed a dynamic protocol that is based on both the patient characteristics and onset of reaction after NSAIDs. This challenge/desensitization protocol is shorter than previously published ones. The objective is to asses short and long-term efficacy and safety prior to stent placement Results A total of 19 patients with history of NSAIDs allergy were challenged with different doses of Aspirin. All patients tolerated the oral protocol at different timings of 30-45-90-120 minutes. The dosage given ranges between (21, 41, 81 and 162 mg) of aspirin given by mouth after premedication with montelukast. We had two patients reacting during the procedure and one during a 6 hourfollow-up. All reactions were limited to the skin. All patients tolerated the required dose of aspirin within 60-150 min. Those requiring urgent catheterization were desensitized within 90 min. Conclusion Our protocol provide an effective and safe short and long-time administration of Aspirin 81mg dose in patients with history of NSAIDs allergy P61 Oral Drug Challenge With Non-Steroidal Anti-Inflammatory Drug Under Spirometric Control - Clinical Series Of 110 Patients João Pedro Azevedo, Emília Faria, Beatriz Tavares, Frederico Regateiro, Ana Todo-Bom Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal Keywords: NSAID; NSAID-Exacerbated Respiratory Disease; Asthma Introduction Oral drug challenge (ODC) is the gold standard for the diagnosis of hypersensitivity reactions to non-steroidal anti-inflammatory (NSAIDs). If suspicion of respiratory symptoms, the ODC might include a lung function evaluation (LFE). Aim: To evaluate the lung function volumes during ODC to NSAIDs performed in our department between 2010 and 2015. Method One-hundred and ten ODCs with NSAIDs under LFE were performed. An alternative drug was tested in 77 of the patients (70%) whereas 33 were diagnostic tests (30%). The drugs tested were meloxicam (n=46, 41.8%); acetylsalicylic acid (19, 17.4%); etoricoxib (16, 14.6%); nimesulide (15, 13.6%); ibuprofen (4, 3.6%); celecoxib (3, 2.7%); metamizol (3, 2.7%); acetaminophen (3, 2.7%) and diclofenac (1, 0.9%). The criteria for a positive ODC were: a decrease in FEV1>/=20% of baseline, a decrease of MMEF75/25>/=25% of baseline or when major symptoms occurred. Statistical analysis based on independent sample t test and paired t test. Results Seventy-nine patients were female (71.8%) (44.8±15.6 years) and 31 were male (28.2%) (40.5±16.4 years). Sixty-two patients had a previous diagnosis of asthma (56.4%), 18 of which with diagnosis of NSAID-exacerbated respiratory disease (NERD) (16.4%). ODC was positive in 7 cases (4 by decrease of volumes and 3 by reported symptoms): 5 alternatives and 2 diagnostic (4 with meloxicam; 1 ibuprofen, 1 metamizol; 1 etoricoxib), 2 patients with no previous asthma diagnosis. Taking into consideration the whole population tested, we observed statistically significant decreases in FEV1 and FVC values at 30 and 120 minutes after medication versus baseline; and also a decrease in volumes at 30, 60, 120, 180 and 240 minutes after the second dose vs baseline (p<0.05). When comparing alternative versus diagnostic ODCs, we found statistically significant differences in the measurement of FEV1 at one hour after the second dose (p<0.05). Conclusion The number of positive ODCs was low (6.36%). Patients with asthma have an increased risk of reaction even with alternative NSAIDs. There was a statistically significant decrease in FEV1 at almost all timepoints after NSAIDs compared to baseline, even including negative challenges in the analysis. This suggests that NSAIDs might have a general effect to reduce FEV1. P62 PREVALENCE AND INCIDENCE OF ANALGESIC HIPERSENSITIVITY REACTIONS IN COLOMBIA Pablo Andrés Miranda1, Bautista De La Cruz Hoyos2 1. Universidad Nacional de Colombia, Cartagena, Colombia 2. Centro de Especialistas Santo Domingo - Alergologia, Cartagena, Colombia Keywords: ANALGESIC, ALLERGY, HIPERSENSITIVITY Introduction The most common drug hypersensitivity reactions (DHR) involve analgesic such as aspirin and other non steroidal anti-inflammatory drugs. Method Records with personal history of allergy analgesics diagnosis (ICD-10 code Z886) of Information System of Social Protection (SISPRO) between 2010 and 2014 were included. To determine the prevalence and incidence of AHR, population estimates from the National Statistics Department of Colombia (DANE) were used. Results 1657 cases with personal history of AHR between 2010 and 2015 were identified. 223 cases were confirmed news diagnoses in the same period. On average 331 cases of AHR per year were estimated. The estimated annual prevalence AHR were 7 cases per million (2010= 6; 2011= 7.1; 2012=8.1; 2013= 6.8 and 2014= 7.2). The estimated annual incidence AHR were 0.9 cases per million (2010= 0.8; 2011= 1.1; 2012= 0.9; 2013= 0.8 and 2014= 1). Most cases range between 19 and 59 years age. Conclusion Both under-diagnosis and over-diagnosis AHR are common in the world. Population studies with confirmatory tests AHR in Colombia are required. PREVALENCE AHR COLOMBIA Cases per million 1-5 años 6-9 años 10-14 años 15-18 años 19-26 años 27-44 años 45-59 años > 60 años Total INCIDENCE AHR 2010 COLOMBIA % (n) Cases per million 1-5 años 0 (0) 6-9 años 5.4 (3) 10-14 años 8 (4) 15-18 años 8.3 (2) 2010 %(n) 2011 %(n) 2012 %(n) 2013 %(n) 0.4 (1) 5.4 (15) 8 (22) 8.3 (23) 14.9 (41) 34.8 (96) 19.2 (53) 9.1 (25) 100 (276) 5.1 (17) 6.9 (23) 6.3 (21) 6.9 (23) 13.9 (46) 2.4 (9) 4 (15) 9.2 (35) 7.4 (28) 2011 % (n) 2012 % (n) 2013 % (n) 2014 % (n) 0 (0) 0 (0) 9.3 (5) 7.4 (4) 0 (0) 2.4 (1) 9.5 (4) 7.1 (3) 2.5 (1) 5 (2) 2.5 (1) 10 (4) 8.2 (4) 10.2 (5) 10.2 (5) 18.4 (9) 5.2 (17) 5.2 (17) 10.8 (35) 7.7 (25) 18.8 19.8 (75) (61) 29.8 26.2 32 (106) (113) (85) 16.6 19 (63) 16.4 (62) (54) 9.7 (32) 11.1 (42) 9.5 (31) 100 100 100 (331) (379) (325) 2014 %(n) 3.8 (13) 3.2 (11) 12.1 (42) 10.8 (37) 16.8 (58) 27.7 (96) 14.5 (50) 11.3 (39) 100 (346) 19-26 años 27-44 años 45-59 años > 60 años Total 14.9 (4) 20.4 (11) 21.4 (9) 22.5 (9) 20.4 (10) 34.8 (10) 35.2 (19) 26.2 (11) 25 (10) 16.3 (8) 19.2 (8) 18.5 (10) 23.8 (10) 22.5 (9) 8.2 (4) 9.1 (7) 9.3 (5) 9.5 (4) 10 (4) 8.2 (4) 100 (38) 100 (54) 100 (42) 100 (40) 100 (49) P63 Recent Endoscopic Sinus Surgery Lessens Reactions During Aspirin Challenge In Patients With Aspirin Exacerbated Respiratory Disease Teresa Pelletier1, Waleed Abuzeid2, Nadeem Akbar2, Marc Gibber2, Marvin Fried2, Weiguo Han1, Taha Keskin2, Robert Tamayev2, Golda Hudes2, Simon D Spivack2, David Rosenstreich2, Elina Jerschow2 1. Albert Einstein College of Medicine, Bronx, United States 2. Albert Einstein College of Medicine/ Montefiore Medical Center, Bronx, United States Keywords: Aspirin Exacerbated Respiratory Disease, Oral Graded Aspirin Challenge, Endoscopic Sinus Surgery, Silent Challenge Introduction Aspirin-exacerbated respiratory disease (AERD) is diagnosed clinically through a positive oral graded aspirin challenge. Upon confirming aspirin hypersensitivity, aspirin desensitization and treatment has been proven to reduce recurrence of nasal polyposis and asthma symptoms. However, negative aspirin challenges have been reported to occur in otherwise aspirin allergic individuals (“silent challenges”) after intake of antihistamines, leukotriene blockers, or oral corticosteroids. We sought to determine whether recent endoscopic sinus surgery (ESS) also affects reactions to aspirin challenge in patients with AERD. Method 19 AERD patients underwent two aspirin challenges: one before and the other after (within eight weeks) their most recent ESS. Reactions to aspirin were evaluated by changes in forced expiratory volume in 1 second (FEVl, percent predicted), nasal peak flow (NPF), and fraction of exhaled nitric oxide (FeNO). Results Decreased time between ESS and challenge was associated with decreased frequency of positive reactions: all 19 patients with a history averaging 32 months (IQR 9-72) since last ESS, reacted to aspirin. In contrast, only 10 (52.6%) of these patients, challenged on average of 1.1 months (IQR 0.8-1.4) after ESS, reacted to aspirin. Nine patients (47.4%) had no clinically apparent reaction to aspirin challenge after recent ESS. In the 10 patients who had a positive challenge after recent ESS, the decrease in FEV1 during this challenge was less than during the baseline challenge before ESS: -8.9±1.2% vs. 19.7±3.7% (p<0.01), respectively. NPF decrease was also smaller during the challenge after recent ESS than before recent ESS, -11.1± 5.1% vs. -25.5±6.2% (p<0.01), respectively. FeNO significantly decreased in all patients during the first challenge (-22.2% (IQR -50.6 to -20.9)) and decreased only in those who had positive challenges after recent ESS (-32.5% (IQR -35.1 to -22.6)), (p=0.3). Conclusion Recent ESS could contribute to a false-negative aspirin challenge. Patients who reacted to aspirin during the challenge after recent ESS had milder reactions comparing to the challenge before ESS. This presents a clinical dilemma: while appearing safer, aspirin challenges after a recent ESS may have a decreased diagnostic sensitivity so that some AERD patients could be misclassified as aspirin-tolerant. Clinicians should consider the possibility of false-negative challenges after recent ESS. P64 Safe Use Of Imidazol Salycilate In A Case Of Multiple NSAIDs Induced Urticaria-Angioedema Elisa Boni, Marina Russello, Marina Mauro Hospital Sant'Anna, Como, Italy Introduction Hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs) has been classified by Ayuso et al. into different phenotypes. Multiple NSAID-induced urticaria-angioedema (MNSAID-UA) is presumably related to cyclo-oxygenase 1 (COX -1) inhibition. Patients with MNSAID-UA have reactions to multiple chemically unrelated molecules while usually they tolerate low COX-1 inhibitors. Case Description We report the case of a 32 years old man who experienced several episodes of angioedema of lips and face after intake of acetyilsalicylic acid (ASA), in one occasion associated to the intake of paracetamol. Diagnosis of MNSAID-UA was confirmed by oral drug provocation test (DPT) to ibuprofen, a strong COX-1 inhibitor chemically unrelated to ASA, that induced labial angioedema. DPT with alternative drugs, defined as low COX-1 inhibitors, was then performed. Angioedema also appeared with nimesulide and paracetamol. Instead, the patient tolerated imidazole salicylate. How this report contributes to current knowledge Low COX-1 inhibitors as paracetamol and nimesulide not always are tolerated by patients with MNSAID-UA. This report confirms the safe use of imidazol salicylate in patients with hypersensitivity to ASA presumably due to non-interference with the cyclo-oxygenase pathway. P65 Selective Hypersensitivity Reactions To Ibuprofen – Seven Years Experience Marta Ferreira Neto CHLN-HSM, Lisbon, Portugal Keywords: Selective, Ibuprofen, Oral Challenges Introduction Immunologically mediated (non cross-reactive) hypersensitivity reactions to nonsteroidal anti-inflammatory drugs(NSAIDs) are classified in two groups: Single NSAID-induced urticaria/angioedema or anaphylaxis and Single NSAIDinduced delayed hypersensitivity reactions. In these entities patients have hypersensitivity to NSAIDS belonging to the same chemical group and tolerate chemically nonrelated ones. Usually there isn’t an underlying chronic disease like asthma or urticaria. Ibuprofen(Ib), belonging to Propionic acid derivatives(Pad) group, is one of the most frequently used NSAIDs, with frequent hypersensitivity drug reactions reports. Method We retrospectively analysed all patients(Pt) referred to our drug outpatient visit, from January 2008 to december 2015, with a selective history of hypersensitivity reaction to Ib. Oral drug challenges(ODC) were performed, in order to establish the diagnosis. Results <span lang="EN-US" style="line-height: 107%; font-family:; font-size: 11pt; mso-bidi-font-size: 16.0pt;" en-us;mso-fareast-language:en-us;mso-bidilanguage:ar-sa"="" mso-hansi-theme-font:minor-latin;mso-bidi-fontfamily:arial;mso-ansi-language:="" minor-latin;mso-fareast-fontfamily:calibri;mso-fareast-theme-font:minor-latin;="">A total of 10 Pt, aged between 18 and 79, 90% female were included. After intake of Ib, 10(100%) Pt reported cutaneous symptoms: 2(20%) Urticaria (U) and 8(80%) U/Angioedema. Besides Ib, Flurbiprofen, Dexcetoprofen and Naproxen were also the culprit drugs in 3 different Pt. All 10 Pt tolerated Acetaminophen after the reaction. Hypersensitivity reactions were immediate in 3(30%) Pt (<1h), late (1-6h) in 1(10%) and accelerated (8-24h) in 6(60%). ODC were performed with Ibuprofen, Acetylsalicylic acid (ASA) and Nimesulide (N) in 6(60%) patients, and in the remaining 4(40%) only with ASA and N. All ODC (100%) with Ib were positive, with reproductible symptoms, even in the non immediate reactions. All Pt (100%) had negative ODC with ASA and N. Conclusion Single NSAID-induced urticaria/angioedema to Ib was established in 10 (100%) Pt and to chemically related compounds of Pad group in 3 (30%) Pt. Women represent the majority, cutaneous symptoms are the only clinical presentation and 70% are non-immediate reactions. Other strong Cox1 inhibitors (except Pad group), Nimesulida and Acetaminophen are the alternatives in the 10 patients. Poster Walk 8: Epidemiological Methods (P66 – P72) P66 Allopurinol Hypersensitivity: A 7-Year Review Lise Brosseron, Daniela Malheiro, Susana Cadinha, Patrícia Barreira, JP Moreira Da Silva Centro Hospitalar Vila Nova de Gaia/Espinho, EPE, Vila Nova De Gaia, Portugal Introduction Allopurinol, an antihyperuricaemic agent, is used as first-line treatment of chronic gout. Allopurinol hypersensitivity (AH) is a rare but important cause of hypersensitivity reactions, ranging from mild cutaneous manifestations to lifethreatening severe cutaneous adverse reactions (SCAR). Despite several risk factors have been proposed, the underlying mechanisms remain unknown. Our aim was to characterize a series of patients with suspected AH referred to our drug allergy department during a 7-year period (2009-2015). Method A retrospective analysis was performed, assessing demographic and clinical data. AH was confirmed by a positive drug provocation test (DPT), positive lymphocyte transformation test (LTT) or reaction upon desensitization, and considered probable based only on a suggestive clinical history. Results Among a total of 954 patients, 29 (3%) had suspected AH. The mean age was 69±10 years and 16 (55%) were male. Allopurinol was prescribed for gout in 14 (48%), asymptomatic hyperuricemia in 12 (41%) and malignancies in 3 (10%) patients; 20 (69%) were polymedicated (≥4 drugs). Cutaneous reactions were reported by 27 (93%) subjects (14 exanthema, 5 urticaria/angioedema, 2 fixed drug eruption, 3 vasculitis and 3 DRESS). Twenty-six (90%) reported delayed reactions (DR), 1 reported immediate reaction and 2 were unable to recall onset. SPT (3) and patch tests (25) were negative in all patients tested. LTT performed in 12 patients (5 exanthema, 1 urticaria/angioedema, 3 vasculitis and 3 DRESS) was positive in 4, negative in 5, doubtful in 2 and undetermined in 1. DPT was positive in 2 out of 11 and long term challenge in 2 out of 8. Four patients were submitted to desensitization: 3 developed reaction during the procedure, confirming diagnosis; 2 were able to tolerate treatment. AH was confirmed in 10 (35%), considered probable in 6 (21%), excluded in 7 (24%) and inconclusive in 6 patients. Among confirmed AH patients, all were DR and 80% had started Allopurinol recently (≤10 days). Conclusion As previously described in the literature, our study suggests that AH is rare, usually presents with delayed cutaneous symptoms and can be related to recent introduction of Allopurinol. In the diagnostic workup of suspected AH, DPT remains the gold-standard while patch tests appear to be unhelpful. We discuss the usefulness of TTL, which seems promising, especially in SCAR where DPT is contraindicated. P67 Antibiotic Allergy Labelling Is Associated With Increased Hospital Readmission Rates In Australia Brittany Knezevic1, Dustin Sprigg1, Michelle Trevenen2, Jason Seet1, Jason Trubiano3, William Smith4, Yogesh Jeelall2, Sandra Vale5, Richard Loh6, Andrew Mclean-Tooke7, Michaela Lucas7 1. Sir Charles Gairdner Hospital, Perth, Australia 2. The University of Western Australia, Perth, Australia 3. Austin Health, Melbourne, Australia 4. Royal Adelaide Hospital, Adelaide, Australia 5. Australian Society of Clinical Immunology and Allergy, Balgowlah, Australia 6. Princess Margaret Hospital, Perth, Australia 7. Pathwest Laboratory Medicine, Queen Elizabeth II Medical Centre, Perth, Australia Keywords: Antibiotic, Allergy, Adverse Drug Reactions, Delabelling Introduction Patients frequently report antibiotic allergies, however only about 10% of labelled patients have a true allergy. This study investigates the documentation of antibiotic “allergy” labels (AALs) and the effect of labelling on clinical outcomes in an adult tertiary hospital in Australia. Method We performed a retrospective single-centre cross-sectional analysis of 737 inpatients in a major teaching hospital in Western Australia. All patients were captured in the 2013 and 2014 National Antimicrobial Prescribing Surveys (NAPS). NAPS is an annual audit of Australian health services, led by The Australian Commission on Safety and Quality in Health Care, to assess volume and appropriateness of antimicrobial prescribing. Data collected by detailed chart review, included antibiotic adverse drug reactions (ADRs), antibiotic cost, prescribing appropriateness, prevalence of multi-drug resistant organisms, length of stay, intensive care admission and readmissions. Results Complete data were captured for 687 patients. 278 (40%) were aged 70 or above, 322 (47%) were female and 279 (41%) were prescribed antibiotics at the time of audit. AALs were recorded in 122 (18%) of all patients. The majority of AALs were penicillin labels (n=87; 71%). Details of the clinical reactions to the culprit antibiotic were documented for 80 of 141 (57%) individual allergy labels: 61 described symptoms consistent with drug allergies and 19 were non-specific symptoms. Five patients were receiving an antibiotic that would be considered contraindicated according to their documented allergy status. Females and older patients were significantly more likely to have an AAL (gender: OR=2.54, 95% CI=1.69-3.82, p<0.001; for a one standard deviation (19.6 years) increase in age: OR=1.31, 95% CI=1.06-1.60, p=0.007). Patients with AALs had significantly more hospital readmissions within 4 weeks (p=0.001) and 6 months (p=0.025) of discharge, compared with unlabelled patients independent of age and gender. The majority of patients with AALs (84%) who were readmitted had a diagnosis of an infection. Conclusion This first Australian study shows that purported AALs are common but poorly documented in hospital records. Patients with AALs are significantly more likely to require readmissions. There may be a role for antibiotic allergy delabelling to mitigate the clinical and associated economic burdens for patients with invalid allergy labels. P68 Experts' Opinions On Severe Cutaneous Adverse Drug ReactionsReport Of A Survey From The 9th International Congress On Cutaneous Adverse Drug Reactions 2015 Roni P. Dodiuk-Gad1, Cristina Olteanu2, Wen-Hung Chung3, Neil H. Shear4 1. Department of Dermatology, Ha’emek Medical Center, Afula, Israel 2. Faculty of Medicine, University of Toronto, Toronto, Canada 3. Department of Dermatology, Drug Hypersensitivity Clinical and Research Center, Chang Gung Memorial Hospitals, Taipei, Taiwan 4. Division of Dermatology, Department of Medicine, Sunnybrook Health Sciences Centre, Linkou, Canada Keywords: SJS/TEN, DRESS, AGEP Introduction On June 8th, 2015, the 9th International Congress on Cutaneous Adverse Drug Reactions (cADR) was held at the 23rd World Congress of Dermatology. Eighty participants attended the congress from 23 countries; a variety of specialists with different areas of expertise included dermatology, regulatory agencies and public health, clinical pharmacology, immunology, infectious disease, oncology, pediatrics, etc. During the Congress, surveys were conducted to learn about the participants’ experiences and perspectives regarding four major topics: Pharmacogenomics and Severe Cutaneous Adverse Drug Reactions (SCAR), Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/ Drug-Induced Hypersensitivity Syndrome (DIHS), Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis (SJS/TEN), and Acute Generalized Exanthematous Pustulosis (AGEP). Method Participants answered survey questions anonymously through an electronic voting system. Results In a survey of the pharmacogenomics of SCAR, 21% of participants regularly conducted genetic screening prior to treatment with carbamazepine (N=53) and 15% of participants regularly conducted genetic screening prior to administration with allopurinol (N=52). Seventy-eight percent reported that there is a lack of knowledge among physicians regarding genetic screening for Human Leukocyte Antigens (HLAs) for preventing SCAR in their country (N=51). In a survey of SJS/TEN, systemic corticosteroids was the preferred treatment in 45% followed by only supportive treatment in 18%, intravenous immunoglobulin in 16%, and cyclosporine in 14% (N=51). In a survey of DRESS/DIHS, 36% regularly assess reactivation of human herpesvirus-6 (HHV-6) in their management of patients with DRESS/DIHS (N=53), and 33% monitor late autoimmune complications in these patients (N=54). In a survey of AGEP, 67% of participants always conduct assessment for systemic involvement (N=47). Conclusion There is a lack of implementation of regulatory agencies recommendations’ regarding genetic screening prior to treatment with carbamazepine or allopurinol. There is still no international consensus for the management of patients with SJS/TEN. Assessing reactivation of HHV-6 and monitoring late autoimmune complications in patients with DRESS/DIHS is not commonly done. Assessing systemic involvement in patients with AGEP was found to be commonly conducted. P69 HLA-A*31-Positive AGEP With Carbamazepine Use And Other Severe Cutaneous Adverse Drug Reactions (SCARs) Detected By Electronic Medical Records Screening Sabine Müller1, Ursula Amstutz2, Lukas Jörg3, Nikhil Yawalkar4, Stephan Krähenbühl1 1. Department of Clinical Pharmacology and Regional Pharmacovigilance Center, Inselspital, University Hospital Bern, Bern, Switzerland 2. University Institute of Clinical Chemistry, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland 3. Department of Rheumatology, Clinical Immunology and Allergology, Inselspital, University Hospital Bern, Bern, Switzerland 4. Department of Dermatology, Inselspital, University Hospital Bern, Bern, Switzerland Introduction Pharmacovigilance (PV) programs based on spontaneous reporting of adverse drug reactions (ADRs) are compromised by underreporting and inconstant data quality. Underreporting of severe adverse drug reactions by hospitals is in the range of 95% (Drug Saf 2006;29:385-96). This study aims to assess underreporting and to evaluate the potential of electronic chart screening for SCARs in two departments (dermatology and allergology) as a proactive case detection method regarding detection rate and data quality. Method Electronic reports from January 2014 - December 2015 of the allergology and dermatology units at the Inselspital Bern (Switzerland) were reviewed monthly for diagnosis of SCARs (AGEP, SJS/TEN, DRESS) and compared to SCARs reported to the PV service of the clinical pharmacology unit. Cases were evaluated for standard PV parameters and results of allergologic and HLA testing if available. Results During this 2-year period, 27 SCARs were registered at our PV unit. 2 SCAR cases were reported spontaneously (1 DRESS, 1 SJS), while 25 SCARs were detected proactively (13 AGEP, 9 DRESS, 3 SJS). Interestingly, among the screened charts, a patient with carbamazepine-induced AGEP was a carrier for HLA-A*31 (HLA-A*3101 to be confirmed), possibly associated with carbamazepine-induced AGEP (Epilepsia 2014;55:496-506). Conclusion Spontaneous reporting is insufficient, even for severe ADRs with well-established causality. Combination of chart screening with standard PV programs is a promising method to enhance detection rate and signal quality for rare idiosyncratic ADRs. P70 Patients With Suspected Drug Allergy: A Specific Psychological Profile? Eunice Dias-Castro1, Ana Leblanc1, Laura Ribeiro2, Josefina R. Cernadas1 1. Allergy and Clinical Immunology Department, Centro Hospitalar S. João EPE, Porto, Portugal 2. Biochemistry Department. Medical Education and Simulation Department. Faculty of Medicine, University of Porto, Porto, Portugal Introduction There are several studies demonstrating an important association between allergic diseases and the psychological characteristics of the patients. The majority involves skin or respiratory diseases and only a few drug allergy (DA). Patients with adverse reactions to drugs appear to have more psychological disturbances than those with asthma/rhinitis. Method We evaluated psychological characteristics of 115consecutively patients >16years-old, studied in our Department for suspected DA. Four self-completed validated questionnaires (anxiety, depression, alexithymia, personality type) were used. Evaluation of patient emotions at the time of the reaction was also performed based on a numerical scale to quantify fear/panic and an open question. The control group included 55 patients from the outpatient clinic without any history of DA. Description of variables was done through absolute and relative frequencies. Chi-square and Fisher test were used to evaluate the association between variables and groups. The magnitude of the associations was measured by the Odds Ratios. The significance of the difference between the medium intensity of fear/panic at the time of the reaction by gender was evaluated by a student t-test for independent samples. All the variables with a proof value <=0.20 in the univariate analysis were considered for the multivariate analysis. The level of significance was considered 5%. Statistical analysis used the SPSS,version 20.0. Results There were no significant differences between the 2 groups concerning demographic or social characteristics, except for age (p=0.025). Allergic diseases were significantly more prevalent in the control group (51.1%vs.87.3;p<0.001) but other diseases were significantly higher in the patient group (67.5%vs.27.8%;p<0.001). The majority of the controls were on regular medication (68.4%vs.94.2%;p<0.001), although psychiatric medication was more frequently used in the case group (32.0%vs.5.8%;p<0.001). After adjustment for age, allergic disease, other diseases and daily medication, the suspicion of DA did not show any association with psychological characteristics. The differences between the medium intensity of fear/panic at the time of the reaction by gender were statistically significant (p=0.022), with males having a lower result (2.7points vs.3.6). Conclusion The suspicion of DA did not show any association with psychological characteristics of the patients. The analysis of those with confirmed DA is still ongoing. P71 Use Of An Electronic Device And A Computerized Mathematic Algorithm To Detect The Allergic Drug Reactions Through The Analysis Of Heart Rate Variability. Arantza Vega1, Raquel Gutierrez Rivas2, Ana Alonso1, Juan Maria Beitia1, Belén Mateo1, Remedios Cárdenas1, Juan Jesus Garcia-Dominguez2 1. Hospital Universitario de Guadalajara, Guadalajara, Spain 2. Universidad de Alcalá, Alcalá De Henares, Spain Keywords: Challenge Test, Heart Rate Variability, Electronic Device, Introduction Challenge test (CT) is the gold-standard for the diagnosis of drug allergy. Its implementation involves a high consumption of time and resources and implies the risk of severe adverse reactions apparence. Currently there is not a diagnostic tool able to perform an early detection of the allergic reactions, thus reducing the length of the challenge test and decreasing the onset of severe allergic reactions. Heart rate variability has been used for help to the diagnosis of several illnesses. It has been recently used for the detection of allergic reactions. We explore the use of a heart rate variability monitoring device to detect in real time the allergic reactions in patients undergoing a CT. Method Patients, older than 12 years, with suspected drug allergy that, following the normal diagnostic protocol, were undergoing a CT and agreed to participate. A remote monitoring device called Shimmer was placed from10 minutes before the star of the test until Its completion. Increasing doses of the drug were administered at 30 or 60 minutes interval untill the end of the test or until the onset of allergic symptoms. Heart rate variability was analysed by the proposed mathematic algorithm, and Its results were compared to the CT results. Results One hundred and twenty thee patients were studied: 81 women, 42 men, mean age 41,8y (14-92). Drugs tested included NSAID (50), Betalactamics (40), other antibiotics (8) and others (25). The drug CT was positive in seven of them (5,6%). The algorithm detection showed a positive result in nineteen patients and a negative one in 104. Its sensitivity and specificity were 57% and 87% respectively. When NSAIDs CT were ruled out the results improved reaching 100% sensitivity and 96% specificity. The global negative predictive value was 97%. The detection took place at least 90 minutes before the onset of symptoms. Conclusion The use of a heart rate variability device with a mathematic algorithm can be a useful tool in drug allergy diagnosis. Further studies are needed. P72 Variation In ERAP Influences Risk For HLA-B*57:01 Positive Abacavir Hypersensitivity Rebecca Pavlos1, Kaija Strautins1, Ian James1, Simon Mallal2, Alec Redwood1, Elizabeth Phillips2 1. Murdoch University, Perth, Australia 2. Vanderbilt University, Nashville, United States Keywords: ERAP, Abacavir, HLA-B*57:01 Introduction Abacavir (ABC) binds non-covalently to the floor of the peptide-binding groove of HLA-B*57:01, altering the chemistry and shape of the antigen binding cleft. This allows previously untolerized self-peptides to be presented by HLA-B*57:01 to T cells. Endoplasmic reticulum aminopeptidases (ERAPs) trim peptides for MHC Class I presentation, influencing the degree and specificity of the CD8+ T-cell response. Genetic variation within ERAP adds to the positive predictive value (PPV) of the HLA class I risk allele in autoimmune diseases such as HLA-B27 positive ankylosing spondylitis. Considering the altered peptide repertoire mechanism of ABC HSR we hypothesize that variation in ERAP may help explain why 45% of patients carrying HLA-B*57:01 can tolerate ABC. Method 3’UTR, intron and exon encoded SNPs which characterise gene haplotypes were examined for ERAP1 in HLA-B*57:01+ ABC patch test positive (PT+) patients [n=53] and HLA-B*57:01+ ABC tolerant controls [n=22] with sequence-based typing. Rs2248374, a tag SNP for functional ERAP2 haplotypes was also examined. Haplotype A is tagged by the (A) allele, while haplotype B is tagged by rs2248374(G). Fisher exact tests and multiple logistic regressions were used to compare genotypes between ABC HSR PT+ and tolerant groups. Results HLA-B*57:01+ ABC tolerance was associated with rs27434(GG) (18/22(82%) vs 24/53(45%) in ABC HSR PT+, p=0.005). This SNP maps to the active site within ERAP1 (AA356). For an HLA-B*57:01 positive population, with 45% of cases tolerant to abacavir, the estimated chances of tolerance given rs27434 genotype are AA(0%), AG(13%) and GG(43%). A missense mutation within the domain junction (rs30187(C)) important in conformational change of ERAP1 (AA528), was overrepresented in HLA-B*57:01+ ABC tolerant individuals (p=0.04). Analysis indicated linkage between rs27044 and rs30187, rs17482078 and rs2287987, and between rs30187 and rs27434 (all p < 0.0001). In a multivariable model with rs27434(GG), the ERAP2 SNP (rs2248374(G)) that tags haplotype B, characterized by a truncated protein, was decreased in tolerant individuals (p = 0.005). Conclusion ERAP variants are important in the development of ABC HSR. ERAP activity may influence the repertoire of peptides presented by HLA-B*57:01 or influence early changes in immunodominant epitope selection. This provides a potential pathogenic mechanism for the development of ABC HSR or ABC tolerance in HLAB*57:01 carriers. Poster Walk 9: DRESS / AGEP (P73 – P81) P73 A Clinical Case Of DRESS Syndrome In A Child After Administration Of Amoxicillin-Clavulanic Acid Rita Aguiar1, Anabela Lopes1, Ana Neves2, Maria Do Céu Machado2, MA PereiraBarbosa1 1. Immunoallergology Department.Hospital de Santa Maria-Centro Hospitalar Lisboa Norte, Lisbon, Portugal 2. Pediatrics Department.Hospital de Santa Maria-Centro Hospitalar Lisboa Norte, Lisbon, Portugal Keywords: DRESS Syndrome, Amoxicillin-Clavulanate, Patch Testing Introduction Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is an uncommon but serious hypersensitivity drug reaction. It is characterized by a polymorphic disseminated eruption with fever and multiple organ dysfunction. DRESS syndrome is a rare entity in children. The authors describe a case of a children admitted to our hospital for amoxicillinclavulanate induced DRESS syndrome. Method CASE REPORT: Male, 31 months-old, presented to the emergency department with diffuse erythema involving trunk and extremities, sparing palms of hands and feet, angioedema of the tongue and fever after treatment with amoxicillin/clavulanate for cutaneous infection. Laboratory findings revealed lymphocytosis, eosinophilia (600/µL), and elevated serum transaminases AST 139 U/L, ALT 440 U/L, LDH 976U/L. No previous drug allergies were reported at the time of presentation. On the second day of hospitalization, the patient’s rash was still persistent ant it appeared petechiae and hemorrhagic suffusion suggestive of vasculitis on the face, forehead and periorbital without worsening throughout the hospitalization. Infectious markers and serological tests were negative. Corticosteroid treatment was started after exclusion of other potentially serious conditions including infections and hematologic malignancies. The results of the skin biopsy taken from the lesions revealed superficial perivascular dermatitis involving spongiotic eosinophils compatible with spongiotic drug eruption. A dramatic improvement was observed and his clinical and laboratory findings were recovered on the 5th day of the treatment. The high fever, lymphocytosis and eosinophilia were resolved (eosinophilia rate was 1,8%). ALT 114, AST 57, without changes of cholestasis (GGT 28, LDH 567, total bilirubin 0,2 mg/dL). Abdominal ultrasound unchanged. Specific IgE β-lactams were negative. Patch tests with β-lactams revealed positive reaction to amoxicillin. Results . Conclusion Given the significant morbidity early recognition of drug reaction with eosinophilia and systemic symptoms syndrome and initiation of appropriate therapy are imperative in limiting morbidity. In this study, patch testing was a safe and useful method in confirming the culprit drug in DRESS induced β-lactam. The pathogenesis of DRESS is not yet entirely clarified, but positive patch tests suggest a drug-dependent delayed hypersensitivity mechanism. P74 Acute Generalized Exanthematous Pustulosis (AGEP) Induced By Mesalazine, Reliable And Oftenly Used Drug To Treat Inflammatory Bowel Disease Ceyda Tunakan Dalgiç, Emine Nihal Mete Gökmen, Fatma Düsünür Günsen, Gökten Bulut, Fatma Ömür Ardeniz, Okan Gülbahar, Ali Kokuludag, Aytül Zerrin Sin Ege University Medical Faculty, Department of Allergy and Clinical Immunology, Izmir, Turkey Introduction Acute generalized exanthematous pustulosis (AGEP) is a rare eruption characterized by acute, extensive formation of sterile nonfollicular pustules on edematous- erythematous skin. It is accompanied by fever, peripheral blood leucocytosis neutrophilia, and sometimes by facial edema, hepatitis and eosinophilia. Most cases of AGEP (90%) is caused by drugs and acute infections. Case Description 34 year- old female patient with ulserative colitis had been taken mesalazine tablets 2400 mg per day for one month. After one month therapy, a cutaneous reaction characterized by disseminated pustules on an erythematous base happened and mesalazine was stopped. During the period, lesions was localised to extremites, so topical therapy used. After the reaction was recovered, because of severe ulserative colitis, 15 days later mesalazine was restarted. Due to the second therapy, after the first dosage, she developed multiple disseminated sterile pustules on an erythematous background, associated with fever and neutrophilia. Laboratory examinations showed the elevation of white blood cells, neutrophils, erythrocyte sedimentation rate and C-reactive protein (white blood cells,9110/mm3; (64.2% neutrophils, 21.4% lymphocytes, 2.7% eosinophils, 11.4% monocytes), erythrocyte sedimentation rate 13 mm/h, C-reactive protein level 3.27mg/dl). Punch biopsy from pustules revealed subcorneal pustular formation, perivascular infiltration rich in leukocyte in dermis and acanthosis in epidermis. No accumulation was detected in immunofluorescence analyses. Clinical and histopathological findings were considered as AGEP. She was treated with intravenous corticosteroids, oral antihistamines and topical corticosteroids. The patient’s rashes decreased within the following 7 days and then diminished with desquamation.Consent: Written informed consent was obtained from the patient. How this report contributes to current knowledge We report a patient with AGEP after the use of mesalazine. It’s important to consider AGEP in the differential diagnosis of acute pustular rashes and drugs should be investigated as causative agents. Knowledge of the clinical features are necessary to be distinguished from other entities . It’s the first AGEP case due to 5-ASA derived mesalazine in the literature. As mesalazine has been oftenly using for inflammatory bowel diseases, clinicians should be aware of its potential about developing AGEP and be careful about it. P75 Changes Of Blood Plasmacytoid Dendritic Cells, Myeloid Dendritic Cells, And Basophils During The Acute Stage Of Drug Reaction With Eosinophilia And Systemic Symptoms (DRESS) And Other Drug Eruptions Shao-Hsuan Hsu, Yung-Tsu Cho, Che-Wen Yang, Kai-Lung Chen, Chia-Yu Chu Department of Dermatology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan Keywords: Drug Reaction With Eosinophilia And Systemic Symptoms, Plasmacytoid Dendritic Cell, Myeloid Dendritic Cell, Basophil, Human Herpes Simplex Virus-6 Introduction Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe cutaneous drug reaction characterized by exanthematous skin rash, fever, lymphadenopathies, eosinophilia, atypical lymphocytosis and internal organ involvement. Reactivation of human herpes virus (HHV)-6 and decreased plasmacytoid dendritic cell (pDC) in the peripheral blood were putatively related to the disease, though the causality remained inconclusive. Method We recruited 18 patients from July 2013 to May 2014 with the diagnosis of drug eruptions including maculopapular eruptions (MPE), Stevens-Johnson syndrome (SJS), fixed drug eruption (FDE) and DRESS. The peripheral blood pDC (linCD123+CD11c-), myeloid DC (mDC, lin-CD123-CD11c+) and basophils (lin-HLADR-CD123+CD11c+) were simultaneously labeled and processed by 4-color assay method, with the frequencies of such cells counted by flow cytometry. HHV-6 reactivation was determined by the presence of viral DNA in the whole blood sample or the elevation of anti-HHV-6 IgG in the serum during the convalescent stage. Results Decreased frequencies of pDC were significantly associated with the diagnosis of DRESS (p = 0.004), presence of atypical lymphocytosis (p = 0.023) and HHV-6 reactivation (p = 0.043), while those of mDC and basophils were unrelated to the type of drug eruption, presence of atypical lymphocytosis, eosinophilia or HHV-6 reactivation. The reactivation of HHV-6 was only found in DRESS patients, in which the pDC frequencies consistently showed a decreasing trend. Conclusion In this study, we found that decreased pDC in the peripheral blood during the acute stage is more common in DRESS patients than the other drug eruptions, while only part of the patients demonstrated measurable HHV-6 reactivation. mDC and basophils did not show remarkable trend among different drug eruptions. The decrement of peripheral blood pDC might be the preceding, or might be the causative, event before HHV-6 reactivation. P76 Characterization Of Isoniazid/Rifampicin-Specific T-Cell Responses In Patients With DRESS Syndrome Young-Min Ye1, Gyu-Young Hur2, Hae-Sim Park1, Seung-Hyun Kim1 1. Department of Allergy & Clinical Immunology, Ajou University School of Medicine, Suwon, South Korea 2. Department of Internal medicine, College of Medicine, Korea University, Seoul, South Korea Keywords: Antituberculosis Drugs, Drug Rash With Eosinophilia And Systemic Symptoms, T Cell Response, HLA Introduction Antituberculosis drugs (ATDs) including isoniazid, rifampicin, pyrazinamide and ethambutol are commonly used for the treatment of tuberculosis, but occasionally associated with drug- induced hypersensitive reactions such as drug rash with eosinophilia and systemic symptoms (DRESS) syndrome and hepatitis. The culprit drug and mechanistic basis of the hypersensitive reaction has not been defined. The aim of this study was to find whether drug-responsive T cell response was detectable in patients with ATD-related DRESS and characterize the mechanistic features of the T-cell response. Method A lymphocyte transformation test (LTT) was performed using peripheral blood mononuclear cells (PBMCs) from ATD-induced DRESS patients. Subsequently, drug-specific T-cell clones were generated from the hypersensitive patients. We measured the drug-specific proliferative responses and interferon-gamma (IFNγ) secretion. Anti-human class I and class II blocking antibodies were used to analyze HLA-restricted T-cell response. Results Strong proliferative responses to isoniazid or rifampicin were detectable in the patient with DRESS by LTT. Isoniazid/rifampicin- specific T-cell clones were generated from blood of the patients, but not pyrazinamide or ethambutol. The T cell clones proliferated and secreted IFNγ when stimulated with isoniazid or rifampicin. They did not cross-react with each other. T-cell responses were blocked in the presence of anti-human class II antibodies. Conclusion This study identifies isoniazid/rifampicin- responsive T-cells in peripheral blood of certain patients with ATD-induced DRESS. It highlights an important role of drugresponsive T-cell immune responses in ATD-induced DRESS syndrome. P77 DRESS Syndrome Secondary To Sulfasalazine With Delayed TEN: A Case Presentation Syed . Ali1, Michaela . Lucas2, Peter N Hollingsworth3, Andrew P C Mclean-Tooke3 1. Department of Immunology, Perth, Australia 2. Department of Immunology, Pathwest; QE2 Medical Centre; SMP, PALM, UWA; IIID, Murdoch University, Perth, Australia 3. Department of Immunology, Pathwest; QE2 Medical Centre, Perth, Australia Introduction Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare and potentially life threatening condition. DRESS preceding toxic epidermal necrolysis (TEN) has only been reported with 3 cases to date. Case Description A 31 year old lady presented with a 3 day history of fever, morbilliform rash, cervical lymphadenopathy and facial oedema. 