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Ivo Boudakov, Ph.D. Ver. 2016 Hypersensitivity IMMUNOLOGY (BMIC550) Learning Objectives FYI Topics and keywords to be discussed: Hypersensitivity I, II, III, and IV. Description of Hypersensitivity type V reaction. Rhesus disease (Erythroblastosis fetalis). Autoimmune hemolytic anemia. Idiopathic thrombocytopenia purpura. Cold hem-agglutinin disease. Graves disease. Arthus Reaction. Serum sickness. Glomerulonephritis. Rheumatoid arthritis. Systemic lupus erythematosus (SLE). Tuberculin test. Contact sensitivity 131. List the Gell and Coomb’s classification of hypersensitivity 132. Describe the pathophysiologic mechanisms associated with Type I (IgE)- mediated injury. 133. Compare and contrast the acute phase reaction with the late phase reaction in anaphylaxis. 134. Explain the role of eosinophils in allergic and anaphylactic reaction. 135. Discuss the therapeutic modulation of Type I hypersensitivity. Explain the proposed mechanism underlying “desensitization” (“allergy shots”). 136. Explain the principles underlying the RAST test and skin test. Explain how they can be used as diagnostic tools. 2 Learning Objectives FYI 136. List the categories of intervention for patients susceptible to Type I hypersensitivities. 137. Explain the principle underlying desensitization therapy. 138. Describe allergic asthma.. Describe the bronchial wall changes that occur in asthma. 139. Compare and contrast Type II and Type III hypersensitivity reactions. 140. Compare complement mediated cell lysis and antibody dependent cell cytotoxicity. 141. Compare immunopathology of Goodpasture’s syndrome and SLE. 142. Compare and contrast drug induced Type I and Type II hypersensitivity reactions. 143. Discuss the underlying reasons for the development of Erythroblastosis fetalis. 144. Describe Type IV cell mediated hypersensitivity. 145. Recall the basis for, and examples of, contact hypersensitivity. 146. Explain the principle of, and immunology of a Mantoux test. 147. Describe granulomatous formation. 3 Hypersensitivity Under some circumstances immune system reaction causes tissue and organ damage instead of protection Such reactions are collectively known as hypersensitivity Reaction could occur in two situations: against environmental antigens against self (autologous) antigens which is usually linked to tolerance failure Allergen is an antigen that causes harmful reaction and technically it is linked with type I hypersensitivity. 4 Basic characteristics of Hypersensitivity Reaction is antigen specific Reaction depends on the participation of antibodies or lymphocytes Prior exposure to an antigen is required (sensitization) First contact with an antigen produces no detectable reaction, but sensitizes the immune system Secondary and any other re-exposure to the same antigen elicit the hypersensitive reaction Additional re-exposures to the same antigen may increase or sometimes decrease the sensitivity of the reaction 5 ANTIBODY MEDIATED Hypersensitivity - Four (Five) Types Type I (Immediate Hypersensitivity) IgE mediated reaction such as allergy or anaphylaxis Type II (Cytotoxic Hypersensitivity) Antibody dependent (IgM or IgG) cytolytic reactions Type III (Immune Complex Hypersensitivity) Immune complex reactions (mediated by IgM or IgG) Type IV (Delayed Hypersensitivity -DTH) cell mediated immunity, such as tuberculin test Type V (Noncytotoxic or Stimulatory Hypersensitivity) same underlining mechanism as type II hypersensitivity (IgG 6 or IgM) but instead of damage it alters tissue activation Type I – Immediate Hypersensitivity Limited number of allergens when deposited in low doses on mucosal epithelial cells or skin trigger mast cells activation Allergens include Pollens, trees, grass, and dust Food allergens Milk, eggs, fish, cereals, nuts Insect bites, mite feces, dogs, cats Reaction against drugs (penicillin) and other haptens, mold spores, etc. 7 Clinical Presentation of Type I Hypersensitivity Wheel and flair – almost immediate vasodilation with infiltrate presenting as wheel and inflammation around Atopic dermatitis (atopic eczema) – itchiness which is not caused by histamines hence anti-histamines would not help with eczema 1/5 infants (due to fragile skin) 8 vs. 1/50 adults develop eczema Clinical Presentation of Type I Hypersensitivity Hives (urticaria) – itchiness linked to histamine release Individual lesions usually do not last longer than 1-2 days healthy