5 weeks prior she had been diagnosed with rheumatoid arthritis (RA) and commenced on hydroxychloroquine and sulfasalazine. Investigations showed an eosinophilia, elevated liver function tests (LFTs) and high inflammatory markers. Infectious screen including viral tests was negative. A clinical diagnosis of DRESS was made, all RA drugs were ceased and she was started on high dose oral corticosteroids. During admission she developed a marked lymphocytosis, neutrophilia and eosinophilia with worsening LFTs and coagulopathy. The rash, LFTs and leukocytosis gradually improved and she was discharged on day 9 to continue on high dose oral steroids. She presented 3 days later with worsening of her rash, high fevers and right upper quadrant abdominal pain associated with worsening of LFTs, anaemia and thrombocytopenia. 3 doses of IV methylprednisolone were administered. Haemophagocytic lymphohistiocytosis was considered given a high ferritin and hypofibrinogenaemia although bone marrow examination showed reactive changes but no evidence of haemophagocytosis. There was again improvement in rash, facial swelling and laboratory markers, and she was discharged to continue high dose steroids. She re-presented 7 days later with return of fevers, rash, jaundice and deterioration in her LFTs. Cyclosporin was added but ceased after 4 days due to concerns regarding worsening LFTs. Liver biopsy showed submassive central necrosis and prominent bile duct damage. Ganciclovir was added following an equivocal PCR for HHV-6 on the liver biopsy tissue and she was considered for liver transplant if her liver failure worsened. On day 40 her LFTs had improved but she developed mucosal ulceration involving the mouth, eyes and genitals with bullous skin lesions involving 80% of the body surface which was Nikolsky sign positive. Skin biopsy was consistent with TEN. She was transferred to the ICU for aggressive management and intravenous immunoglobulin but deteriorated and passed away the next day. How this report contributes to current knowledge Here, we present a fatal case of DRESS with fulminant liver failure followed by extensive TEN despite immunosuppression and broad anti-microbial cover. P78 Drug Rash With Eosinophilia And Systemic Symptoms (DRESS) Features According To The Culprit Drug Zohra Chadly, Nadia Ben Fredj, Karim Aouam, Haifa Ben Romdhane, Naceur A Boughattas, Amel Chaabane Faculty of Medicine/University hospital/University of Monastir, Monastir, Tunisia Introduction The aim of this study was to evaluate the clinical and chronological Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) characteristics according to the culprit drug. Method We carried out a retrospective study including all cases of DRESS notified to the Pharmacovigilance Unit of Monastir during 11 years. Diagnosis of DRESS was based on European RegiSCAR criteria. Imputability was established according to Begaud’s method. Skin tests were performed according ENDA recommendations. Results Fourty seven cases of DRESS were included in our study: 27 men and 20 women, with a mean age of 47 years ±19. Antiepileptics drugs (18 cases: 15 carbamazepine, 2 phenobarbital, and 1 lamorigine) were the most frequent responsible drugs in our study followed by antibiotics (12: 6 betalactams, 4 glycopeptides, 1 cotrimoxazole and 1 ethambutol), allopurinol (10) and salazopyrin (7). All patients had pruritic maculopapular rash involving more than 50% of their body surface area. Mucosal involvement was observed mainly with antiepileptics drugs (5 cases) and allopurinol (4 cases). Lymphadenopathy was more frequent with salazopyrin and antiepileptics drugs (55% each). Eosinophilia was observed in 90% of cases with allopurinol, 66% with antibiotics and antiepileptics drugs, and 57% with salazopyrin. Atypical lymphocytosis was observed only in 8 cases. Liver was the most common organ affected (74.5%) in our series. The most frequent type of liver injury was: cytolytic with antibiotics and allopurinol (58% and 30% respectively) and mixed with salazopyrin and allopurinol (57% and 50% respectively). Renal failure was observed in all cases induced by allopurinol. Pulmonary involvement was observed in 5 cases (3with salazopyrin and 2 with antiepileptic drugs). The mean incubation period was similar in the four groups of incriminated drugs. The outcome was favorable after drug withdrawal in 95.7% of cases. Two patients with DRESS induced by allopurinol died because of multiple organ failure. Skin tests (patch or intradermal tests) were done in 33 cases. 75% of skin tests with antiepileptics drugs and antibiotics were positive. Skin tests with salazopyrin and allopurinol were all negative. Conclusion Throughout this study, we point out the variability of DRESS clinical characteristics according to the culprit drug in one hand and the unsefulness of skin tests with salazopyrin and allopurinol in the other hand. P79 Drug Reaction With Eosinophilia And Systemic Symptoms Induced By Allopurinol: Not Always Easy To Diagnose. Marina Lluncor Salazar1, Beatriz Pola1, Ana Fiandor2, Teresa Bellón3, Elena Ramírez4, Javier Domínguez Ortega2, Santiago Quirce5, Rosario Cabañas2 1. Allergy Department. La Paz Hospital Institute for Health Research (IdiPAZ)., Madrid, Spain 2. Allergy Department. La Paz Hospital Institute for Health Research (IdiPAZ). Consorcio Piel en RED, Madrid, Spain 3. Immunology Department. La Paz Hospital Institute for Health Research (IdiPAZ). Consorcio Piel en RED, Madrid, Spain 4. Department of Clinical Pharmacology, Hospital La Paz Health Research Institute (IdiPAZ), School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain. Consorcio Piel en RED, Madrid, Spain 5. Allergy Department. La Paz Hospital Institute for Health Research (IdiPAZ), Madrid, Spain Keywords: DRESS, Allopurinol, Oxypurinol, LTT Introduction DRESS is a life threatening hypersensitivity reaction. Allopurinol is a frequent cause. Lymphocyte transformation test(LTT) and epicutaneous tests with allopurinol are usually negative. We report a case with positive LTT to allopurinol and its metabolite, oxypurinol. Method A 37-year-old female attended the emergency room complaining of asthenia, cough, and generalized edema. She had a history chronic renal insufficiency stage 4 secondary to focal segmental glomerulosclerosis, high blood pressure and migraine. She was admitted with respiratory infection, acute kidney injury, and desquamative skin lesions that had appeared 20 days before. Initially she had erythema and face swelling, difficulty swallowing, painful papular lesions on face, scalp and upper trunk, abdomen and thighs. She had been treated with antihistamines, topical and systemic low dose corticosteroids with clinical improvement. She was on treatment with omeprazole, valsartan, prednisone, acetazolamide, allopurinol and ezetimibe/simvastatin. DRESS was suspected. A team of specialists (dermatologist, allergologist, pharmacologist, nephrologist) evaluated the patient. Laboratory tests and herpes virus serology were performed. After discharge she was evaluated on Allergy Unit. LTT was performed two months later according to Pichler et al. LTT is positive if stimulation index(SI)≥2 Results Tests revealed WBC 11,400, 700 eosinophils/mm3(6,2%), creatinine 4,38mg/dl (baseline 2,8mg/dl), CRP 49,8, GPT 483, GGT 1264 and hyperamilasemia. Serology was only positive for herpes 6(1/320). According to Kardaun score, “probable” DRESS diagnosis was established(4 points). She was included in Piel en Red Registry. Causality assessment according the Spanish Pharmacovigilance System Algorithm(SFEV) results were: allopurinol +7(probable) and Conditional(Unrelated) the other drugs. Allopurinol treatment was stopped. She received a bolus of metylprednisolone intravenously 3 consecutive days, antihistamines and antibiotics with improvement. She was discharged 15 days later with corticosteroid treatment (reducing dose) during 14 weeks. Patch tests were negative with allopurinol, ezetimibe and simvastatine. LTT was positive to allopurinol and to its metabolite oxypurinol at different concentrations with the highest stimulation index for oxypurinol(SI 14,84) Conclusion We report a case of DRESS by allopurinol in which the diagnosis was difficult to establish. LTT has been useful to identify the etiological agent. P80 Drug Reaction With Eosinophilia And Systemic Symptoms Syndrome Induced By Two Drugs Simultaneously: A Case Report. Krasimira Baynova, Marina Labella, Manuel Prados HUVR Seville, Seville, Spain Introduction Drug reaction with eosinophylia and systemic symptoms ( DRESS) is a severe potentially life-threatening druh hypersensitivity reaction with delayed onset( two to eight weeks after beggining a drug intake). It is characterized by rash, fever, blood abnormalities and/or internal organ involvement. Most frequently implicated drugs in DRESS are anti-epileptic drugs. We present a case of DRESS induced by carbamzepine and paracetamol simultaneously. Case Description A 84 year-old cauacsian woman with no previous drug hypersnsitivity history, complained of generalized maculopapular itchy purplish rash( trunk, abdomen, upper and lower extremities), peeling skin, fever and general weakness. A month before she was diagnosed of trigeminal neuralgia and started a treatment with pregabalin, carbamazepine and paracetamol.Previously the patient had used paracetamol without adverse reactions. Pregabalin and carbamazepine were used for the first time. Symptoms disppeared when the three drugs were interrupted and oral corticoid treament was established. Peripheral blood test was done when patient was symptomatic. Skin patch test and lymphocyte activation test ( LAT)with paracetamol, carbamazepine and pregabalin were performed four weeks after complete recovering. In blood test was observed eosinophylia( 1000/mm3) and leucocytosis( > 11 000/mm3). Kidney and liver function were normal. Skin patch test( interpretation in 48 and 96 hours) and lymphocyte activation test were positive to paracetamol and carbamazepine, and negative to pregabalin. Pregabalin treatment was continued without adverse reactions. A few months later our patient took a pill of paracetamol and experienced eosinophylia and maculopapular rush in abdomen and lower extremities. How this report contributes to current knowledge DRESS is a type IV drug hypersensitivity reaction and is commonly induced by aromatic anticonvulsnts as carbamazepine. Nevertheless any drug intake could induce this severe reaction , including " innocuous" drugs as paracetamol. The allergy work-out should be carried out 4 to 6 weeks after the complete recovering and should include all involved drugs. P81 The Drug Reaction With Eosinophilia And Systemic Symptoms (DRESS) Induced By The Second-Line Antituberculosis Drugs And Epstein-Barr Virus Infection Agne Ramonaite, Ieva Bajoriuniene, Brigita Sitkauskiene, Raimundas Sakalauskas Department of Pulmonology and Immunology, Lithuanian University of Health Sciences, Kaunas, Lithuania Introduction Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe drug-induced reaction that involves both skin and viscera. Antiepileptic agents, allopurinol and sulfonamides are the most frequently reported causes. Other causal factors such as drug metabolites, genetic factors and viral infections have been also reported. Case Description 31-year-old female was admitted to the hospital for the treatment of multidrugresistant pulmonary tuberculosis. She was treated with second-line antituberculosis drugs: moxifloxacin, kanamycin, cycloserine, prothionamide, para-aminosalicylic acid. After three weeks of therapy she developed high fever (>39°C), lymphadenopathy in the cervical and axillary regions and pruritic maculopapular eruption all over the body. Hematologic abnormalities such as leukocytosis with eosinophilia (1,81x 109/l) and monocytosis (1,85x 109/l) were detected in peripheral blood of the patient. Hepatitis was asymptomatic and detected using the liver function tests: serum aspartate aminotransferase (AST 1379 IU/l) and alanine aminotransferase (ALT 1221 IU/l) levels were increased by approximately 30-40 fold above the normal limits. The positive diagnosis of Ebstein-Barr infection was based on an increase in the anti Ebstein-Barr immunoglobulin G titer, implicating an Ebstein-Barr virus reactivation. Based on the clinic and laboratory findings diagnosis of DRESS was suspected, and all the drugs were discontinued. Patient’s condition improved after 8 weeks. The skin patch tests with moxifloxacin, kanamycin, cycloserine, prothionamide and paraaminosalicylic acid were done 2 months after the hypersensitivity syndrome resolved. The patch tests showed a positive reaction to prothionamide and paraaminosalicylic acid. How this report contributes to current knowledge This case reports the development of DRESS caused by late type of hypersensitivity to second-line antituberculosis drugs (prothionamide and paraaminosalicylic acid) in association with Epstein-Barr virus infection. Poster Walk 10: Miscellaneous drug hypersensitivity (P82 – P91) P82 A Case Of Cycloserine-Induced Lichenoid Drug Eruption Confirmed With A Lymphocatye Transformation Test Jae-Woo Kwon1, Shinyoung Park2 1. Department of Allergy and Clinical Immunology, Kangwon National University School of Medicine, Chuncheon, Korea 2. The research department, Kangwon regional cancer center, Kangwon national university hospital, Chuncheon, Korea Introduction LDE (Lichenoid drug eruption) is a rare form of delayed type drug eruptions. Among anti-Tb (antituberculosis) drugs, ethambutol is one of the most common causative drugs to induce LDEs and cycloserine has been reported known as a rare causative drug of the LDEs. Case Description 38 years old man presented with pururitus, lichenoid skin lesion on whole body, and blood eosinophilia (16,824 /ul). He had been treated with isoniazid, rifampicin, ethambutol, and pyrazinamide for 2 months and then with ethambutol, levofloxacin, cycloserine for next 2 months because of elevated liver enzymes. Mild pruritus developed at the start of anti-Tb medications and aggrevated with development of lichenoid skin lesion 1 month ago. pruritus, skin lesions, and eosinophilia were improved since anti-Tb medications were stoped. Patch test showed mild reaction for ethambutol and strong reaction for cycloserine. Then we performed an LTT (lymphocyte transformation test) and successfully comfirmed cycloserine as the offending drug. How this report contributes to current knowledge This suggests that the cycloserine should be considered as a possible causative drug of LDE and an LTT could be an option for the diagnosis of lichenoid drug eruption due to cycloserine. P83 Allergic Reaction To Topical Eye Drops: 5 Years’ Retrospective Study In A Drug Allergy Unit Diana Silva1, Leonor Carneiro Leão1, Fabricia Carolino2, Eunice Castro2, Josefina Cernadas2 1. Allergy and Clinical Immunology Department, São João Medical Center; Laboratory of Basic & Clinical Immunology, Faculty of Medicine, Porto University, Porto, Portugal 2. Allergy and Clinical Immunology Department, São João Medical Center, Porto, Portugal Keywords: Drug Allergy; Ocular Allergy Introduction Ophthalmic products are widely used and long-term application is frequently needed. This might lead to ocular surface changes and increase the frequency of adverse reactions. However, the underlying mechanisms and the causal agent are usually difficult to ascertain. We aimed to evaluate the patients referred to our drug allergy unit with suspected hypersensitivity reaction to topical eye drops. Method A cross-sectional, retrospective analysis of the clinical files of all patients studied in the Drug Allergy Unit of a University Hospital, in the last five years (January 2010 to December 2015) was made. Those with a suspected hypersensitivity reaction to topical eye drops were selected. Demographic, clinical history and diagnostic procedures data were collected. Results Four patients, two children (2 and 11 years of age) and two adults (49 and 72 years), were referred due to a suspicion of hypersensitivity reaction to topical eye drops. Both children reacted after atropine conjunctival application. The two adults reacted with each of the following topical drugs: timolol and moxifloxacin with tobramycin. All showed local symptoms of conjunctival erythema and ocular/facial edema immediately after drug administration. The patient who reacted to timolol presented dyspnea. For diagnostic study, the 2-year-old child performed conjunctival provocation test (CPT) with increasing doses of atropine (1mg/ml; 5 mg/ml and 10 mg/ml), with positive reaction with facial erythema at 10mg/ml dose; the 11-year-old child was submitted to skin prick and intradermal tests with atropine, which were negative, and waits for CPT to complete the study. The two adult patients performed only diagnostic CPT. The 49-year-old woman, which reacted with timolol, did CPT with spirometry control, without a significant change in FEV1 or any clinical symptoms; the 72-year-old male performed two separate CPT with moxifloxacin and tobramycin, both with negative results. Conclusion Hypersensitivity reactions to topical eye drops are probably underreported in our clinical practice. In three out of four patient’s hypersensitivity reaction was excluded after diagnostic work-up. Facial erythema is a frequent dose-dependent adverse effect to topical atropine, graded conjunctival challenge is important for establishing the diagnosis. Awareness should be increased for unneeded avoidance of topical eye drops. P84 ALLERGY TO HEPARINS Diana Perez-Alzate, Natalia Blanca-López, Maria Luisa Somoza Alvarez, Maria Garcimartin, Maria Vazquez De La Torre, Francisco Javier Ruano Pérez, Elisa Haroun, Gabriela Canto Diez Hospital Universitario Infanta Leonor, Madrid, Spain Keywords: Allergy, Hipersensitivity, Unfractionated Heparin And Low Molecular Weight Heparins,Cross-Reactivity Introduction The Incidence of reactions to heparins may be higher than previously thought. Extensive cross-reactivity among unfractionated heparin and low molecular weight heparins (LMWH) has been described. Aim: To characterize the patients with hypersensitivity to Heparins and the cross-reactivity among heparins in our clinical practice Method Retrospective study was performed in our Allergy Unit from 2013-2015. Clinical data were registered from all patients who developed heparins hypersensitivity. Skin/challenge test were performed with the heparin involved and with others LMWH. Results From a total of 20 patients, 10 were finally diagnosed of allergy to at least one heparin. Mean age: 61,25y.o. From these, 37.5% had other drug allergies (NSAID, Contrast agents) and 37.55% were atopic. Nine out of 10 cases developed cutaneous symptoms and one anaphylaxis. Patch test with the suspected drug was positive in one case to Bemiparin and Enoxaparin. Prick/ID were performed in all patients, with one positive result in delayed reading. Positive Subcutaneous challenge were: Enoxaparin in 40%, Bemiparin in 10%, Enoxaparin and Bemiparin i30%, Enoxaparin, Bemiparin, Nadroparin, Tinzaparin and Heparin in 10% and Heparin in10%. Intravenous provocation with heparin was not performed because of the severity of the episodes developed by the patient (4 anaphylaxis). Conclusion - In this study the frequency of heparin allergy is low but increasing, being the most common type of reaction delayed-type hypersensitivity (DTH). - We observed a high cross-reactivity among LMWHs and Heparin. - Challenge is considered the gold standard for the diagnose, being the clinical findings similar to previous reported. P85 Allopurinol-Induced Adverse Drug Reactions Katinka Ónodi-Nagy1, Ágnes Kinyó2, Lajos Kemény1, Zsuzsanna Bata-Csörgo1 1. Department of Dermatology and Allergology, Szeged, Hungary 2. Department of Dermatology, Venereology and Oncodermatology, Pécs, Hungary Keywords: Allopurinol, Adverse Reactions, Clinical Characteristics Introduction Allopurinol, a xanthine oxidase inhibitor, is the most widely administered urate lowering drug in the long-term management of chronic hyperuricemia and gout. In 2% of the treated patients adverse drug reactions, life-threatening cutaneous and systemic symptoms can develop. Human leukocyte antigen (HLA) genes play central role in immune reactions. Important association between HLA-B*5801 allele and allopurinol-induced severe cutaneous adverse drug reactions have been reported. Method In the past few years an increase in allopurinol-induced adverse drug reaction have been experienced among patients at our clinic (University of Szeged). Therefore we decided to investigate the clinical characteristics of these patients. Results Between 2002 and 2008 81 patients were sent to our laboratory center with suspected allopurinol hypersensitivity for Lymphocyte Transformation Test (LTT). This number rose to 222 between 2009 and 2015. LTT was positive in 4 cases out of the 81 patients and in 20 cases out of the 222 patients respectively, indicating 4.9% and 9% sensitivity. Of all these patients we were able to obtain a complete clinical history of 35 patients (mean age 68 years), 4 patients in the first period and 31 patients in the second period. They presented generalized maculopapular exanthems in 37.14%, drug reaction with eosinophilia and systemic symptoms in 31.43%, Stevens-Johnson syndrome in 8.57%, erythema multiforme in 5.71%, vasculitis in 5.71%, bullous drug exanthems in 2.86%, toxic epidermal necrolysis in 2.86%, acute generalized exanthematous pustulosis in 2.86% and erythroderma in 2.86%. The primary indication of the treatment was asymptomatic hyperuricemia in 88.6% of the patients. We concluded that the concomitant use of allopurinol and certain diuretics, furosemide and/or hydrochlorothiazide in 28 cases of our 35 patients, and impaired renal function enhance allopurinol toxicity increasing the risk of adverse drug reaction developments. Evaluation of the HLA-B*5801 studies are in progress. Conclusion Our data show that the use of allopurinol and thus the number of the resulting hypersensitivity reactions is increasing. The more and more common hypersensitivity reactions may be the result of the improper drug prescription, indication and advanced age. Based on our results LTT is not sensitive enough in proving allopurinol-induced adverse drug reactions. P86 Analysis Of A Population With Immediate Hypersensitivity To Corticosteroids - An 11 Year Review Joana Sofia Pita1, Emília Faria1, Rosa Anita Fernandes1, Ana Moura1, Nuno Sousa2, Carmelita Ribeiro1, Carlos Loureiro1, Ana Todo Bom1 1. Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal 2. Centro Hospitalar de Leiria, Leiria, Portugal Keywords: Hypersensitivity, Corticosteroids, Skin Tests Introduction Due to their anti-inflammatory and immunomodulatory properties, corticosteroids are highly prescribed. The prevalence of hypersensitivity (HS) reactions is estimated at <1%. The aim of our study was to characterize a population of patients referred to our outpatient clinic for suspected immediate HS to corticosteroids. Method Retrospective analysis including 61 patients sent to our Drug Allergy consultation for suspected corticosteroid HS, from January 2005 to December 2015. We proceeded to the patients’ clinical evaluation and analysis of the results of skin prick (SPT) and intradermal tests (IDT) of the following drugs: prednisolone succinate 125mg/ml, dexamethasone sodium phosphate 5mg/ml, methylprednisolone sodium succinate 40mg/ml, hydrocortisone 100mg/ml, betamethasone diopropionate 5mg/ml. IDT were performed with the following dilutions: 1:1000, 1:100 and 1:10. The tests were read at 20 minutes, and at 24-48h. Results We analysed 61 patients with suspected immediate HS to corticosteroids, in which 77% was female, with a median age of 47 years. Twelve patients had positive tests results (19%). The population with positive results was mainly female, 58%, with a median age of 39 (± 16 years). Half of this population had associated atopic disease (asthma and/or rhinitis). The clinical manifestations after the drug administration were: anaphylactic reactions in 50%, urticaria and/or angioedema in 41% and syncope in 8%. In these 12 patients we obtained 6% of positive SPT, and 12% of positive IDT. Thirty percent of positive reactions occurred with methylprednisolone, followed by dexamethasone (26%), prednisolone (17%), hydrocortisone (13%) and betamethasone (13%). Eight patients (66%) presented HS to more than one corticosteroid. Conclusion We obtained 19% positive prick and intradermal tests to corticosteroids, being anaphylaxis the most common reaction in these patients. There was a high frequency of sensitization to methylprednisolone and dexamethasone. 66% of patients had HS to more than one corticosteroid, which probably correlates with the presence of cross-reactivity among these drugs. P87 Anaphylaxis Against Mivacurium In A 12-Months Old Boy At FirstTime Exposure Wolfgang Pfützner Department of Dermatology and Allergology, Philipps University Marburg, Marburg, Germany Keywords: Anaphylaxis, Mivacurium, Infant, Anaesthesia Introduction Since sensitization against an allergen is an important requirement for the development of anaphylaxis, drug hypersensitivity reactions are very uncommon in infants. We report on a 12-months old boy who experienced a severe anaphylactic reaction during perioperative anaesthesia. Method About 5 minutes after receiving fentanyl, propofol and mivacurium for the induction of anaesthesia, a persistent rush was noticed, followed by a fall of blood pressure down to 70/40 mm Hg, tachycardia (f = 150/min) and respiratory distress. Emergency treatment was initiated by i.v.-application of epinephrine, after which the little boy fully recovered. Two months later he was referred to our department for allergological evaluation, including both laboratory analysis and skin tests with different drugs. Results Total IgE was 25.5 kU/l with no allergen-specific IgE-antibodies detectable against pholcodine, latex, egg white and soja, and basal serum mast cell tryptase was 2.77 µg/l (Thermo Fisher, Germany). Skin prick tests revealed a positive result to mivacurium but showed negative reactions against fentanyl, remifentanyl, propofol, rocuronium, and cis-atracurium. Thus, diagnosis of drug allergy against mivacurium was established, together with cross-reactive sensitization against another neuromuscular blocking agent (NMBA), cisatracurium. Surgery was rescheduled utilizing rocuronium for muscle relaxation, which was well tolerated. Conclusion NMBAs are the major cause of perioperative anaphylaxis, accounting for about 70% of all cases, with IgE-antibodies directed against quaternary ammonium compounds (QAC). Hypersensitivity reactions against NMBAs without prior exposure to this drug class have been reported previously, suggesting sensitization induced by other QAM-containing substances like disinfectants, food or industrial materials. However, we are not aware about reports of anaphylaxis against NMBAs in infants of such a young age. Thus, this case underlines both the risk of allergic reactions against NMBAs at first exposure and the necessity of comprehensively testing these drugs even in very small children with the history of perioperative anaphylaxis. P88 Antihistamine-Exacerbated Chronic Spontaneous Urticaria: A Paradox? Nadine Marrouche, Clive Grattan Norfolk and Norwich University Hospital, Norwich, United Kingdom Introduction Histamine released from mast cells plays a key role in the pathogenesis of chronic spontaneous urticaria (CSU). However, it is unlikely that histamine alone is the only mediator of the disease. From clinical experience we know that H1antihistamines, even at high doses, are ineffective in at least 30% of patients. Antihistamine hypersensitivity has been reported in the literature but CSU exacerbation by multiple antihistamines in the same patient is rare. Case Description A 38-year old female patient presented with a one-year history of recurrent itchy hives. The clinical history was suggestive of CSU. She was prescribed various antihistamines including chlorphenamine, loratadine, fexofenadine, and cetirizine. The patient noticed significant worsening of her urticaria within an hour of taking any antihistamine. Her urticaria exacerbations responded well to systemic steroids. The patient was re-challenged with cetirizine when her CSU was in remission. Within 90 minutes, she developed generalized itchy wheals which lasted several days. A skin biopsy showed typical urticaria with unusual prominence of eosinophils suggestive of urticaria with superimposed drug reaction (Figure 1). The patient was subsequently challenged with oral acrivastine and a similar reaction was observed. How this report contributes to current knowledge The underlying mechanism of antihistamine hypersensitivity remains unclear. Our patient had a positive oral challenge to multiple antihistamines with at least a 90-minute delay which suggests that the underlying mechanism is likely nonimmunological. In one case report it was suggested that, in some patients, antihistamines could paradoxically shift the H1 histamine receptor to the active confirmation leading to adverse reactions after dosing [*]. Our case highlights the rare possibility of a drug most commonly used to treat urticaria acting as the causal agent itself. *Urticaria induced by antihistamines. González de Olano D et al. J Investig Allergol Clin Immunol. (2006) P89 Anti-Osteoporotic Agents-Induced Cutaneous Adverse Drug Reactions In Asians Yu-En Chen1, Chun-Bing Chen2, Wen-Hung Chung2, Yu-Ping Hsiao3, Chia-Yu Chu4 1. College of Medicine, Chung Shan Medical University Hospital and Chung Shan Medical University, Taichung, Taiwan 2. Department of Dermatology, Drug hypersensitivity clinical and research center, Chang Gung Memorial Hospitals, Linkou,Taipei And Keelung, Taiwan 3. Department of Dermatology, Chung Shan Medical University Hospital and Chung Shan Medical University College of Medicine, Taichung, Taiwan 4. Department of Dermatology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan Keywords: Severe Cutaneous Adverse Reactions,Anti-Osteoporotic Agents, Bisphosphonates,Strontium Ranelate, Denosumab Introduction New medications such as bisphosphonates and strontium ranelate (a strontium salt of ranelic acid) have been introduced in the market for the treatment of osteoporosis and there are few case reports of severe cutaneous adverse reactions (SCAR) related to anti-osteoporotic agents.Therefore,we tried to identify the association between anti-osteoporotic agents and cutaneous adverse drug reaction(cADR) and the appropriate selection of alternative drugs. Method We retrospectively analyzed cADRs, including maculopapular exanthema(MPE),Stevens-Johnson syndrome (SJS) , drug rash with eosinophilia and systemic symptoms (DRESS), related to use of anti-osteoporotic agents in Taiwan and Hong Kong from 2011 to 2015. We analyzed the causative antiosteoporotic agents, clinical characteristics, outcomes and further assessed patients’ tolerability to alternative anti-osteoporotic agents after the development of anti-osteoporotic agents-related cADRs. We also review the literatures of antiosteoporotic agents-related SCAR. Results There were 14 cases of anti-osteoporotic agents-related cADRs, including 6 SJS, 1 DRESS and 7 MPE. The most common causative agents were strontium ranelate and bisphosphonates. Strontium ranelate was found to be related to most SCAR cases, including 6 SJS and 1 DRESS. For MPE, there were 3 cases caused by bisphosphonates, 3 cases caused by strontium ranelate and 1 case caused by teriparatide. There was no mortality and long-term sequelae of all SCAR cases. There was no cross hypersensitivity among strontium ranelate, bisphosphonates, and denosumab (a monoclonal antibody). Patients with strontium ranelate-related cADRs were tolerant of alternative bisphosphonates and denosumab. One case of bisphosphonate-induced MPE was also tolerant of denosumab. Conclusion Most of the anti-osteoporotic agents-related cADRs are usually mild. In Asia, strontium ranelate seems to cause more SJS/TEN than DRESS in comparison with that in Europe. No mortality was reported among patient with SCARs. Owing to the structural difference in anti-osteoporotic agents, denosumab was well tolerated in patients allergic to either strontium ranelate or bisphosphonates as alternative drug. Table 2. Strontium ranelate–induced severe cutaneous adverse reactions Region Asia Europe Tan et Case series This study al.[1]/ Lee Cacoub et al.[3] et al.[2] Taiwan Country and Hong Singapore France etc Kong Culprit anti-osteoporotic agent SR1 SR SR 2 Indication to anti-osteoporotic agent OPO PM OPO OPO Ethnicity Chinese Chinese Caucasian Patients’ Gender F (83.3) F (100.0) F (100.0) profile 68.7 (in DRESS Average age (year) 64.7 69.5 group) No. of SCARs patients 7 2 52 Total case No. 6 (85.7) 2 (100.0) 5 (9.6) Average latent 29.2 16 Not mentioned period (days) SJS/TEN3 Eye 1 (16.7) 1 (50) Not mentioned involvementa Orogenital Phenotype 5 (83.3 ) 2 (100.0) Not mentioned involvement Total case No. 1 (14.3) 0 47(90.4) Average latent 90.0 0 33.5 DRESS4 period (days) Liver 0 (0) 0 (0) 37 (79.0) involvementb Kidney involvementc Eosinophiliad 0 (0) 0 (0) 1(100.0) 0 (0) 12 (25.0) 43 (91.0) Persistent DRESS symptoms (21.3) Clinical sequelae Nil Nil and relapse of DRESS (2.0) 8.5 % (in DRESS Mortality rate 0% 0% group) Abbreviation: 1.SR, strontium ranelate; 2.PM OPO, postmenopausal osteoporosis; 3. SJS/TEN, Stevens-Johnson syndrome/Toxic epidermal necrolysis; 4.DRESS, drug rash with eosinophilia and systemic symptoms *data are n(%) of patients unless otherwise specified a. Eye involvement : corneal ulcer or symblepharon b. Liver involvement : 2-fold increase from normal or baseline levels of serum glutamic oxaloacetic transaminase(GOT),glutamic pyruvate transaminase(GPT) or total bilirubin c. Kidney involvement : >1.5-fold elevation of serum creatinine from the normal range d. Eosinophilia : eosinophils count > 500/μL Ref. 1.Tan, K.W., Y.S. Wang, and Y.K. Tay,Stevens-Johnson syndrome due to strontium ranelate. Ann Acad Med Singapore, 2011. 40(11): p. 510-1. 2.Lee, H.Y., et al.Strontium ranelate-induced toxic epidermal necrolysis in a patient with post-menopausal osteoporosis. Osteoporos Int, 2009. 20(1): p. 161-2. 3.Cacoub, P., et al.,Drug rash with eosinophilia and systemic symptoms (DRESS) in patients receiving strontium ranelate. Osteoporos Int, 2013. 24(5): p. 1751-7. P90 DIAGNOSIS OF ALLERGIC REACTIONS TO EYE DROPS Maria Vazquez De La Torre, Natalia Blanca-Lopez, Diana Perez-Alzate, Maria Isabel Garcimartin, Francisco Javier Ruano, Maria Luisa Somoza, Elisa Haroun, Gabriela Canto Hospital Infanta Leonor, Madrid, Spain Keywords: Allergy, Eye Drops, Introduction Allergic reactions to eyedrops are rare in spite of the extensive use of these drugs by ophthalmologists. The percentage of this kind of adverse drug reactions (ADR) is reported to be less than 6 %. Method A total of 62 patients with suspect of ADR to eyedrops were evaluated in a period of 6 years (2008-2014). The allergological evaluation included: clinical history, patch tests (PTs) and conjunctival drug provocation test (CDPT). PTs with delayed readings at 48 and 96 hours were performed with the culprit eyedrops, alternative eyedrops and, in addition, the preservatives of the drugs. The culprit drugs used were: mydriatics (phenylephrine 100mg/ml, tropicamide 10mg/ml, cyclopentolate 10mg/ml and atropine 10mg/ml), local anesthetics (tetracaine 1mg/ml, oxibuprocaine 4mg/ml), solutions for glaucoma theraphy (brimatroprost 0.3mg/ml, travoprost 0.4mg/ml, brinzolamide 10mg/ml and timolol 5mg/ml) and fluorescein 20mg/ml. The preservatives included were: benzalkonium chloride 0.1%, ethylenediamine 1%, phenylmercuric acetate 0.01%, parabens 16%, polymixin B 3% and thimerosal 0.1%. The CDPT was carried out by instilling one drop of the ophthalmic solution in the eye, with readings made at 20 minutes and 24h later. Results From the total group, 40 patients (64.5%) were finally diagnosed of allergy to eyedrops. In 67.5% several mydriatics were involved in the reaction, and in 17.5% of these, a local anesthetic was also implicated. The clinical history reported by these 40 patients was: blepharoconjunctivitis in 23 cases (57.5%), conjunctivitis in 16 (40%) and cutaneous erythema only in one case. PTs were positive in 32 (80%) patients: 100% to phenylephrine and, in only one subject cyclopentolate in addition to phenylephrine. The CDPT was necessary for the diagnosis in the remaining 8 (20%) patients, being 7 positive to phenylephrine, and one to timolol. Phenylephrine was positive in 95% of patients finally diagnosed of eyedrop allergy. All patients with allergy to phenylephrine tolerated tropicamide, atropine, and cyclopentolate, except one that had a positive PT with cyclopentolate. Conclusion Phenylephrine is responsible for most of the allergic reactions induced by eyedrops. PTs are a safe and useful tool for the diagnosis. Tropicamide, atropine and cyclopentolate seems to be good mydriatic alternatives for these patients. P91 Diagnostic Approach In Suspected Hypersensitivity Reactions To Corticosteroids Fabrícia Carolino, Eunice Dias De Castro, Josefina R Cernadas Serviço de Imunoalergologia, Centro Hospitalar São João E.P.E., Porto, Portugal Keywords: Drug Hypersensitivity, Corticosteroids, Skin Tests Introduction Hypersensitivity reactions (HSR) to corticosteroids (CS) are rare although there are a growing number of reports both to systemic and topical CS. There are no standardized procedures for diagnostic skin testing with these drugs but a panel is recommended to assess cross-reactivity between steroids. Incremental drug challenge is still necessary for diagnostic or tolerance assessment purposes, but in this point safety issues may overcome. Method Retrospective analysis of consecutive patients evaluated in our Drug Allergy Unit for suspected CS HSR, during a 5-years-period. Skin prick tests (SPT) and intradermal tests (IDT) were performed with commercially available sterile CS formulations – betamethasone (7 mg/ml), budesonide (0.5 mg/ml), dexamethasone (4 mg/ml), hydrocortisone (100 mg/ml), methylprednisolone (62.5 mg/ml) and/or prednisolone (25 mg/ml). Oral solution of deflazacort (22.75 mg/ml) and nasal-spray suspension of fluticasone (27.5 μg/dose) were also used for SPT. Patch tests (PT) with a standard and/or complementary CS series were performed. Drug challenges (DC) used a selected-CS dose ranging between approximately 0.5 and 1.5 mg/kg/day. Results A total of 31 patients were assessed (74.2% females, mean±SDage 36.8±23.2 years) for suspected CS HSR. The main implicated CS were oral deflazacort (n=11) and oral betamethasone (n=5). 45.2% had immediate reactions and 38.2% late-onset symptoms; 51.6% presented skin/mucosal manifestations. IDT were performed in 12 patients and were positive to at least one of the tested drugs in 4 (2 with anaphylaxis and 2 with late-onset skin/mucosal involvement); 2 patients tested positively in IDT for more than 1 CS (dexamethasone/hydrocortisone and methylprednisolone/hydrocortisone). IDT were also performed in non-atopic controls. Patch tests in 10 patients revealed positive results (including the suspected CS) in 2 of them. DC was undertaken with the suspected systemic CS in 8 patients (no positive challenges and 2 doubtful); the remaining patients were tested for an alternative CS. Conclusion Proper validated skin tests may provide the necessary diagnostic evidence in drug allergy. They are particularly useful in more severe index reactions when re-challenging is not an option. The accuracy of skin tests needs to be further established with larger studies. Poster Walk 11: Miscellaneous drug hypersensitivity 2 (P92 – P94, P96 – P101) P92 16 Years Of Experience With Proton Pump Inhibitors (PPIs) Javier Dionicio Elera, Cosmin Boteanu, Maria Aranzazu Jimenez Blanco, Rosario Gonzalez-Mendiola, Irene Carrasco García, Antonio Alvarez, Jose Julio Laguna Martinez Hospital de la Cruz Roja Madrid, MADRID, Spain Introduction Proton Pump Inhibitors (PPIs) are commonly used for the treatment of acidrelated disorders. They are generally well tolerated, with a low incidence of adverse effects (1%). Omeprazole is the most common PPIs used and its intake has tripled from 2003 to 2012 in spain. Although hypersensitivity reactions to PPIs are rare, they are being more reported in recent years maybe due to the growing use of these drugs. The aim of this study was to review our experience with the use of PPIs in the last 16 years. Method We undertook a retrospective analysis of 10 858 patients who attended to the Drug Allergy Unit of Hospital de la Cruz Roja-Madrid, from 1999 to 2014. We devided our patients in 2 groups according to the increase of intake of PPIs. Group 1 from 1999 to 2008 and Group 2 from 2009 to 2014. We consider positive cases those who had Positive skin Prick test or positive drug provocation test or positive basophil activation test or suggestive history of PPIs allergy. We excluded patients who quit or refused the study. Results A total of 253 patients (2,3%) were attended in the Allergy Unit with suspected history of PPIs allergy in the last 16 years . From those, 16 (6,3%) were positive cases. In group 1, we included 5563 patients, from those, 91 were suspected cases, and 4 (4,4%) of them were positive In group 2, we included 5295 patients, from those 162 were suspected cases, and 12 (7.4%) of them were positive Conclusion In our experience, we found an increase in the number of reactions due to PPIs in the last years. Our results are according to the literature: Hypersensitivity reactions to PPIs are rare. P93 ALLERGY EVALUATION OF QUINOLONE INDUCED ADVERSE REACTIONS Jaume Martí Garrido, Carla Torán Barona, Carolina Perales Chorda, Ramón López Salgueiro, Miguel Díaz Palacios, Dolores Hernández Fernández De Rojas IIS La Fe, Valencia, Spain Keywords: Quinolone, Allergy. Introduction The increasing use of quinolone antibiotics is associated with an increase in hypersensitivity reactions. The objective of this study is to analyse the cases of suspected allergy to quinolones referred to an allergy department in a tertiary level centre during 2015. Method We performed a descriptive, retrospective study. Cases were identified from the medical record administrator programme by searching the terms “quinolone, norfloxacin, moxifloxacin, levofloxacin or ciprofloxacin”. We collected demographic and medical data, information of the adverse events, results of the allergy evaluation and the recommendations for the future use of quinolones. Results We analysed 60 cases (26 male/34 female) with an average age of 60,5 years (6-88). The most frequent clinical manifestations were cutaneous (70%), 11% digestive, 7% respiratory, 7% neurological, 4% cardiovascular and 1% renal. The most common symptom were pruritus (25%) and erythema (24%). The reaction was immediate (within minutes) in 37% and delayed in 45%. The type of reaction was not described in 18% of cases. The involved quinolones were ciprofloxacin (40%), levofloxacin (37%), norfloxacin (8%) and moxifloxacin (8%). The most frequent route of administration was oral (66%), followed by intravenous (30%), topical (2%) and otic (2%). In two cases quinolones were directly banned after the adverse event due to the patient clinical condition or it was not considered necessary due to the lack of evidence on the reliability of the tests. Skin tests were performed in 40% of cases, with positive results for ciprofloxacin 78%, moxifloxacin 77%, levofloxacin 57% and none for norfloxacin. In a case of a generalized delayed reaction, patch tests were negative. In one case a fixed drug erythema due to norfloxacin was diagnosed without further check. In 10 cases of severe immediate reactions, BAT was performed 17 times with 4 positive results for ciprofloxacin and 3 for levofloxacin. In these cases quinolones were banned. All patients tolerated alternative quinolones to the one eliciting the adverse event, even when skin tests were positive. Conclusion Ciprofloxacin and levofloxacin were the most frequently involved quinolones. Skin symptoms were the most common clinical manifestations. Allergy evaluation included skin tests, BAT and controlled exposure in order to identify the responsible quinolones and search for safe alternatives. The sensitivity and specificity of these tests are still undetermined. P94 Bupropion-Induced Acute Urticaria And Angioedema, A Case Report Emre Ali Acar1, Ayse Aktas2, Aylin Türel Ermertcan3, Peyker Temiz4 1. Celal Bayar University, Faculty of Medicine, Department of Internal Medicine, Manisa, Turkey 2. Celal Bayar University, Faculty of Medicine, Department of Allergy and Immunology, Manisa, Turkey 3. Celal Bayar University, Faculty of Medicine, Department of Dermatology, Manisa, Turkey 4. Celal Bayar University, Faculty of Medicine, Department of Pathology, Manisa, Turkey Introduction Bupropion is a new-generation antidepressant, while its sustained release (SR) formulation is used in smoking cessation for a long time successfully. Urticaria, pruritus and rashes can be seen in 1-4% of the patients and anaphylactoid reactions like angioedema and dyspnea can be seen in 0,1-0,3% of the patients using bupropion. We wanted to report a case with urticaria and angioedema due to SR bupropion treatment. Case Description A-27-year-old woman without any disease history admitted to a hospital for smoking cessation. She had 15-pack-year of smoking history and she had started using 150 mg of SR bupropion. In first 3 days, she had used it once a day, then she started using twice a day. On tenth day of treatment, generalized rash with pruritus had been developed. In physical examination, she had generalized plaques and papules with edema and erythema on his neck, trunk, upper and lower extremites (Picture 1). She had swelling on her lips as well. With suspicion of adverse drug reaction, skin biopsy was made. Other physical examination, blood and urinary laboratory findings were normal. With these clinical and histopathological findings, urticaria and angioedema diagnosis were made. She was hospitalized and bupropion treatment was stopped. Systemic corticosteroid and antihistaminic treatments were started. On third day of treatment, her skin lesions were regressed. How this report contributes to current knowledge Buproprion is a commonly used drug in smoking cessation clinics. Although it is rare, physicians should be cautious about urticaria, angioedema and anaphylaxis as adverse drug reactions of bupropion treatment. P96 Delayed Type Hypersensitivity And Study Of Cross-Reactivity Between Proton-Pump Inhibitors Chien-Yio Lin1, Chung-Yee Rosaline Hui2, Ya-Ching Chang2, Chih-Hsun Yang2, Wen-Hung Chung2 1. Department of Dermatology, Chang Gung Memorial Hospital, Linkou, Taiwan 2. Department of Dermatology, Drug Hypersensitivity Clinical and Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan Introduction There are six PPIs available for clinical use, which could be set into two groups, omeprazole/esomeprazole/pantoprazole vs. lansoprazole/dexlansoprazole/rabeprazole, based on the same basic skeleton, but differed by virtue of substitutions on both rings. The former three have changes in their benzimidazole ring, whereas the latter three have changes in their pyridine ring. Although proton-pump inhibitors (PPI) are relatively well tolerated, some patients may develop hypersensitivity reactions, which vary from mild symptoms to life-threatening severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), acute generalized exanthematous pustulosis (AGEP), and drug rash with eosinophilia and systemic symptoms (DRESS). Clinicians often overlook the potential of PPI-related SCARs. Method We retrospectively analyzed patients of PPI-related cutaneous adverse reactions from Chang Gung Memorial Hospital health system during January 2003 to December 2015. We analyzed the causative PPIs, cutaneous manifestation, organ involvement, treatment, and complications. We also assessed the crosshypersensitivity to other PPI after the hypersensitivity episode. The causality of the culprit drugs was further confirmed by in vitro lymphocyte activation test (LAT) and patch test in some cases. Results There were 48 cases of PPI-related cutaneous adverse reactions, with maculopapular eruption (MPE, n=20), DRESS (n=10), and SJS/TEN (n=9), contributing the most. Esomeprazole was the most common causative PPI (n=23, 47.9%), and the liver was the most frequently involved internal organ (26.7%). One patient (2.1%) died of esomeprazole-induced TEN. Seven patients allergic to one group of PPI would able to tolerate the other different structured PPI group, whereas two patients showed cross-hypersensitivity when shifting to alternative PPI of the same group with similar structure. The drug causality and cross-reactivity were confirmed by lymphocyte activation test in 53.8% patient of whom tested; besides, 2 of 5 patient with patch test performed showed corresponding result to the LAT. Conclusion The clinicians should be cautious of PPI-related SCARs. The potential of crosshypersensitivity to similar structured PPI should be aware of, and shifting to different structured PPI could be considered when PPI is the treatment of choice. P97 Diagnostic Work-Up In Suspected Hypersensitivity To Proton-Pump Inhibitors: Looking At Cross-Reactivity Fabrícia Carolino1, Diana Silva2, Eunice Dias De Castro1, Josefina R Cernadas1 1. Serviço de Imunoalergologia, Centro Hospitalar São João E.P.E., Porto, Portugal 2. Serviço de Imunoalergologia, Centro Hospitalar São João E.P.E.; Laboratório de Imunologia, Faculdade de Medicina, Universidade do Porto, Porto, Portugal Keywords: Drug Hypersensitivity, Proton-Pump Inhibitors, Skin Tests, CrossReactivity Introduction Proton-pump inhibitors (PPI) are widely used in clinical practice and there are multiple reports of hypersensitivity reactions (HSR), most of them immediate, and cross-reactivity (CR) between PPI. Specificity of skin tests has to be determined and there are currently no specific recommendations from the ENDA group. Aim: We present a consecutive case series of patients with suspected PPI HSR. Method The present study is a case series of patients evaluated in our Drug Allergy Unit for suspected PPI HSR, in an 8-year period. CR in skin prick tests (SPT) and intradermal tests (IDT) was assessed using the commercially available parenteral PPI formulations (esomeprazole 20mg/ml, omeprazole 4mg/ml, pantoprazole 4mg/ml) and crushed tablets in saline (lansoprazole 15mg/ml, rabeprazole 10mg/ml) for SPT. IDT were only performed with parenteral formulations (1/1000-1/1 dilutions), due to safety and accuracy reasons. Results In the studied period, 19 patients (11 female; mean±SD age 50.7±14.2 years) were assessed for the suspected HSR. PPI were mainly prescribed for dyspepsia/stomach ache (n=11) or Helicobacter pylori eradication (n=4). Implicated PPI were omeprazole (n=13), esomeprazole (n=4), pantoprazole (n=2), lansoprazole (n=2), with 2 patients reacting to different PPI (omeprazole/lansoprazole and omeprazole/pantoprazole). Eight patients had immediate reactions (6 anaphylaxis and 2 urticaria) and 3 of them had positive SPT (one had positive SPT to both omeprazole and pantoprazole). Seven patients (5 urticaria, 1 anaphylaxis and 1 MPE) had positive IDT to omeprazole only (undiluted) and 1 patient (anaphylaxis) had a positive IDT to pantoprazole alone (1/100). Cutaneous CR (this is, positive IDT for >1 PPI) was present in 3 patients, as described below: - one patient with anaphylaxis to omeprazole and positive IDT to omeprazole (1/1000) plus esomeprazole (1/10); - another patient with anaphylaxis to omeprazole and positive IDT to omeprazole (1/10) plus pantoprazole (1/1); - and a patient with urticaria to esomeprazole and positive IDT to esomeprazole (1/10) plus pantoprazole (1/10). Non-atopic controls were also tested for PPI. Conclusion Cross-reactivity in 4 patients can be explained by the similar chemical structure of PPI. Additional multicentre studies are needed to standardize procedures for skin tests with PPI. Oral challenges are also important to increase the diagnostic accuracy to this pharmacological group. P98 Management Of Infusion-Related Hypersensitivity Reactions To Enzyme Replacement Therapy For Lysosomal Diseases Luis Felipe Ensina1, Carolina Aranda1, Ines Camelo Nunes1, Alex Lacerda1, Ana Maria Martins1, Ekaterini Goudouris2, Marcia Ribeiro2, José Francisco Da Silva Franco3, Leandra Queiroz4, Dirceu Solé1 1. Federal University of São Paulo, São Paulo, Brazil 2. Federal University of Rio de Janeiro, Rio De Janeiro, Brazil 3. Pontificia Universidade Católica de Campinas, Campinas, Brazil 4. Private Practice, Goiania, Brazil Keywords: Desensitization, Lysosomal Diseases Introduction Enzyme replacement therapy (ERT) has been used in the treatment of lysosomal diseases (LD). ERT with human recombinant enzymes has shown to slow disease progression and improve the quality of life. Infusion-related reactions (IRR) to ERT can occur and be severe, including hypersensitivity reactions (HSRs) such as anaphylaxis. A diagnostic and treatment protocol was proposed to manage those reactions. Method Patients under ERT for Mucopolysaccharidosis (I, II and VI), Gaucher, Fabry and Pompe diseases under treatment in 7 centers from Brazil were assessed from January 2011 through December 2015. In the presence of suggestive signs or symptoms of an adverse reaction, ERT was stopped and skin tests for specific IgE assay were performed. In patients with symptoms of acute infection after infusion and with negative skin tests, ERT was maintained at the same infusion rate. In patients without a history of infection and with negative tests, ERT was maintained with an increased infusion rate. For those patients with positive ST that continued reacting after adjustments in the IR, a 3 bags 12-steps desensitization protocol was generated. Results Thirteen patients presented a suggestive HSR with positive skin tests, during treatment with laronidase (n=3), galsulfase (n=2), betagalsidase (n=7), imiglucerase (n=1). Urticaria was the most commom symptom observed (50%), followed by fever (20%), chills (10%), cough (10%) and anaphylaxis (10%). Of the 911 desensitizations performed, 20% induced mild reactions, but all patients received their full target dose. No severe, life-threatening HSRs or deaths occurred during the procedure. Conclusion Considering the importance of ERT in the treatment of LD, a standardized diagnostic protocol for IRR allows us to establish a correct diagnosis and propose an efficient treatment algorithm, which includes infusion rate modification and desensitization P99 Management Of Insulin Allergy With Continuous Subcutaneous Insulin Infusion Ceyda Tunakan Dalgiç, Aytül Zerrin Sin, Fatma Düsünür Günsen, Gökten Bulut, Fatma Ömür Ardeniz, Okan Gülbahar, Emine Nihal Mete Gökmen, Ali Kokuludag Ege University Medical Faculty, Department of Allergy and Clinical Immunology, Izmir, Turkey Introduction Insulin allergy is uncommon, particularly in patients with Type 2 diabetes mellitus (DM). Management of the condition can be difficult. We report a patient with Type 2 DM and insulin allergy successfully managed with continuous subcutaneous insulin infusion (CSII). Case Description 35 years old woman diagnosed as type 2 diabetes mellitus used detemir insulin at first. On the third day of detemir, 12 hours after the dose, a pruriginous papule occured at the site of injection area. Local reaction was continued. On the seventh day, detemir was changed with NPH. Local reaction occured at first dose of NPH. All of the local reactions were late onset. Therapy was changed to glargine. One hour after the first dose of glargine, local reaction and generalize pruritus were occurred. All insulin types were stopped and four weeks later, skin tests were performed. Prick tests were negative. Intradermal tests were positive with the dilutions of 1/100 detemir, 1/100 glargine, 1/1000 NPH, 1/1000 regular insulin. Glulisin, aspart and lispro were negative. Insulin specific IgE (194 Ku/L (0-87)) and anti-insulin antibody %47.8 (reference <8.2) were high and specific Ig G4 was normal (35 mg/ dL (0-125)). The therapy started with glulisin and there wasn’t any reaction at first. Therefore, since blood glucose and serum glycated hemoglobin A1c levels (10%) were still higher, as a long acting insulin, NPH had to be added together with antihistaminic. No reaction was observed with NPH. At the 20th day of glulisin, late onset local reactions were seen again. Glulisin was changed to aspart. Similar reactions were seen with those insulins. Finally, the only insulin which has never been used before was lispro. We suggested CSII pump with lispro. After this method, insulin hypersensitivity was successfully treated and glycemic control was achieved.Consent: Written informed consent was obtained from the patient. How this report contributes to current knowledge Allergy to insulin analogues is rare and requires early diagnosis, leading to a major therapeutic challenge. In this case, local reactions continued although types of insulins and application areas were changed. Interestingly, blood glucose was increasing to uncontrolled levels always following by the cutaneous reactions, also. As we consider anti-insulin antibodies and late onset local reactions, insulin allergy is thought to be mediated by type 1 and type 2 hypersensitivity reactions in this case. P100 Off-Label Use Of Icatibant For Management Of Serious Angioedema Associated With Angiotensin Inhibitors Ana M Montoro De Francisco, Talía Mª De Vicente Jiménez, Adriana M Mendoza Parra, Angella M Burgos Pimentel, Amelia García Luque Hospital Central de la Defensa, IMIDEF, Madrid, Spain Keywords: Angioedema, Angiotensin Inhibitors, Icatibant Introduction Angioedema is a serious, infrequent and well-known Adverse Drug Reaction (ADR) to antihypertensive drugs: Inhibitors of Angiotensin Converting Enzyme (ACEI), Angiotensin II Receptor Blocker (ARB) and Direct Inhibitor of Renin (DIR). ACEI/ARB/DIR are largely used worldwide, therefore, the morbidity and mortality from ADR could be considerable. No medications are currently approved for management of this ADR. Icatibant, a bradykinin receptor type 2 antagonist, is a potential treatment for a serious bradykinin-mediated angioedema associated with angiotensin inhibitors. Method Design: A case series of 100 patients with angioedema associated with ACEI/ARB/IDR. Scope: Allergy service, Hospital Central de la Defensa, Madrid. Period: March 2009 to December 2015. Main Variables assessed: demographic and clinical variables, treatment, and evolution. The patients have given written informed consent for the publication research. Results One hundred patients with episodes of angioedema all of them associated with ACEI/ARB/DIR. In addition to angioedema, patients showed cough, conjunctivitis, pruritus and rhinitis. Twenty had severe angioedema with airway compromise, speech impairment and hoarseness and poor response to antihistamines and corticosteroids which required hospitalization. They were treated with icatibant 30mg subcutaneous injection improving in their symptoms after 20 minutes-3 three hours. All patients experienced complete resolution of angioedema and avoidance of intubation and tracheotomy. Age 66,3 years (37-90), 12 females and 8 males. Ten patients had previously experienced serious angioedema attacks. Eight drugs were involved: ACEI 15 (enalapril, captopril and lisinopril), ARBII 4 (valsartan, losartan, olemesartan and ibersartan) and DIR 1 (aliskiren). More frequently involved drug was enalapril (9 cases). Conclusion Angioedema associated to angiotensin inhibitors is a serious ADR, it is rare but not unusual due to the widespread use of this class of drugs. Icatibant used offlabel helped to improve the acute angioedema attacks and avoidance of intubation and tracheotomy. P101 Thiocolchicoside Anaphylaxis: An Unusual Suspect? Luis Amaral, Fabricia Carolino, Leonor Carneiro Leão, Eunice Castro, Josefina Cernadas Serviço de Imunoalergologia, Centro Hospitalar de São João E.P.E., Porto, Portugal Introduction Thiocolchicoside is a sulfureted semi-synthetic molecule derived from colchicoside and is used frequently as adjuvant treatment for acute muscle contractures in spinal pathology. Immediate hypersensitivity reactions are rarely reported and only two documented cases of immediate anaphylaxis are described in the literature. Moreover, the allergy diagnosis with validated skin tests is lacking. Method We describe a first case of a 56-year-old woman that reported generalized pruritus, a rash involving palms and soles, dyspnea and colicky abdominal pain, 5 minutes after intramuscular (IM) administration of thiocolchicoside. These symptoms quickly reversed with IM adrenaline and intravenous (IV) hydrocortisone. A few months later we received a second case of a 52-year-old man who experienced dizziness, malaise and hypotension, 40 minutes after IM administration of thiocolchicoside and diclofenac. This clinical scenario was inverted with volume reposition with saline, IV hydrocortisone and adrenaline wasn’t administered. Results In the first case the emergency lab results showed serum tryptase 47 mcgr/L. Skin Prick test (SPT) [2 mg/ml] was negative and 5 minutes after performing intradermal test (IDT) [2 mg/ml] the patient experienced throat tightness that was reversed with ebastine 20mg. In the second case the SPT [2 mg/ml] was negative and IDT [2 mg/ml] was positive with a 7mm wheal diameter. The skin tests and oral provocation with diclofenac were negative. SPT and IDT with the same concentration were also negative in 6 patients with suspected immediate reaction to thiocolchicoside, confirmed by negative drug provocation test. Conclusion Thiocolchicoside is often administered as an adjuvant therapy with nonsteroidal anti-inflammatory drugs and is probably underestimated as a cause of immediate hypersensitivity reactions. Since the skin tests are not yet validated, many times it can be forgotten on the diagnostic workup. To our knowledge, this is the third study reporting documented anaphylaxis to thiocolchicoside and the first to support this diagnosis with intradermal tests. Poster Walk 12: Betalactam hypersensitivity (P102 – P111) P102 A Curious Delayed Reading- A Case Report Of A ß-Lactam Allergy In A Child Nicole Pinto, Joana Belo, João Marques, Pedro Carreiro- Martins, Paula LeiriaPinto Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, Lisbon, Portugal Introduction β-lactam antibiotics are commonly prescribed drugs worldwide and the most frequent cause of adverse drug reaction mediated by immunological mechanisms. Nonimmediate reactions, specially maculopapular and urticarial exanthems, are common. Skin tests are used to evaluate drug hypersensitivity and delayed reading might be useful in the diagnosis. Case Description A 2,5 year old girl, with no relevant past medical history, was referred to our outpatient clinic for suspected drug allergy to β-lactams. The patient had been admitted to the hospital for acute mastoiditis. Upon admission, amoxicillinclavulanic acid (Ax/C), which she had been taking for 4 days, was discontinued due to vomiting and she was started on triple IV antibiotherapy with ceftriaxone, vancomycin and metronidazole. On the 15th day of treatment, physical examination revealed a diffuse pruriginous maculopapular rash and fever, without palpable adenopathies. C-reactive protein was increased, eosinophil count was within normal range values and serologies for EBV and CMV were negative. An allergic reaction to ceftriaxone was suspected and the drug was discontinued by the 23rd day of treatment. Due to persistence of symptoms, the remaining 2 antibiotics were also discontinued 3 days later. Skin biopsy was suggestive of erythema multiforme and a course of systemic corticotherapy was started with resolution of symptoms. Skin prick tests and intradermal tests (IDT) with Ax/C, penicillin, cefuroxime and ceftriaxone were performed, using the maximal non-irritant dose, all of which were negative on immediate reading. 48 hours later, both the prick and IDT were positive for Ax/C as well as the IDT for ceftriaxone. How this report contributes to current knowledge Few nonimmediate reactions to cephalosporin are confirmed, due to the fact that most are caused by infections. Nonetheless, allergic reactions can occur even in young children, and in our case, the culprit agents were confirmed by a positive skin prick test on delayed reading. Skin prick tests and IDT with delayed readings seem to be useful in the evaluation of these reactions. P103 Betalactam-Induced Hypersensitivity: A 10-Years’ Experience Amel Chaabane, Haifa Ben Romdhane, Nadia Ben Fredj, Zohra Chadly, Naceur A Boughattas, Karim Aouam Faculty of Medicine/University hospital/University of Monastir, Monastir, Tunisia Keywords: Betalactam, Skin Tests, Diagnosis, Cross Reactivity Introduction Betalactams hypersensitivity remains overestimated because of the lack of an objective diagnosis tool leading to unjustified therapeutic alternatives This study has been performed in order to analyze the epidemiological, clinical and chronological features of betalactams hypersensitivity, to evaluate the skin tests value, and to establish a practical approach exploring such drug hypersensitivity. Method We included all adverse effects suspected to be induced by betalactams and notified to the pharmacovigilance unit of Monastir during 11 years. The drug imputability was established according to Begaud et al. method. Skin tests were performed as recommended by ENDA. Results Betalactms hypersensitivity was diagnosed in 168 patients. Almost all reactions were cutaneous mainly maculo-papular rashes. The severity was estimated at 11.3%. The delayed reactions occurred in 60.7% of cases. All reactions resolved after drug withdrawal. We identified 19 positive rechallenges. Skin tests were performed in 386 cases and were positive in 26.2% of them. Penicillins were implicated in 62.5% of cases. Almost all of immediate reactions were induced by penicillins. The hypersensitivity was selective to one betalactam in nearly half of cases. Cross-reactivity was objectified among penicillins in one third of cases, between cefotaxime and cefazolin in one case, between penicillins and cephalosporins in 19% of cases, involving piperacillintazobactam in two cases and imipenem in one case. Conclusion Through the current study, we have demonstrated that the betalactam hypersensitivity reactions are mostly delayed and non severe. The diagnosis was confirmed using skin tests which were useful not only in identifying the culprit drug but also in assessing cross reactivity. These findings have to be improved by the drug provocation test which is still not performed in our centre. P104 Cefazolin Hypersensitivity: Towards Optimized Diagnosis Astrid P. Uyttebroek1, Chris H. Bridts1, Antonino Romano2, Didier G. Ebo1, Vito Sabato1 1. University of Antwerp, Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and Antwerp University Hospital, Immunology, Allergology, Rheumatology, Antwerp, Belgium 2. Allergy Unit, Complesso Integrato Columbus, Rome, Italy; IRCCS Oasi Maria S.S., Troina, Italy Keywords: Drug Hypersensitivity, Cefazolin, Diagnosis, Skin Testing Introduction Correct diagnosis of cefazolin hypersensitivity is not straightforward, mainly because of the absence of in vitro tests and uncertainties associated with the optimal skin test concentrations. Cross-reactivity patterns involving cefazolin suggest that cefazolin hypersensitivity is an isolated hypersensitivity. Objectives: As a first objective of this study, we sought to confirm whether the application of a higher than 2 mg/mL test concentration could increase skin test sensitivity, and add to the diagnosis of cefazolin hypersensitivity. A second part of our study aimed at investigating the cross-reactivity between cefazolin and other β-lactam antibiotics. Method 66 patients referred to our outpatients’ clinic for diagnostic evaluation after experiencing perioperative anaphylaxis, and exposed to cefazolin, underwent skin testing with cefazolin up to 20 mg/mL. Patients exhibiting a positive skin test with cefazolin had a panel of skin tests with other β-lactams and, if indicated, graded drug challenges in order to study cross-reactivity. Results Increasing the skin test concentration from 2 mg/mL to 20 mg/mL identified an additional 7/19 (27%) patients, who would otherwise have displayed negative skin testing. The concentration was proven to be non-irritating in 30 cefazolin exposed control individuals in which an alternative culprit for peri-operative anaphylaxis was identified. Graded challenge testing, following negative skin testing, displayed that all the patients tolerated alternative β-lactam antibiotics. Of them, 11 individuals also tolerated an alternative cephalosporin, suggesting that cefazolin hypersensitivity (generally) is a selective allergy. Conclusion Increasing cefazolin skin test concentration up to 20 mg/mL benefits the sensitivity of diagnosis. Furthermore, our data further confirm that cefazolin hypersensitivity seems to be a selective allergy with good tolerance to other βlactam antibiotics. P105 Clavulanic Acid Allergy – Two Cases Report Anabela Lopes1, Joana Cosme1, Rita Aguiar1, Tatiana Lourenço1, Maria-João Paes1, Amélia Spínola-Santos1, Manuel Pereira-Barbosa2 1. Immunoallergy Department - Hospital de Santa Maria – Centro Hospitalar Lisboa Norte, Lisbon, Portugal 2. Immunoallergy Department - Hospital de Santa Maria – Centro Hospitalar Lisboa Norte; Faculdade de Medicina de Lisboa, Lisbon, Portugal Keywords: Clavulanic Acid, Delayed Reactions, Selective Reactions, ß-Lactams Introduction Beta-lactams (BL) are frequently prescribed antibiotics. Allergic reactions to BL can be immediate (IgE reactions) and non-immediate reactions (T cell reactions). There are two major types of BL allergic patients: cross-reactive patients that are allergic to common BL ring and selective patients, allergic to side chains. In the last years, several cases of clavulanic allergic patients were described. Frequently, the reactions to clavulanic acid (CL) are immediate and, until now, there are only reports of selective reactions to CL. Method The authors report two cases of unusual CL allergic patients. The patients were submitted to skin tests (ST) with penicilloylpolylysine (PPL), minor determinant mixture (MDM), amoxicillin (AX), CL (Diater laboratory), benzylpenicillin, ampicillin, cefuroxime, ceftriaxone, cefipime, determination of specific IgE to BL and oral provocation tests to alternative and culprit drugs. Results 1st case: male, 45 years old, presented to our allergy clinic with maculopapular rash, seven days after beginning treatment with amoxicillin-clavulanic acid (AX/CL) and ibuprofen for pharygintis. He had previously received AX/CL with good tolerance. Drug provocation with ibuprofen was performed with negative results. Specific IgE to BL were negative. ST with PPL, MDM, AX, benzylpenicillin and AX/CL were negative and the patient was performed an oral AX/CL drug provocation. On the 5th day after drug provocation, he developed a generalized maculopapular rash. ST with CL was performed with a positive late reaction in the intradermal test (20mg/mL) and a new drug provocation only with AX was negative then. 2nd case: female, 40 years old described 2 previous allergic reactions: generalized urticaria 10 minutes after the intake of one AX tablet at 36 years and an episode of anaphylaxis 5 minutes after one AX/CL tablet at 39 years. Specific IgE to BL were negative. ST with PPL, MDM, AX and CL and benzylpenicillin revealed positive results with a positive immediate prick test to AX and a intradermal test to CL (20mg/mL). ST and drug provocation with cefuroxime and ceftriaxone were negative. Conclusion The first case concerns a rare delayed reaction to CL. To the best of our knowledge, the second case describes the first case of positivity to both AX and CL. P106 Diagnosis Of Betalactam Allergy In An Allergy Department Cíntia Rito Cruz, Rute Pereira Dos Reis, Elza Tomaz, Ana Paula Pires, Filipe Inácio Serviço de Imunoalergologia, Hospital de São Bernardo, Setúbal, Portugal Keywords: Betalactam Allergy, Immediate Hipersensitivity Introduction Betalactams (BL) are still the most frequent drugs implicated in allergic reactions. All BL currently available may cause these reactions. Immediate hypersensitivity (IH) reactions usually appear within 1 h of drug intake and are mediated by specific IgE (sIgE) antibodies. They can be evaluated by different methods: clinical history, skin tests (ST), in vitro quantification of sIgE and drug provocation tests (DPT). The determination of sIgE has safety advantages over ST and DPT, but has low sensitivity. ST should be performed with PPL, MDM, penicillin G, amoxicillin and ampicillin. If these are all negative, a DPT should be executed to ultimately confirm or exclude allergy. Method Retrospective study that included patients who had undergone ST with PPL and MDM for investigation of BL allergy in 2014 and 2015. Data were then collected regarding the results of ST (PPL, MDM, penicillin G, amoxicillin, ampicillin and a cephalosporin), sIgE (penicillin G, penicillin V, ampicillin, amoxicillin and cefaclor) and DPT (to amoxicillin and/or a cephalosporin). Results One hundred and one patients (24% male), with a mean age of 42 years old. The suspected BL was: penicillin G (40), amoxicillin (37), cephalosporins (6), ampicillin (2) and unknown (16). Eleven percent of the patients had positive ST to PPL or MDM, with only 1 having positive sIgE. Five of these patients underwent ST with an alternative cephalosporin (cefuroxime): 2 were positive and 3 were negative. Two of these underwent DPT, that were negative. Out of 90 patients with negative ST to PPL and MDM, 55 were submitted to ST with ampicillin and/or penicillin G and/or amoxicillin, being positive in 7% of the patients; they all had negative sIgE. ST with amoxicillin didn’t add any extra information. Out of 84 patients with negative ST, 36 proceeded to DPT, which were positive in 6% of the cases. Twelve patients underwent ST with a cephalosporin, being positive in 2 (when the suspected BL was also a cephalosporin). IH to BL was confirmed in 19% of the cases. Conclusion Of the 19 cases of confirmed IH to BL, only 1 had positive sIgE, corroborating the extremely low sensitivity of the method. Only 19% of the suspected cases of BL IH were confirmed, emphasizing the importance to refer patients to an Allergy Centre for investigation. Some patients never concluded the BL allergy study, and some are still undergoing. We highlight the need for new less expensive and time consuming tests, which would also reduce the number of dropouts. P107 Diagnostic Work-Up Of 410 Patients With Suspicion Of Betalactam Antibiotic Hypersensitivity Filipe Benito-Garcia, Inês Mota, Magna Correia, Ângela Gaspar, Marta Chambel, Susana Piedade, Mário Morais-Almeida CUF Descobertas Hospital, Lisboa, Portugal Keywords: Adults, Beta-Lactams, Drug Allergy, Children, Skin Tests Introduction The aim of this study was to characterize the activity developed at our drug allergy outpatients’ center with patients (pts) referred with suspicion of hypersensitivity (HS) to betalactam antibiotics (BL). Method Retrospective analysis of clinical files, in vivo / in vitro test results and drug provocation tests (DPT) from January 2011 to December 2015. All pts were studied according to standardized diagnostic procedures of ENDA/EAACI: serum specific IgE (sIgE) (ImmunoCAP®,ThermoFisher) to penicillin G/V, amoxicillin and ampicillin; skin prick and intradermal tests (IDT) to PPL/MD (DAP®,Diater), penicillin G, amoxicillin and cefuroxime with immediate and delayed reading. Other penicillin derivatives / cephalosporins were tested if they were the culprit drug. DPT with culprit drug was performed if previous investigation was negative. In confirmed cases an alternative BL was tested. Results 410 pts with suspicion of HS to BL were included: mean age was 34.6 (SD±18) yrs, 21% had <18yrs and 68% were female. Penicillins/derivatives were the main culprit drugs (314 pts), mostly amoxicillin (229 pts), 149 in association with clavulanic acid. Cephalosporins were mentioned by 42 pts, namely cefazolin (15 pts). Mucocutaneous symptoms were the most frequent manifestations (81%); anaphylaxis occurred in 54 pts, 18 with loss of consciousness. HS to BL was confirmed in 88 pts (21.5%), all with a DPT negative to an alternative BL. HS was excluded in 289 pts (70.5%); 33 pts are under study. Confirmation of HS was made by: sIgE in 10 pts; skin testing in 65 pts and DPT in 13 pts (amoxicillin-11, clavulanic acid-2). Skin tests were positive to: amoxicillin-33, penicillin-16, PPL-15, MD-3, flucloxacilin-1 cefazolin5, cefuroxime-1. Delayed reading of IDT was positive in 7 pts: penicillin-3, amoxicillin-4. A systemic reaction during skin testing occurred in 13 pts, in 3 with anaphylaxis: one child during IDT with amoxicillin (2.5mg/mL) and 2 adults during IDT with amoxicillin (25mg/mL). Conclusion To investigate the suspicion of HS to BL is of outmost importance because in most of these pts allergological workup is negative and HS to BL is excluded. Although the majority of confirmed cases are IgE-mediated, in about one fourth a non-IgE mediated mechanism seems to be involved (positive DPT or positive delayed reading of IDT). Systemic reactions during IDT and DPT also reinforce the need of referral these pts to specialized centers. P108 Immediate Selective Hypersensitivity Reactions To Clavulanic Acid Alla Nakonechna1, Yurij Antipkin2, Tetiana Umanets2, Fernando Pineda3, Francisca Arribas3, Volodymyr Lapshyn2 1. Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, United Kingdom 2. Institute of Pediatrics, Obstetrics and Gynaecology, Kiev, Ukraine 3. Diater Laboratorios, Madrid, Spain Introduction Clavulanic acid (CLV) is b-lactamases inhibitor with weak antibacterial activity and low immunogenic capacity widely used in combination with beta-lactam antibiotics. Despite there is a number of reports of allergy to CVL in the combination with amoxicillin (AX-CVL), it is important to distinguish this kind of hypersensitivity as of the clinical implications of an amoxicillin allergy diagnosis. Method We present here 23 patients (14 women and 9 men, aged 23-62) with immediate hypersensitivity reactions to amoxicillin-clavulanic acid. Clinical symptoms occured within 30-60 minutes after AX-CLV intake and included urticaria/angioedema, bronchospasm and anaphylaxis. Skin prick and intradermal tests with: major determinant benzylpenicilloyl polyL-lysine (PPL-0.04 mg/mL), minor determinant mixture (MDM-0.5 mg/ml), CLV (20mg/ml) and amoxicillin (20mg/ml), all provided by Diater (Madrid, Spain), along with benzylpenicillin (10,000IU/mL; Normon SA), ampicillin and cefuroxime (20mg/ml; GlaxoSmithKline Beecham) were performed. In those cases with a positive skin test to CLV the AX-CLV (20/4 mg/ml) (GlaxoSmithKline Beecham) was also tested. Specific IgE antibodies against penicillin V, penicillin G, amoxicillin and ampicillin were measured by ELISA. Drug provocation test (DPT) with amoxicillin was performed in selective CLV hypersensitivity patients group. Results Specific IgE antibodies against penicillin V, penicillin G, amoxicillin and ampicillin were less than 0.35 UI/mL in all patients. Among 23 patients with immediate hypersensitivity reactions to AX-CLV only 2 patients (8.7%) had a positive skin test to benzylpenicillin determinants and 14 patients (60.8%) to amoxicillin. Among 7patients (30.4%) who had a positive intradermal test to selective CLV component and good tolerance to amoxicillin in DPT only 4 patients (17.4%) were detected by AX-CLV. Conclusion Our investigation show: Immediate selective hypersensitivity reactions to CLV found in around 30% of patients with immediate allergic reactions to AX-CLV combination. Although allergy to clavulanic acid is infrequent, this molecule should be used in diagnostic assessment when evaluating an immediate reaction to AX-CLV and conventional skin testing with benzylpenicillin and amoxicillin determinants are negative. Testing with selective CLV component is more sensitive and reliable than detection by AX-CLV for proving allergy to clavulanic acid. P109 PREVALENCE AND INCIDENCE OF PENICILLIN HYPERSENSITIVITY REACTIONS IN COLOMBIA Pablo Andrés Miranda, Bautista De La Cruz Hoyos Universidad Nacional de Colombia, Cartagena, Colombia Keywords: PENICILLIN, ALLERGY, HIPERSENSITIVITY Introduction Penicillin remains one of the most widely used antibiotics in the world. Hypersensitivity reactions are more common adverse effects to this antibiotic. Method Records with allergy status of penicillin (ICD-10 code Z880) and adverse effects to penicillin (ICD-10 code Y400) of Information System of Social Protection (SISPRO) between 2010 and 2014 were included. To determine the prevalence and incidence of AHR, population estimates from the National Statistics Department of Colombia (DANE) were used. Results 781 cases with allergy status of penicillin and adverse effects to penicillin (PHR) between 2010 and 2015 were identified. 148 cases were confirmed news diagnoses in the same period. On average 156 cases of PHR per year were estimated. The estimated annual prevalence PHR were 3.3 cases per million (2010= 4.3; 2011= 3.3; 2012=3.8; 2013= 2.7 and 2014= 2.7). The estimated annual incidence PHR were 0.4 cases per million (2010= 0.53; 2011= 0.43; 2012= 0.60; 2013= 0.55 and 2014= 0.25). Most cases it presenting in adult aged 60 years or younger, in children aged 5 years or younger and between 19 and 26 years age in 2010-2011; and in adult aged 60 years or younger and between 19 and 26 years age in 2012-2014. Conclusion Both under-diagnosis and over-diagnosis PHR are common in the world. Population studies with confirmatory tests PHR in Colombia are required. PREVALENCE PHR COLOMBIA Cases per million 1-5 años 6-9 años 10-14 años 15-18 años 19-26 años 27-44 años 45-59 años > 60 años Total INCIDENCE PHR 2010 COLOMBIA % (n) Cases per million 1-5 años 0.47 (2) 6-9 años 0.58 (2) 2010 %(n) 2011 %(n) 2012 %(n) 2013 %(n) 2014 %(n) 20.4 (12) 3.0 (35) 4.1 (13) 5.4 (14) 12.7 (24) 6.1 (45) 1.2 (39) 28.5 (13) 4.3 (195) 13.9 (17) 1.4 (24) 1.5 (6) 3.2 (5) 10.2 (14) 4.8 (36) 1.5 (31) 21.3 (17) 3.3 (150) 2011 % (n) 2012 % (n) 2013 % (n) 2014 % (n) 0.47 (2) 0.58 (2) 1.17 (5) 1.46 (5) 0.93 (4) 1.17 (4) 0.47 (2) 0.59 (2) 3.5 (26) 6.9 (33) 2.9 (32) 2.1 (6) 2.6 (9) 4.1 (9) 12.5 (18) 4.9 (44) 3.0 (32) 24.5 (34) 3.8 (178) 0.5 (12) 3.0 (5) 1.5 (2) 1.8 (13) 2.3 (5) 3.3 (6) 7.7 (10) 7.7 (14) 2.8 (27) 1.6 (19) 17.0 (19) 2.7 (127) 2.8 (27) 1.3 (19) 17.2 (15) 2.7 (131) 10-14 años 15-18 años 19-26 años 27-44 años 45-59 años > 60 años Total 1.36 (6) 0.91 (4) 0.23 (1) 0.92 (4) 0.00 (0) 1.70 (6) 1.13 (4) 0.28 (1) 1.14 (4) 0.00 (0) 0.16 (1) 0.31 (2) 0.46 (3) 0.15 (1) 0.30 (2) 0.09 (1) 0.18 (2) 0.26 (3) 0.09 (1) 0.17 (2) 0.44 (3) 0.28(2) 0.69 (5) 0.54 (4) 0.26 (2) 0.67 (3) 0.43 (2) 1.04 (5) 0.81 (4) 0.39 (2) 0.53 (24) 0.43 (20) 0.60 (28) 0.55 (26) 0.25 (12) P110 Selective Sensitization To Amoxicilin And Clavulanic Acid Jose Julio Laguna Martinez, Aranzazu Jimenez Blanco, Javier Dionicio Elera, Cosmin Boteanu, Rosario Gonzalez-Mendiola, Marta Del Pozo Allergy Unit.Hospital Central Cruz Roja, Madrid, Spain Introduction Beta-lactam (BL) antibiotics are the drugs most frequently involved in IgEmediated allergic reactions. Differences in the pattern of consumption are related with the specific BL involved in the allergic reactions and vary among countries and over the time. Since specific recognition of the amoxicillin (AX) side chain was described, a significant increase in the number of selective immediate reactions to AX and more recently selective reactions to Clavulanic acid (CLV) have been reported. Patients with allergic reactions after AX-CLV administration can react to either AX or CLV. No evidence of cross reactivity between CLV and other BL has been reported. Case Description We present an atopic 44 year-old man referred to our allergy unit due in 2008 he took amoxicillin 500mg/day as treatment for respiratory infection, 30 minutes after the first tablet he developed pharyngeal pruritus, cutaneous erythema and flushing following generalised itching and erythema. Method Skin prick test (SPT) and intradermal test (IDT) were performed using classic penicillin determinants, amoxicillin, ampicillin and clavulanic acid determinants according ENDA protocol. Total IgE and specific IgE (Thermo Fisher Scientific) with penicillin determinants (penicilloyl G, amoxicilloy, penicilloyl V and ampicilloyl) were performed Drug provocation Test (DPT) if skin and in vitro test were negatives As reaction was several years before, we performed second work up 1 month later. Results Total IgE 270 KU/L, Specific IgE with penicillin determinants were negative. Skin tests show positive results only to CLV (20 mg/ml IDT) DPT was positive to AX, 30 minutes after first dose (125 mg) patient developed pruritus, facial erythema and cutaneous rash in thorax and back DPT with BP following 3 days domiciliary intake was negative Second work up Skin tests show positive results only to CLV 20 mg/ml IDT DPT and with BP following 3 days domiciliary intake was negative again How this report contributes to current knowledge Conclusions We present a double selective sensitization to clavulanic acid and amoxicillin with tolerance to BP. We confirm that tolerance to BP is a stable phenomenon performing a second BP administration one month later, according recently studies, where selective patients tolerate subsequent administrations of other BL. Our exceptional case highlights the need to be aware of new patterns of betalactams sensitization. We recommend using AX and CLV separately for skin test P111 Infliximab-Specific T Cells Are Detectable Also In Treated Patients Who Have Not Developed Anti-Drug Antibodies Alessandra Vultaggio1, Francesca Nencini2, Sara Pratesi2, Andrea Matucci1, Enrico Maggi2 1. AOU careggi, Florence, Italy 2. Dept of Internal Medicine, Florence, Italy Introduction Infliximab (IFX) carries potential risk of immunogenicity, with the expansion of memory T cells and the production of anti-drug antibodies (ADA). Little is known about the possibility that sensitization to IFX may occur also in treated ADApatients. This study was aimed to evaluate whether IFX may be immunogenic in the latter group of patients. Method Seventy-one IFX-treated patients, including both ADA+ and ADA- patients were enrolled. Untreated patients and healthy donors were also selected as controls. Memory T cells was evaluated by the proliferation of drug-stimulated PBMC or co-cultures of IFX-pulsed DC plus autologous CD4+ T cells. Measurement of drug-induced cytokines production was performed in the culture supernatants by ELISA. Cytokines mRNA expression was also studied. Results T cell proliferation and cytokine production were mainly detectable in ADA+ patients, but cytokines were observed in about 25% of non-proliferating cultures as well. IL-10 was the most frequently detectable cytokine. Additionally, the proportion of patients expressing IL-10 mRNA in IFX-stimulated PBMC was significantly higher in ADA- than in ADA+ patients. IL-10 mRNA levels resulted higher in ADA- than in ADA+ patients. Anti-IL-10 mAbs were able to significantly increase both IFX-driven proliferation and expression of T cell-related cytokines in PBMC. Conclusion Cell sensitization to IFX may be detectable in a proportion of ADA- treated patients. Proliferation assay combined with cytokines evaluation may work better than the single test in evaluating cell sensitization. In ADA- patients IFX-induced IL-10 may overcome the effects of other T cell-related cytokines Poster Walk 13: Biologicals, Local anesthetics, others (P112 – P118) P112 A Case Report Of Allergic Immediate Systemic Reaction To Adalimumab And Certolizumab Ceyda Tunakan Dalgiç, Fatma Düsünür Günsen, Gökten Bulut, Fatma Ömür Ardeniz, Okan Gülbahar, Emine Nihal Mete Gökmen, Aytül Zerrin Sin, Ali Kokuludag Ege University Medical Faculty,Department of Allergy and Clinical Immunology, Izmir, Turkey Introduction Adalimumab, recombinant fully humanized anti-tumor necrosis factor (anti-TNF) antibody, had been using for the patients with inflammatory artritis and bowel diseases. Adverse reactions to adalimumab are limited mainly to injection site, immediate systemic reactions are very rare. Generalise skin reactions to this antibody are around 1%. Certolizumab is humanized from mouse, anti-TNF recombinant antibody with the same indications. Systemic adverse reactions to certolizumab is very rare, also. Case Description We report a 59-year-old woman with spondylartritisi (SpA) who was treated with adalimumab every two weeks for 4 years. At the 4th year, adalimumab was changed to prefilled ready to use form. 30 minutes after the first application of this form, local reaction and also vomiting, dispnea, laryngeal edema, hipotension with generalise itching happened. Than adalimumab was stopped. Therapy was changed to certolizumab pegol. 