lung airway inflamed lung airway Asthma – allergens act on the tracheobronchial tree Inflammation causes edema of PENTAX Medical Company. the airway wall Hyper-secretion of mucus 9 causes airflow obstruction Clinical Presentation of Type I Hypersensitivity Allergic rhinitis: (hay fever) – acts on the mucus membranes of the nose and eye Congestion, itchiness, and sneezing 10 Clinical Presentation of Type I Hypersensitivity Anaphylaxis: life threatening reaction do to systemic flood of immunomodulators triggered by allergens (peanuts, bee sting, shellfish food, penicillin, etc.) lower-air way obstruction and hypotension caused by intense constriction of bronchioles and bronchi, contraction of smooth muscles, and dilatation of capillaries Food allergy will cause inflammation, diarrhea, and/or vomiting if the allergen penetrates the GIT wall then it may cause systemic reactions: skin eruptions (urticaria), bronchospasm, and anaphylactic shock 11 Allergic March Eczema (atopic dermatitis) is often linked with food allergy, asthma, or allergic rhinitis (hay fever) This order is also known as atopic (allergic) march Children with atopic dermatitis are more likely to develop asthma or rhinitis 12 http://e-allergy.org/eng/contents/sub03_01.html Mechanism of Type I Hypersensitivity Immediate reaction is a quick release of preformed immunomodulators, known as mast cells degranulation: Histamine: vascular dilation, smooth muscle contractions 13 Proteases: tissue damage Mechanism of Type I Hypersensitivity Late phase can be broken into two blocks: Switch in the expression drives production of lipid mediators from arachidonic acid – known as slowreacting substance of anaphylaxis (SRS-A) Hours later there is a 14 recruitment of eosinophils and neutrophils due to release of cytokines (TNFα; IL-4; IL-13) causing localized inflammation Immediate vs. Late Reaction 15 Mechanism of Type I Hypersensitivity Sensitization phase – allergen triggers IgE production some individuals (20%) are genetically predisposed to make IgE against harmless environmental antigens Association between some HLA alleles and allergic reaction has been documented for number of allergens. TH2 drives IL-4 production leading to IgE buildup Mast cells in the mucosal tissues or under the skin have high affinity FcεRI which binds IgE even in absence of allergen Activation phase – re-exposure to allergen associates with existing IgE bound to FcεRI on mast cells within minutes Mast cells are activated leading to immediate and 16 followed by late reaction of type I hypersensitivity Type I- Hypersensitivity Primary mediators Histamine Vascular permeability, smooth muscle contraction Serotonin Neurotransmitter – smooth muscle contraction ECF-A Eosinophil chaemotaxis NCF-A Neutrophil chaemotaxis Proteases mucus secretion, connective tissue degradation Tryptase serine proteinase of mast cells Heparin initiates bradykinin production causing swelling, anaphylaxis Secondary Mediators Leukotrienes vascular permeability, smooth muscle contraction vasodilation, smooth muscle contraction or dilation , platelet Prostaglandins activation Bradykinin vascular permeability, smooth muscle contraction numerous effects causing activation of vascular endothelium, Cytokines eosinophil recruitment and activation Cells involved in type I hypersensitivity Mast cells Degranulation leading to release of inflammatory mediators TH2 IL-4 production promotes Ig class switch to IgE, blocks TH1 Eosinophils Produces a variety of mediators and cytokines: IL3 and IL5 17 Allergy (Skin Prick) Test 18 http://www.medicalook.com/tests/Allergy_Skin_Tests.html 5 Diagnosis In vivo skin prick test with batteries of allergens takes 5 -30 min to observe wheal and flare reaction Late-phase reaction – may last 24 hours More edematous then the early reaction Dense infiltration of eosinophils and T cells ELISA: measurement of allergen specific serum IgE Radio-allergo-sorbent test (RAST) is serum based and permits identification of specific IgE against potential allergens. RAST is now consider obsolete do to the development of the more sensitive “fluorescence enzyme-labeled assays” 19 Hygiene Hypothesis Allergic individuals have increase of allergen specific CD4 TH2 cells greater amount of IL-4 which inhibits TH1 There is an increasing evidence that lack of exposure to bacteria (stimulation of the Th1 responses) in early life favors the Th2 phenotype. Lower incidence of allergic disease in individuals who farm