30 minutes after the first injection of certolizumab , she had nause, dizziness and visual disturbances without skin reactions. 15 days later she injected the second certolizumab dosage and the same reactions repeated. She was referred to allergy clinic. Skin prick test with 50 mg/mL of adalimumab was found negative. Intradermal test with (5 mg/ml) 1/10 dilusion was 10 /45 mm and 1/100 dilusion was 8/40 mm (histamin intradermal : 10 /50 mm).Both skin prick and intradermal tests with certolizumab pegol were negative. Depending on the uncertainty of her history about certolizumab, drug provocation test was administered with total therapy dose. No adverse or allergic reaction occured during provocation. The patient was continued certolizumab therapy seamlessly. Consent: Written informed consent was obtained from the patient for publication of this case report and any accompanying images. How this report contributes to current knowledge Although adverse systemic reactions to adalimumab are rare , we describe a immediate systemic reaction to adalimumab; fully humanized recombinant biological. We thought the reaction was not due to the new form, because the contents are completely same. Allergic reaction after changing the form seems to be coinsidental. Alternative monoclonal antibodies should be searched for those patients. P113 Allergy To Local Anesthetics: Negative Predictive Value Of Skin Tests Ivana Cegec, Danica Juricic Nahal, Viktorija Erdeljic Turk, Matea Radacic Aumiler, Ksenija Makar Ausperger, Iva Kraljickovic, Iveta Simic University Hospital Zagreb, Zagreb, Croatia Keywords: Local Anesthetics, Skin Test, Hypersensitivity, Negative Predictive Value Introduction Although true allergy to local anesthetics (LA) is rare, patients often report unwanted reactions after the administration of LA, requiring allergy consultations. Diagnosis of hypersensitivity reaction to LA is made after skin tests followed by exposition tests. The aim of this study was to determine the negative predictive value (NPV) of skin tests to LA. Method A retrospective chart review was performed on patients undergoing local anesthetic skin testing. A total of 50 patients tested for hypersensitivity to LA in the period from January to August 2015 at the Division of Clinical pharmacology at the University Hospital Zagreb were enrolled in this study. All patients underwent skin tests (‘prick’ and intradermal tests with 1:100 dilution) followed by incremental subcutaneous challenge with undiluted LA. Skin tests were performed with lidocaine, articaine, bupivacaine or articaine+adrenaline, while exposition was performed using mainly lidocaine. Telephone follow-up visits were performed during December 2015. On the basis of the follow-up results, the NPV of skin tests was calculated. Results Skin tests were performed using two or more LA (lidocaine in 50 patients, articaine in 35 patients, bupivacaine in 27 patients, articaine+adrenaline in 11 patients). All skin tests were negative. Subcutaneous challenge was performed with lidocaine in 41 pts, articaine in 7pts, bupivacaine in1pt, and articaine+adrenaline in1pt. All patients had negative subcutaneous challenge. In the follow-up period 20 pts received LA, 20 pts have not received LA while 10 pts were unavailable for follow-up. Of the patients who received LA after testing, 19 had no reactions during exposure while 1 pt experienced a severe hypertensive reaction with generalized exanthema. The NPV of skin tests to LA was 95%. NPV for subcutaneous challenge tests was not calculated due to incomplete data on specific LAs used in subsequent exposures. Conclusion Skin tests to LA are safe and have an excellent negative predictive value which allows the selection of a local anesthetic that can be safely administered in the future. P114 Cutaneous Adverse Reactions Of Molecular Targeted Agents -A Retrospective Analysis In 150 Patients In Our DepartmentYukie Yamaguchi, Tomoya Watanabe, Megumi Satoh, Tomohiko Tanegashima, Kayoko Oda, Hidefumi Wada, Michiko Aihara Yokohama City University Graduate School of Medicine, Yokohama, Japan Keywords: Molecular Targeted Agents, Biologics Introduction Molecular targeted agents are widely used in various inflammatory and immune diseases and tumors. Differently from adverse reactions induced by conventional drugs, these drugs demonstrate various new types of adverse reactions. Some of events may be induced by cross-reactions related to the expression of the same antigen on different tissue. Immune imbalance caused by a depletion of specific antigen may be a trigger of unpredictable reactions. It is important to know the prevalence, clinical types, and severity of the side-effects in each drugs. Method We retrospectively analyzed patients who visited our department due to cutaneous adverse reactions caused by molecular targeted agents from 2010 to 2015. Types of drugs, clinical features of cutaneous adverse reactions, and subsequent outcome were evaluated. Results One hundred and fifty patients were evaluated in this study. High frequency agents were EGFR inhibitors (63%), multikinase inhibitors (8%), TNF-a inhibitors (6%), and programmed death-1 (PD-1) inhibitors (5%). Regarding clinical phenotypes, acneiform eruptions and perionychia were highly observed (68%) mainly caused by EGFR inhibitors as the target antigen EGFR is also involved in skin homeostasis. Maculopapular drug eruption (10%) and hand-foot syndrome (7%) were observed in users of multikinases inhibitors and EGFR inhibitors. Of note, systemic drug eruption (erythroderma, erythema multiforme, maculopapular) was highly observed in patients treated with multikinase inhibitors. Psoriasis-like and palmoplantar pustulosis-like eruptions (5%) were caused by TNF-a inhibitors and IL-6R inhibitors. Although the frequency was low, lupus-like reaction, vitiligo, and other unexpected reactions were caused by inhibitors of TNF-a or PD-1, supposedly those inhibitors lead to immune imbalance further causing autoimmunity and inflammatory reactions. As for the outcome, 85% of patients continued molecular targeted agents, while 15% of patients required discontinuation of the drug. Conclusion Predicteable cutaneous reaction, like acneiform eruptions by EGFR inhibitors, would be possible to manage without discontinuation of the drug. Some drugs, such as immune checkpoint inhibitors, may cause unexpected immune responses. Since adverse reactions of molecular targeted agents are variable depending on drugs. It is important to recognize the function of targeted antigen, and close monitoring is recommended P115 Generalized Paralysis Induced By Local Lidocaine Injection Jaechun Jason Lee, Jay Chol Choi, Hwa Young Lee Jeju National University School of Medicine, Jeju, South Korea Introduction Local anesthetics, such as lidocaine, are widely used for numbing. Adverse drug reactions related to lidocaine are variable, unpredictable, and rarely reproducible, with the exception of some typical cases. Case Description A 42-year-old female who had shown a bizarre neurological reaction after lidocaine injection for dental procedures was referred for diagnosis and safe anesthetic alternatives. Within a few minutes after exposure to lidocaine, she was unable to move any extremity, or to speak, while sensory and high cranial nerve functions were preserved. She was alert and able to communicate with eye blinks. This reaction was repeatedly reproduced after intradermal injection of 2% lidocaine, with complete recovery within 1 h without treatment. No crossreactivity with mepivacaine and bupivacaine was observed. How this report contributes to current knowledge This is the first report of immediate and transient generalized paralysis related to lidocaine. P116 HYPERSENSITIVITY TO LOCAL ANAESTHETICS – A TEN YEAR REVIEW Rosa-Anita Rodrigues Fernandes1, Emília Faria1, Joana Pita1, Nuno Sousa2, Carmelita Ribeiro3, Isabel Carrapatoso1, Ana Todo Bom1 1. Allergy and Clinical Immunology Department, Coimbra University Hospital Center, Coimbra, Portugal 2. Allergy and Clinical Immunology Consult, Leiria Hospital Center, Leiria, Portugal 3. Coimbra University Hospital Centre, Coimbra, Portugal Keywords: Local Anaesthetics, Hypersensitivity Introduction True allergy to local anaesthetics (LA) is uncommon. Allergic reactions account for less than 1% of all adverse reactions. Immediate reactions are rare. The aim of this study was to describe the main characteristics of the population with confirmed LA allergy among patients referred to our outpatient clinic for suspected hypersensitivity (HS) to LA. Method Retrospective analysis of the medical files of patients with suggestive history of immediate HS reactions to LA, referred to our outpatient centre between January 2006 and December 2015. In order to confirm the diagnosis, we conducted skin prick tests and subcutaneous drug provocation test (DPT) with the undiluted commercial solution of the culprit or an alternative LA. DPT was performed in increasing doses, every 15 minutes, up to a cumulative dose of 3.6ml. Sensitization to latex was excluded. Results A total of 65 patients with history of an adverse reaction to LA underwent DPT, 75% female with a median age of 44 years (±17.4). Only 5 patients (7.7%) had positive DPT (lidocaine in 2 patients, mepivacaine in 2 patients and ropivacaine in 1 patient). Of those patients, 60% were female and the median age was 35 years (±20.6 years). Sixty percent of the patients had past history of multiple surgical interventions (with general anesthesia) and allergic diseases, asthma and rhinitis being the most frequent. Cutaneous symptoms (urticaria and angioedema) were the main manifestation, in 4 patients (66%). There was no registry of severe adverse reactions. All reactions started within 2 hours following LA application and regressed spontaneously without any treatment. Sensitization to both lidocaine and mepivacaine was determined in 2 patients. Comorbidities such as hypertension (2 patients), diabetes (1 patient) and thyroid disease (1 patient) were also seen. Eighty three percent of these reactions occurred during dental procedures and 60% of these after administration of lidocaine. Conclusion As stated in other studies, we find a low positivity rate to DPT. And our findings were similar to those found in the literature: adverse reactions to LA are more prevalent in the mid-age and with cutaneous symptoms being the most frequent manifestation of HS. Although rare, consequences of true allergy to local anaesthetics can be serious, considering a patient’s future management and therapy. P117 Local Anaesthetics: A Rare Culprit In Hypersensitivity Reactions Ana Rodolfo, Eunice Dias-Castro, Josefina Cernadas Centro Hospitalar de São João, Porto, Portugal Keywords: Local Anaesthetics, Local Anaesthetics Hypersensitivity Introduction Local anaesthetics (LA) are widely used drugs with an exceptional benefit-risk profile. Adverse reactions are scarce. Hypersensitivity reactions are especially rare, accounting for less than 1% of all adverse reactions. When a reaction occurs, an allergy work-up should be performed in order to exclude an allergic reaction or to identify an alternative drug. Method Retrospective analysis of data from patients referred to our drug allergy unit with suspected LA allergy in the past 5 years. The analysis was performed using SPSS, version 21. Results We studied 47 patients for suspected LA allergy (83% females, with median age 49, and interquartile range 23). Six patients were atopic. Thirty six % of patients were referred by their family physician and 26% by dentists. Of the 47 patients, 38% had a suspected reaction during a dental procedure, 14% had positive patch tests with LA and 13% had peroperative anaphylaxis. Considering the patients who had a suspected reaction,74% had immediate reactions. In 49% of these cases, there was mucocutaneous involvement, 33% had respiratory symptoms and 33% vasovagal response. The LA used was known in 70% of these cases, none of them were an ester. Lidocaine was the culprit in 20 cases, mepivacaine in 5, articaine in 5 and ropivacaine in 4. Skin prick tests (SPT) and intradermal tests (ID) were performed with validated concentrations, without vasoconstrictor. Only 2 patients had positive tests: 1 positive SPT to mepivacaine and one positive ID to procaine; the other patient had a positive ID to ropivacaine. All 45 patients with negative skin tests were submitted to subcutaneous challenges that were negative. None of the patients referred because of positive patch tests to LA had a positive study. Conclusion The majority of adverse reactions to LA may be attributed to non-immune mediated mechanisms, pharmacologic, psycho or neuro-vegetative reactions. When LA are used, the patients are usually under stress. Our experience is in agreement with literature since hypersensitivity was excluded in the majority of the patients with suspected LA reactions. P118 Stevens-Johnson Syndrome In Clinical Practice: A Variant Of Clinical Course MARINA Voronova State Hospital 52, Moscow, Russia Keywords: Stevens-Johnson Syndrome, Clinical Case Introduction A 44 year-man was urgently admitted to our allergy clinic with complaints of pain in the area of scrotum, painfulness in oral cavity, rash on hands, eyelids and foot. Anamnesis excerption: Alcohol abuse for a long time. About two years ago, following one of patient’s drinking-bouts, episode with loss of consciousness emerged, qualified as secondary epilepsy; carbamazepine was administered. The patient described vesicular rash on lips and hands following the carbamazepine medication; he did not seek medical attention, though. The therapy was cancelled. Within two weeks the skin rash passed. The present episode had also been related with a prolonged period of alcohol ingestion, whereupon a detoxification treatment was administered, and, taking into account the possibility of episyndrome, carbamazepine was ordered, too. On the second day vesicular rash appeared on hands, thereupon in the scrotum area, on eyelids and on mucous tunic of mouth, forcing the patient to seek medical attention. Condition on admittance: of moderate gravity. Rash on hands with big serous fluid-filled vesicles; negative Nikolsky symptom. There were erosion with diapedetic bleeding and scrotal oedema in the area of scrotum and penis. Cheilitis, multiple aphthae on the internal surface of cheeks, on hard and soft palate and on tong were revealed, as well as haemorrhagic crustings on eyelids, moderate injection in scleral vessels. Physical state: with no specific findings. Systemic glucocorticoids and antihistamine preparations were administrated, as well as antibacterial, infusion therapy and topical treatment. On the second day a total relief of diapedetic bleeding in the scrotal area was achieved. To the end of the 10th day a total epithelization in the area of penis and scrotum occurred. Aphtae on hard and soft palate relieved totally within the first three days. Laboratory results have shown increasing levels in circulating thrombocytes according to the relief of diapedetic bleeding. Maximal levels were attained by the 6th day (667 *109/L) with the following return to normal values. On admission C-reactive protein levels were elevated up to 136.65 mg/L, by the 7th day they returned to normal values. No eosinophilia or leukocytosis had been revealed. The described case represents a favorable variant of clinical course of carbamazepine intolerance, with a quick epithelisation, and no injury in liver, kidneys or blood islands. Method Results Conclusion - Poster Walk 14: RCM (P119 – P128) P119 13 CASES OF SEVERE ANAPHYLACTIC REACTIONS DUE TO RADIOCONTRAST MEDIA Jaume Martí Garrido, Ramon Lopez Salgueiro, Diana Kury Valle, Verónica Pacheco Coronel, Carolina Perales Chordá, Dolores Hernandez Fernandez De Rojas IIS La Fe, Valencia, Spain Introduction The increasing use of radiocontrast media (RCM) is associated with an increase in adverse reactions with these preparations. Method We revised a total of 249 cases referred during 2012-2014 for allergic evaluation due to adverse with RCM. We collected information about the radiological procedures, adverse reactions and results of allergy study of patients who developed severe anaphylactic reactions. Results We analysed 5 men and 8 women with an average age of 63 years (37-86). In 69% respiratory symptoms were reported, 62% neurological, 54% cutaneous, 31% cardiovascular and 31% digestive symptoms. 31% complaint of subjective symptoms (general discomfort, heat or flushing). The reaction was immediate (within minutes) in 69% of cases. One patient required admission to the intensive care unit and another had a repeated episode of anaphylaxis after readministration of RCM despite of the premedication. In 4 cases the reaction occurred during a computed tomography (CT), in 4 with intravenous urography (IVU), and 3 with magnetic resonance (MR). In 2 cases the radiological procedure was not specified. In 2 of the 13 patients (15%), intradermal tests were positive with the RCM involved: iomeprol and dimeglumine gadopentetate. The basophil activation test (BAT) with the RCM was positive in 4 cases: 2 with iomeprol and iodixanol, 1 with iopamidol and 1 with gadobenate and gadopentate. Conclusion TC and IVU were the most frequently involved radiological procedures. Respiratory symptoms were the most common clinical manifestations. Skin tests and BAT helped to identify the agents responsible for the reactions. The sensitivity and specificity of these tests are still undetermined. P120 Anaphylactic Shock After Administration Of Iodinated Contrast Medium During Cardiac Catheterization Roselle Catherine Yu Madamba, Marta Ferrer, Maria Jose Goikoetxea, Carmen D´ Amelio, Amalia Bernad, Olga Vega, Gabriel Gastaminza Clinica Universidad de Navarra, Pamplona, Spain Introduction Iodinated contrast media (ICM) are one of the most commonly used in the field of diagnostic medicine today. Though considered generally safe, they can cause hypersensitivity reactions that can either be immediate or nonimmediate. Anaphylactic shock reactions to ICM are rare but serious and could be life threatening. Hence, urgent and timely treatment should be administered. Case Description We present a case of a 64 year old hypertensive patient with ischemic cardiopathy who presented with intense cephalic heat, tachycardia, hypoxemia and hypotension of 50/30mmHg without any cutaneous lesions immediately after the administration of 35 grams of Iomeprol contrast medium for cardiac catheterization. Epinephrine IM, Dexchlorpheneramine and corticosteroid IV and intravenous fluid therapy were administered which afforded the reversal of the hypotension. The tryptase at the time of the reaction and 2 hours post reaction were both elevated, 85.70ug/L and 88.70ug/L respectively. Baseline tryptase was normal (6.86ug/L). Skin prick test and basophil activation test to different contrast media were negative while intradermal test to Iomeprol showed a positive result and negative to Iohexol, Iodixanol and Meglumine. Thus, challenge test to Iodixanol reaching a total dose of 47 grams as an alternative medium was done which he tolerated well. One month later, the patient underwent another cardiac catheterization. However, 10 minutes after the administration of 15 grams of Iodixanol, he presented another episode of anaphylactic shock. He was given the same medications he had received previously which reversed the anaphylactic shock. Tryptase level was positive (30.20 ug/L). Due to the episode of anaphylactic shock, the contemplated cardiac catheterization was discontinued. Skin tests the next day resulted positive to Iohexol, Iodixanol and Iomeprol. How this report contributes to current knowledge Despite that the patient tolerated well the challenge test with Iodixanol and skin test was negative, possible hypersensitivity reactions can still occur. Although challenge test is considered the gold standard in drug allergy, it can also provoke sensitisation to the drug or increase the sensitivity that could not be detected prior due to cross reaction. As of the present, the pathophysiological mechanism of these allergic reactions still needs to be exemplified. P121 ANAPHYLACTIC SHOCK AND CARDIAC ARREST INDUCED BY GADOLINIUM-BASED CONTRAST AGENTS Beatriz Pola Bibián, Marina Lluncor Salazar, Gemma Vilà Nadal, Ana María Fiandor Roman, Javier Dominguez Ortega, Miguel Gonzalez Muñoz, Santiago Quirce Gancedo, Maria Rosario Cabañas Moreno La Paz Hospital, Madrid, Spain Keywords: Paramagnetic Contrast Agents, Anaphylaxis Introduction Gadobenate Dimeglumine and Gadoteric Acid are two gadolinium-based contrast agents that enhance the contrast images obtained by magnetic resonance imaging. Allergic reactions to them are rare. Method We report two cases of IgE-mediated anaphylactic shock, induced by these gadolinium-based contrast agents and documented by positive allergy assessment. The first case is a 26-year-old woman with no previous drug allergy who developed dizziness, generalised erythrodermia and throat tightness, when a nuclear magnetic resonance with MultiHance (Gadobenate Dimeglumine) was being performed. On physical examination, she had hypotension, tachycardia, tachypnea, 69% of basal oxygen saturation and generalized pulmonary hypoventilation. She recovered after treatment with corticosteroids and adrenaline. Nine months later the patient was referred to the allergy unit. The second case is a 51-year-old woman with a history of high blood pressure treated with betablockers, rhinoconjunctivitis and asthma due to sensitization to house dust mites and dog dander. Immediately after the intravenous infusion of Dotarem (Gadoteric Acid) she developed dizziness, loss of consciousness and cardiac arrest. On physical examination, she had universal rash without wheals, 90% of basal oxygen saturation and generalized wheezing. CPR was started and 1mg of Adrenaline was administrated. She recovered after 15 minutes and was admitted to the ICU. Two months later she was referred to the allergy unit. Results Case 1: Basal serum tryptase was normal. Skin prick tests (SPTs) were positive with Gadobenate Dimeglumine and negative with other paramagnetic contrasts agents and latex. The patient tolerated a MRI with Gadobutrol two years later. Case 2: Basal serum tryptase was normal. Basophil activation test (BAT) was positive with Gadoteric Acid, and negative with other paramagnetic and iodinated contrast agents. Conclusion We report two cases of an anaphylactic shock, one with cardiac arrest, immediately after the intravenous infusion of a paramagnetic contrast agent. Positive SPTs to Gadobenate Dimeglumine and positive BAT to Gadoteric Acid suggest an IgE-mediated mechanism. Hypersensitivity reactions with paramagnetic contrasts are very unusual. There are few cases with positive SPTs or BAT reported in literature. We should take into account that SPTs and BAT can be helpful to identify the responsible agent and the alternative contrasts that could be administered safely to the patient in the future. P122 Anaphylaxis To Gadobenate And Cross-Reactivity To Other Gadolinium-Based Contrast Agents In Two Patients Kathrin Scherer Hofmeier Allergy Unit, Department of Dermatology, University Hospital Basel, Basel, Switzerland Keywords: Anaphylaxis, Gadolinium, Gadobenate Introduction The frequency of adverse reactions to gadolinium-based contrast media is estimated to be 0.07%-2.4%. True allergic hypersensitivity reactions are very rare, presenting usually as urticarial exanthems of minor severity. The reported incidence is 0.004%-0.007%. Severe life-threatening reactions were extremely rare (0.001%-0.01%). Prior allergic reactions to gadolinium contrast media (GCM) are considered risk factors for new sensitizations to other GCM. We report on two female patients with severe immediate type reactions to Gadobenate, with cross reactivity to other GCM. Method Patient 1 (48 yrs): An MRI with Gadobenate was performed for diagnosis of pancreatitis. Immediately after application of the GCM she developed generalized itch and erythema, dyspnoea and cardiac arrest after 10 min. Mechanical and drug resuscitation was successfully performed. No definite prior exposure. Patient 2 (74 yrs): MRI with Gadobenate was performed for cardiac diagnostics. Within few minutes after application of the drug she developed a generalized sensitization of head, erythema, dysphagia, dyspnoea and swelling of the tongue. Prior exposure to an unknown GCM. Results Pricktests were negative for Gadoterate, Gadobutrol, Gadoxetate and Gadopentetat in both patients. Gadobenate was postive in patient 2. Intradermaltests were positive for Gadobenate and Gadobutrol in both patients, and Gadoxetate, Gadoterat and Gadopentetat in patient 1. Mastcell tryptase and Basophil activation tests were normal/negative in both patients. Conclusion We report on two cases of rare severe hypersensitivity reactions to Gadobenate with skin test cross-reactivity to Gadobutrol in both patients, and further GCM in one patient. Gadopentetat, a linear non-ionic GCM, was skin test negative in both patients, whereas the linear ionic culprit Gadobenate was cross-reactive with the cyclic Gadobutrol in both patients, and cross-reactive to other linear ionic and cyclic GCM in patient 1. P123 Anaphylaxis To Glatiramer Acetate In A Patient With Multiple Sclerosis Fabrícia Carolino1, Vladyslava Barzylovych2, Josefina R Cernadas1 1. Serviço de Imunoalergologia, Centro Hospitalar São João E.P.E., Porto, Portugal 2. Serviço de Imunoalergologia, Centro Hospitalar São João E.P.E., Porto, Portugal; Drug Allergy Diagnostics Centre, Institute of Paediatrics, Obstetrics and Gynaecology of NAMS, Kiev, Ukraine Introduction Glatiramer acetate (GA) or Copaxone®(marketed by Teva Pharmaceuticals Europe B.V.) is an injectable immunomodulatory treatment approved for relapsing-remitting multiple sclerosis (MS) in preventing relapses and slowing the disability progression. Rare cases of hypersensitivity reactions to this drug have been published in the literature. The authors describe a case of systemic symptoms associated with GA and the diagnostic workup of the patient. Case Description The authors report the case of a 34 year-old woman diagnosed with MS in 2008, initially treated with interferon-β1a (Avonex®). As relapses were frequent despite treatment, this was changed in January/2013 to natalizumab (Tysabri®), which is a monoclonal antibody (α4-integrin antagonist) with similar therapeutic indications to those described for GA. After 12 months of treatment, natalizumab was stopped because the patient developed persistent anti-drug antibodies. Considering that the patient was planning a pregnancy a new treatment (with GA) was started in March/2015. Four months later, the patient presented a generalized skin-burning sensation, dyspnoea and palpitations, 1 minute after GA administration with no additional signs or symptoms. At this point, the patient was referred to our Drug Allergy Department for assessment. Skin tests were performed with GA plus the inactive ingredient of Copaxone® with allergenic potential, mannitol; the dilutions were prepared with saline solution. For skin prick tests we used GA 20 mg/ml in the 1/100, 1/10 and 1/1 dilutions, and mannitol 100 mg/ml (undiluted). Intradermal tests were performed with 1/1 000 000 to 1/10 dilution of GA (20 mg/ml), with a strong positive result at 1/10 concentration. Intradermal test to mannitol (1/10 dilution) was negative. How this report contributes to current knowledge We also tested three (2 atopic and 1 non-atopic) controls for GA at 1/10 dilution with negative results. These results point to an underlying immunological mechanism in this case. A desensitization approach with GA might be considered for this patient. P124 Delayed Hypersensitivity Reaction To Radiocontrast Media Fabrícia Carolino1, Diana Silva2, Leonor Leão1, Josefina R Cernadas1 1. Serviço de Imunoalergologia, Centro Hospitalar São João E.P.E., Porto, Portugal 2. Serviço de Imunoalergologia, Centro Hospitalar São João E.P.E.; Laboratório de Imunologia, Faculdade de Medicina, Universidade do Porto, Porto, Portugal Introduction Iodinated contrast media (ICM) may associate with different types of adverse events including allergic and non-allergic hypersensitivity reactions as defined by the European Academy of Allergy and Clinical Immunology. Immune-mediated reactions are either immediate or non-immediate reactions that become apparent later than 1 h (and up to several days) after exposure and these are less frequently reported. Case Description The authors report the case of a 46 year-old woman, with history of Hodgkin’s lymphoma, evaluated in our Drug Allergy Unit for two suspected hypersensitivity reactions to ICM. In 2014, the patient underwent a contrasted CT scan with iomeprol (Iomeron®) and 72h later developed a generalized pruritic micropapular exanthema that resolved completely in a week (with antihistamine and corticosteroid medication). She had been previously exposed to ICM with tolerance. In 2015, a new high-resolution CT scan was performed using the same ICM (iomeprol), and again a diffuse pruritic exanthema developed (6h later) but this time with facial angioedema and fever (39ºC); the symptoms resolved in 4 days under medication (antihistamine and corticosteroid), leaving residual purplish lesions that eventually disappeared (after weeks). Skin prick tests with idopovidone (Betadine®), and undiluted ioversol (Optiray®), iobitridol (Xenetix®), iopromide (Ultravist®) and iomeprol (Iomeron®) were negative. Intradermal tests were performed with 1/100 and 1/10 dilutions of ioversol (Optiray®), iobitridol (Xenetix®), iopromide (Ultravist®) and iomeprol (Iomeron®); immediate reading was negative for all tested ICM but late reading (at 48h) was positive to ioversol (Optiray®) and iomeprol (Iomeron®) in both dilutions. How this report contributes to current knowledge The results confirmed a delayed hypersensitivity to ICM, with cutaneous crossreactivity between ioversol and iomeprol. P125 Drug Reaction With Eosinophilia And Systemic Symptoms Induced By Iodixanol Gemma Vilà-Nadal1, Beatriz Pola1, Marina Lluncor1, Ana Fiandor2, Teresa Bellón3, Javier Domínguez2, Santiago Quirce2 1. Allergy Department. La Paz Hospital Institute for Health Research (IdiPAZ), Madrid, Spain 2. Allergy Department. La Paz Hospital Institute for Health Research (IdiPAZ), Consorcio Piel en RED, Madrid, Spain 3. Immunology Department. La Paz Hospital Institute for Health Research (IdiPAZ), Consorcio Piel en RED, Madrid, Spain Introduction We describe a case of a Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) following a coronary catheterization with iodixanol.Late reactions to iodinated contrast media are frequent.We describe the tests used for the diagnosis in this case. Case Description Method:We report a case of a 74-year-old man admitted to the coronary unit with cardiac arrest.A cardiac catheterization was performed without complications.Three days later he received another cardiac catheterization and within 24 hours he presented a generalized maculopapular exanthema with pruritus and facial angioedema. Over the next few days the body temperature rose up to 38,5º C. Blood tests showed eosinophilia (1200 per mcL), total white blood cell count 19000/mcL, neutrophils 16700/mcL, renal impairment (creatinine 1,89mg/dL, previously being normal).The contrast used for catheterization was iodixanol. The patient also received ticagrelor, carvedilol, enalapril, furosemide, fondaparinux and lorazepam. Assessment of causality was established using the Spanish Pharmacovigilance System Algorithm. Results were (+6) “probable” for iodixanol and (+4) “possible” for carvedilol and ticagrelor. A multidisciplinary group composed by a dermatologist; a pharmacologist and an allergist evaluated the patient. This case was included in the Piel en RED registry. Six months after the reaction the patient was referred to the allergy unit and tests were performed. The allergy study included epicutaneous tests and the lymphocyte transformation test (LTT) according to Pichler et al. An stimulation index (SI) was calculated. Results: The diagnosis of a “probable” DRESS was established according to the scoring system described by Kardaun et al. Our patient received a score of 4. A skin biopsy showed spongiotic dermatitis with eosinophils. The patient had a positive LTT to iodixanol; the SI was over 8 in two concentrations. LTT showed also positive results for other iodinated contrast media. We also tested carvedilol and ticagrelor with a lightly positive result. Epicutaneous test showed remarkable positivity to iodixanol beginning at the 48 h reading. The test was negative to carvedilol, iobitridol and iomeprol. How this report contributes to current knowledge LTT and patch test were useful to identify this agent as responsible for the reaction. DRESS requires a multidisciplinary approach and an allergy study is essential to determine the etiology of the disease. P126 Electronic Consultation Support System For Radiocontrast Media Hypersensitivity Changes Clinician’s Behavior Min-Suk Yang1, Sun-Sin Kim2, Sae-Hoon Kim3, Hye-Ryun Kang4, Heung-Woo Park4, Sang-Heon Cho5, Kyung-Up Min5, Yoon-Seok Chang3 1. Seoul National University Borame Hospital, Seoul, South Korea 2. Seoul National University Hosptial Healthcare System Gangnam Center, Seoul, South Korea 3. Seoul National University Bundang Hospital, Seongnam, South Korea 4. Seoul National University Hosptial, Seoul, South Korea 5. Seoul National University College of Medicine, Seoul, South Korea Keywords: Drug Hypersensitivity, Radiocontrast Media, Clinical Decision Supporting System Introduction Patients with a previous history of radiocontrast media (RCM) hypersensitivity could be overlooked, resulting in repeated reactions. To avoid this, 'consultation support system for RCM hypersensitivity' has been embedded to Seoul National University Bundang Hospital (SNUBH) since Dec 2011. We analyzed the influence of this system on doctors' practice pattern. Method A retrospective study was conducted with the patients with previous RCM reactions (Dec 1st 2010-Nov 30th 2012). Control period was between Dec 2010 and Nov 2011 and intervention period was Dec 2011 and Nov 2012. Primary outcome was composite outcome of premedication and consultation. Premedication was defined as the preventive medication prescribed by the doctor who ordered RCM enhanced CT (CT) at the same time. Secondary outcomes were the recurrence rate after the consultation support system and ther rate of premedication using systemic steroid for those with previous history of moderate to severe RCM reactions. Results In the control period, 189 clinicians prescribed 913 CT scans and 225 clinicians did 1,153 examinations in the intervention period. The odds of achieving composite outcome increased significantly after the consultation support system (OR 1.54, 95% CI 1.15-2.05). Clinicians in both medical (OR=1.48, 95% CI 1.06-2.07) and surgical (OR=2.07, CI 1.24-3.46) part showed significant changes in their behavior, but emergency department did not (OR=1.07, 95% CI 0.41-2.78). Professors (OR=1.47, 95% CI 1.06-2.04) and trainees (OR=1.97, 95% CI 1.22-3.18) showed significant changes in their behavior to the patients with previous RCM reactions. The rate of premedication using systemic steroid for the patients with previous history of moderate to severe RCM reactions did not changed significantly (OR=1.68, 95% CI 0.70-0.404). The results of analyses with 86 clinicians who ordered CT scans during both control and intervention periods were not altered. Conclusion The consultation support system for those with previous RCM hypersensitivity reactions changed doctor's practice patterns and decreased recurrent RCM hypersensitivity reactions as well. P127 Hypersensitivity Reactions To Iodinated Contrast Media: Skin Testing And Follow-Up Danica Juricic Nahal, Ivana Cegec, Viktorija Erdeljic Turk, Iva Kraljickovic, Matea Radacic Aumiler, Ksenija Makar Ausperger, Iveta Simic University Hospital Zagreb, Zagreb, Croatia Keywords: Iodinated Contrast Media, Hypersensitivity, Skin Test, Follow-Up Introduction Iodinated contrast media (ICM) are frequently used to enhance radiological procedures. Hypersensitivity reactions to ICM can be classified as immediate or nonimmediate. Skin tests have been performed in the diagnosis of both types of reactions to ICM. The sensitivity of skin tests has not been adequately validated. Method A retrospective chart review was performed on patients (pts) undergoing ICM skin testing. A total of 45 pts tested for ICM allergy at the Division of Clinical Pharmacology at the University Hospital Zagreb between July 2014 and October 2015 were enrolled. All pts underwent skin tests (prick test and intradermal test with immediate and delayed reading) to iohexole and/or iodixanole. Pts were contacted during December 2015 and questioned about exposure to ICM after testing. Eligible pts (n=40) were classified into 3 groups: nonimmediate or immediate hypersensitivity reaction to ICM, and previously unexposed group. Results The nonimmediate group comprised 15 pts with hystory of exanthema (53.3%), urticaria (20%), angioedema (13.3%) and pruritus (6.7%) to ICM. One pt had positive skin tests to iodixanole and negative to iohexole. All other performed tests were negative. In the follow-up period 4 pts were exposed to ICM without adverse reactions; 10 pts were not exposed to ICM; 1 pt was unavailable for follow up. The immediate group comprised 11 pts with hystory of gastrointestinal symptoms (27.3%), urticaria (27.3%), angioedema (18.2%), general symptoms (18.2%) and flush (9.1%) to ICM. One pt tested positive to iohexole. All other performed tests were negative. In the follow-up period 7 pts were exposed to ICM; 6 pts experienced no adverse reactions; 4 pts were not exposed to ICM and 1 pt developed angioedema. The previously unexposed group comprised 14 pts. All skin tests were negative. The reason for referral to ICM testing was a hystory of serious allergic reaction to different allergens. In the follow-up period 5 pts were exposed to ICM without adverse reactions; 4 pts were not exposed to ICM; 5 pts were not available for follow up. Conclusion Overall, 16 pts were exposed to ICM in the follow-up period and of those, 1 pt developed an immediate reaction. The calculated negative predictive value in this study is thus 93.8%. This study adds further knowledge to the field of ICM hypersensitivity. Studies including follow-up data on sebsequent ICM exposure are needed in order to adequately validate ICM skin tests. P128 Would Iodine Allergy Exist? Clémence Delahaye, Jenny Flabbee, Julie Waton, Olivia Bauvin, Annick Barbaud Dermatology and Allergy department, Brabois hospital, University hospital of Nancy, Lorraine University, 54500 Vandoeuvre-Lès-Nancy, France Keywords: Allergy - Iodine - Multiples Reactivity Introduction Allergies to povidone iodine (PVI) are related to povidone (PV), those due to radio contrast media (RCM) to cyclic structures and those with seafood related to animal protein such as tropomyosin. The iodine allergy is a mythical entity, but nevertheless ! Method A 39 year old diabetic man, with end stage renal disease undergoing peritoneal dialysis, was referred for immediate hypersensitivity (IH) reactions. Betadine dermique® containing povidone iodine triggered an immediate contact pruritic rash disappearing in 30 minutes (mns). Angioedema and urticaria occurred a few mns after ingestion of shrimps, mussels, oysters, whelks, trout and salmon. Awaiting kidney transplant, having never received RCM, a predictive assessment of RCM IH was required. Patch and prick tests (pt), IDT, specific IgE and RCM reintroduction were performed under hospital supervision. Results While all patch tests were negative, pt were positive for pure Betadine dermique® and iodized alcohol at 1% in water but negative for Lugol 2% (potassium iodide) and PV. Pt to a native oyster was positive but negative for crab, mussel and shrimp. IgEs were negative for salmon, mussel, oyster and shrimp. Pt and IDR were negative for iobitridol, ioxaglate and iodixanol in pure form (use concentration), but the intravenous administration of 1 ml iobitridol induced a generalized pruritus, a trunk and face erythema with ear edema, occurring after 30 mns and resolution in 60 mns after treatment with intravenous methylprednisolone and antihistamines. Conclusion This exceptional case of multiple reactivities to iodine products and oyster suggests that for this patient iodine itself could be the common allergen. The positive pt to oyster is probably not related to a tropomyosin sensitization. Unlike previous published cases of allergy to povidone iodine, in this case the IH does not appear due to PV. While IDT was negative, iobitridol induced an immediate reaction. We emphasize 1) in case of PVI IH, the need to do a pt to PVI and PV before concluding to the lack of iodine sensitization and thus allow RCM; 2) if negative IDT with RCM, we must continue investigations by an intravenous introduction test with a limited volume of RCM and 3) even if it is exceptional, an iodine allergy may exist. Investigations are continued with in vitro tests. Poster Walk 15: MPE /Type 4 (P129 - P137) P129 Delayed Hypersensitivity Cutaneous Reactions: A Case/Control Study From A Tunisian Database Karim Aouam, Najah Ben Fadhel, Zohra Chadly, Nadia Ben Fredj, Naceur A Boughattas, Amel Chaabane Faculty of Medicine/University hospital/University of Monastir, Monastir, Tunisia Keywords: Case/Noncase, Drug Allergy, Delayed Reactions, Epidemiology Introduction Drug hypersensitivity reactions represent a heterogeneous clinical entity with diverse pathogenesis and result in a considerable burden of morbidity and mortality. Diagnostic procedures rely on clinical history, skin testing and in some cases, provocation tests. Drug imputability is still difficult to establish due to the weakness of sensitivity of some skin tests and the impossibility to perform provocation test in case of severe reactions. The aim of our study is to evaluate delayed-type cutaneous allergic reactions associated with drug use. Method The data were obtained from a Tunisian pharmacovigilance database of adverse drug reactions (ADRs). Analyzed reports were retrieved from the pharmacovigilance unit of Monastir (Tunisia) database collected from 2004 to 2015. The association between drugs and skin reactions was assessed using the case/non-case method, calculating the adverse reaction reporting odds ratio (ROR) and their 95% confidence intervals as a measure of disproportionality. The “cases” were defined as reports of type III and IV skin allergic reactions (according to gelle and Coombs classifications). The “non-cases” were all other reports. Results Overall 1800 reports of adverse reactions related to drug use were analyzed; of which 1523 (84%) were judged as type III and IV skin allergic reactions (cases) and the remaining were considered non-cases. Drug classes associated with a significant increase of ROR were anticonvulsive agents (ROR=2.2, 95% CI [1.43.3], p<10-3) and antibacterial drugs (ROR=1.6, 95% CI [1.3-2], p<10-3). Among antibacterial agents, betalactams were associated with a significant ROR (1.5; 95% CI [1.2-1.8], p<10-3). Regarding betalactams, only oxacilline and the third generation cephalosporins were associated with a significant risk (ROR=1.9; 95% CI [1.1-3.2], p=0.01) and (ROR=1.81; 95% CI [1.3-2.4], p<10-3), respectively, while only carbamazepine (ROR=3; 95% CI [1.6-5.7], p<10-3) and phenobarbital (ROR=2.3; 95% CI [1.1-5.2], p=0.03) have shown a significant ROR values among anticonvulsive agents. Conclusion Results highlight the frequency of association of delayed hypersensitivity skin reactions with betalactams, carbamazepine and phenobarbital. Given the widespread use of these drugs, awareness should be raised among patients and prescribers about these risks. P130 Delayed Hypersensitivity Reactions To Cephalosporins: A Review Of Seven Cases Joana Cosme1, Anabela Lopes1, Amélia Spínola-Santos1, Manuel PereiraBarbosa2 1. Immunoallergy Department - Hospital de Santa Maria – Centro Hospitalar Lisboa Norte, Lisbon, Portugal, Lisboa, Portugal 2. Immunoallergy Department - Hospital de Santa Maria – Centro Hospitalar Lisboa Norte, Lisbon, Portugal; Faculdade de Medicina de Lisboa, Lisboa, Portugal Keywords: ß-Lactams, Cephalosporins, Cross-Reactivity, Delayed Hypersensitivity Reactions Introduction Delayed hypersensitivity reactions to cephalosporins are poorly described reactions that occur more than 1 h after drug administration. The mechanisms involved seem to be heterogeneous and not totally characterized. Objectives: To characterize the delayed hypersensitivity to cephalosporins and determine the clinical profile of these patients and the cross reactivity with other antibiotics. Method Retrospective review from the patients with delayed confirmed hypersensitivity reactions to cephalosporins between 2013-2014. The patients were submitted to skin tests with penicilloylpolylysine (PPL), minor determinant mixture (MDM), benzylpenicillin, ampicillin, amoxicillin, cefuroxime, ceftriaxone, cefipime and other antibiotics that were eventually involved. Results for specific IgE to βlactams and oral provocation challenge tests (OPT) with the alternative and/or culprit β-lactms were also reviewed. Results Within the 7 patients that were reviewed 71% were female, with a median age of 56 [32.5-66] years and 43% had personal history of atopy. The clinical manifestations reported by these patients were delayed urticaria in 57% of the cases and 43% described delayed rash. In all cases the symptoms appeared more than 24 hours after the beginning of the antibiotic. In 6(85.7%) the episodes occurred after cephalosporins intake. One patient had an adverse event with amoxicillin and the sensitization to cephalosporins was only found after investigation. All had negative specific IgE for β-lactams. Four (57.1%) had sensitization only to cephalosporins. The cephalosporins involved and the delayed results of the IDT and OPT are summarized on table 1. All the suspected cephalosporins were confirmed: 6 (85.7%) on the basis delayed IDT, in 1 (14.3%) cephalosporins' sensitization was determined after OPT. Regarding cross reactivity with other β-lactams 3 (42.9%) patients had reactivity to aminopenicillins. Conclusion Delayed reactions to cephalosporins are associated with delayed clinical manifestations and all had only skin involvement. The reactivity with other βlactams, within the patients with delayed cephalosporins hypersensitivity, was heterogeneous. P131 Diclofenac Induced Allergic Contact Dermatitis - Case Series Of Four Patients Sandra Jerkovic Gulin1, Anca Chiriac2 1. Department of Dermatology and Venereology, General Hospital Sibenik, Sibenik, Croatia 2. Dermatology Department, Nicolina Medical Centre, Apollonia University, „P.Poni“ Research Institute of Macromolecular Chemistry, Iasi, Romania Introduction Allergic contact dermatitis is an immune-mediated antigen-specific skin reaction to an allergenic chemical that corresponds to a delayed-type hypersensitivity response (type IV reaction). Allergic contact dermatitis should be suspected when skin lesions are localized to the site of previous applications of the culprit drug. The gold standard for diagnosis is patch testing; identification and removal of any potential causal agents is crucial. Diclofenac cream/gel contains propylene glycol, diclofenac, dimethyl sulfoxide, ethanol and glycerin. It is a widely used non-steroidal anti-inflammatory drug, known to cause especially photoalergic contact reactions. Case Description We present four cases of diclofenac induced allergic contact dermatitis, diagnosed based on clinical grounds: intensly itchy eczematous lesions on the sites of drug application, after several days of treatment. No allergic history, no other drug intake were reported by the patients. The application of topical diclofenac was strictly avoided in all cases, potent topical steroids proved to be effective in all cases within two weeeks of therapy. Patch tests were performed in all cases with european standard batery and with patients' own cream or gel three weeks after completion of local steroid therapy. Reading was performed at 96 hours and proved to be positive only to diclofenac. No sun exposure was allowed during the testing, any other treatments were forbidden. How this report contributes to current knowledge Patients and physicians must be aware of the risk of cutaneous sensitization induced by topical diclofenac, a drug extensively used also as self medication. P132 Late-Onset Maculopapular Rash To Irbesartan Bárbara Kong Cardoso, Elza Tomaz, Regina Viseu, Filipe Inácio Hospital de S.Bernardo - Centro Hospitalar de Setúbal, Setúbal, Portugal Introduction Hypertension is one of the most common worldwide diseases. Angiotensin II receptor blocker are one of antihypertensive drugs most prescribed. Some wellknown adverse effects of irbesartan are dizziness, urticaria and angioedema. Irbesartan cutaneous non-immediate reactions have been reported previously in a limited number of case reports. Case Description Sixty years old female patient referred to our clinic with a three week history of an itchy erythematous maculopapular eruption affecting the torso (thorax and abdomen) and proximal part of upper and lower limbs which resolved with hyperpigmentation. The patient reported since then similar but short-lasting lesions that she related to atorvastatin intake. The patient current medications were: atorvastatin, irbesartan, chlordiazepoxide, levothyroxine, estradiol patch, olanzapine and paroxetine. All of them but irbesartan and paroxetine had been taken for several years. Irbesartan was the latest drug introduced, approximately 2 months before the exanthematous rash beginning and paroxetine was only introduced after the symptoms appearance. There was no history of any infectious disease. Previously performed histopathologic examination of the lesions showed lymphocytic infiltrate and eosinophils in the dermis, compatible to drug reaction. Irbesartan was changed to diltiazem in patient therapy. Patch tests (PT) to irbesartan, candesartan and atorvastatin (5% in petrolatum) were performed and a lymphocyte transformation test (LTT) to irbesartan was executed. Results: PT to irbesartan was positive at 48 and 96 hour. LTT (irbesartan 100µg/mL) showed 6.3 stimulation index. The patient did not refer new lesions after stopping irbesartan and was diagnosed as non-immediate drug reaction due to irbesartan based in clinical, histopathologic and analytic features. Three months later candesartan was introduced in patient therapy, without skin reaction after 3 months. How this report contributes to current knowledge There are few reports about non immediate cutaneous side effects due to irbesartan. PT and LTT proved useful in the diagnosis. In spite of the similarity of chemical structure, candesartan may be tried in patients allergic to irbesartan. P133 Nonimmediate Hypersensitivity Reactions To Betalactams – A Retrospective Analysis Ana Moreira, Susana Cadinha, Ana Castro Neves, Patricia Barreira, Daniela Malheiro, JP Moreira Da Silva Centro Hospitalar Vila Nova Gaia e Espinho, Vila Nova Gaia, Portugal Keywords: Betalactams, Hypersensitivity, Nonimmediate Reactions Introduction Betalactams (BL) are the most widely prescribed antibiotics and the most frequent cause of drug allergic reactions. Benzylpenicillin, the major responsible for BL drug allergic reactions, has been progressively replaced by amoxicillin and to a lesser extent by cephalosporins or other BL. Our aim was to characterize a series of subjects with suspected nonimmediate hypersensitivity (NIH) to natural penicillins and aminopenicillins/clavulanic acid (CA) and evaluate the usefulness of different diagnostic procedures in the study of these reactions. Method A total of 391 patients with suspected betalactam hypersensitivity (BH) were referred to our department from 2009 to 2015 and those with suspected NIH to natural penicillins and aminopenicillins/CA were evaluated. Demographic data, atopy, allergic diseases, comorbidities, clinical manifestations and diagnostic procedures were assessed. BH was confirmed by positive skin tests (ST), drug provocation test (DPT) or long term-challenge (LTC) and considered probable based on a suggestive history and/or positive lymphocytic transformation test (LTT). ST were performed with PPL, MDM, Amoxicillin, Amoxicilin/CA, Ampicillin and Penicillin G; DPT was performed with Amoxicillin, Amoxicilin/CA and Penicillin. Results 169 (43%) patients had suspected NIH to natural penicillins and aminopenicillins/CA: 67% female; median age 37 years (1-81); 34% atopic; 16% had rhinitis/rhinoconjunctivitis, 14% asthma/rhinitis and 8% chronic urticaria/angioedema. Cutaneous reactions were reported by 84% of patients. Skin prick tests were negative in all patients tested (129). Intradermal tests were performed in 110 patients and 11 had positive late-reading. Patch tests were positive in 7 out of 111 patients. LTT was positive in 5 out of 11 patients. DPT performed in 120 patients was positive in 10. LTC performed in 86 patients was positive in 8. BH was confirmed in 29 patients (11 by ST, 10 by DPT and 8 by LTC), considered probable in 7 patients, excluded in 103 and inconclusive in 30. Conclusion As previously reported in the literature, our study suggests that BH usually presents with cutaneous symptoms and affects mainly adults. BH was established in 17% of the patients, 38% by ST, 34% by DPT and 28% by LTC. According to the ENDA guidelines, DTP is the gold-standard for definitive diagnosis of BH. Nevertheless, 8 patients would not have been diagnosed if LTC was not included in the diagnostic work-up. P134 OCCUPATIONAL AIRBORNE CONTACT DERMATITIS TO OMEPRAZOLE Ružica Jurakic-Toncic1, Suzana Ljubojevic1, Petra Turcic2 1. Department of Dermatology and Venereology, University Hospital Center Zagreb, School of Medicine University of Zagreb, Zagreb, Croatia 2. Department of Pharmacology, Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia Keywords: Omeprasole, Proton Pump Inhibitor, Eczema Introduction Omeprazole is a proton pump inhibitor for the treatment of gastric acid-related disorders. It is administered orally. Method We present 52-years-old chemist who worked in a pharmaceutical company for 5 years and she was exposed to omeprazole during the manufacturing process. When working in the laboratory, she was wearing protective latex free gloves. Whenever they were manufacturing omeprazole she had eczema with scaling on the eyelids face and neck, later hands were also affected. When she was on sick leave or when she was on vacation she had completely regression of skin dermatitis. The patient was treated with topical corticosteroids, which resulted with temporally regression of skin symptoms. Results We preformed lymphocyte transformation test (LTT) which was negative. Patch test to baseline series was negative, but patch test to omeprazole (0.1% and 0.5% in saline solution) was positive at day 2 (+) and day 3 (++). Conclusion Omeprazole constitute a high-sensitizing chemical. Although direct contact with the skin is not always present, distribution of dust containing omeprazole through the air and deposition on exposed areas may result in an airborne pattern of contact dermatitis. Our case confirms the risk of sensitization to omeprazole from occupational exposure. P135 Ornidazole-Induced Fixed Drug Eruption Confirmed By Positive Patch Test On A Residual Pigmented Lesion Liesbeth Gilissen, Sara Huygens, An Goossens University Hospitals Leuven, Leuven, Belgium Keywords: Fixed Drug Eruption; Ornidazole; Patch Testing Introduction Ornidazole is a 5-nitroimidazole derivative commonly prescribed for the treatment of diarrhea caused by anaerobic bacteria. Previous cases of fixed drug eruptions (FDE) from ornidazole were reported in the literature (1-6), however, in only one of them the diagnosis has been confirmed by a positive patch test (5); their patient had also shown a FDE following oral intake of fluconazole (5). In another case (6) cross-reactivity occurred following oral intake with secnidazole. A 40-year-old male patient presented with two pigmented lesions, one on the upper arm, and one with a central erosion on the glans penis. These had occurred since the intake of ornidazole (Tiberal®, Laboratoires SERB, Paris, France) and budesonide (Entocort®, AstraZeneca, Brussels, Belgium), 2 weeks previously. The provisional diagnosis of FDE was put forward. Method Five weeks later, patch tests with ornidazole (tablet crushed and diluted 30% in petrolatum) and budesonide (0.01% in petrolatum) were performed on a residual pigmented lesion on the upper arm, and also on a non-lesional skin site as a control, using vander Bend Chambers® (vander Bend, Brielle, The Netherlands). Results Only the patch test with ornidazole on the residual pigmented lesion showed a positive reaction at day 4, while the control on the non-lesional skin remained negative. Discontinuation of ornidazole resulted in clearance of the lesions. Conclusion In the unlikely event of a fixed drug eruption, clear identification of the culprit may be difficult, in particular when multiple medications are administered. Patch testing in a previously affected lesion may identify the causative agent, as in the present case. References: 1. Gupta R. Fixed drug eruption due to ornidazole. Indian J Dermatol 2014: 59(6): 635. 2. Marya C et al. Mucosal fixed drug eruption in a patient treated with ornidazole. J Dermatol 2012: 27: 6(1): 21-24. 3. Gupta S et al. Fixed drug eruption caused by ornidazole. Contact Dermatitis 2005: 53: 300–301. 4. Gupta S et al. Multiple fixed drug eruption caused by ornidazole. Dermatitis 2010: 21: 330–333. 5. Bavbek S et al. Fixed drug eruption caused by ornidazole and fluconazole but not isoconazole, itraconazole, ketoconazole and metronidazole. J Dermatol 2013: 40(2): 134-135. 6. Sanmukhani J et al. Fixed drug eruption with ornidazole having crosssensitivity to secnidazole but not to other nitro-imidazole compounds: A case report. Br J Clin Pharmacol 2010: 69: 703–704 P136 REPEATED DELAYED REACTION INDUCED BY AMOXICILLIN AND AMOXICILLIN CLAVULANATE Inmaculada Andreu1, Ramon Lopez-Salgueiro1, Alicia Martinez Romero2, Pau Gomez Cabezas2 1. IIS La Fe, Valencia, Spain 2. CIPF, Valencia, Spain Introduction There are no techniques validated for the diagnosis of drug induced delayed allergic reactions. In vivo tests are inconvenient and in vitro tests are neither sensitive nor validated. We describe a case of recurrent delayed reactions related to therapy with amoxicillin and amoxicillin clavunalate by in vivo and in vitro tests. Method The patient developed repeated episodes of generalized skin rash, pruritus, malaise, chest pain and dysphagia after 5-7 days of therapy with amoxicillin clavunalate or amoxicillin. Blood tests showed an elevation in CRP, GGT, fibrinogen and monocytosis during the acute phase. The reactions resolved with corticosteroids and antihistamines. Intradermal and patch tests were performed with amoxicillin and amoxicillinclavunalate. Total IgE and specific IgE and IgG to amoxicillin were measured by ImmunoCAP®. Cell activation analysis by the culprit drugs and clavulanate was performed by flow cytometry. Basophil Activation Test (BASOTEST®) was considered positive if activation > 5% or SI (stimulation index) >2. Mononuclear cell activation was evaluated by the expression of CD69 after drug exposure for 48 hours. Antibodies anti-CMV, Herpes, Epstein-Barr and parvovirus were analyzed. Results Intradermal and patch tests with amoxicillin and amoxicillin clavunate acid were negative. Total IgE: 198 kUI/l. Specific IgE for amoxicillin and penicillin were negative (0,07 kUI/l). Specific IgG was 3,42 mgA/L. Basophil activation test was positive for amoxicillin (1/160: 10,87%;SI:16,73 - 1/40: 48,55%;SI:35,69) and amoxicillin clavunalate (1/160: 22,76%;SI:16,73 - 1/40: 74,68%;SI:54,91), but negative for clavunalate (100 microgr/ml: 3,55%;SI: 1,26 – 200 microgr/ml: 3,98%;SI:1,41). A 3-fold increase occurred when the mononuclear cells were treated with amoxicillin, 2.5-fold increase with clavulanate and 10-fold increase when the samples were treated with amoxicilline clavunalate. Serologies showed positive IgG for Epstein-Barr, herpes and parvovirus. Conclusion Delayed adverse reactions to amoxicillin and amoxicillin clavulanate may be diagnosed by alternative tests such as basophil and lymphocyte activation tests when conventional in vivo and vitro tests show negative results. We hypothesize that specific IgG may induce anaphylactic reactions through basophil activation. Although the role of T cell activation is not clear, we observed a synergic effect of both drugs. P137 Systemic Photosensitivity From Fenofibrate In A Patient PhotoSensitized To Ketoprofen Liesbeth Gilissen, An Goossens University Hospitals Leuven, Leuven, Belgium Keywords: Fenofibrate; Patch Testing; Photo-Allergic Contact Dermatitis; Systemic Contact Dermatitis Introduction Fenofibrate is widely used in the treatment of hypercholesterolemia and hypertriglyceridemia. Cutaneous side effects such as pruritus, rash, urticarial lesions, but also cases of photosensitivity have been previously described (1-3). A 47-year old female patient presented with a severe vesicular eruption involving the sun-exposed body areas, except under the wristwatch. The face was only slightly affected to which she had applied a sunscreen. She had been taken several medications, i.e., fenofibrate (Lipanthyl®, Mylan EPD, Wavre, Belgium), metformine (Metformax®, Menarini, Zaventem, Belgium), spironolactone, and allopurinol (Zyloric®, Laboratoires SMB, Brussels, Belgium). Method Patch tests with the European baseline series and photo-patch tests with the European photo-patch test series were performed, using IQ Ultra® Chambers (Chemotechnique Diagnostics, Vellinge, Sweden). Results A strong positive photo-patch test to ketoprofen (D2 -, D4 +++, D8 +++) and also a positive patch test to benzophenone-3 (D2 +, D4 ++) were obtained. Conclusion Photo-allergic contact dermatitis from ketoprofen often gives rise to simultaneous reactions to other nonsteroidal anti-inflammatory drugs (NSAIDs), sunscreens, and fragrance components (4), as well as to fenofibrate (5), which, administered systemically, may induce photosensitivity. The benzophenone moiety is responsible for the photosensitization reaction (3,5). References 1. Gardeazabal J, Gonzalez M, Izu R, Gil N, Aguirre A, Diaz-Perez J. Phenofibrateinduced lichenoid photodermatitis. Photodermatol Photoimmunol Photomed 1993: 9(4):156-158. 2. Barbaud A, Schmutz J, Trechot P, et al. Photoallergie au fenofibrate (Lipanthyl®): à propos de 3 cas. Lett GERDA 1992: 9: 6–10. 3. Serrano G, Fortea J, Latasa J, Millan F, Janes C, Bosca F, Migual A Photosensitivity induced by fibric acid derivatives and its relation to photocontact dermatitis to ketoprofen. J Am Acad Dermatol 1992: 27(2): 204-208. 4. Matthieu L, Meuleman L, Van Hecke E, Blondeel A, Dezfoulian B, Constandt L, Goossens A. Contact and photocontact allergy to ketoprofen. The Belgian experience. Contact Dermatitis 2004: 50(4): 238–241. 5. Leroy D, Dompmartin A, Szczurko C, Michel M, Louvet S. Photodermatitis from ketoprofen with cross-reactivity to fenofibrate and benzophenones. Photodermatol Photoimmunol Photomed 1997:13(3): 93-97. Poster Walk 16: HLA Genetics (P138 – P146) P138 A Copy Number Variation In ALOX5 And PTGER1 Is Associated With Nonsteroidal Anti-Inflammatory Drugs Induced Urticaria And/Or Angioedema. Pedro Ayuso Parejo1, Maria Del Carmen Plaza-Serón1, Inmaculada Doña2, Natalia Blanca López1, Carlos Flores3, Luisa Galindo2, Ana Molina4, James Richard Perkins4, Jose Antonio Cornejo-García4, José Augusto García-Agúndez5, Elena García-Martín6, Paloma Campo2, María Gabriela Canto1, Miguel Blanca2 1. Allergy service, Infanta Leonor Hospital, Madrid, Spain, Madrid, Spain 2. Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain, Málaga, Spain 3. Research Unit and Centro de Investigación Biomédica en Red de Enfermedades Respiratorias de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain, Madrid, Spain 4. Research Laboratory, IBIMA, Malaga Regional University Hospital, UMA, Malaga, Spain, Málaga, Spain 5. Department of Pharmacology, University of Extremadura, Cáceres, Spain, Cáceres, Spain 6. Department of Biochemistry and Molecular Biology, University of Extremadura, Cáceres, Spain., Caceres, Spain Keywords: NSAIDs Hypersensitivity, Genetic Association Study, Cyclooxygenases, Prostaglandin E Receptors, Arachidonate 5-Lypoxygenase. Introduction Cross-intolerance to nonsteroidal anti-inflammatory drugs (NSAIDs) is a class of hypersensitivity reaction in which NSAIDs-induced urticaria and/or angioedema (NIUA) is the most frequent entity. It is thought to involve dysregulation of the arachidonic acid (AA) pathway. However, this mechanism has not been confirmed for NIUA. In this work we assessed copy number variations (CNVs) in 8 of the main genes involved in the AA pathway and their possible genetic association with NIUA. Method CNVs in ALOX5, LTC4S, PTGS1, PTGS2, PTGER1, PTGER2, PTGER3 and PTGER4 were analyzed using TaqMan copy number assays. Genotyping was carried out by real time quantitative PCR. Individual genotypes were assigned using the CopyCallerTM Software. Statistical analysis was carried out using GraphPad prism 5, PLINK, EPIDAT and R version 3.1.2. Results 151 cases and 139 controls were analyzed during the discovery phase and 148 cases and 140 controls were used for replication. CNVs in open reading frames were found for ALOX5, PTGER1, PTGER3 and PTGER4. Statistically significant changes in CNVs between NIUA and controls were found for ALOX5 (pc=0.017) and PTGER1 (pc=1.22E-04). Moreover, we described that there was not a correlation between the presence of a deletion in ALOX5 with the presence of a deletion in PTGER1 (R2 = 0.274). Conclusion This study represents the first analysis showing an association between CNVs in exonic regions of ALOX5 and PTGER1 and NIUA. This suggests an important role of CNVs in this pathology that should be further explored in future studies. P139 Association Of Galectin-3 (LGALS3) Single Nucleotide Polymorphisms With Non-Steroidal Anti-Inflammatory Drugs-Induced Urticaria/Angioedema José Antonio Cornejo-Garcia1, Inmaculada Doña2, Rosa María GuéantRodríguez3, Natalia Blanca-López4, María Carmen Plaza-Serón5, Raquel JuradoEscobar5, Esther Barrionuevo2, María Salas2, María Luisa Galindo2, Gabriela Canto4, Miguel Blanca2, Jean-Louis Guéant3 1. Research Laboratory and Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 2. Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 3. University of Lorraine and University Hospital Center (CHU) of Nancy, INSERM U-954, Faculty of Medicine, Vandoeuvre-Les-Nancy, France 4. Allergy Service, Infanta Leonor University Hospital, Madrid, Spain 5. Research Laboratory, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain Introduction NSAIDs are the first cause of drug hypersensitivity reactions (DHRs), being those mediated by non-specific immunological mechanisms (cross-intolerance, CI) the most frequent. Skin is the most commonly affected organ and NSAIDs-induced urticaria/angioedema (NIUA) the most frequent clinical entity. Galectin-3 plays an important role in the biological responses of skin cells, and it is being regarded as a novel therapeutic target for a variety of skin disorders. We analyzed the association of several nonsynonymous single nucleotide polymorphisms (SNPs) in LGALS3 with CI in a large group of patients with different clinical entities, including NIUA, NSAIDs-exacerbated respiratory disease and a mixed pattern of response that includes both skin and respiratory involvement. Method The population studied was obtained from two Allergy Services integrated into the Spanish network RIRAAF. Cases included had to develop more than two episodes of CI after the intake of two or more NSAIDs from different chemical groups. We studied several SNPs in LGALS3 using TaqMan® probes. s both skin and respiratory involvement. Results A total of 504 subjects with CI to NSAIDs were included and 271 age and sexmatched healthy controls. Statistically significant associations were found between NIUA and LGALS3 rs11125 (p<0.001) and rs4644 (p=0.032). Conclusion Our results suggest a role for SNPs in LGALS3 in NIUA, the most important clinical entity induced by HRDs. The association of such genetic variants with NIUA provides us with new clues for understanding their underlying mechanisms. Further studies are required to analyze the potential role of other genetic variants in galectins and related genes in HRDs to NSAIDs. P140 Detection Of T-Cell Responses To Ticlopidine Using Peripheral Blood Mononuclear Cells From HLA-A*33:03+ Healthy Donors. Toru Usui, Arun Tailor, Lee Faulkner, John Farrell, Ana Alfirevic, B Kevin Park, Dean J Naisbitt University of Liverpool, Liverpool, United Kingdom Introduction Ticlopidine is an anti-platelet drug used in the treatment of atherothrombosis and is known to cause idiosyncratic drug induced liver injury (DILI). The recent identification of human leukocyte antigen (HLA)-A*33:03 as a susceptibility factor and the delayed nature of the liver injury are both indicative of an immune pathogenesis. However, the role of the adaptive immune system in ticlopidineinduced DILI has not yet been defined. The aim of this study was to investigate whether drug-specific T cell responses could be detected in healthy volunteers who expressed HLA-A*33:03. Any T cell responses would then be fully characterized for drug specificity, HLA restriction and the mechanism(s) of antigen presentation Method Peripheral blood mononuclear cells were isolated from HLA-typed healthy volunteers who did or did not express the risk allele: HLA-A*33:03. Subsequently, naïve T-cells were separated and co-cultured with autologous monocyte-derived dendritic cells (DCs) in the presence of the ticlopidine for a period of 8 days, to expand the number of drug-responsive T-cells. T-cells were then harvested and incubated with freshly prepared dendritic cells and drug to test their antigen specificity using readouts for cell proliferation and cytokine secretion. T-cell clones were also generated following priming and drug-specific T cell clones analysed for cytokine secretion and HLA restriction. Results Using the DC priming assay all four HLA-A*33:03 positive donors showed ticlopidine-specific proliferation and IFNγ secretion. However, no ticlopidinespecific responses were detected in HLA-A*33:03 negative donors. Around one thousand CD8 positive clones were generated from three HLA-A*33:03 positive donors, but ticlopidine specific clones were only obtained from one donor. These CD8 positive clones showed ticlopidine-specific IFNγ secretion. This response was restricted by HLA-A*33:03 and was not dependent on the presence of antigen presenting cells. Conclusion In conclusion, ticlopidine-specific T-cells were detected in healthy volunteers expressing the risk allele HLA-A*33:03 using the DC priming assay. P141 Epistasis Approaches To Identify Novel Genes Potentially Involved In NSAIDs Hypersensitivity James Richard Perkins1, Jose Antonio Cornejo García1, Oswaldo Trelles2, Inmaculada Doña3, Esther Barrionuevo3, María Salas3, María Auxiliadora Guerrero3, Miguel Blanca3, Alex Upton2 1. Research Laboratory, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 2. Department of Computer Architecture, University of Malaga, Malaga, Spain 3. Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain Keywords: NSAIDs-Hypersensitivity, GWAS, Genetics, Epistasis, Systems Biology Introduction A handful of genome wide association studies (GWASs) have been performed to detect genetic variation associated with NSAID hypersensitivity, by comparing the frequencies of hundreds of thousands of single nucleotide polymorphisms (SNPs) between NSAIDs hypersensitive subjects and control individuals. This is done on a SNP-by-SNP basis, meaning that each variant is considered independently. However, the effect of a single SNP on phenotype is influenced by other factors, including the individual’s genetic background. An alternative approach to analyse this data is the use of epistasis methods, which look for associations between pairs of SNPs and a phenotype that are stronger than the sum of the individual SNP-phenotype associations, suggesting an interaction between the SNPs. Method We analysed data from an NSAIDs hypersensitivity GWAS using an epistasis detection method, MBMDR. The resulting pairs of interacting SNPs were used to build networks, both at the SNP level and at the gene level, by mapping SNPs to their closest protein coding gene (within 500kb). These networks were analysed to identify SNPs and genes with a potential role in NSAIDs hypersensitivity using graph metrics. This approach identifies important hub nodes based on the strength and number of connections they have, which can be interpreted as the number of distinct pair-wise interactions they are involved in. Results Our approach identified a number of genes with potential roles in NSAIDs hypersensitivity, including genes potentially involved in asthma (KCNB2, PPP1R3C and CSMD1), rhinitis (SCN11A) and immune system functioning (TSPAN33). It also found a number of genes with a potential role in lipid related processes, such as SGSM2 and BUB3. The gene CGNL1, whose expression has been shown to change following aspirin intake, was also identified. Additionally, pathway analysis of the networks found enrichment for ALK1 and TGF-beta signalling. Conclusion The study presented here shows how weighted epistatic analysis approaches can complement traditional SNP-by-SNP analyses. Additional studies are necessary to replicate these findings, and they should be applied to other NSAIDs hypersensitivity pathologies. Moreover, the mechanisms by which the SNPs and genes identified here affect NSAIDs hypersensitivity must be investigated further. P142 Genetic Predisposition Of Cold Medicine Related SJS/TEN With Severe Ocular Complications Mayumi Ueta1, Hiromi Sawai2, Chie Sotozono3, Katushi Tokunaga2, Shigeru Kinoshita1 1. Department of Frontier Medical Science and Technology for Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan 2. Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan 3. Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan Keywords: Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), Severe Ocular Complications (SOC), Cold Medicines (CM), Genetic Predisposition Introduction Stevens-Johnson syndrome (SJS) is an acute inflammatory vesiculobullous reaction of the skin and mucosa such as the ocular surface, oral cavity, and genitals. In patients with extensive skin detachment and a poor prognosis, the condition is called toxic epidermal necrolysis (TEN). Severe ocular complications (SOC) appear in about 40% of SJS/TEN patients diagnosed by dermatologists. Among SJS- and TEN patients, especially those with SJS/TEN with SOC, cold medicines (CM) including multi-ingredient cold medications and non-steroidal anti-inflammatory drugs were the main causative drugs. We reported that in the Japanese, CM-SJS/TEN with SOC was strongly associated with HLA-A*02:06 and significantly associated with HLA-B*44:03; in Indian and Brazilian caucasian populations it was associated with HLA-B*44:03, and in Koreans with HLAA*02:06. In our 1st genome-wide association study, we analyzed our SJS/TEN with SOC patients using the Affymetrix GeneChip Mapping 500K array set, and found an association between prostaglandin E receptor 3 (PTGER3) and SJS/TEN with SOC, and subsequently found that this association was stronger in patients with CM-SJS/TEN with SOC than in patients with all SJS/TEN with SOC. In this study, we performed the 2nd genome-wide association study using the Japanese CM-SJS/TEN with SOC. Method We performed a genome-wide association study of Japanese 117 CM-SJS/TEN with SOC patients and 691 controls using the Affymetrix AXIOM Genome-Wide ASI 1 array. For the examination of 17 SNPs in regions near TSHZ2, we genotyped 101 of the patients and 200 of the 691 controls. Results Manhattan plots showed that the HLA-A region was most strongly associated with the susceptibility for CM-SJS/TEN with SOC. Outside of the HLA region, there were 60 SNPs with a value of p < 10-3 in either allele frequency, the dominant-, or the recessive model. Among the 11 SNPs of 8 genes with p < 10-5, IKZF1 manifested particularly low p-values [rs897693 (CC+CT vs TT), OR = 5.0, p = 2.1×10-8]. Among the 11 SNPs of 8 genes whose value in our second genomewide association study was p < 10-5, TSHZ2 also had especially low p-values [rs4809905 (AA+AG vs GG), OR=0.3, p = 1.5×10-7]. Furthermore, we have examined 17 SNPs in regions near TSHZ2 using 101 CM-SJS/TEN patients and 200 controls, and found that 8 SNPs exhibited a significant genome-wide association with CM-SJS/TEN with SOC. Conclusion TSHZ2 is one of the susceptibility gene for CM-SJS/TEN with SOC in the Japanese. P143 HLA-B*13:01 And Dapsone Induced Hypersensitivity In Thai Population. Chonlaphat Chonlaphat Sukasem1, Patompong Satapornpong2, Therdpong Tempark3, Pawinee Rerknimitr4, Kulprapat Pairayayutakul5, Jettanong Klaewsongkram6 1. Ramathibodi hospital, Mahidol university, Bangkok, Thailand 2. Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand 3. Division of Pediatric Dermatology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand 4. Division of Dermatology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand 5. 6Raj Pracha Samasai Institute, Department of disease control, ministry of public health, Nonthaburi, Thailand 6. Division of Allergy and Clinical Immunology, Department of Medicine, Faculty of Medicine, Allergy and Clinical Immunology Research Group, Chulalongkorn University,, Bangkok, Thailand Keywords: HLA-B*13:01, Dapsone, Thai, Dapsone Induced Hypersensitivity Reactions, DISH Introduction Background: Dapsone is regarded as the treatment of choice for infections, various dermatological diseases and inflammatory diseases. Drug hypersensitivity syndrome is considered as a severe cutaneous adverse drug reaction which is commonly precipitated by dapsone. A previous publication showed that the HLA-B*13:01 allele is a strong marker for dapsone-induced hypersensitivity syndrome of leprosy patients in China. Although dapsoneinduced hypersensitivity reactions is common, however there are no data describing whether HLA-B*13:01 could be used as a genetic marker for prediction of dapsone-induced hypersensitivity reactions in Thai. Objective: The aim of this study was to investigate the predisposition of dapsone-induced DHS, conferred by HLA-B*13:01 in a Thai population. Method A total of 22 patients, included 11 patients in dapsone-induced hypersensitivity syndrome, 11 patients in dapsone-tolerant control group (dapsone treatment for more than 6 months but without any episode of dapsone-induced hypersensitivity syndrome) and 986 healthy Thai population group. HLA-B genotype were determined by two-stage sequence-specific oligonucleotide probe system (SSOP). This study was approved by the Ethics Committee of Ramathibodi hospital. Results The results presented HLA-B*13:01 allele in patients of dapsone-induced hypersensitivity syndrome, dapsone tolerant controls and healthy Thai population were 63.64% (7/11), 18.18% (2/11) and 13.59% (134/986) respectively. The HLA-B*13:01 allele were not significantly different between DIHS cases and dapsone tolerant controls (p-value = 0.0805, OR = 7.88, 95% CI = 1.11 – 56.13), but there were significant different between DIHS cases and healthy Thai population (p-value = 0.0002, OR = 11.13, 95% CI = 3.21 – 38.52). Conclusion Discussion: Although the samples size of DIHS cases and dapsone tolerant controls in this research were limited, there were found the HLA-B*13:01 allele could predisposition toward to dapsone-induced hypersensitivity in Thailand. P144 HLA-B*15:02 Alleles And Lamotrigine-Induced Cutaneous Adverse Drug Reactions In Thai Chonlaphat Sukasem1, N Koomdee1, T Jantararoungtong1, S Santon1, A Puangpetch1, U Intusoma2, W Tassaneeyakul3, V Theeramoke4 1. 1Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand 2. .Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Songkla, Thailand 3. Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand 4. Manarom Hospital, Bangkok, Thailand Keywords: Lamotrigine; HLA-B*1502; Cutaneous Adver Sereactions; StevensJohnsonsyndrome; Toxic Epidermal Necrolysis Introduction Background: Lamotrigine (LTG) is one of the antiepileptic drugs (AEDs) commonly used in the treatment of epilepsy for partial seizures and psychiatric patients in clinical practice. Several HLA alleles have been associated with Lamotrigene-induced cutaneous adverse drug reactions (cADRs) in different populations, however, this has not been investigated in Thai. Objective: The aims of this study were to determine the possible associations of lamotrigine-induced cADRs with the HLA-B alleles in Thai patients. Method A total of 645 patients, including 16 patients with lamotrigine-induced cADRs, vary from maculopapular exanthema (MPE) to Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), 50 lamotrigine-tolerant controls and 580 healthy controls were included in this study. HLA-B genotyping was performed. This case-control study was approved by the Ethics Committee of Ramathibodi Hospital. Results The differences in the starting dosage of LTG among the SJS/TEN, MPE, and LTGtolerant control groups were not statistically significant. HLA-B*15:02 allele was present in 33.3% (1/3; LTG-induced SJS/TEN group), 38.5% (5/13; LTG-induced MPE group) of Thai patients but only 12.0% (6/50) of lamotrigine-tolerant controls and 14.8% of 580 healthy controls. There was significant difference in the frequency of subjects with the HLA-B*1502 allele between SJS/TEN and LTGtolerant groups (p < 0.05, OR = 3.559, 95% CI 1.71-7.40), and healthy controls (p = 0.003, OR = 2.75, 95% CI 1.38-5.47). Significant difference between the MPE group and LTG-tolerant group (p < 0.05, OR = 4.613, 95% CI 2.23-9.51), and healthy controls (p < 0.05, OR = 3.565, 95% CI 1.80-7.03). Conclusion In conclusion, In this study, we found a statistically significant association between the HLA-B*1502 allele and LTG-induced cADRs in Thai population. Therefore, an application of HLA-B*1502 as a screening test before prescribing LTG will help to prevent LTG-induced cADRs in Thailand. Table 1. Clinical characteristics of LTG-induced cADRs group and LTG-tolerant group. LTG-induced cADRs LTG-tolerant group (n=50) p-Value group (n=16) 6:10 12:38 0.340 Gender 1:2 (SJS/TEN) 1.000 (male: female) 5:8 (MPE) 0.353 35.5±21.7 38.2±19.0 0.646 Mean age (years) 52.3±24.0 (SJS/TEN) 0.415 32.0±20.9 (MPE) 0.353 51.6±26.6 77.6±62.0 0.109 Starting dosage of 41.7±14.4 (SJS/TEN) 0.325 LTG (mg/day) 53.8±28.6 (MPE) 0.186 No significant differences were observed in gender, mean age, and mean starting dosage of LTG between cases and LTG-tolerant controls. Table 2. Comparison of HLA-B*15:02 frequency among groups. Group1 ( frequency of HLA- Group2 ( frequency of HLA- pORa B*15:02) B*15:02) Value LTG-induced SJS/TEN LTG-tolerant group LTG-induced SJS/TEN Healthy control LTG-induced SJS/TEN LTG-induced MPE LTG-induced MPE LTG-tolerant group 95% CIb 1.717.40 1.380.003 2.750 5.47 0.061.000 0.800 11.29 <0.05 4.613 2.230.0004 3.559 LTG-induced MPE a b 9.51 1.81<0.05 3.565 7.03 Healthy control OR: odds ratio. CI: confidence interval. Table 3 The association of individual HLA-B allele with Lamotrigine induced Cutaneous Adverse Drug Reactions (cADR) cADR cases versus cADR cases versus Lamotrigine Healthy control HLA- Lamotrigine Lamotrigine Healthy tolerant control B induced tolerant control OR allele cADR (n=16) (n=50) (n=580) OR (95% P value (95% P value CI) CI) 1301 2 (12.5) 6 (12) 1502 6 (37.5) 6 (12) 1513 1 (6.3) 0 (0) 1535 1 (6.3) 1 (2) 3901 1 (6.3) 1 (2) 4001 3 (18.8) 13 (24) 4403 4 (25) 2 (4) 4601 5 (31.3) 11 (22) 5101 2 (12.5) 2 (4) 5201 1 (6.3) 1 (2) 5801 2 (12.5) 5 (10) OR: odds ratio. CI: confidence interval. 