or live in rural communities: they are presumably exposed to organisms from livestock. Lower incidence of allergic disease in third world countries with limited access to sanitation facilities 20 Treatment Environmental: avoidance of allergen Pharmacological treatment Antihistamine: block histamine receptors Sodium cromoglycate: prevents degranulation by stabilizing the cell membrane of mast cells and basophils Epinephrine: the most effective for life saver Reverses anaphylactic shock caused by histamine: relaxes smooth muscles, decrease vascular permeability Increase heart beat rate – increase blood pressure Corticosteroids: Block metabolic pathways involving arachidonic acid They have general anti-inflammatory effects 21 Underlining Mechanism of Immunotherapy by Desensitization SLIT - sublingual immunotheraphy; SCIT - subcutaneous immunotheraphy 22 Update in the Mechanisms of Allergen-Specific Immunotheraphy; Allergy Asthma Immunol Res; v.3(1); Jan 2011 ; Tunc Akkoc,1 Mübeccel Akdis,2 and Cezmi A. Akdi Immunotherapy by Desensitization Desensitization also known as allergy vaccination Small amounts of allergen are injected on regular intervals to switch the response away from TH2 induced IgE IFN cytokine production by TH1 suppresses TH2 IgG4 production driven by IL-10 cytokine (Tr1 and others) wipes away the available allergen Suppresses production of IL-4 by TREG blocks TH2 Desensitization has to be done under doctor’s monitoring due to a risk of anaphylactic reaction and if stopped it is lost. 23 Type II – Cytotoxic Hypersensitivity Antibodies involved are IgG and/or IgM Occurs when specific antibodies attack antigens on cell surfaces, tissues, or organs. Such antibodies will initiate: Damage (e.g. cell lysis) due to activation of the complement Attack by neutrophils through Fc receptor and release of cytokines, oxygen radical, and other inflammatory mediators Opsonization and phagocytosis of cells such as RBC Killing of antibody coated cells by antibody dependent cellular cytotoxicity (ADCC) 24 Type II – Cytotoxic Hypersensitivity 25 Examples of Type II Cytotoxic Hypersensitivity Blood transfusion reactions Individuals with blood type O have natural IgM antibodies against blood type A and B antigens If type O person receives blood transfusion of type A or B, the preformed IgM will bind and lyse the transfused RBC Rh incompatibility reactions: Erythroblastosis fetalis Rh antigen first isolated in Rhesus monkey Rh are antigens on RBC, like the AB antigens A person could Express the antigen as homozygous dominant (Rh+Rh+) or heterozygous (Rh+Rh-) Lack the antigen as homozygous recessive, (Rh-Rh-) 26 Hypersensitivity Type II: Rhesus Disease. 27 Hypersensitivity Type II: Rhesus Disease There is a potential problem when a Rh- Rh- mother conceives Rh+Rh- fetus from Rh+ father First child (Rh+ ) will normally be born without problems During delivery the mother will be sensitized by Rh+antigen IgG antibodies are produced against Rh factor (anti-D ; anti- RhD) and will circulate in the mother Next time the woman gets pregnant with Rh positive fetus, IgG will cross the placenta and destroy fetal red blood cells This is known as hemolytic disease of the newborn: erythroblastosis fetalis 28 Prevention of Erythroblastosis Fetalis Treatment is in a form of a passive immunization Rh negative mothers are given RhoGAM: human preparation of anti-RhD IgG antibodies Given about 28 weeks of pregnancy, and within 72 hours after childbirth. RhoGAM prevents sensitization of the maternal immune system to Rh D antigens that causes rhesus disease. A possible mechanism is that RhoGAM mopes away the reacting anti-RhD antibodies (RhoGAM is in minute amounts). Currently it is believed that RhoGAM is tolerogenic and induces some kind of regulatory cells. The widespread use of anti-Rho(D) immunoglobulin have led 29 to disappearance of the Rh disease Daily Mail: “Man with the golden arm' saves 2million babies in half a century of donating rare type of blood” Read more: http://www.dailymail.co.uk/news/worldnews/article-1259627/Mangolden-arm-James-Harrison-saves-2million-babies-half-century-donating-rare-blood.html An Australian man who has been donating his extremely rare kind of blood for 56 years has saved the lives of more than two million babies. James Harrison, 74, has an antibody in his plasma that stops babies dying from Rhesus disease, a form of severe anaemia. He has enabled countless mothers to give birth to healthy babies, including his own daughter, Tracey, who had a healthy son thanks to her father's blood. Mr Harrison has been giving blood every few weeks since he was 18 years old and has now racked up a total of 984 donations. When he started donating, his blood was deemed so special his life was insured for one million Australian dollars. He was also nicknamed the 'man with the golden arm' or the 'man in two million‘.His blood has since led to the development of a vaccine called Anti-D. He said: 'I've never thought about stopping. Never.' He made a pledge to be a donor aged 14 after undergoing major chest surgery in which he needed 13 litres of ………. 