1.083 (0.4682.505) 4.423 86 (14.8) (2.1429.134) 2.064 10 (1.7) (1.7852.386) 3.128 12 (2.1) (0.61615.886) 3.128 11 (1.9) (0.61615.886) 0.743 109 (0.377(18.8) 1.464) 8.000 48 (8.3) (2.66923.982) 1.539 101 (0.844(17.4) 3.006) 3.545 43 (7.4) (1.11411.280) 3.128 16 (2.8) (0.61615.886) 1.330 116 (20) (0.5543.190) 81 (14) 0.907 (0.4032.043) 3.418 0.000026 (1.7306.751) 3.128 0.029 (0.61615.886) 3.128 0.279 (0.61615.886) 3.128 0.279 (0.61615.886) 1.000 0.389 (0.4932.027) 3.833 0.000025 (1.6348.991) 2.194 0.149 (1.1204.296) 1.963 0.024 (0.7495.146) 2.064 0.279 (0.5028.493) 0.591 0.523 (0.2761.265) 0.852 0.814 0.000273 0.279 0.279 0.279 1.000 0.001 0.020 0.164 0.498 0.173 P145 HLA-B*38:01 And HLA-A*24:02 Allele Frequencies In Spanish Patients With Lamotrigine-Induced SCARs Teresa Bellón1, Elena Ramirez2, Alberto Manuel Borobia2, Hoi Tong3, Jose Luis Castañer4, Francisco José De Abajo5 1. IdiPAZ, Madrid, Spain 2. Hospital Universitario La Paz, IdiPAZ, Madrid, Spain 3. Hospital Universitario La Paz, Madrid, Spain 4. Hospital Universitario Ramón y Cajal, Madrid, Spain 5. Hospital Universitario Príncipe de Asturias, Alcalá De Henares, Madrid, Spain Introduction Some HLA-I alleles are risk factors for the development of severe cutaneous adverse drug reactions (SCARs). HLA-B1502 is strongly associated with the development of Stevens Johnson syndrome /toxic epidermal necrolysis (SJS/TEN) to carbamazepine (CBZ) in Southeast Asian populations where the allele is prevalent. On the other hand, HLA-A3101 has been found to be a risk factor for (CBZ)-induced drug reaction with eosinophilia and systemic symptoms (DRESS) in European and Asian patients. HLA-A3101 has been weakly associated to CBZ-induced SJS/TEN in Europeans, and no association has been found with other aromatic antiepileptic drugs (AEDs). No HLA-I alleles have been definitely associated with lamotrigine (LTG)- or phenytoine (PHE)- induced SCARs in Europeans Method To explore the association of HLA-I allele frequencies with SCARs to AEDs in our population, 12 patients with DRESS and 14 cases with SJS/TEN included in the Spanish registry PIELenREd were studied. Six cases were related to LTG (3 SJS/TEN; 3 DRESS), 6 were related to CBZ (2 SJS/TEN; 4 DRESS), and 14 cases were induced by PHE (9 SJS/TEN; 5 DRESS). DNA was prepared from total blood and four digits HLA typing was performed. The frequencies of HLA-I alleles in patients with LTG-induced SCARs were compared with frequencies in patients within the other groups, and with previously published HLA-I frequencies in 253 Spanish individuals (Balas et al Tissue Antigens, 2010). Results HLA-B3801 allele was present in all 3 cases of LTG-induced SJS/TEN suggesting a strong association (OR=37.92; 95% CI: 5.4-269.53; p<0.0001). Only 2 out of 9 SJS/TEN cases induced by PHE were carriers of HLA-B3801 (OR=4.74; 95%CI: 0.67-25.12; p=0.09). None of the 12 DRESS cases analyzed were carriers of HLA-B3801. On the other hand, the 3 LTG-induced DRESS patients were carriers of HLA-A2402 showing a significant association as compared to the control sample (OR=5.25; 95%CI: 1.0-24.75; p=0.04). HLA-A2402 was found in 3 out of 5 cases of PHE-induced DRESS (OR=4.5; 95%CI: 0.88-20.27; p=0.054) and was absent in all CBZ cases and in SJS/TEN cases to PHE. Conclusion Our results suggest that HLA-B3801 may be a risk factor for LTG-induced SJS/TEN, in agreement with previous data (Lonjou et al, Pharmacogenetics and Genomics 2008). On the other hand HLA-A2402 might be related with LTGinduced DRESS or exantematic reactions, as recently published in the Norwegian population (Shirzadi et al Epilepsy Research 2016). P146 Overrepresentation Of A Class II HLA Haplotype In Severe Hypersensitivity Type I Reactions To Carboplatin Violeta Régnier Galvao1, Rebecca Pavlos2, Elizabeth Mckinnon2, Kristina Williams3, Alicia Beeghly-Fadiel4, Alec Redwood2, Elizabeth Phillips3, Mariana Castells1 1. Brigham and Women`s Hospital, Division of Rheumatology, Immunology and Allergy, Harvard Medical School, Boston, United States 2. Institute for Immunology and Infectious diseases, Murdoch University, Perth, Australia 3. Vanderbilt University Medical Center, Nashville, United States 4. Vanderbilt Epidemiology Center, Institute for Medicine and Public Health; Vanderbilt University Medical Center, Vanderbilt-Ingram Cancer Center, Nashville, United States Keywords: HLA Genotyping, Rapid Drug Desensitization, Carboplatin, IgEMediated Reaction, Drug Allergy Introduction HLA class I and class II genotyping has identified patients at risk for both T-cell mediated and IgE/mast cell mediated severe drug hypersensitivity (HSR). Class II HLA-DRA variants have been associated with immediate allergic reactions to beta-lactams and the HLA-DRB1*07:01 allele has been associated with IgEmediated reactions to asparagine. Up to 27% of women exposed to 6 or more cycles of carboplatin present with immediate HSR and 50% of these reactions are anaphylactic. BRCA1/2 mutations have been found to be more common among patients who develop immediate reactions to carboplatin and these reactions, including anaphylaxis, have been successfully addressed by rapid drug desensitization (RDD).We sought to evaluate the HLA profile of patients who presented an initial carboplatin-induced severe hypersensitivity reaction including anaphylaxis, had a positive skin test and were treated with the BWH rapid drug desensitization 3-4 bags protocol. Method HLA ABC DR DQ DP typing was conducted for a cohort of Caucasian ovarian cancer patients (n=11) with a history of grade 2 or 3 type I HSR to carboplatin undergoing RDD and a control group of Caucasian ovarian cancer patients treated with carboplatin, who tolerated 8 or more cycles (n=12). Allele carriage amongst cases and controls was compared using Fisher’s exact test. The Haploblocks program was used to generate cobygram visuals of HLA cocarriage. Results Among allergic patients, 36% (4/11) had grade 2 and 64% (7/11) grade 3 initial HSR. All successfully tolerated the RDD and were able to complete their treatment plans. We found that the HLA-DRB1*15:01 allele was more prevalent among allergic patients (5/11, 45%) than among the control group (1/12, 8.3%) (p=0.06). Cobygram analysis suggests that the HLA class II association may extend to the DQA1*01:02-DQB1*06:02-DRB1*15:01 haplotype (Figure 1). Conclusion In this Caucasian cohort of ovarian cancer patients, a specific HLA class II allele, DRB1*15:01, was suggested to be associated with immediate hypersensitivity to carboplatin. Further carboplatin HSR cases and carboplatin tolerant controls are currently been accrued to verify the validity of this association and assess its extension to the DQA1*01:02-DQB1*06:02-DRB1*15:01 haplotype. Poster Walk 17: in vivo Diagnosis + sIgE (P147 – P154) P147 Absence Of Specific Ig-E Against Beta-Lactams Nine Months After An Allergic Reaction To Amoxicillin-Clavulanic Acid Elisa Boni, Marina Russello, Marina Mauro Hospital Sant'Anna, Como, Italy Introduction In case of immediate reactions to beta-lactams, allergological work up consists of detection of specific Immunoglobulin-E (Ig-E) against beta-lactams in serum and skin tests, i.e. prick test and intradermal tests with major and minor antigenic determinants of penicillin, amoxicillin, ampicillin and benzilpenicillin. Levels of specific Ig-E decrease after the reaction and they are no more detectable after some years. It is recommended to perform in vivo and in vitro tests after 3 weeks and no later than 6-12 months after the reaction. Sensitivity of tests then decreases and false negative result may occur. In case of remote history of immediate reaction to beta-lactam, if tests are negative, a provocation test with the culprit drug is necessary and should be followed by repetition of skin tests. Case Description We report the case of a woman aged 61 years who experienced a systemic reaction (urticaria, vomit, diarrhea, fatigue) 15 minutes after intake of amoxicillin/clavulanic acid. Four months later, she underwent a visit in our Allergy Unit and serological and skin tests were scheduled. Serological specific Ig-E against penicilloyl G, penicilloyl V, ampicillin, amoxicillin, cefaclor as well as skin tests gave negative result. They were performed respectively 5 and 9 months after the reaction. A drug provocation test (DPT) with amoxicillin was then performed and was considered positive for the occurrence of generalized pruritus 20 minutes after the intake of the last dose (cumulative dose 875 mg). Skin tests were repeated with positive results to both amoxicillin and ampicillin, at the concentration of of 1 mg/ml and 20 mg/ml, respectively. How this report contributes to current knowledge Specific Ig-E levels against beta-lactams decrease after immediate-type reactions. Guidelines recommend to perform allergological work up within 6-12 months. Our case shows how this period might be too long and false negative tests can occur even if performed within one year. DPT should always follow negative skin tests to obtain a correct diagnosis. P148 Drug Provocation Tests In Suspected Opioid Allergy Kok Loong Ue, Krzysztof Rutkowski Department of Allergy, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom Keywords: Anaphylaxis, Codeine, Drug Provocation Test, Morphine, Opiod Allergy Introduction There are no good epidemiological data regarding opioid allergy (OA). Many side effects can occur with this group of drugs. These are often misinterpreted as an IgE-mediated OA. As a consequence, many patients receive an unsubstantiated diagnosis of OA and avoid opioid unnecessarily. Diagnosis of OA can be challenging as skin tests (ST) and opioid-specific IgE have a poor predictive value. Drug provocation tests (DPT) remain the gold standard for the diagnosis of OA. However, there are almost no studies of opioid DPT and no validated opioid DPT protocols. Method 30 suspected cases of OA (12 morphine, 18 codeine) were studied using detailed history and oral DPT. Opioid ST and specific IgE were not performed. Standardised local protocols were used. For morphine: 2, 3, and 5mg morphine sulphate oral solution (10mg/5mls) was administered at 30min interval with 120min monitoring. For codeine:10, 20 and 30mg codeine phosphate syrup (25mg/5mls) was administered at 30min interval with 60min of monitoring. All DPT were performed on a specialist allergy unit. Results 25 females and 5 males (median age of 46.5) experienced various symptoms reported as OA. Opioids were prescribed mainly for analgesia. 20 patients (67%) had cutaneous symptoms: angioedema: 5, urticaria: 4, angioedema and urticaria: 2, unspecified rash: 5, angioedema, unspecified rash and pruritus: 3, angioedema and unspecified rash: one. 11 patients (37%) experienced symptoms suggestive of anaphylaxis: dyspnoea, tachycardia, hypotension, dizziness and collapse. 2 of these (18%) experienced cutaneous symptoms too. Other non-specific symptoms included nausea: 2, paraesthesia: 2, tremor: 1, anxiety: 1. DPT were negative in 23 patients (77%). 6 patients (20%) had symptoms of intolerance: pruritus, nausea, dizziness, tremor to morphine (2) and codeine (4). Only 3% of DPT were positive: 1 patient experienced angioedema with codeine. Conclusion DPT-confirmed OA appears to be very rare (3%). Most symptoms misinterpreted as OA could be due to a dose-dependent mast cell degranulation, genetic polymorphism of CYP2D6 gene or the underlying acute illness. Morphine and codeine DPT are a safe and reliable diagnostic tool. Our ongoing multi-centre study will endeavour to validate this approach in a larger cohort of suspected OA patients (including other opioids) and produce standardised DPT protocols to improve the diagnosis of OA in Europe and worldwide. P149 IMPROVEMENT TO THE SPECIFIC IgE CUT-OFF IN THE ASSESS OF ß-LACTAMIC ALLERGY Victor Soriano Gomis, Jorge Frances Ferre, Angel Esteban Rodriguez, Vicente Cantó Reig, Javier Fernandez Sanchez Universitary General Hospital of Alicante, Alicante, Spain Introduction Specific IgE against β-lactams by CAP FEIA system (Thermo Scientific®) used to use the cut-off of 0.35 kU/L, but now we can get a detection limit of the assay of 0.10 kU/L. We pretend to evaluate if this change of cut-off from 0.35 to 0.10 kU/L improves the sensitivity without compromise its specificity. Method 74 patients older than 18 years evaluated in the allergy outpatient clinic since January 2011 to April 2014 were studied. They were classified as allergic by history and skin tests positive to β-lactamic antibiotics. Specific IgE against penicilloyl G, penicilloyl V, amoxicilloyl and ampicilloyl were analyzed by CAP FEIA system (Thermo Scientific®). With these IgE values and positive or negative diagnosis of allergy, sensitivity and specificity of both cut-offs (0.35 and 0.10 kU/L), the ROC curves were obtained. In addition, the AUC value (with their confidence interval) was calculated. The SPSS (v19.0) and “Analyse-it”- Excel were used. Results ROC results Specific IgE Penicilloyl G Penicilloyl V Ampicilloyl Amoxicilloyl AUC value 0.780 0.748 0.783 0.844 CI 95% 0.66-0.90 0.638-0.858 0.674-0.892 0.758-0.930 Sensitivity and specificity with the 0.10 kU/L cut-off Specific IgE Sensitivity (%) Specificity (%) Penicilloyl G 55.6 85.7 Penicilloyl V 47.1 80.0 Ampicilloyl 74.2 69.0 Amoxicilloyl 74.2 74.4 Sensitivity and specificity with the 0.35 kU/L cut-off Specific IgE Sensitivity (%) Specificity (%) Penicilloyl G 33.3 94.6 Penicilloyl V 23.5 97.5 Ampicilloyl 35.5 97.6 Amoxicilloyl 45.2 93.0 Conclusion The cut-off of 0.10 kU/L may be more appropriate to use in the clinical practice because it improves the correct classification of b-lactams allergy patients. The amoxicilloyl obtains the best performance with this new cut-off. P150 Initial False Negative Specific IgE To Gelatin In A Patient With Gelatin-Induced Anaphylaxis. Christine Breynaert1, Erna Van Hoeyveld2, Rik Schrijvers1 1. Laboratory of clinical immunology, department of microbiology and immunology, KU Leuven, Leuven, Belgium 2. Laboratory medicine, Immunology, University Hospitals, KU Leuven, Belgium, Leuven, Belgium Introduction The time of determination of specific IgE (sIgE) to potential culprit drugs, as an aid in the diagnosis of peri-operative anaphylaxis, is not well defined for all drugs. Case Description A 62-year old man experienced an anaphylaxis within 15 minutes after receiving a gelatin-containing plasma expander during general anesthesia for hip surgery after a high velocity trauma. Decontamination was performed with chlorhexidine, and propofol, lidocaine, sufentanil, rocuronium, dexamethasone, was adminstered 2h15 and cephazolin 1h45 prior to the event. The gelatin infusion was stopped and treatment with epinephrine, norepinephrine, promethazine, hydrocortisone, and saline fluid expansion installed. Serum tryptase was transiently increased (95.7 ng/dl 1h30 after the onset of the reaction versus 6.0 ng/dl > 24 h after the event). ImmunoCAP sIgE (Thermofisher - Phadia, Sweden) to gelatin, galactose-alpha-1,3-galactose, ethylene oxide, latex, and chlorhexidine was negative on the sample obtained 1h30 after the event, and independently confirmed. However, repeat sampling 16 days after the event with a serial dilution of the gelatin-containing plasma expander, mimicking the timing of the initial testing, demonstrated the inhibition of sIgE determination with a 50% inhibitory concentration (IC50) of 0.02% (Fig. 1). No serum before the anaphylaxis was available to confirm a pre-existing sensitization. Skin testing 4 weeks after the event was positive for the 4% gelatin-containing plasma expander (3 mm and 5 mm wheal diameter after skin prick testing at a 1:10 and 1:1 dilution respectively) and negative for chlorhexidine, latex, and cephazoline. How this report contributes to current knowledge A rare case of IgE-mediated gelatin allergy is reported. We hypothesized that the initial sIgE for gelatin was false negative due to competition of infused gelatin with the gelatin-immunoCAP assay rather than a boostin phenomenon had taken place, suggesting careful interpretation of sIgE determinations very early after the event, at least in the case of gelatin-sIgE. P151 Inmediate Reactions To Beta-Lactam Antibiotics. Pattern Of Skin Test Response Over The Time Jose Julio Laguna Martinez1, Rosario Gonzalez Mendiola1, Javier Dionicio Elera1, Cosmin Boteanu1, Aranzazu Jimenez Blanco1, Marta Del Pozo1, Raquel Fuentes Irigoyen2 1. Allergy Unit. Hospital Central de la Cruz Roja, Madrid, Spain 2. Pharmacy Service. Hospital Central de la Cruz Roja, Madrid, Spain Keywords: Beta-Lactams, Amoxicillin, Skin Test, Allergy,Inmediate Reaction Introduction Beta-lactam (BL) antibiotics are the drugs most frequently involved in IgEmediated allergic reactions. Skin testing is the most widely used diagnostic method to evaluate IgE mediated reactions to BL. Skin test respond to penicillin determinants vary in different populations over time related with pattern of consumption. but precise studies The aim of our work is to study the variation of the skin response over long time in a well-defined series of allergic to BL. Method All patients submitted to our centre, in ten year period (1999-2009) with a compatible history of beta-lactam allergy underwent allergy work-up according to the ENDA protocols for immediate reactions. Skin tests (prick and intradermal) with the classical penicillin reagents (Allergopharma Reinbeck, Germany (1999 to 2005) and from 2005 (Diater reagents DAP, Madrid, Spain): penicilloyl polylysine (PPL), minor determinants mixture (MDM :benzylpenicillin and sodium benzylpenicilloate) and benzylpenicillin (penicillin G) and Semi-synthetic penicillins (amoxicillin, amoxicilin/clavulanic acid and ampicillin) were also systematically tested, as well as any other suspected beta-lactam. In the case of negative results, we perform provocation tests with the suspected drug. Considering the temporal variation for immediate reactions in terms of skin test positivity, Patients were classified according to the year they referred the reaction, in four periods (>1980, 19801990, 1991-2000 and >2001-2009) Results From a total of 2716 patients initially evaluaed, 296 were finale confirmed as inmediate reactions to Betalactamic. A total of 247 were diagnosed by skin testing, this represents 83% of total (247/296). Considering the temporal variation for immediate reactions in terms of skin test positivity, the analysis of the AX determinants showed that there was a gradual increase over the years that varied from 38,5% to 81,2%. Statistical analysis confirm a strong signification p< 0,0001. In parallel a decreased of antigenic determinants of penicillin (including PPL, MDM and Benzylpenicillin) from 30,8 % to 12,7% also statistic significance p<0,007. Conclusion Our study confirm that the variation of beta-lactam pattern consumption modify the skin test response in a long series over 10 years. Strong statistical significance of amoxicillin skin tests rising p < 0.001 correlates with the progressive increase in amoxicillin consumption since 2001. P152 New Fluorescent Dendrimeric Antigens For The Evaluation Of Dendritic Cell Maturation As A Test To Detect Allergy Reactions To Amoxicillin Daniel Collado1, Yolanda Vida1, Francisco Najera1, Ezequiel Perez-Inestrosa1, Pablo Mesa-Antunez1, Cristobalina Mayorga2, María José Torres2, Miguel Blanca2 1. University of Malaga, Malaga, Spain 2. Allergy Service, Carlos Haya, Malaga, Spain Keywords: Confocal Microscopy; Dendritic Cell; Maturation Introduction ln order to emulate the recognition process working in vivo, much effort have been made to prepare hapten(drug)-carrier(protein) conjugates attempting to work like the antigen responsible for the allergic drug reaction. Method In our efforts to exploit the dendrimer properties in the interaction with the immunological system, we have prepared a series of Dendrimeric:Antigens (DeAn), to study the dendritic cell (DC) maturation as a test to detect allergy reactions to amoxicillin. Recently our research group developed a new kind of dendrimer, called BAPAD, that we have used in this work to obtain the dendrimeric moiety of the target molecule. To this avail we synthesized a generation two BAPAD dendrimer using cystamine as core. Then, the free amine groups on the surface of the dendrimer were functionalized with an amoxiciloyl group (AXO). The fluorescent DeAn has been fully characterized by NMR and MS techniques, and their fluorescent properties well established in aqueous biological media using confocal microscopy. The fluorescent dendron (De) without the haptenic moieties at the periphery has been also obtained and fully characterized as a control assay. The fluorescent DeAn and De was used in dissolution and supported in solid surface (cellulose disk). The solid conjugates were immunologically evaluated by RAST inhibition using sera from 7 patients allergic to amoxicillin. DC from four amoxicillin allergic patients have been incubated with fluorescent DeAn and De and studied with a flow cytometer to determine whether or not the cells were able to uptake both compounds. Results Flow cytometry and confocal microscopy show that these dendrimeric structures interact with DC and are internalized by them to the cellular cytoplasm. The maturation of DC was tracked by by flow cytometry. In all cases, low maturation induced by DeAn in allergic patients is observed. This effect can be due to two factors: 1) that the concentration of compound that enters the DC is low and 2) that the hapten density presented in DeAn is low. The RAST inhibition studies of solid supported DeAn showed a higher RAST inhibitions values for allergic patients compare with negatives controls. This value was also compared with solid surfaces conjugated with PLL-AXO showing similar results. Conclusion These dendrimeric structures assayed in RAST inhibition studies letting us check that inhibition occurred, so recognition existed between IgE of patients allergic to amoxicillin and DeAn structures. P153 Positive Skin Test Or Positive Specific IgE To Penicillin Does Not Predict Penicillin Allergy Line K Tannert1, Charlotte G Mortz2, Per Stahl Skov3, Carsten Bindslev-Jensen2 1. Odense Research Center for Anaphylaxis, Odense C, Denmark 2. Department of Dermatology and Allergy Center, Odense C, Denmark 3. Odense Research Center for Anaphylaxis, Odense C/Copenhagen, Denmark Introduction Diagnosis of penicillin allergy is based on case history, skin testing (ST, prick and intracutaneous tests) and measurement of specific IgE (s-IgE) to a penicillin and challenge with penicillin. If ST or s-IgE is positive, the patient is classified as allergic to penicillin according to the European Network of Drug Allergy guidelines and challenge is omitted. Therefore, the true sensitivity and specificity of ST and s-IgE are presently not known. The aim of this study was to investigate the clinical relevance of a positive skin test and s-IgE to penicillin. Method Forty-four patients with a positive ST and/or s-IgE were included; ST with penicillin was done and s-IgE was measured in all 44 patients at the time point designated T0. Challenge with the culprit penicillin was performed immediately hereafter although abstained in patients with recent anaphylaxis to penicillin (n=8), systemic reactions to ST (n=3) or development of delayed positive ST (n=8). These were classified as allergic to penicillin; thus, 25 patients were challenged. 18 of the patients had been evaluated previously (T-1) and reproducibility of the results were compared to T0 and again four weeks post challenge (T1). Results Nine of the 25 challenged patients were positive. There was a significantly increased probability of being allergic to penicillin if both skin test and s-IgE were positive at T0 (p=0.007). Positive ST or s-IgE alone did not predict penicillin allergy (p=0.313/p=0.051). Among the 18 patients repeatedly tested, only 12/26 (46.2%) of positive skin tests at T-1 were reproducibly positive at T0, and only one further ST became positive at T1. For s-IgE, 14/24 (58.3%) of positive measurements were still positive at T0 and seven further became positive at T1, although s-IgE levels at T0 and T1 did not differ significantly (p=0.599). Conclusion In this study, the best predictor for a positive penicillin challenge was history combined with both positive ST and s-IgE. There was a relatively low reproducibility of a previously positive ST and s-IgE. P154 Significance Of Skin Testing And In-Vitro-Analysis Of Neuromuscular Blocking Agents In Diagnosis Of Perioperative Drug Hypersensitivity: Evaluation Of A Negative Control Population Wolfgang Pfützner, Hannah Dörnbach, Johanna Visse, Michele Rauber, Christian Möbs Department of Dermatology and Allergology, Philipps University Marburg, Marburg, Germany Keywords: Perioperative Anaphylaxis, Anaesthesia, Neuromuscular Blocking Agents, Skin Test, Basophil Activation Test Introduction Perioperative drug hypersensitivity (PDH) presents a major problem resulting in unexpected, often severe anaphylactic reactions. Diagnosis of anaphylaxis during anaesthesia mainly relies on skin testing, since assays for the detection of IgEantibodies are not available and provocation tests are not feasible for most of the involved drugs. Neuromuscular blocking agents (NMBAs) are recognized as the most prevalent elicitors of PDH, however, skin tests with NMBAs might result in false-positive results due to unspecific, non-IgE-mediated release of histamine. Method To further investigate this subject, we evaluated the potential of NMBAs eliciting positive results in individuals with known NMBA-tolerance in both skin prick (SPT) and intracutaneous tests (ICT) and compared these with the reactivity in basophil activation tests (BAT). Eleven individuals (5 females, 6 males; 25-60 years old, median (m) = 50) without known allergy to NMBAs, but tolerant to a recently perioperative applied NMBA were included in this study. The NMBAs Suxamethonium, Rocuronium, Cis-Atracurium and Mivacurium were tested by both titrated SPT and ICT, and NMBAs eliciting a positive skin reaction were further analyzed by BAT with the individuals’ serum. Results SPT yielded positive results in 0/11 participants for Suxamethonium, Rocuronium and Cis-Atracurium and in 2/11 for Mivacurium. ICT was positive in 2/11 for Suxamethonium, 9/11 for Rocuronium, 8/11 for Cis-Atracurium and in 11/11 for Mivacurium. BAT analysis confirmed the positive skin tests in only one individual, while it was negative for the NMBAs in all others. Conclusion These findings show that skin test results with NMBAs have to be carefully interpreted regarding their clinical relevance and the implementation of more reliable test systems would be helpful for diagnosis of PDH. Poster Walk 18: in vitro /ex vivo (P155 – P158, P160 – P164) P155 Diagnostic Value Of The Lymphocyte Toxicity Assay (LTA) And The In Vitro Platelet Toxicity Assay (IPTA) For ß-Lactam Allergy Abdelbaset A Elzagallaai, Lindsey Chow, Awatif M Abuzgaia, Michael J Rieder Western University, London, Canada Keywords: Drug Allergy, Drug Hypersensitivity, In Vitro Diagnosis Introduction β-lactam antibiotics (BLAs) are the drugs most associated with immune-mediated hypersensitivity reactions (drug allergy). They can elicit all types of allergic reactions i.e., types I, II, III and IV. Although the immediate IgE-mediated reaction has been well studied, the pathophysiology of non-immediate hypersensitivity reactions is not well understood. Cross-reactions among BLAs with different side chains are variable. The diagnosis and prediction of BLAsinduced allergic reactions is challenging and based mostly on clinical history. The lymphocyte toxicity assay (LTA) and the in vitro platelet toxicity assay (iPTA) are in vitro tests with a potantial value for diagnosis and prediction of drug allergy. Their value in diagnosis of reactions to BLAs, however, is still unknown. This work is an attempt to evaluate the performance of in vitro toxicity testing for diagnosis of different types of allergy to BLAs and to investigate the their different underlying pathophysiology. Method One hundred and seventy individuals (85 drug allergy-suspected patients and 85 healthy volunteers) were included in this study. Patients were identified from clinical records and included using a rigorous internationally recognized inclusion criteria based on their clinical presentation and available diagnostic investigations (i.e., skin testing and RAST). The LTA and iPTA tests were performed after resolution of the reaction symptoms. Data was expressed as percentage of cell death compared to control (vihicle without the drug) after incubation with the suspected drug in presence of rat microsomes (MICs). Results Patients were grouped according to their exhibited symptoms into 3 groups constituted of 8 patients type I, 28 patients type III and 49 patients type IV. Patients with type IV reactions exhibited higher degrees of cell death than the other 2 groups (p<0.05) with type I patients exhibiting the lowest degree of cell death among all groups. Conclusion Using the in vitro toxicity testing (LTA and iPTA) we were able to identify patients susceptible to develop allergy to BLAs. In addition, cells isolated from patients with different types of reactions exhibit variable degrees of cell death, which indicate possible distinct pathophysiological mechanisms. The LTA and iPTA can be a useful tool to both diagnose drug allergy to BLAs and investigate its underlying pathophysiology. Characteristic Sex (female/male; n[%]) Age (mean; y [range]) Type of reaction (n [%]) Type I Type III Type IV Total Value 53/31 [63.1/36.9] 24 [1-88] 8 [9.4] 28 [32.9] 49 [57.6] 85 [100] P156 Enzyme Linked Immunospot Assay Used In The Diagnosis Of Severe Cutaneous Adverse Reactions To Antimicrobials Alec Redwood1, Jason Trubiano2, Rebecca Pavlos1, Emily Woolnough2, Kaija Stautins1, Christina Cheng2, Elizabeth Phillips3 1. Institute of Immunology and Infectious Diseases, Murdoch University, Perth, Australia 2. Department of Infectious Diseases, Alfred Health, Melbourne, Australia 3. Vanderbilt University Medical Center, Nashville, United States Introduction The ability to define drug causality in cases of Severe Cutaneous Adverse Reactions (SCAR) where multiple antimicrobials are implicated remains problematic. We describe a case of toxic epidermal necrolysis (TEN) in the setting of multiple implicated antimicrobials and the utility of T-cell enzyme linked immunospot assay (ELISpot) to define antimicrobial causality Case Description A 20-year old man was admitted to a tertiary referral trauma centre for management of wound sepsis and femoral stump osteomyelitis in the setting of recent below-knee amputation following a high-speed motorbike accident. Whilst receiving escalating antimicrobial treatment, for bacteraemia and fevers > 38.3°C, he developed a blistering rash involving greater than 30% of body surface area (BSA) associated with a positive Nikolsky sign, consistent with TEN. Multiple antimicrobials were administered prior to onset of TEN, four of whichvancomycin, meropenem, linezolid and teicoplanin - were temporally associated with the onset of TEN. How this report contributes to current knowledge We sought to use cellular assays, IFN-gamma ELISpot and flow cytometry, to identify the causative agent of TEN in a patient receiving multiple antibiotics. Following informed consent, patient whole blood was collected on day 4 post onset of TEN. PBMCs were extracted and cryopreserved. HLA ABC DR DQ DP typing was performed and the PBMCs were used for ex vivo ELISpot testing. PBMCs were also incubated with candidate drugs for 18-20 hours at 37°C in 5% CO2 and assessed by flow cytometry for upregulation of the T cell activation marker CD137. Patient HLA was HLA-A*01:01 and 02:02, HLA-B*37:01 and 41:01, HLAC*10:01 and 17:01, HLA-DPB1*10:01, HLA-DQA1*01:01 and 02:01, HLADQB1*02:02 and 05:01, HLA-DRB1*07:01 and 10:01. Positive ELISpot responses were reproducibly produced only to the glycopeptide antibiotic teicoplanin, with up to 300 SFU/million cells. ELISpot data were confirmed by flow cytometry analysis, where only teicoplanin induced up-regulation of the activation marker CD137 (0.3% of total CD8+ T-cells). All other antibiotics including vancomycin and meropenem were negative by ELISpot and flow cytometry. We believe this to be the first reported use of T-cell ELISpot to assign isolated teicoplanin causality to TEN. P157 Evaluation Of In-Vitro Diagnostic Methods For Identifying The Culprit Drugs In Drug Hypersensitivity Kenichi Kato1, Hiroaki Azukizawa2, Takaaki Hanafusa3, Ichiro Katayama1 1. Department of Dermatology, Osaka University, Osaka, Japan 2. Department of Dermatology, Nara Medical University, Nara, Japan 3. Department of Dermatology, Tokyo Medical and Dental University, Tokyo, Japan Introduction The drug-induced lymphocyte stimulation test (DLST), or lymphocyte transformation test (LTT), is used to identify the culprit drug in cases of cutaneous adverse drug reactions (cADR). While DLST is widely used as in-vitro diagnostic tool, its sensitivity and specificity are unsatisfactory. Determination of antigen-specific IFN-γ production by enzyme-linked immunospot assay (conventional IFNγ-ELISpot) is well-established diagnostic method for tuberculosis infection, and recent reports suggested that drug-induced conventional IFNγ-ELISpot is useful for identifying the culprit drug of cADR cases. The aim of this study was to establish a novel diagnostic method for identifying the culprit drug in cADR patients through the efficient detection of the drugspecific IFN-γ production by IFNγ-ELISpot. Method Ten cases of cADR caused by clinically convincing culprit drugs were enrolled in this study. Peripheral blood mononuclear cells (PBMCs) from all 10 patients were used for both DLST and drug-induced conventional IFNγ-ELISpot. In addition, drug-induced IFNγ-ELISpot was also performed by using PBMCs which were nonspecifically stimulated with monoclonal antibodies for 7 days before exposing culprit drugs (modified IFNγ-ELISpot) in all cases. Results Drug-induced IFN-γ production was detected by modified IFNγ-ELISpot in 5 patients of which DLST and conventional IFNγ-ELISpot were both negative. Moreover, IFN-γ secretion was observed by modified IFNγ-ELISpot in all 4 patients of which DLST were positive. Conclusion Modified IFNγ-ELISpot using expanded PBMCs is more sensitive than conventional IFNγ-ELISpot for detecting drug-induced IFN-γ production. Therefore, this novel IFNγ-ELISpot could be a useful in-vitro tool for identifying culprit drugs in cADR cases. P158 Ex-Vivo Expanded Skin-Infiltrating T Cells From Severe Drug Eruptions Are Reactive With Causative Drugs: A Possible Novel Method For Determination Of Causative Drugs Toshiharu Fujiyama1, Hideo Hashizume2, Takatsune Umayahara1, Taisuke Ito1, Yoshiki Tokura1 1. Hamamatsu University School of Medicine, Hamamatsu, Japan 2. Shimada City Municipal Hospital, Shimada, Japan Keywords: T Cells, IFN-Gamma, Introduction Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and druginduced hypersensitivity syndrome/ drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS) are life-threatening adverse drug reactions. For prevention of relapse, it is mandatory to determine the causative drug. Patch test and lymphocyte stimulation test (LST; also known as DLST in Japan) are frequently used for this purpose, but their positivity ratios are not sufficiently high. We sought to explore a novel method using skin-infiltrating T cells for determination of causative drugs because it is considered that antigen-specific T cells infiltrate in skin lesions of the severe drug eruptions and participate in its pathogenesis. Method We expanded skin-infiltrating T cells from 4-mm biopsied lesional skin samples of severe drug eruption using anti-CD3/CD28 antibodies and IL-2. More than 107 T cells/specimen were obtained by two-week cultivation. To investigate their cytokine production by in vitro stimulation with causative drugs, the expanded T cells were co-cultured with drugs peripheral blood mononuclear cells (PBMCs) from the same patient, and IFN-g production was assessed by ELISpot assay. Moreover, to see the drug-induced T-cell proliferation, the expanded T cells were labeled with CFSE and cultured with drugs and X-ray-irradiated PBMCs for a week, and the proliferation was assessed by flow cytometry. The cytokine profile of the cells which proliferated in response to drugs was also assessed by flow cytometry. Results The ELISpot assay showed a significantly high number of T cells produced IFN-g by drug stimulation as compared to no addition control. The CFSE assay revealed that both CD8+ and CD4+ T cells proliferated in response to causative drugs in SJS/TEN and DIHS/DRESS. Notably, the majority of CD8+ T cells proliferating to causative drugs expressed IFN-g in SJS/TEN. Conclusion Our study suggests that the use of ex-vivo expanded skin-infiltrating T cells can yield a novel method for determination of causative drugs in the severe drug eruptions. P160 In Vitro Release Of IL-2, IL-5 And IL-13 In Diagnosis Of Patients With Delayed-Type Nickel Hypersensitivity Mira Silar1, Mihaela Zidarn1, Helena Rupnik2, Peter Korosec1 1. University Clinic for Respiratory and Allergic Diseases, Golnik, Slovenia 2. ARSDERMA, Ljubljana, Slovenia Introduction T cells play a major role in delayed-type of hypersensitivity reactions. Their reactivity can be assessed by lymphocyte transformation test or upregulation of cell surface activation markers, and those tests are of limited practicability or diagnostic sensitivity. Some previous report suggested that in vitro secretion of cytokines by peripheral blood mononuclear cells (PBMC) could be a promising tool for improved detection of T-cell sensitization. For that reason we wanted to test this methodology in patients with well-defined delayed-type nickel hypersensitivity. Method PBMC of 10 nickel hypersensitive patients and 9 healthy controls were incubated for 48 hours with two different concentration of NiSO4x6H2O (0.5 to 5 μg/ml). IL-2, IL-5, IL-13 and IFN-γ concentrations were measured in supernatants with multiplex flow cytometry CBA Flex Array. Results We showed a significantly increased secretion of IL-2 (median 182 vs 3 ng/ml), IL-5 (9 vs 0 ng/ml), IL-13 (36 vs 0.5 ng/ml) in response to NiSO4x6H2O in patients nickel hypersensitivity when compared with healthy controls. The response in the patients was concentration dependent. No difference was evident for IFN-γ . The ROC curve analysis demonstrated the highest AUC of 0.99 for IL2 and IL-13, followed by AUC of 0.91 for IL-5. Conclusion The measurement of IL-2 and IL-13 appearing to be a superb approach to identify antigen reactive T cells in the peripheral blood of patients with the hypersensitivity reactions. This cytokine approach could be now tested on the clinical important issue of the diagnosis of the delayed-type hypersensitivity reactions to drugs. P161 Single Cell Analysis Of Drug Responsive T Cells; Identification Of Candidate Drug Reactive T Cell Receptors In Abacavir And Carbamazepine Hypersensitivity Alec James Redwood1, Kaija Strautins1, Katie White2, Abha Chopra1, Katherine Konvinse2, Shay Leary1, Rebecca Pavlos1, Simon Mallal2, Elizabeth Phillips2 1. Institute for Immunology and Infectious Diseases, Murdoch University, Perth, Australia 2. Vanderbilt University Medical Center, Nashville, United States Keywords: T Cell Receptor, Abacavir, Carbamazepine Introduction T cell mediated drug hypersensitivity requires three essential components, a target drug, a scaffold for the drug (MHC class I or class II) and a pathogenic T cell receptor (TCR). For several drugs including, abacavir and carbamazepine, two components of this trimolecular complex have been defined. For abacavir hypersensitivity reaction (HSR) the associated MHC is HLA-B*57:01 and for carbamazepine induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), the associated MHC is HLA-B*15:02. In the former instance the association of drug with MHC has been further defined with the successful resolution of the crystal structure of the abacavir complexed to HLA B57:01. To fully understand T cell mediated hypersensitivity reactions the nature of the T cells involved and ultimately the mechanism by which the TCR interacts with MHC plus drug must be elucidated. This study seeks to sequence and clone the TCR mediating drug hypersensitivity in response to a series of drugs. Method Working from a cohort of cryopreserved PBMCs on HLA-typed patients with confirmed histories of T-cell mediated drug hypersensitivities (abacavir hypersensitivity and carbamazepine SJS/TEN and DRESS) we performed flow cytometry, single cell cloning and single cell TCR sequencing and used these to develop and interrogate T-cell responses. PBMC samples with confirmed T-cell reactivity (ELISpot) were treated with drug for 18-20 hours. Upregulation of the activation marker CD137 was used to sort drug reactive CD8+ or CD4+ T cells. T-cells lines or clones were produced and individual T-cells were sorted for single or bulk TCR sequencing. Results We have developed a pipeline for the identification of pathogenic TCRs. T-cell lines maintained reactivity to candidate drugs. TCR sequencing from abacavir HSR patients (n=3) identified no public TCR, rather multiple putative pathogenic TCRs have been identified. For carbamazepine induced SJS/TEN (n=1) and DRESS (n=1) we have also identified multiple putative pathogenic TCR. Conclusion Several candidate pathogenic TCRs have been identified in patients with hypersensitivity to abacavir or carbamazepine. These putative TCRs will be cloned into Jurkat T-cell lines to determine if multiple T-cell clones contribute to hypersensitivity or if only a single clone in each patient is pathogenic. Ultimately these cloned TCR will be used to define the crystal structure of the trimolecular complex of drug/MHC/TCR. P162 Specificity And Sensitivity Of LTT In DRESS: Analysis Of Agreement With The Spanish Pharmacovigilance System Probability Algorithm Rosario Cabañas1, Elena Ramirez2, Ana María Fiandor3, Teresa Bellón4 1. Servicio de Alergia, Hospital Universitario La Paz, Madrid, Spain 2. Servicio de Farmacología Clínica, Hospital Universitario La Paz, Madrid, Spain 3. Servicio de Alergia , Hospital Universitario La Paz, Madrid, Spain 4. IdiPAZ, Madrid, Spain Introduction DRESS (drug reaction with eosinophilia and systemic symptoms) is a severe cutaneous adverse reaction (cADR). Causality assessment is often a problem in polymedicated patients. The probability algorithm of the Spanish Pharmacovigilance System (Capellá & Laporte, 1993) establishes different categories of causality after scoring of chronology, bibliography, drug withdrawal, re-exposure, and alternative causes (unlikely: <0, conditional: 1-3; possible 4-5, probable: 6-7, definite: >8). LTT has been used as a tool to determine the causality of cADR. LTT specificity and sensitivity are difficult to ascertain as the gold standard (re-challenge) is not acceptable in severe cases Method A total of 34 LTT assays were performed with suspected drugs in 15 DRESS cases included in the Spanish registry PIELenRED. Results were considered positive if stimulation indexes (S.I.) were ≥2, except for betalactam antibiotics (S.I. ≥3) or iodinated contrast media (S.I. ≥4). The Spanish Pharmacovigilance System algorithm (SPA) was applied and suspected drugs were divided into two categories: unrelated (SPA score ≤3) and related (SPA score ≥4). Results Positive LTT results were obtained in all patients. In 19 out of 23 positive LTT assays the drugs were related to the adverse reaction (SPA score ≥4). Ten out of the 11 drugs that tested negative were predicted to be unrelated to the adverse reaction (SPA score ≤3). A contingency table was built (Table 1). Fisher’s exact test was used to analyze the data. There was a significant agreement between the two methods (OR=47.5; 95% IC: 3.9-1342.94). If the pharmacovigilance algorithm was considered as gold standard, 95%sensitivity and 71% specificity were obtained for LTT assays, with a positive predictive value (PPV)=82% and negative predictive value (NPV)= 90% (p<0.001). On the other hand, if LTT was considered as gold standard, 82% sensitivity and 90% specificity was obtained for the SPA, with a PPV=90% and NPV=70% (p<0.001). Conclusion Although this is a small case series, the results indicate that LTT is a sensitive tool for causality assessment in DRESS. Moreover, the probability algorithm of the Spanish pharmacovigilance system can be useful to identify the culprit drug during the acute disease. Table 1. Drug causality data in DRESS patients Pharmacovigilance algorithm (SPA) results Related drug (SPA ≥4) Unrelated drug (SPA≤3) Positive LTT 19 4 Negative LTT 1 10 Total 20 14 Total 23 11 34 P163 The Role Of Interleukin-22 In ß-Lactam Hypersensitivity. Andrew Sullivan1, Paul Whitaker2, Daniel Peckham2, B Kevin Park1, Dean J Naisbitt1 1. University of Liverpool, Liverpool, United Kingdom 2. St James’s Hospital, Leeds, United Kingdom Introduction Antigen-specific T cells are important in the aetiology of cutaneous drug hypersensitivity. Classical Th1/Th2 phenotypes are used to classify drug hypersensitivity reactions, though these do not fully characterise the function of immune cells as the newer Th subsets such as Th9, Th17 and Th22 have not been studied. Method The aim of this study was to use the β-lactam antibiotic piperacillin as a paradigm to fully characterise the phenotype and function of drug-specific T cells. T cells were cloned from both blood and inflamed skin of hypersensitive patients and naïve T cells from healthy donors were primed to piperacillin using dendritic cells. Results Drug-specific clones were generated from both blood (n=570, 84% CD4) and skin (n=96, 83% CD4) from patients hypersensitive to piperacillin. All clones secreted high levels of IFNγ and IL13 following drug stimulation. Interleukin-22, perforin and granzyme B were also secreted by over 50% of clones. In contrast, IL17A secretion was not detected. Naïve T cells primed to piperacillin using autologous dendritic cells, proliferated in the presence of drug (p=0.001, SI>2) and had a similar pattern of cytokine secretion to clones generated from hypersensitive patients. Significant differences in chemokine receptor expression were observed between the different populations of T cell clones. CLA, CXCR6 and CCR1 expression was higher on piperacillin-specific skin-derived clones when compared to non piperacillin-specific skin-derived clones (P=0.01). CCR2, CCR4, CXCR1 and E-cadherin were higher on skin-specific clones when compared to blood-specific clones (P=0.01). Piperacillin-specific clones isolated from blood and skin of hypersensitive patients, as well as piperacillin-specific T cells from healthy donors migrated in the presence of chemokines specific to their respective cell surface receptors, with migration to CCR4 and CCR10 most prevalent. Finally, regulation of the cytokine secretion through modulation of nuclear receptor signalling was studied. Inhibition of the aryl hydrocarbon receptor during naïve T cell priming abrogated the drug-specific cytokine response. Conclusion Our data describe a subset of piperacillin-specific T-cells that secrete IL-22, IFNγ, perforin and granzyme B, but not IL-17, in response to antigen challenge. Taken together this suggests that IL-22 is important in the progression of β-lactam hypersensitivity. P164 Vancomycin-Specific T Cell Responses And Teicoplanin CrossReactivity Wei Yann Haw, Marta E Polak, Carolann Mcguire, Michael R Ardern-Jones University of Southampton, Southampton, United Kingdom Keywords: Drug Hypersensitivity Reactions, T Cell, Vancomycin, In-Vitro Diagnostic Tests Introduction Glycopeptide antibiotics, vancomycin and teicoplanin, share a similar structure and are the mainstay of therapy for severe gram-positive organisms. Hypersensitivity responses to vancomycin are well recognised but the risk of cross-reactivity with teicoplanin is unclear. Our study aims to examine the role of T cell responses in vancomycin hypersensitivity reactions and explore the potential for cross-reactivity between vancomycin and teicoplanin. Method Our cohort comprised of vancomycin exposed allergics who had suffered delayed skin drug hypersensitivity reactions n=17; non-allergic previously vancomycin exposed controls n=5; and vancomycin naïve controls n=12. We tested ex-vivo drug induced lymphocyte proliferation and cytokine release. Vancomycin-specific T cell lines were grown to test for teicoplanin cross-reactivity. Results In our cohort of vancomycin allergics, vancomycin hypersensitivity reaction patterns were drug exanthems (47.1%), DRESS (29.4%), or SJS/TEN (23.5%). Circulating IFN-γ vancomycin-specific T cells were identified at higher frequency than naïve controls: (IFN-γ p<0.0001; SI p=0.042). Interestingly, detectable frequencies in vancomycin exposed controls were higher than naïve controls (p<0.0001; SI p=0.12) suggesting that low frequency responses were the result of vancomycin priming even in the context of a non-allergic individual. This was confirmed by the expansion of short term T cell lines in vancomycin exposed controls (IFN-γ p=0.008; SI p=0.016). Cross-reactivity against teicoplanin was found to be minimal (42.7 x10-4% IFN-γ and SI 1.0 in vancomycin-specific T-cell lines compared to 48 x10-4% IFN-γ and SI 1.3 in non-vancomycin-specific T-cells lines). Conclusion Circulating vancomycin specific-T cell frequencies were found to be higher in vancomycin allergics than vancomycin exposed controls, which in turn were higher than naïve controls. Using vancomycin-specific T cell lines we did not see any evidence of teicoplanin cross-reactivity despite the similar molecular structures of the two drugs. We also showed that low-level of vancomycinspecific responses identified ex-vivo in exposed controls were able to efficiently expand on short term culture, confirming that they were genuine vancomycinspecific T cells. This suggests both immune predisposition and potentially adaptive regulation may be important in regulating the development of hypersensitivity reactions to vancomycin. Poster Walk 19: BAT and Biomarkers (P165 – P173) P165 A Combination Of Early Biomarkers Useful For The Prediction Of Severe ADRs Yumi Aoyama1, Tetsuo Shiohara2 1. Kawasaki Hospital Kawasaki Medical School, Okayama, Japan 2. Kyorin University School of Medicine, Tokyo, Japan Keywords: Biomarker, Cytokines,Stevens-Johnson Syndrome,Toxic Epidermal Necrolysis, Drug-Induced Hypersensitivity Syndrome Introduction Severe adverse drug reactions (ADR) including Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and drug-induced hypersensitivity syndrome (DiHS)/drug reaction with eosinophilia and systemic symptoms (DRESS) are acute life-threatening conditions. Although previous studies demonstrated the pathogenic role of soluble mediators including cytokines/chemokines secreted by different immune cells including TNF-a, IFN-g, IL10, perforin/granzyme B, FasL and granulysin, there are few biomarkers or prognostic tests available to predict disease progression that can be used in clinical routine for diagnosis and to monitor patients with ADRs. Method We therefore, measured serum levels of cytokines/chemokines as well as other biological markers in patients who presented with clinical symptoms suggestive of ADRs at their initial presentation. Results The results show that sFasL represents a useful early biomarker that can predict the subsequent progression to TEN, but not SJS, particularly when combined with the increase in IL-6 and IFN g-induced protein 10 (IP-10). Granulysin was increased in severe ADRs. Interestingly, the IL-17 level was significantly increased in patients with viral exanthema but not in severe ADRs and rather decreased in DiHS/DRESS patients. Increased IL-10 levels were observed in SJS and DiHS/DRESS, but not in TEN. One surprising finding was that serum IL-10 levels in SJS were much higher than those in TEN despite clinical similarities between the two diseases. Increased IL-10 levels associated with increased levels of IL-2, IL-5 and IFN-g at the initial presentation may be a useful predictor of SJS patients who will not progress to TEN. Alternatively, relatively low levels of IL-10 associated with increased IL-6 and IP-10 levels could be interpreted as suggesting the subsequent progression to TEN. The increased levels of IL-6 and IP-10 are reliable biomarkers predictive of the progression to severe ADRs, such as SJS/TEN and DiHS/DRESS. Conclusion The use of a combination of several early biomarkers, although not sufficiently sensitive or specific on its own when used alone, could increase the diagnostic and prognostic utility for the prediction of severe ADRs. P166 Basophil Activation Test In The Diagnostic Approach Of Reactions During General Anaesthesia Ana Moreira1, Susana Cadinha1, Patrícia Barreira1, Ana Castro Neves1, Daniela Malheiro1, Sara Correia2, JP Moreira Da Silva1 1. Centro Hospitalar Vila Nova Gaia, Vila Nova Gaia, Portugal 2. Centro Hospitalar de Setúbal, Setúbal, Portugal Keywords: Basophil Activation Test, General Anaesthesia Introduction Neuromuscular blocking agents (NMBAs), latex and antibiotics are the most frequent agents causing hypersensitivity reactions (HR) in the perioperative setting, followed by hipnotics and opioid analgesics. The diagnostic approach is complex and relies on suggestive history and skin tests (ST), since basophil activation test (BAT) has not yet been validated and drug provocation test has limited indications because of the pharmacological effects of these drugs. Our aim was to characterize a series of subjects with suspected HR during general anaesthesia (GA) and to evaluate the concordance between ST and BAT in patients submitted to both diagnostic procedures with the suspected drugs: fentanyl (F), propofol (P) and rocuronium (R). Method Retrospective analysis of medical records from patients referred to our department, from 2009 to 2015, with suspected HR during GA. The data collected were: demographic data, atopy, clinical manifestations, results from ST and BAT. ST and BAT were performed in the following concentrations: 0,05 mg/ml for F and 10 mg/ml for P and R (SPT); 1/100 dilution for R and 1/10 for F and P (ID); 25, 12.5 and 6.25 ug/ml for F; 100, 50 and 10 ug/ml for P; 10, 5, 2.5 ug/ml for R (BAT). Results From a total of 34 patients referred to our department, we enrolled 15: mean age 44 (± 21) years; 8 female; 5 atopic; 1 had asthma and 3 had hypertension. Cutaneous reactions were reported by 7 patients, anaphylaxis by 6 and isolated respiratory symptoms by 2. BAT and ST to F were performed in 12 patients, to P in 13 and to R in 12. SPT and ID performed with F (12) and P (13) were all negative. In the case of R SPT were positive in 1 out of 12 tests and ID were positive in 2 out of 11. TAB performed with F (12) was negative in 10 cases, positive in 1 and indetermined in another one. TAB performed with P (13) was negative in 9, positive in 3 and indetermined in 1. In the case of R (12) TAB was negative in 10 and positive in 3. Results to ST and BAT were concordant in 83% of patients tested with F, 69% with P and 67% with R. Allergy was excluded by subsequently administration of the suspected drugs in 5 patients (1 F, 4 P). One of them had negative ST and positive BAT (P). Conclusion ST and BAT to the suspected drug were concordant in the majority of cases (83% F, 69% P, 67% R). According to this results BAT seems to be a valuable contribution in the diagnostic approach of these patients. P167 IL-10 Can Be Related To Successful Desensitization Asli Gelincik, Semra Demir, Fatma Sen, Hamza Ugur Bozbey, Muge Olgac, Derya Unal, Raif Coskun, Bahauddin Colakoglu, Suna Buyuozturk, Esin ÇatinAktas, Gunnur Deniz Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey Keywords: IL-10, Desensitization Introduction The mechanism of drug desensitization is scarcely understood. The aim of the study is to observe the cytokine levels in the serum of patients who underwent a successful drug desensitization. Method Patients with a hypersensitivity reaction to any culprit drug and therefore has to be desensitized with the drug were included into the study. IL-4, IL-5, IFN γ and IL-10 levels were determined with ELISA in the peripheral serum samples of the patients before the desensitization to any culprit drug and within 24 hours after the procedure. The results were compared with the serum samples of patients who could tolerate the same drugs and healthy subjects who were not exposed to these drugs. Results 26 patients who experienced allergic reactions due to various drugs and therefore had to be desensitized, 10 patients who could tolerate the same drugs and 5 healthy subjects were included. The diagnosis of the patients were as follows: malignancy (14 patients), multiple sclerosis (2 patients), metabolic storage disorders (2 patients), iron salt deficiency (2 patients) and Basedow Graves disease (1 patient), coronary heart disease ( 1 patient), and congenital adrenal hyperplasia (1 patient). The drugs used for desensitization in the order of the most frequent to the least were as follows: parenteral or per oral chemotherapeutics, aspirin, corticosteroids, storage enzymes, iron salts and antithyroidal drugs. Skin prick tests were positive in 5 patients with parenteral chemotherapeutics, 2 patients with iron salts, 2 patients with storage enzymes and in one patient with methylprednisolone. The baseline cytokine levels were not statistically different between the three groups. The desensitization was not successful in 4 of the patients and because of this insufficient patient number their cytokine levels were not further analyzed. The IL-10 levels after the successful desensitization procedure in 22 patients significantly increased when compared to their baseline levels (p: 0,006). The rise in IL-10 levels were greater in chemotherapeutic desensitizations than the desensitizations with other drugs (p: 0.005) whereas the other three cytokines did not significantly change. Conclusion Successful desensitization can be related with increase in IL-10. In order to further elucidate the mechanism of successful desensitization, cells secreting IL10 should be examined. P168 Immediate Reactions To Proton Pump Inhibitors: Value Of Basophil Activation Test. Maria Salas1, Jose Julio Laguna2, Esther Barrionuevo3, J Dionicio2, Tahia Fernandez4, R Gonzalez-Mendiola2, I Olazabal5, Maria Dolores Ruiz1, Miguel Blanca1, Cristobalina Mayorga6, Maria José Torres1 1. Regional Hospital of Málaga-IBIMA, Málaga, Spain 2. Hospital de la Cruz Roja, Madrid, Spain 3. Regional Hospital of Málaga-IBIMA, Mdálaga, Spain 4. Research Laboratory, IBIMA, Málaga, Spain 5. Inmunology Department. Alfonso X el Sabio University, Madrid, Spain 6. Research Laboratory-IBIMA, Málaga, Spain Introduction The incidence of allergic reactions to proton pump inhibitors (PPI) has increased in recent years. Most publications describe isolated cases and limited data are available about the value of skin tests. Therefore, the diagnostic approach is the drug provocation test (DPT), which is not risk free, especially for severe reactions. The aim of the study was to assess the value of the basophil activation test (BAT) for the diagnosis of immediate allergic reactions to PPI. Method We evaluated 49 patients with immediate allergic reactions to PPI. Twenty two subjects with good tolerance to PPI were included as controls. Patients with anaphylaxis or shock were diagnosed by clinical history, once other possible causes were ruled out, and those with urticaria-angioedema or pruritus, by DPT. BAT with omeprazole and pantoprazole at 3 different concentrations (2, 0.2 and 0.02 mg/ml) using CD193 (CCR3) and CD203c for basophil selection and CD63 as activation marker, was performed in all patients and controls. Results The PPIs involved were omeprazole (N=43), pantoprazole (N=1) lansoprazole (N=2) and esomeprazole (N=2), one patient had two reactions, one with omeprazole and other one with pantoprazole. A total of 20 cases (40.81%) reported anaphylaxis, 12 (24.48%) anaphylactic shock,13 (26.53%) urticariaangioedema, and 4 (8.16%) pruritus. BAT was positive in 36 cases (73.46%): 14 to omeprazole and pantoprazole (28.5%), 19 to omeprazole (38.7%) and 3 to pantoprazole (6%). BAT was negative in control patients, indicating a specificity of 100%. BAT sensitive was 82%. Conclusion Immediate hypersensitivity reactions to PPI do occur, with omeprazole being the most frequently involved. Anaphylaxis is the most common clinical entity. BAT is a useful method for diagnosing these patients with a good sensitivity and specificity. P169 Improvement Of The Elevated Tryptase Criterion To Discriminate IgE From Non-IgE Mediated Allergic Reactions. Gabriel Gastaminza, Alberto Lafuente, Carmen D'Amelio, Amalia Bernad, Olga Vega, Roselle Catherine Madamba, M Jose Goikoetxea, Marta Ferrer, Jorge Núñez Clinica Universidad de Navarra, Pamplona, Spain Keywords: Anaphylaxis, Tryptase Introduction There is no consensus on an optimal cutoff point (COP) of blood tryptase during the reaction (TDR) to discriminate IgE- from non-IgE-mediated reactions. We aimed to compare the diagnostic accuracy between TDR and TDR/basal tryptase (TDR/BT) index for discriminating IgE- from non-IgE-mediated reactions, and to estimate a COP for the best of these tests. Method Patients with an immediate allergic reaction treated in Clínica Universidad de Navarra (Spain) from 2009-2015. Allergological study was performed to classify the reaction into IgE- or non-IgE-mediated. The area under de curve (AUC) of the receiver operating characteristic (ROC) analysis was calculated to indicate the discriminative power of each test. Results We included 102 patients (45% men; aged 3-99 years; 48% with IgE-mediated reaction; 54% with anaphylaxis criteria) who had an allergic reaction (emergency room, n=27; hospitalization, n=15; perioperative, n=44; other hospital areas, n=16). The median TDR for the IgE-mediated reactions was 7.6 µg/L (p25-75: 4.9- 13.8 µg/L) and 5.2 µg/L (p25-75: 3.6- 7.5 µg/L) for the non-IgE-mediated reactions (p=0.047). The median TDR/BT ratio was 2.6 (p25-75: 1.7- 4.3) in IgE-mediated reactions and 1.2 (p25-75: 1.0- 1.6) in non-IgE-mediated reactions (p=0.001). The TDR/BT ratio showed the greatest ability to discriminate IgE from non-IgE meditated reactions compared with TDR (AUC TDR/BT=0.78 and AUC TDR=0.65; p=0.003). The optimal COP for TDR/BT to discriminate between IgE and non-IgE reactions was 1.66. Conclusion TDR/BT ratio showed a significantly better diagnostic performance than TDR to discriminate IgE from non-IgE mediated allergic reactions. An optimal TDR/BT ratio threshold around 1.7 may be useful in clinical practice to classify allergic reactions as IgE or non-IgE mediated. P170 Low Expression Of Tim-3 Could Serve As A Biomarker For Control And Diagnose Maculopapular Exanthema Induced By Drugs Tahia Diana Fernández1, Inmaculada Doña2, Francisca Palomares1, Rubén Fernández1, Maria Salas2, Esther Barrionuevo2, Maria Isabel Sanchez2, Miguel Blanca2, Maria José Torres2, Cristobalina Mayorga1 1. Research Unit for Allergic Diseases. IBIMA-Regional University Hospital of Malaga-UMA, Málaga, Spain 2. Allergy Unit. IBIMA-Regional University Hospital of Malaga-UMA, Málaga, Spain Keywords: Skin, Peripheral Blood, Lymphocytes, Tim3,Maculopapular Exanthema Introduction Previous studies have been showed that in cutaneous non-immediate reactions to drugs, like maculopapular exanthema (MPE), several lymphocyte subtypes are involved, mainly CD4 lymphocytes with a Th1-phenotype. However the involvement of other lymphocyte subtypes, that have shown effector activity in autoimmune diseases such as rheumatoid arthritis, multiple sclerosis or psoriasis like Th17-cells has not been studied yet. Moreover, numbers of both lymphocyte subsets can be controlled by the interaction of the receptor Tim3 with Gal9 inducing their apoptosis and the differentiation of regulatory T cells. The aim of the study was to analyse the expression of Tim3 in patients with drug induced MPE during the acute phase and after resolution of the reaction. Method Peripheral blood cells (PBMC) and skin biopsies were obtained from 18 allergic patients and 10 tolerant subjects. Immunohistochemical staining and flow cytometry were carried out to determine the presence of Th1 (CXCR3+) and Th17 (RORgt+IL17+) CD4-cells and the expression of Tim3. Results The involvement of Th1-CD4-cells in EMP were confirmed, with higher levels compared to controls in both, skin (p<0.0001) and PBMC (p=0.032 during the acute phase and p=0.039 after resolution). However, we could not find any difference in the frequencies of Th17-cells between patients and controls in any of the conditions. The expression of Tim3, was strongly decreased in patients mainly in the skin (p<0.0001) and in Th1-CD4-cells (p<0.0001) during the acute phase, but, interestingly, also after resolution (p=0.039). The expression of Tim3 in Th17-cells was similar in patients and controls. Conclusion The low expression of Tim3 in the effector cells during the acute phase could be the responsible of the impaired regulation of these cells in MPE affecting their homeostasis in these patients. The low expression of Tim3 after resolution could serve as a biomarker for this type of reactions and could be a target to develop strategies to control and diagnose the disease. P171 Role Of Basophil Activation Test Using Two Different Activation Markers For The Diagnosis Of Allergy To Fluoroquinolones Esther Barrionuevo1, Tahía Fernandez2, Arturo Ruiz1, Adriana Ariza2, Maria Salas1, Inmaculada Doña1, Ana Molina2, Miguel Blanca1, Maria Jose Torres1, Cristobalina Mayorga2 1. Regional Hospital of Málaga, Málaga, Spain 2. Research Laboratory-IBIMA, Málaga, Spain Introduction Fluoroquinolones (FQ) are the second most frequent cause of hypersensitivity to antibiotics after betalactams. Most reactions induced by FQ were immediate. For the in vitro diagnosis only the basophil activation test (BAT) has shown to be useful although with suboptimal sensitivity. The aim of our study was to analyze the BAT to FQ using two different activations markers, CD63 and CD203c, in the evaluation of patients with immediate allergic reactions to these drugs. Method Seventeen patients with confirmed immediate allergic reactions to FQ (6 to Ciprofloxacin and 11 to Moxifloxacin) were included in the study. Eighteen controls with tolerance to FQ were also included. BAT was performed with Moxifloxacin and Ciprofloxacin at 2 and 0.2 mg/mL using CD203c and CD63 as activation markers. Positive results were considered when SI > 3 to at least one of the concentrations used in the test. Results Data indicated that although both Ciprofloxacin and Moxifloxacin are able to induce both activation marker expression (CD63 and CD203c), there is a predominance in the expression of each one depending on the drug included in the test. Thus Ciprofloxacin was able to mainly increase the expression of CD63 (40%, p=0.0053) whereas Moxifloxacin mainly increase the expression of CD203c (10%). In addition, analyzing the expression of both markers in basophils from Moxifloxacin allergic patients stimulated with the culprit drug, we found a higher expression of CD203c in patients suffering anaphylactic shock (7%), whereas was CD63 the marker that showed a higher up-regulation in patients with anaphylaxis (17%). When we analyzed the sensitivity and specificity of the test using these activation markers we can see that the best results were observed using the culprit drug and CD203c as activation marker for Moxifloxacin (S= 36.4% and E= 94.4%) and CD63 for Ciprofloxacin (S=83.3% and E= 88.9%). Conclusion The BAT must be performed using the culprit drug and CD203c for Moxifloxacin or CD63 for Ciprofloxacin as activation marker to diagnose Quinolone Allergy. Although this differential expression of both activation markers seems to be also related with the culprit drug and clinical entity.Using this criteria and a cut-off of 3, we have obtained a better sensitivity for Ciprofloxacin. P172 The Importance Of Basophil Activation Test In Anaphylaxis Due To Celecoxib Amalia Bernad Alonso, Carmen D'Amelio Garófalo, Olga Vega Matute, Marta Ferrer Puga, María José Goikoetxea Lapresa, Roselle Catherine Yu Madamba, Gabriel Gastaminza Lasarte Clínica Universidad de Navarra, Pamplona, Spain Introduction Celecoxib, is a specific COX-2 inhibitor which is an alternative treatment for patients with intolerance to NSAIDs. Case Description We present two cases of anaphylaxis due to Celecoxib. The first is a 57 year old male who was taking Celecoxib as an alternative medication for sciatic pain since he had poor gastric tolerance with NSAIDs. He had a history of idiopathic recurrent urticaria. He had an episode of anaphylactic shock 30 minutes after taking 1 tablet of Celecoxib which prompted him to sought consult at the emergency room wherein he was administered with Epinephrine IM. On follow up after one month, prick test with Celecoxib revealed negative. Because the suspicion that the reaction was caused by allergy to Anisakis, a challenge test with Celecoxib was done that resulted positive, and epinephrine was administered. Basophil activation test was positive with Celecoxib and negative to Parecoxib. Two months later, he presented with hives two hours after taking 750 mg of acetylsalicylic acid (ASA). Tolerance test with Meloxicam and Nabumetone were performed which the patient tolerated well. The second case is a 58 year old male who had an episode of anaphylaxis three hours after taking Celecoxib for headache. Tryptase was elevated, 19.9 ug/L. A month earlier, he had generalized itching after taking one tablet of celecoxib. He took Metamizol previously which he tolerated well. No history of atopy nor allergy to medications. Skin tests to NSAIDs were negative. Basophil activation test was positive with celecoxib and negative to ASA, Metamizole, Paracetamol, Parecoxib and Dexketoprofen. He underwent challenge test with Aspirin with positive result. Both patients were diagnosed with intolerance to NSAIDs and anaphylaxis secondary to Celecoxib. How this report contributes to current knowledge Anaphylaxis due to Celecoxib is considered a rare entity as patients with intolerance to NSAIDs usually tolerate Celecoxib and other COX-2 inhibitors. The positive result in the basophil activation test together with a compatible clinical history makes us hypothesize that these are cases of a selective hypersensitivity to Celecoxib, instead of the fact that both patients were finally NSAIDs intolerant. Hence, BAT can be useful for the diagnosis, given the low sensitivity of skin tests. P173 The Role Of Basophil Activation Test In The Diagnosis Of Immediate Type Drug Hypersensitivity To Betalactam Antibiotics. Antonia Thinnes, Hans F. Merk, Jens Malte Baron, Martin Leverkus, Galina Balakirski Department for Dermatology and Allergology, University Hospital of Aachen, Aachen, Germany Keywords: Basophil Activation Test, Betalactam Antibiotics, Immediate Type Drug Hypersensitivity Introduction Basophil activation test (BAT) is reported to be a useful and very promising technique in the diagnosis of immediate type drug hypersensitivity reactions. It is used in combination with in vivo and in vitro diagnostic tools and may contribute to the sensitivity of the diagnostic work out. Method In order to investigate the role of BAT in the diagnosis of immediate type drug hypersensitivity to betalactam antibiotics we analyzed all BATs performed with betalactam antibiotics in our department during the period from 2009 to 2012. We compared the results of in vivo diagnostics (skin prick test, intracutaneous test, patch test) and in vitro diagnostics (specific IgE) with the results of the BAT under the aspect, if BAT represent a useful tool for assessment of the individual risk of the patient to experience another immediate type drug hypersensitivity reaction on reexposure to the tested drug. Results We performed BAT with betalactam antibiotics in 64 cases: 20% (n=13) with penicillin (PEN), 38% (n=24) with aminopenicilins (AMP) and 42% (n=27) with cephalosporins (CPH). In the PEN-group 23% (n=3) of the patients had at least one positive in vivo test, but negative BAT and 15% (n=2) had positive BAT, but negative in vivo tests. In the AMP-group 17% (n=4) of patients had at least one positive in vivo test, but negative BAT and 17% (n=4) had positive BAT, but negative in vivo tests. Only 8% (n=2) of patients had positive both BAT und at least one in vivo test. 4% (n=1) of patients had both positive at least one in vivo test and specific IgE, but negative BAT. In the CPH-group 22% (n=6) of the patients had positive BAT, but no other positive test results and 4% (n=1) had positive both BAT und at least one in vivo test. Conclusion In case of the negative in vivo and in vitro test results (inclusive BAT) the individual risk of the patient to experience another immediate type drug hypersensitivity reaction on reexposure to the tested drug was considered to be low, so drug provocation test (DPT) as the next diagnostic step was recommended: from overall of 41 such cases DPT was performed in 32% (n=13) and was unremarkable in 100% (n=13). Our results confirm that BAT may be an important tool to increase the sensitivity of the diagnostic and make the better risk assessment possible. However, the limitation of this study is that we didn’t perform DPT in patients with positive in vivo or in vitro results and therefore are not able to estimate the frequency of false positive BATs. Frequency of positive in vivo and in vitro results in the diagnostic work out of immediate type drug hypersensitivity reactions to betalactam antibiotics in Department of Dermatology and Allergology at the University Hospital of Aachen, Germany during the period from 2009 to 2012. Positive BAT results in patients with negative in vivo tests and specific IgE may provide important information for assessment of the individual risk of the patient to experience another immediate type drug hypersensitivity reaction on reexposure to the tested drug. Penicillin Aminopenicillins Cephalosporins Total 20% 38% (n=24) 42% (n=27) 100%(n=64) (n=13) positive in vivo results 23% 17% (n=4) 11% (n=7) and negative BAT (n=3) negative in vivo results as well as absence of 15% 19% 17% (n=4) 22% (n=6) specific IgE and (n=2) (n=12) positive BAT positive in vivo results 8% (n=2) 4% (n=1) 4,5% (n=3) and positive BAT positive in vivo results, positive specific IgE and 4% (n=1) 1,5% (n=1) negative BAT negative in vivo results 62% 54% (n=13) 74% (n=20) 64% (n=41) and negative BAT (n=8) Poster Walk 20: TCR recognition, cellular (P174 – P183) P174 Characterisation Of The Effect Of Co-Inhibitory Signalling On The Activation Of Drug-Derived Antigen-Specific T-Cells. Andrew Gibson, Monday Ogese, Lee Faulkner, B Kevin Park, Dean J Naisbitt University of Liverpool, Liverpool, United Kingdom Introduction The factors governing inter-individual susceptibility to drug hypersensitivity remain ill-defined. Although the association of specific HLA alleles with hypersensitivity is important, for most drugs, the majority of individuals who are positive for an HLA risk allele do not develop a reaction. Thus, predisposition is likely mediated by other parameters, which may include T-cell co-inhibitory pathways. As polymorphisms in co-inhibitory pathways are associated with dysregulated immune responses, we investigated the role of these pathways during drug (SMX-NO)-specific T-cell responses. Programmed death-1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 (CTLA4) are considered to be key immune checkpoints, and TIM-3 is of current interest due to its reported upregulation alongside PD-1. Method Naïve and memory T-cells from healthy donors were incubated for 8 days with SMX-NO and dendritic cells ±PD-L1, CTLA4, TIM-3 blocking antibody. Antigenreactivity was then assessed by T-cell cytokine secretion and proliferation. Cell phenotype was assessed by flow cytometry. T-cell clones were then generated from these cultures. Results While blockade of PD-L1 or CTLA4 enhanced the activation of SMX-NO-primed naïve T-cells, only the blockade of CTLA4 enhanced the proliferative response of antigen-stimulated memory T-cells suggesting a greater regulatory role for CTLA4 during secondary T-cell responses. Blockade of TIM-3 had no effect on Tcell activation of either naïve or memory cells. While all receptors were upregulated on T-cells after antigen exposure, PD-1 was upregulated at earlier time points than CTLA4 and TIM-3 indicating a differential role for these receptors during early and late stage T-cell activation. High expression of individual co-inhibitory receptors has previously been associated with exhausted T-cells, while other studies indicate that these cells are highly functional. We found no correlation between the level of individual co-inhibitory receptor expression and the strength of T-cell activation in the T-cell clones. Conclusion Drug-induced stimulation of naïve T-cells was significantly enhanced by blocking PD-L1 or CTLA4. However, the co-inhibitory pathways did not have a great effect on memory T-cell responses. Any differences in the control of the different T-cell co-inhibitory pathways may be important in determining whether a particular individual develops a hypersensitivity response to a drug. P175 Characterization Of Drug Hapten-Specific T Cell Responses In Piperacillin Hypersensitive Patients. Zaid Al-Attar1, Fiazia Yaseen1, Xiaoli Meng1, Rozalind Jenkins1, Paul Whitaker2, Daniel Peckham2, Lee Faulkner1, John Farrel1, Kevin Park1, Dean Naisbitt1 1. MRC Centre for Drug Safety Science, Dept Molecular & Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom 2. Regional Adult Cystic Fibrosis Unit, St James’s Hospital, Leeds, United Kingdom Introduction Piperacillin is a b-lactam frequently used to combat bacterial infections in patients with cystic fibrosis. However, its use is associated with high incidence of delayed-type hypersensitivity reactions. Previous studies have identified lymphocyte proliferative responses and cytokine secretion from PBMCs isolated from approximately 75% of hypersensitive patients but not from tolerant controls. The drug forms a hapten that binds covalently to specific lysine residues on serum albumin (HSA). Aim: To generate a synthetic piperacillin-HSA conjugate and to quantify the level of modification at specific lysine residues. Furthermore, the activation of T-cells with free drug and the drug-protein conjugate was assessed. Method Piperacillin was incubated with HSA at different molar ratios (10:1–250:1 drug:protein). Mass spectrometry was used to characterize modification at specific lysine residues. PBMCs from hypersensitive patients were cultured in the presence of parent drug and the piperacillin-HSA conjugate and T-cell clones generated by serial dilution. T cell clones were analysed for antigen-specific proliferative responses, cytokine release and TCR-Vb usage. Results Cyclised and hydrolysed forms of piperacillin hapten were detected on over 10 lysine residues of HSA. Quantitative analysis revealed that 3-23% of lysine 541 was modified with piperacillin haptens. Sixty CD4+ clones displayed reactivity against piperacillin-modified HSA but did not respond to free piperacillin or to other b-lactam HSA adducts. T cell activation was dependent on protein processing by antigen presenting cells and the level of modification with the piperacillin hapten, as low levels of modification failed to activate the clones. A further sixty CD4+ clones were responsive to free piperacillin and were not activated with the piperacillin-HSA conjugates. T-cell clones secreted a variety of molecules: IFN-γ (72% of clones), IL5 (48%), IL13 (37%), perforin (48%), granzyme B (26%) & FasL (52%) and showed a restricted expression of TCR-Vb9 (68%). Conclusion We have shown that drug hapten-responsive CD4+ T-cells with divergent antigen specificities circulate in hypersensitive patients. These data have important implications for studies investigating the nature of the drug antigen. It is necessary to synthesize conjugates with different drug haptens to fully investigate the antigen specificity of the T-cell repertoire. P176 Characterization Of The Response Of T-Cells To Telaprevir And Its Metabolite In Normal Volunteers Zaid Al-Attar, Khetam Alhilali, Yanni Xue, John Farrell, Lee Faulkner, Kevin Park, Dean Naisbitt MRC Centre for Drug Safety Science, Dept Molecular & Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom Introduction Telaprevir is antiretroviral drug developed for the treatment of hepatitis C. Human exposure is associated with a high frequency of cutaneous side effects varying in severity from mild rash (56%) to Stevens Johnson syndrome/toxic epidermal necrolysis (<1%). Telaprevir interconverts to an R-diastereomer (VRT127394), which is the major metabolite. There is no known HLA risk allele associated telaprevir hypersensitivity. However, this does not rule out a role for antigen-specific T-cells in mediating hypersensitivity. Aim: The aims of this study were to (1) generate T-cell clones with specificity for telaprevir and/or its metabolite and (2) explore the nature of the induced response. Method The optimal T-cell priming concentration of telaprevir and its metabolite was identified using a PBMC toxicity assay. Naïve T-cells from 3 normal volunteers were primed with autologous dendritic cells (DCs) and telaprevir or VRT-127394 for 10 days. Alternatively, PBMCs from 3 normal volunteers were cultured with telaprevir or VRT-127394 for 14 days. T-cells from both experimental procedures were cloned by serial dilution and repetitive mitogen stimulation. T-cell proliferative responses were assessed using [3H] thymidine incorporation and IFN-γ. Antigen-specific clones were phenotyped for CD4, CD8 and TCR Vb expression. Results T-cell responses to telaprevir or VRT-127394 were not detected using the DC priming assay. However, 13 telaprevir-responsive T-cell clones were isolated from PBMC cultures from one volunteer. All 13 clones were stimulated to proliferate in the presence of telaprevir and its metabolite in a dose-dependent manner at a similar concentration range. Clones were not activated in the presence of antigen presenting cells pulsed with telaprevir for 1-16 hr. 11 clones secreted IFN-γ when activated with telaprevir. 10 clones were CD4+ and 3 were CD8+. Clones expressed a restricted pattern of TCR-Vb which was dominated by Vb2 and Vb22. Conclusion The data presented here shows that telaprevir-responsive T-cells were detected in healthy volunteers. CD4+ and CD8+ clones were activated with both telaprevir and the major metabolite VRT-127394. Future work will focus on assessing the nature of the T-cell response in hypersensitive patients. P177 Characterization Of The T Cell Receptor Signatures Of DrugResponsive T Cells Patricia Illing1, Nicole Mifsud1, Heidi Fettke1, Jeffrey Lai1, Rebecca Ho1, Patrick Kwan2, Anthony Purcell1 1. Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia 2. Royal Melbourne Hospital, University of Melbourne, Parkville, Australia Keywords: Human Leukocyte Antigen, Carbamazepine, Allopurinol, Abacavir Introduction The strongest associations reported to date between adverse drug reactions and specific Human Leukocyte Antigen (HLA) allotypes are between HLA-B*57:01 and abacavir hypersensitivity syndrome, HLA-B*58:01 and allopurinol hypersensitivities, and HLA-B*15:02 and carbamazepine induced StevensJohnson Syndrome/Toxic Epidermal Necrolysis. A lesser association also exists between HLA-A*31:01 and carbamazepine induced hypersensitivities. In this study we examined the diversity of the T cell response to these drugs (and metabolites) by characterising the T cell receptor (TCR) signatures of drugresponsive CD8+ T cells at a single cell level in patients and healthy donors. These studies were complimented by analyses of the diversity and perturbation of the HLA peptide repertoire following drug/metabolite exposure. Method To characterise drug responsive TCR signatures, peripheral blood mononuclear cells were stimulated with the parent drug or metabolite in vitro and drugresponsive T cells characterized (phenotype and function) by flow cytometry. Single-cell flow cytometric sorting of drug-responsive CD8+ T cells was performed prior to a paired analysis of TCR alpha and beta chain variable regions using a novel multiplex nested RT-PCR methodology. To assess the influence of drugs/metabolites on peptide presentation by HLA molecules, HLA transfected BLymphoblastoid cell lines were grown to high density in the presence of the molecule of interest. 5-10x108 cells were harvested, the HLA molecules immunoaffinity purified, and the peptide/small molecule ligands dissociated and analysed using Liquid Chromatography Tandem Mass Spectrometry. Results Our data demonstrated that the TCR signatures for abacavir-responsive CD8+ T cells were oligoclonal, correlating with previous reports of a large and diverse perturbation in HLA-B*57:01 peptide repertoire during abacavir exposure. Interestingly, whilst both carbamazepine and allopurinol hypersensitivities are postulated to occur via a direct interaction of the HLA-peptide-drug-TCR at the cell surface, and cause minimal change of the HLA peptide repertoire, their TCR usage profiles are divergent with carbamazepine being more restricted and allopurinol/oxypurinol exhibiting greater diversity. Conclusion These data suggest a spectrum of diversity in the T cell response that may correlate with altered modes of drug presentation in HLA associated drug hypersensitivity. P178 Defining The Signals Between Hepatocytes And Immune Cells In Idiosyncratic Drug-Induced Liver Injury (DILI) Monday O Ogese1, Lee Faulkner2, B. Kevin Park2, Catherine Betts1, Dean J Naisbitt2 1. AstraZeneca R&D, Cambridge, United Kingdom 2. University of Liverpool, Liverpool, United Kingdom Keywords: DILI, Hepatocytes, Idiosyncratic, Cytokines Introduction An association between HLA genotype and the development of certain forms of DILI is well established. Furthermore, it is now apparent that drug-specific T-cells are activated in certain patients with DILI. The cross-talk signals between hepatocytes and the immune cells resident in the liver and circulation are likely to be critical in determining the outcome of drug exposure and development of immune-mediated DILI. However, tissue-specific immune signalling with respect to human DILI remains largely unexplored. Thus, the aim of this study was to profile the signals released by fresh human hepatocytes upon drug exposure and to characterise the impact of these molecules (cytokines and chemokines) on the phenotype and function of antigen presenting cells (APC). Method Fresh human hepatocytes were exposed to three test compounds implicated in DILI (flucloxacillin, amoxicillin and isoniazid) and one reactive metabolite, nitroso-sulphamethoxazole (SMX-NO), and end-points of hepatocyte toxicity, cell viability and oxidative stress assessed. Results HMGB1 and LDH release as well as ATP depletion occurred in a drug- and concentration-dependent manner. Furthermore, compound-specific activation of Nrf2 marker genes was observed with each of the test drugs. SMX-NO differentially induced the expression of NQO1, TXNRD1 and SRXN1 responsible for cytoprotection against chemically reactive metabolites. Also, the expression of AKR1B10, SRXN1 and LOC344887 were significantly increased by all the test compounds. Hepatocytes cultured with test drugs released a mixture of proinflammatory (IFN-gamma, GM-CSF, IL-12p40, IL-12p70, IL-1β, TNF-α, TNF-β, IL-8 and MCP-1) and anti-inflammatory cytokines (IL-1RA, IL-10 and IL-13). Coculture of APC with supernatant from drug treated hepatocytes resulted in a highly drug-dependent release of cytokines as well as significant changes in expression of MHC class II and CD86 on the cell surface of dendritic cells. Conclusion In conclusion, our study begins to define the various factors that might be important in determining whether drug exposure in patients results in an immune response and tissue injury. We found that cross-talk signals were highly drug specific. The development of a liver/immune cell culture system will be an important step forward in advancing our understanding of the molecular mechanisms underlining the development of idiosyncratic DILI. P179 Development Of Novel Chemicals That Do Not Bind To HLA-B*57:01 Or Activate CD8+ T-Cells Through Modification Of The 6-Amino Cyclopropyl Group Of Abacavir. Paul Thomson, John Farrell, Mohammad Alhaidari, Neill Berry, Paul M O'Neill, B Kevin Park, Dean J Naisbitt University of Liverpool, Liverpool, United Kingdom Introduction Exposure to the reverse transcriptase inhibitor abacavir has been associated with hypersensitivity reactions mediated by CD8+ T-cells in individuals carrying the human leukocyte antigen (HLA-B*57:01) risk allele. It has been shown that abacavir can interact directly with the antigen binding cleft of HLA-B*57:01, altering its conformation and thereby causing an alteration of the peptides displayed on the cell surface. It has been hypothesized that these alternative self-peptide sequences trigger the CD8+ T-cell response in abacavir hypersensitive patients. We examined whether it is possible to synthesize compounds that retain antiviral activity, but do not bind to HLA-B*57:01 and activate CD8+ T-cells. Method Twenty five abacavir analogues were synthesized with modifications around the cyclopropyl group with compounds divided into three main groups. Abacavir responsive CD8+ T-cell clones were generated from healthy donors positive for the HLA-B*57:01 risk allele. IFN-g secretion was measured when the clones were cultured in the presence of autologous antigen presenting cells and abacavir or abacavir analogues using an ELISpot assay. Anti-viral activity of the analogues was assessed using a range of established assays. In silico docking studies were carried out to find potential binding orientations of the abacavir analogues within the F-pocket of HLA-B*57:01. Results CD8+ T-cell clones proliferated and secreted IFN-g in response to abacavir. Several analogues in groups 1 and 2 displayed some antiviral activity without triggering CD8+ T-cell responses. Molecular docking studies of these analogues to HLA-B*57:01 demonstrated a quantitative relationship between the protein binding and the T-cell response. These data prompted us to synthesize a 3rd group of compounds where the NH-cyclopropyl group of abacavir was replaced with substituted cyclic amine derivatives. This third series was subjected to additional antiviral activity and T-cell response assays and several molecules were shown to be devoid of T-cell activity, whilst maintaining a favourable antiviral profile. Conclusion These studies demonstrate that modification of the cyclopropyl moiety of abacavir may result in compounds that retain the antiviral activity, without generating an unwanted T-cell response. This approach represents an exciting approach to the design of safe antiviral drugs eliminating the need for personalised medicine therapy regimes. P180 Generation And Characterization Of Dapsone- And NitrosoDapsone-Specific T-Cell Clones Using Lymphocytes From Healthy Volunteers Abdulaziz Alzahrani1, Monday O Ogese2, John Farrell1, Lee Faulkner1, Andrew Gibson1, Arun Tailor1, B Kevin Park1, Dean J Naisbitt1 1. University of Liverpool, Liverpool, United Kingdom 2. AstraZeneca R&D, Cambridge, United Kingdom Keywords: Dapsone, Hypersensitivity, T-Cells, Dendritic Cells,Cytokines Introduction Dapsone is an antibiotic commonly used in the treatment of leprosy. Its use is associated with development of hypersensitivity in 0.5-3.6% patients. HLAB*13:01 is associated with an increased susceptibility to dapsone hypersensitivity but no studies have been carried out to determine the immunological mechanism(s) underlying the reactions and/or the role of the HLA risk allele in antigen presentation. The aims of this study were to: (i) Prime naive T-cells to dapsone and nitroso-dapsone (ii) Generate dapsone-and nitrosodapsone-specific T-cell clones from healthy donors and (iii) Characterize the pathways of drug-specific T-cell activation. Method Peripheral blood mononuclear cells (PBMCs) were isolated from healthy volunteers, and CD14+ monocytes and naïve T-cells were isolated by magnetic bead separation. Monocyte-derived dendritic cells (DC) were used to prime naïve T-cells in the presence of either dapsone or nitroso dapsone using an established DC priming assay. Drug-specific T-cell clones were generated by serial dilution and repetitive mitogen stimulation. Antigen specificity was assessed by measurement of proliferation and cytokine release using [3H]-thymidine release and IFN-gamma Elispot, respectively. Results Moderate priming of naive T-cells to both dapsone-and nitroso-dapsone was detected but only five dapsone-specific T-cell clones were generated from one out of three donors tested. No nitroso-dapsone-specific T-cell clones were detected in any of the 3 donors. The dapsone-responsive clones were stimulated to proliferate is a dose-dependent manner, but showed no cross reactivity with nitroso-dapsone or three closely related structures. The clones secreted IFNgamma, IL-5 and IL-13 alongside the cytolytic molecule granzyme B. All of the dapsone-specific clones were CD4+, and showed MHC class II-restricted activation. Use of fixed or pulsed antigen presenting cells suggested that activation of T cell clones by dapsone did not require antigen processing. Conclusion : Naïve T cells were primed to both dapsone and nitroso dapsone. Dapsonespecific T-cell clones were activated via a processing independent pathway, thus suggesting a non-covalent interaction between drug, MHC and T cell receptor. On-going studies using PBMCs from volunteers ezxpressing HLA-B*13:01 will investigate the role of HLA*B13:01 in the activation of dapsone- and nitrosodapsone-specific T cells. P181 Identification Of Benzylpenicillin-Hapten Peptides Responsible For Naïve T-Cell Activation And Immunization Of Allergic Patients To Penicillin Marie Eliane Azoury1, Lucia Fili2, Rami Bechara1, Noémie Scornet3, Cathy Nhim1, Richard Weaver4, Nancy Claude4, Delphine Joseph3, Bernard Maillere5, Paola Parronchi2, Marc Pallardy1 1. University Paris-Saclay, Univ Paris-Sud, INSERM UMR996, ChâtenayMalabry, France 2. University of Florence, Department of Experimental and Clinical medicine, Florence, Italy 3. University Paris-Saclay, Univ Paris-Sud, UMR CNRS8076, ChâtenayMalabry, France 4. Institut de Recherches Internationales Servier, Suresnes, France 5. SIMOPRO, IBiTecS, CEA, Saclay, France Introduction Allergic reactions to drugs are often unpredictable and may have many side effects including anaphylaxis. According to the hapten hypothesis, drug of low molecular weight can bind to proteins and form immunogenic complexes. Antigen presenting cells, such as dendritic cells (DCs), recognize and internalize drug hapten complexes, and digest them into benzylpenicillin-hapten peptides (BP-P), which are presented on HLA molecules to drug-specific T-cells. This lead to the immunization of the exposed person. There is in vitro evidence that T-cells from allergic patients react to benzylpenicillin-Human Serum Albumin (BP-HSA) bioconjugate and our group has recently shown the existence of naïve CD4+ T lymphocytes specific to BP-HSA in healthy donors. In this context, we were interested in identifying BP-P from HSA able to immunize patients to BP thus contributing to hypersensitivity reactions. Method We have considered HSA as a good model for BP haptenization since BP is known to bind covalently to HSA and because HSA is the most abundant protein in the sera. We have synthetized BP-HSA bioconjugate, investigated BP-HSA-specific naïve CD4+ T-cell responses in healthy donors and identified BP binding positions on HSA using mass-spectrometry. Twelve 15-mer BP-P were identified as potential T-cell epitopes using the predictive IEDB computational approach and were synthesized using an original BP-lysine monomer. Naïve CD4+ T cells from non-allergic donors were stimulated once a week with autologous DCs loaded with BP-HSA or BP-P to amplify BP-HSA- or BP-P-specific T-cells respectively. Activation of specific CD4+ T-cells was detected using interferon-γ ELISpot and their frequency was calculated using the Poisson distribution. Results In this study, BP-HSA- and BP-P-specific naïve CD4+ T cells were detected in 15/16 and 11/14 of the tested healthy donors respectively. Most donors responded to 3 peptides with BP covalently bound on lysines 159, 212 and 525 respectively. Two of these benzylpenicillinoylated peptides (lysines 159 and 525) were found to induce peripheral blood mononuclear cells (PBMC) proliferation in patients with allergic reaction to BP using the lymphocyte transformation test. Conclusion This study showed the capacity of BP-HSA to be recognized by naïve T-cells from multiple healthy donors and allowed the identification for the first time of BP-P responsible for naïve T-cell activation and immunization of allergic patients to BP. P182 Massive Expansion Of Clonotypic And Polycytotoxic CD8+ T Cells In Toxic Epidermal Necrolysis Axel Patrice Villani1, Aurore Rozières2, Benoît Bensaïd3, Mathilde Tardieu3, Floriane Albert3, Virginie Mutez3, Tugba Baysal3, Marc Pallardy4, Janet Maryanski5, Jean-François Nicolas6, Osami Kanagawa3, Marc Vocanson3 1. Inserm U1111 - CIRI, Lyon I University, Edouard Herriot Hospital, Lyon, France 2. Inserm U1111 - CIRI, Lyon I University, Lyon, France 3. Inserm U1111 - CIRI, Lyon, France 4. INSERM UMR 996, Université Paris-Sud, Châtenay-Malabry, Lyon, France 5. Unité de Thérapie Cellulaire et Génique (UTCG) and URE 004 (ImCelVir), Université Nice Sophia Antipolis, Nice, France 6. Inserm U1111 - CIRI, Lyon I University, Lyon-Sud Hospital, Lyon, France Keywords: Toxic Epidermal Necrolysis, CD8+ T Cells, Polycytotoxicity, Clonotypic Introduction Toxic epidermal necrolysis (TEN) is a life-threatening and blistering adverse drug reaction, characterized by an acute epidermal necrolysis. Diverse studies have reported that the onset of TEN correlates with skin infiltration by cytotoxic lymphocytes (T, NK cells) and inflammatory monocytes. Method To further characterize the phenotype of skin-infiltrating lymphocytes at the acute phase of TEN, we conducted a prospective study on the blood and blister fluids from 11 TEN patients, using flow and mass cytometry, as well as next generation TCR sequencing. Results Our results confirm that conventional CD8+ T cells (CD45+TCRab+CD8b+) and, at a lesser extend CD4+ T cells, were the main leucocyte subsets found in recent TEN blisters. Consequently, the CD4/CD8 ratio was inversed in blisters (mean: 0.8) compared to blood (mean: 2). However, we failed to repeatedly detect NK (CD45+TCRab+NKP46+) or NKT cells (CD45+TCRab+TCRVa24+) in TEN blisters. Strikingly, deep sequencing of the T cell receptor CDR3 repertoire revealed massive clonal expansions of T cells in blister cells of 6 TEN patients, which were confirmed at TCR-Vb usage level by flow cytometry. Over-represented TCR-Vb+ blister cells were mainly effector memory CD8+CD45RA-CD27+ T cells and displayed a poly-cytotoxic phenotype since they co-expressed Granulysin, Granzyme B, Granzyme A, Perforin and TWEAK, as demonstrated by mass cytometry. Conclusion Our results highlight a massive skin recruitment of clonotypic and poly-cytotoxic CD8+ T cells in TEN patients, which could explain the severity of this lifethreatening disease. P183 Pharmaco-Immunological Synapse Of HLA-Drug-TCR In SCAR Shuen-Iu Hung National Yang-Ming University, Taipei, Taiwan Keywords: Immune Synapse, TCR, HLA, Drug Antigen,SCAR Introduction Life-threatening severe cutaneous adverse reactions (SCAR), including drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are known as T cellsmediated drug hypersensitivity, some of which showed strong HLA genetic predisposition. Our previous studies have discovered that HLA-B*15:02, HLAA*31:01, and HLA-B*58:01, are the genetic markers of carbamazepine-induced SJS/TEN, -DRESS, and allopurinol-SCAR, respectively. Although we recently also have identified that HLA can directly interact with the drugs and metabolites (JACI 2012; JACI 2015), the role of TCR and immune synapse of HLA-drug-TCR in SCAR remain unclear. Method We enrolled patients with SCAR caused by carbamazepine, allopurinol, phenytoin, lamotrigine or antibiotics, and collected the blister cells from skin lesions or PBMC from patients in the acute or recovery stage. We applied the technology of next-generation sequencing to investigate the TCR repertoire of SCAR. Real-time quantitative PCR was used to measure and validate the gene expression of TCR. We generated the recombinant TCRalpha/beta fusion protein, TCRalpha/beta transfectants, and used in vitro cell cultures to examine the molecular interaction of HLA-drug-TCR in drug hypersensitivity. Results We found that different drugs-induced SCAR showed various profiles of TCR usage. Particularly, limited and shared drug-specific CDR3 clonotypes were predominantly expressed in the blister cells and PBMC of SCAR patients. The in vitro drug-expanded T cells highly expressed the specific CDR3 clonotypes and produced granulysin upon drug stimulation. Furthermore, we generated drugspecific TCRalpha/beta recombinant protein, and found it could directly interact with the drug antigen and show cross-reactivity to the structure-related compounds or metabolites. Using in vitro cell culture and ELISPOT assays, we found that the specific TCRalpha/beta transfectants were activated upon drug stimulation, and the response was facilitated by the co-culture of antigenpresenting cells with the expression of matched HLA transgene. Conclusion Our data suggest that clonotype-specific TCRalpha/beta directly interacts with drug antigens presented by HLA in the T cells-mediated drug hypersensitivity. This study provides a new insight into the pharmaco-immunological synapse of HLA-drug-TCR in SCAR. Poster Walk 21: New in vitro methods, Haptens, etc. (P184 - P194) P184 Amoxicillin-Clavulanate Forms Distinct Multiple Haptenic Structures On Human Serum Albumin In Patients Xiaoli Meng1, Arun Tailor1, Caroline J Harrison1, Rosalind E Jenkins1, Paul Whitaker2, Neil S French1, Dean J Naisbitt1, B Kevin Park1 1. University of Liverpool, Liverpool, United Kingdom 2. St James’s Hospital, Leeds, United Kingdom Keywords: Covalent Binding, Haptenic Structures, Albumin Introduction Amoxicillin-clavulanate (AC) is one of the most common causes of drug induced liver injury (DILI) in Europe and the US. The mechanisms of amoxicillinclavulanate–induced liver injury (AC-DILI) remain to be defined, however, recent studies have shown that AC-DILI is associated with both HLA class I and class II alleles, indicating immune-mediated mechanisms have been involved. Method In order to investigate the molecular basis involved in AC-DILI, we have characterized the binding of AC to proteins in vitro and in patients receiving amoxicillin-clavulanate therapy using novel mass spectrometric methods. Clavulanic acid was incubated with N-acetyl lysine in phosphate buffer and the structures of adducts were characterised by mass spectrometry. In addition, amoxicillin and clavulanic acid were incubated with human serum albumin (HSA) in vitro to identify possible adducts formed on proteins, and the protein adducts formed in cell culture medium and in patients were also characterised by mass spectrometric methods. Results Amoxicillin formed adducts with lysine residues on HSA in vitro, with K190, K199 and K525 being the most reactive sites. In addition, amoxicillin-modified K190 and K525, and novel adducts derived from amoxicillin dimmer were also detected in plasma samples from patients, and more extensive modification was observed in patients that had been administered higher doses of amoxicillin. The binding of clavulanic acid to HSA was rather complicated compared to amoxicillin. A total of seven types of adducts were identified when clavulanic acid was incubated with HSA at high concentration in vitro, including that formed by direct binding of clavulanic acid to lysine residues, novel pyrazine adducts derived from binding to the degradation products of clavulanic acid, and a cross-linking adduct. Importantly, stable adducts derived from formylacetic acid and pyrazine were also detected in all patients. Conclusion The finding of distinct novel types of AC haptens formed in patient is vital for further exploration of the immunological consequences to define the mechanisms of drug hypersensitivity exemplified by AC. P185 Dendrimeric Antigens For Studying The Influence Of Penicillin Determinants Orientation On IgE Recognition Maria Isabel Montañez1, Cristobalina Mayorga2, Francisco Najera3, Adriana Ariza1, Tahia D Fernandez1, Maria Salas2, Angela Martin-Serrano1, Miguel Blanca2, Ezequiel Perez-Inestrosa3, Maria Jose Torres2 1. Research Laboratory. IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 2. Allergy Unit. IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 3. Department of Organic Chemistry, University of Malaga, IBIMA, BIONAND, Malaga, Spain Keywords: Dendrimer, IgE, Penicillin Introduction Benzylpenicilloyl-dendrimer conjugates are recognized by IgE specific to BP (benzylpenicillin). Dendrimers are monodisperse synthetic carriers, which chemical structure can be perfectly characterized. Their use compared to the conventional poly-L-lysine carrier improves the reproducibility and sensibility of in vitro tests to diagnose allergy. Moreover, increasing understanding of the immunological recognition of drug-carrier conjugates in vitro would help to improve diagnostic tests. Herein we include other penicillin epitope, AX (amoxicillin), and study Dendrimeric Antigen (DeAn) conjugates that contain two types of epitopes, BP and AX, in the same carrier dendrimer molecule. We hypothesize that the orientation and tridimensional disposition of the peripheral epitopes in the DeAn may play key roles in the IgE recognition. Method Synthesis of DeAn conjugates was accomplished by reaction of generation 4 PAMAM (PolyAMidoAMine) dendrimers with either one kind of penicillin (BP or AX) or both penicillins (BP and AX). Their chemical and tridimensional structures were studied by mono- and bi-dimensional NMR (Nuclear Magnetic Resonance) and MDS (Molecular Dynamic Simulation). The conjugates were immunologically evaluated by RAST (Radio-Allergo-Sorbent-Test) inhibition using sera from 6 patients allergic to penicillins (selective and cross-reactive). Results Spatial conformation showed differences between benzylpenicilloyl, with a hidden side chain, and amoxicilloyl, exposing the entire molecule outside the dendrimeric skeleton. Concerning immunological assays, at the maximum conjugate concentration, serum allergic to BP showed 80% of RAST inhibition to both BP-DeAn and biepitope-DeAn, and negative to AX-DeAn. Sera allergic to AX showed 90% of inhibition to both AX-DeAn and biepitope-DeAn, with no inhibition to BP-DeAn. All sera with cross-reactivity to both penicillins inhibited above 90% to both AX-DeAn and biepitope-DeAn and above 60% to BP-DeAn. Conclusion Experimental data show less recognition of benzylpenicilloyl compared to amoxicilloyl units in those biepitope-DeAn, probably due to the different accessibility of the side chain of both penicillins to IgE recognition. Therefore there is a correlation between the tridimensional chemical structures of penicillin epitopes and the way DeAn are recognized by sIgE. Moreover, the biepitope DeAn conjugates could represent the basis of a novel method for screening a wider proportion of allergic patients with a single test. P186 Dendrimeric Antigens On Solid Supports: Designed Materials For IgE Quantification. Yolanda Vida1, Maria Isabel Montañez2, Noemi Molina1, Daniel Collado1, Francisco Najera1, Adriana Ariza3, Maria Jose Torres4, Cristobalina Mayorga2, Ezequiel Perez-Inestrosa1 1. Universidad de Malaga-IBIMA, Department of Organic Chemistry. Andalusian Centre for Nanomedicine and Biotechnology-BIONAND, Malaga, Spain 2. Research Laboratory Carlos Haya Hospital-IBIMA. Andalusian Centre for Nanomedicine and Biotechnology-BIONAND, Malaga, Spain 3. Research Laboratory Carlos Haya Hospital-IBIMA., Malaga, Spain 4. Allergy Service, Carlos Haya Hospital, Malaga, Spain. Andalusian Centre for Nanomedicine and Biotechnology-BIONAND, Malaga, Spain Keywords: IgE Quantification, Dendrimers, Dendrimeric Antigens, Introduction Complex functional materials consisting of bioactive molecules immobilized on solid supports present potential applications in biosensoring. Advances in the fabrication of these surface materials are of growing interests in antibody-based diagnostic. We describe recent progress in the preparation of new materials for biosensor applications where Dendrimeric Antigens (DeAn), synthetic antigens where the role of the carrier protein is performed by a dendrimer, were supported on silica particles to assemble DeAn@SiO2 composites. DeAn@SiO2 containing the allergenic determinant to amoxicillin (AXO) has been studied for quantifying IgE specific to Amoxicillin. Method We report on the use of silica particles as a solid support for RAST (RadioAllergo-Sorbent-Test) with a view to its use as a complementary diagnostic method for identifying allergic responses to penicillin. We prepared nanoconjugated Dendrimeric Antigens (DeAn) consisting of second-generation PAMAM dendrimers (PAMAM-G2) peripherally decorated with the suspected amoxicillin hapten (AXO). These organic-inorganic hybrid materials were carefully characterized and the preparation methodology was checked to be highly reproducible. To study the potential of those composites in the detection and quantification of antibodies, they were clinically tested by RAST using sera from allergic patients and control individuals tolerant to this drug, according to conventional protocols applied in the clinical practice. Results : 0.4 mg of DeAn@SiO2 composites were used in each assay, producing positive RAST results (7%) in sera from three allergic patients. No signal was obtained in the RAST on two control individuals (even though being one of them with diagnosed immediate allergic reaction to benzylpenicillin), ensuring a high specificity in the detection of antibodies. Additionally, larger amounts of composites (1 and 1.6 mg) were used in the assays, increasing the RAST level for patients allergic (14% and 18% respectively), which successfully improves the sensitivity of the test. The percentage of RAST obtained with the control gave negatives values, maintaining the specificity of the test. Conclusion DeAn@SiO2 composites, containing the allergenic determinant to AXO, proved effective in detecting and quantifying IgE in sera from patients allergic to amoxicillin, in a specific and selective way. This new material is thus promising candidate for improving in vitro clinical diagnostic practice. P187 Development Of A Screening Assay For Drug Hypersensitivity Using Naïve T Cells From Donors With Seven Different HLA Class I Risk Alleles. Lee Faulkner, Sally Wood, Ana Alfirevic, Munir Pirmohamed, Dean J Naisbitt, B Kevin Park University of Liverpool, Liverpool, United Kingdom Introduction A small proportion of adverse drug reactions (ADRs) are due to drug hypersensitivity where the immune response causes an unexpected and sometimes severe clinical reaction. Genome-wide screens have identified many different genetic associations between drugs and ADRs. Of particular interest to hypersensitivity reactions are the HLA Class I and Class II risk alleles. Not all individuals with a HLA risk allele will develop hypersensitivity. Thus, the frequency/severity of a reaction is a function of the chemistry of the drug, the biology of the immune system, the genotype of the individual and the underlying medical condition. Drug hypersensitivity reactions are rare and are rarely detected during clinical trials. It is only once the drug is widely prescribed that these reactions become apparent. Since hypersensitivity reactions that target skin and liver are a major cause of drug withdrawal from the market, there is a need to develop a screening assay which could potentially detect these reactions during drug development. Method We have established a biobank of lymphocytes isolated from 1000 HLA-typed volunteers and have developed a DC priming assay which can prime naïve T cells to various drugs. The current form of the DC assay is labour intensive, requires large numbers of cells, uses different plate formats, has multiple readouts and takes 3-4 weeks to run. The aim is to modify this into a screening assay using a single plate with a single readout. We have selected up to 5 donors expressing seven different HLA Class I risk alleles: A*3101, A*3303, A*6801, B*1301, B*1502, B*5701 and B*5801. Ten donors without the HLA risk alleles will be included as negative controls and a unique donor exposed to nitrososulfamethoxazole (SMX-NO) will be used as a positive control. Results Initial development has concentrated on using the SMX-NO and 2 β-lactam antibiotics as positive controls to optimise the assay conditions, to assess the frequency of T-cell responses and to measure the strength of the response induced. Early results show that proliferative responses to SMX-NO have been detected in the screening assay at a similar intensity to that detected in the existing form of the assay. Further work will concentrate on reproducibility and inter-donor variation. Conclusion Once established, the screening assay will be used to investigate responses to ticlopidine, dapsone, carbamazepine, flucloxacillin allopurinol and abacavir. P188 Different Patterns Of Recognition Of Structures Derived From Amoxicillin By IgE Antibodies From Patients With Immediate Hypersensitivity Reactions To Betalactams Adriana Ariza1, Cristobalina Mayorga1, María Isabel Montañez2, María Salas3, Inmaculada Doña3, Ángela Martín-Serrano2, Ezequiel Pérez-Inestrosa4, Dolores Pérez-Sala5, Miguel Blanca3, Antonio E Guzmán6, María José Torres3, María José Torres3 1. Research Laboratory, IBIMA – Regional University Hospital of Malaga – University of Malaga, Málaga, Spain 2. Research Laboratory, IBIMA – Regional University Hospital of Malaga – University of Malaga; BIONAND, Málaga, Spain 3. Allergy Unit, IBIMA – Regional University Hospital of Malaga – University of Malaga, Málaga, Spain 4. Department of Organic Chemistry, IBIMA – University of Malaga; BIONAND, Málaga, Spain 5. Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Madrid, Spain 6. Pharmacy Unit, Regional University Hospital of Malaga, Málaga, Spain Keywords: Amoxicillin, IgE, Carrier Molecule, Hypersensitivity Introduction Amoxicillin (AX) is the most frequent antibiotic elicitor of allergic reactions to drugs. It is widely accepted the requirement of the binding of the AX to a carrier molecule for its optimal IgE recognition. Although the carrier molecule seems to form part of the antigenic determinant, its contribution in the pattern of response is not fully known. The aim of this work was to study the recognition of different structures derived from AX by IgE antibodies from allergic patients to this drug. Method Patients (N=21) with an immediate allergic reaction to AX and radioallergosorbent test (RAST) values >7% were included. The IgE recognition study was performed by RAST inhibition using on the solid phase AX bound to poly-L-lysine and in the fluid phase the following inhibitors: AX, amoxicilloic acid, AX bound to butylamine (AXO-BA) and to human serum albumin (AXO-HSA), and fractions of different molecular weights of human serum modified with AX. Results Two well-defined patterns of recognition were observed: A group of patients in whom AX itself was significantly higher recognized (Group A, N=8) and another group of patients who preferentially recognized AXO-BA and AXO-HSA (Group B, N=13). No significant differences were observed for amoxicilloic acid, being significantly the lowest recognized structure in both groups. Regarding the pattern of recognition of different fractions from AX-modified human sera, groups A and B showed differences, with a higher recognition of the lowest molecular weight fraction (<3 kDa) in Group A and no differential recognition in Group B. Interestingly, all patients classified as Group A had selective allergic reactions to AX, and all those in Group B had cross-reactive reactions. Conclusion Although both AX derivatives and carrier molecules are important for the IgE recognition, differences exist between patients with a selective or a crossreacting response. In selective patients, it is necessary that the side chain of the AX was preserved in the AX-carrier adducts and exposed to the IgE, and this fact is influenced by the conditions in the formation of adducts. However, for crossreactive patients, whose IgE antibodies recognize the AX side chain and part of the common structure of penicillins, the conditions for the generation of AXcarrier adducts seem not to be relevant for their recognition. The poor recognition of the amoxicilloic acid reinforces the need for binding the AX to a carrier molecule for an optimal recognition. P189 High-Resolution Typing Of HLA Polymorphism And T-Cell Receptor Repertoire For Severe Adverse Drug Reactions Based On The CostEffective Next-Generation Sequencing Approaches Tai-Ming Ko, Yuan-Tsong Chen, Jer-Yuarn Wu Academia Sinica, Taipei, Taiwan Introduction Immune-related severe adverse drug reaction (ADR) is widely hypothesised triggered by the combination of HLA, drugs, peptides, and T-cell receptor (TCR) molecules. Currently, numerous types of severe ADRs are reported to be related to particular HLA polymorphisms, such as HLA-B*15:02 allele associated with carbamazepine-induced Steven’s Johnson syndrome (SJS) and HLA-B*58:01 allele associated with allopurinol-induced severe cutaneous adverse reactions (SCARs). The use of TCR by drug-specific T cells is also considered a co-factor responsible for severe ADR. The major challenges of using Sanger sequencing, for high-throughput typing of HLA and TCR gene in large cohort studies, is the high cost involved. Moreover, it is unknown whether CBZ-SJS or allopurinolSCARs is linked to more specified HLA types. Our aim was to identify which specified HLA types and TCR profiling correlated with CBZ-SJS or allopurinolSCARs based on using cost-effective next-generation sequencing approaches. Method We enrolled patients with CBZ-SJS, CBZ-tolerant subjects, patients with allopurinol-SCARs, allopurinol-tolerant subjects, and healthy controls. For HLA typing, we developed an analysis pipeline for illumina Miseq or PacBio sequencing platform. For TCR typing, a widely used primer set was used and an analysis pipeline for illumina Miseq or Hiseq sequencing platform was developed. Sanger sequencing for the validation of HLA and TCR was performed. Results We genotyped all major HLA regions, including HLA-A, HLA-B, HLA-C, HLA-DPB1, HLA-DQB1, and HLA-DRB1, in all the subjects. Compared with sequence-based typing ($400 per sample) for HLA typing, the cost based on next-generation sequencing ($240 per sample) was reduced. CBZ-SJS patients or allopurinolSCAR patients were HLA-B*15:02:01-positive or HLA-B*58:01:01-positive, respectively. For TCR, we genotyped all the V beta subfamilies. Dominant CDR3 sequences were verified by Sanger sequencing. Compared with Sanger sequencing ($500 per sample), the cost based on next-generation sequencing ($50 per sample) was much lower. Additionally, novel TCR clonotypes, possibly associated with SJS patients, were identified. Conclusion A cost-effective method for high-throughput and high-resolution typing of HLA and TCR was developed. HLA-B*15:02:01 and HLA-B*58:01:01 were found as more specified HLA genotypes for developing CBZ-SJS and allopurinol-SCARs, respectively. P190 Identification And Fate Of Intracellular Proteins Haptenated By Amoxicillin Francisco J. Sánchez-Gómez1, Juan M. González-Morena1, Yolanda Vida2, Ezequiel Pérez-Inestrosa2, Miguel Blanca3, María J. Torres3, Dolores Pérez-Sala1 1. Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas-CSIC, Madrid, Spain 2. Department of Organic Chemistry, University of Málaga, Málaga, Spain 3. Allergy Unit, IBIMA-Regional Hospital of Málaga, Málaga, Spain Keywords: Allergy, Amoxicillin, Haptenation, Exosomes, Intercellular Communication Introduction The common use of beta-lactams during the last decades is leading to an increase in the prevalence of allergic responses. In the allergic response, the adduct formation between small drugs and proteins, called haptenation, allows drugs to be recognized as antigens by the immune system. Moreover, it has been hypothesized that structures from target proteins can also contribute to the formation of the antigenic determinants. Identification of protein targets for haptenation is relevant for their potential use in novel diagnostic tools as well as for understanding the complete mechanisms involved in antigen presentation and the role played by the cells that participate in allergy induction. In recent years our lab has undertaken the identification of targets proteins for the haptenation by beta-lactams. Method We have attempted the identification of protein targets for covalent modification by amoxicillin (AX) and a biotinylated analogue (AX-B) as model compounds. To accomplish these aims, we decided to use a B-lymphocyte cell line as cellular model. The identification of the proteins haptenated by AX and AX-B has been approached with mass spectrometry experiments. In addition, intercellular communication mediated by vesicular delivery of molecular messages has been explored by microscopy techniques. Results In our experiments we have observed a complex pattern of proteins modified by amoxicillin. Among them, we have isolated and identified several novel targets for haptenation by AX in B-lymphocytes. In addition, these haptenated proteins have been observed both intracellularly and in the conditioned medium, where they were found both in soluble and vesicular fractions. Conclusion Our results indicate that intracellular proteins may be haptenated by beta-lactam antibiotics and reach the extracellular medium. The importance of these targets in the development of allergic reactions will be the subject of further investigations. Funding: MINECOSAF2012-36519; ISCIII RD12/0013/0008 P191 In Vitro Detection Of Terbinafine Protein Adducts. Arun Tailor, Toru Usui, Yanni Xue, Xiaoli Meng, Dean J Naisbitt, B Kevin Park University of Liverpool, Liverpool, United Kingdom Introduction Idiosyncratic drug induced liver injury (iDILI) is a severe adverse reaction which manifests in some, but not all drug recipients. The incidence of these reactions is so low that these adverse events cannot be attributed to the normal pharmacological action of a drug, but are probably due to the individual biology of a patient. To support this claim, an increasing number of genetic associations have been found in cases of iDILI, and many of these are with HLA alleles. This indicates that iDILI may have an immunological aetiology and there is increasing evidence to support this. For example: the detection of T-cells in liver biopsies from iDILI patients and the isolation of drug specific T-cells in patients suffering from flucloxacillin and co-amoxiclav induced liver injury. This sets a precedence to investigate other iDILI drugs such as terbinafine in the context of drug hypersensitivity reactions. Terbinafine can form a chemically reactive metabolite and like β-lactam antibiotics, may form drug-protein haptens to activate an immune response. Although the hapten model for drug hypersensitivity is well established, the precise nature of the drug antigen is unclear. The aim of this study is to investigate the formation of terbinafine adducts using a chemically reactive metabolite of terbinafine: allylic aldehyde, 7,7-dimethylhept-2-ene-4ynal (TBF-A). Method TBF-A was incubated for 24 hours at a 10:1 molar ratio for synthetic peptides and a 1:1 ratio for other molecules. Mass spectrometric analysis was conducted using an API 4000 or an QTRAP 5500 hybrid quadrupole-linear ion trap mass spectrometer (AB Sciex). Conjugates were detected using multiple reaction monitoring and also enhanced product ion scanning methods Results TBF-A showed binding to N-acetyl cysteine and glutathione but not to N-acetyl lysine. Additionally, TBF-A was shown to bind covalently to glutathione stransferase pi. Following incubation with human serum albumin, no conjugates were detected. Synthetic cysteine containing peptides were also generated and shown to bind TBF-A. Conclusion TBF-A binds to cysteine residues in small molecules, larger proteins and also in synthetic peptides. Thus, we are now conducting additional studies to isolate TBF-A specific T-cells in order to investigate whether formation of this metabolite is important for the activation of the adaptive immune system in patients with iDILI. P192 MicroRNAs Dysregulation In PBMCs From Drug Hypersensitivity Patients During Drug Challenge In Vitro. Alejandra Monroy Arreola1, Jesus Agustin Badillo Corona1, Silvia Mendez Flores2, Judith Dominguez Cherit2, Dean J Naisbitt3, Noe Valentin Duran Figueroa1, Jose Luis Castrejon Flores1 1. Instituto Politecnico Nacional, Mexico, Mexico 2. Instituto Nacional de Ciencias Medicas y Nutricion, Mexico, Mexico 3. University of Liverpool, Liverpool, United Kingdom Keywords: MicroRNAs, Drug Hypersensitivity, Mechanisms. Introduction Drug hypersensitivity reactions account for approximately 15% of all adverse drug reactions, where the skin is the main organ affected generating an important health problem. During the last twenty years, we have gained insight in to the immunological mechanism(s) behind different forms of cutaneous hypersensitivity, but our knowledge of post-transcriptional immune regulators remains poorly understood. MicroRNAs (miRNAs) play a key role in several immunological processes and in the pathogenesis of several diseases including severe skin conditions; nonetheless, their cellular origin and the changes in the expression as a result of drug exposure needs to be further investigated. Method Two allergic patients to sulfamethoxazole (SMX1 & SMX2) and one allergic patient to levofloxacin (LFV1) were enrolled in the study. Approval for the study was obtained from local research ethics committee, and informed written consent was obtained from each donor. The presence of drug specific T-cells was determined by LTT. Additionally, PMBCs (1.5x105 cells/mL) from each patient were incubated by triplicate in cell culture alone or in the presence of the culprit drugs at different concentrations. The change in the pattern of expression of the miRNAs was compare between drug free cells and drug incubated cells at 0, 12, 24 & 48 h by RT-PCR using commercial specific probes for miR-18a, -21, -142 & -155. The U6 gene was used as reference, and the relative expression was calculated using the delta Cq method. Results Positive stimulation indexes were obtained from the three patients at different concentrations. Moreover, a significant increase in the expression of miR-18a, 21, -142 & -155 was detected after 12-48 h in the PBMCs of all the patients. Quantitative relative expression of the different miRNAs showed a fold change between 2 to 100 during the incubation time when compared with cells without drug. When a different drug, not related with the reaction, was used, the change in the pattern of expression was reduced or similar to basal levels. Conclusion Our findings clearly show that the incubation of the culprit drugs with PBMCs from hypersensitive patients modify the expression of miRNAs in a dose and time dependent manner. At the presence, we are evaluating the change in the pattern of expression of miRNAs in PBMCs of hypersensitive patients caused by anticonvulsants and in patients with severe cutaneous reactions. Table 1. Clinical information and functional assays results from three hypersensivity patients to antibiotics. Lymphocyte Patient transformation Change in the pattern of information. test expresion of miRNAs with drugs. Skin Drug Relative Code SexAge S.I. / Drug [ug/mL] miRNA Time reaction [ug/mL] Expression 142 SMX [400] 153 ± 28 12 h SMX-NO 5.0 / SMX [200] 18a 71.6 ± 1.21 24 h SMX1F 60 MPE [12] 5.2 / SMX-NO [20] SMX-NO 155 5.6 ± 1.1 24 h [12] 18a SMX [400] 2.5 ± 0.6 24 h 2.0 / SMX [400] SMX-NO SMX2M 35 MPE 21 6.3 ± 3.2 24 h 3.0 / SMX-NO [20] [12] 142 SMX [400] 3.9 ± 0.7 24 h 142 LVF [10] 12.2 ± 0.9 24 h LVF1 M 47 MPE 2.0 / LVF [10] 18a LVF [10] 4.0 ± 0.4 48 h 155 LVF [10] 5.1 ± 1.1 48 h SMX, Sulfamethoxazole; SMX-NO, Sulfamethoxazole Nitroso; LVF, Levofloxacin; MPE, Maculopapular Exanthema. Relative expression results are presented as the Mean ± S.D. obtained by the delta Cq method. P193 NSAIDs-Exacerbated Cutaneous Disease: High Throughput Gene Expression Profiling José Antonio Cornejo-García1, James Perkins2, Natalia Blanca-López3, Diana Pérez-Alzate3, Raquel Jurado-Escobar2, Inmaculada Doña4, Gador Bogas4, María J Torres4, Gabriela Canto3, Miguel Blanca4 1. Research Laboratory and Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 2. Research Laboratory, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain 3. Allergy Service, Infanta Leonor University Hospital, Madrid, Spain 4. Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain Keywords: Drug Hypersensitivity, NSAIDs, NECD, Gene Expression Introduction Some patients with a history of chronic spontaneous urticaria may suffer from an exacerbation of this pathology after aspirin and other non-steroidal antiinflammatory drugs (NSAIDs) intake, a condition termed NSAIDs-exacerbated cutaneous disease (NECD). In addition to the participation of COX-1 inhibition the underlying mechanism may be influenced by differential gene expression. To assess the genetic mechanisms potentially implicated in NECD we analysed gene expression patterns using microarrays technology. Method Total RNA was obtained during the acute phase from skin biopsies in 3 patients with NECD, and 14 heathy controls. After quality control evaluation, gene expression patterns were compared through the GeneChip Human Gene 2.0 ST microarrays system (Affymetrix). echanism may be influenced by differential gene expression. To assess the genetic mechanisms potentially implicated in NECD we analysed gene expression patterns using microarrays technology. Results We found 163 differentially expressed transcripts in NECD patients from a total of 48227 analysed (FDR p value <0.05, and a log fold change >1 or < 1). Top upregulated transcripts were related to the structural integrity of epithelial cells (KRT16, KRT17), the HLA system (HLA-DQB1) and microRNAs (MIR4427). Some downregulated transcripts were also related to microRNAs (MIR3127) and microRNA-mediated gene repression (DND1), adhesion and migration of epithelial cells (POSTN), transcription factors (ZNF667), and collagen integrity (COL6A5). Conclusion We described a differential expression pattern in NECD suggesting intricate interactions in gene regulation affecting skin structural integrity, cell adhesion and migration, and the HLA system. Our results shed new light for understanding the mechanisms underlying this entity.:normal'>KRT16, KRT17), the HLA system (HLA-DQB1) and microRNAs (MIR4427). Some downregulated transcripts were also related to microRNAs (MIR3127) and microRNA-mediated gene repression (DND1), adhesion and migration of epithelial cells (POSTN), transcription factors (ZNF667), and collagen integrity (COL6A5). P194 Utility Of Skin Tests In Non-Immediate Reactions To Amoxicillin Luis Mario Tubella Marti1, Fernando Pineda De La Losa2, Francisca Arribas Poves2, Jaime Tubella Lopez1, Teodora Lopez Santiago1 1. Alergology Service. Hospital Delfos., Barcelona, Spain 2. DIATER Laboratorios, Madrid, Spain Keywords: Diagnostic, Skin Test, Amoxicillin, Non-Immediated Introduction Allergy to beta-lactam antibiotics, specifically penicillins, is presented differently depending on the time spent from administration of the drug until the reaction. Thus we can classify these manifestations as immediate, accelerated or delayed, or simply as immediate or not immediate. Method Patient who comes to be attended after having suffered 2 episodes of RAM after taking amoxicillin. Both episodes coursed with generalized skin rash, eight days after taking amoxicillin 500 per a picture of tonsillitis and the second 5 days after taking amoxicillin 500 per a tooth extraction. On both occasions the picture is manifested after a latency period of 48-72 hours after the last intake. Skin tests with amoxicillin (DAP DIATER kit) by prick test and ID to 1:10 and 1: 100 and undiluted. Oral challenge test against Cefuroxime increasing doses up to the maximum cumulative dose of 500 mg. RAST tests against penicilloyl G and V, ampicillin, amoxicillin and cefaclor Results The skin tests were positive for amoxicillin ID undiluted, 1:10 and 1: 100 at 72 hours. The oral food challenge to cefuroxime at the doses administered was negative. RAST tests against penicilloyl G and V, Ampicillin, Amoxicillin and negative cefaclor. Conclusion We report a case of delayed reaction to amoxicillin with tolerance to cefuroxime, where the history and skin tests were essential in the diagnosing of this case.