30 Examples of Type II Cytotoxic Hypersensitivity 31 Noncytotoxic or Stimulatory Type II Hypersensitivity Also Known as Type V Auto-antibodies (IgG or IgM) against receptors instead of destroying the tissue they will alter their function Instead of cell lyses the antibodies will interfere by blocking or enhancing receptor function Graves disease: Stimulating auto-antibodies against thyroid-stimulating hormone (THS) receptor on thyroid cells: hyperthyroidism Symptoms: fatigue, nervousness, increased sweating, palpitation, weight loss and heat intolerance Children born from mothers with Grave’s disease may show hyperthyroidism (IgG) 32 Associated with HLA-DR3; and others: HLA-Bw35, etc. Type V Hypersensitivity: Myasthenia Gravis Auto-antibodies against acetylcholine (Ach) receptor will block the binding of acetylcholine at the neuromuscular junction: Initially there is suppression of neuromuscular signaling and eventual damage of acetylcholine receptors Pregnant mother can transfer IgG antibodies to the unborn children causing transient neuromuscular dysfunction Symptoms include: muscle weakness that improve with rest blurry or double vision (diplopia) eyelid drooping (ptosis) difficulty in swallowing shortness of breath impaired speech 33 Hypersensitivity Type III: Immune Complex 34 Type III: Immune Complex Hypersensitivity Triggered by high level of circulating immune complex (IC) when IgG or IgM binds foreign (infection) or self antigens Under normal conditions circulating Ag/Ab complex is cleared by monocytes / microphages excessive amount of antigen leads to overwhelming amount and deposition of immune complex (Ag-Ab) that monocytes fail to remove Immune complex can be deposited in various tissues: skin, kidney, blood vessels, joints, lungs and leads to complement activation and induction of inflammation attraction of neutrophils followed by tissue damage 35 Examples of Type III Hypersensitivity Arthus reaction (cutaneous vasculatis): Localized cutaneous and subcutaneous inflammatory response triggered by injection and deposition of antigen Localized inflammation starts with complement activation e.g. on blood vessel: results in vasodilatation and rupture of blood vessels, edema, induration, and some cases hemorrhagic necrosis of local tissue Farmer’s lung: (alveolar inflammation) Inhalation of antigen, e.g. mould from Actinomyces species or various Aspergillus species , mouldy hay grain Causing hypersensitive pneumonia 36 Examples of Type III Hypersensitivity Serum sickness: originally has been observed as reaction against treatment with horse serum as passive immunization Type III systemic inflammatory response to the presence of immune complexes . not like arthus reaction which is localized) Symptoms appear few days after exposure to antigen and include Fever, urticaria (hives), arthralgia, lymphadenopathy, spleenomegaly Symptoms disappear after few days when antibody level increases and antigen level falls down 37 Circulating Ag-Ab Complex in Serum Sickness http://www.foamem.com/2014/03/27/briefs-serum-sickness-like-reaction/ 2014, Brad Sobolewski, MD, MEd 38 Delayed Type IV Hypersensitivity Delayed type hypersensitivity (DTH) is also known as cell- mediated immune memory response It is entirely relying on T lymphocyte function and antibody-independent mechanism The response is delayed because it takes hours (days) to recruit inflammatory cells and often lasts for days. The T cell response may be directed against Auto-antigens Fixed chemicals that get in contact with skin, e.g. contact dermatitis Transplant tissue 39 Microbes Delayed Type IV Hypersensitivity Sensitization stage: Contact of T cell with antigen on APC This results in the activation of the naïve T cell (priming) Challenge state: Repeated exposure or persistent antigens will drive APC presentation to T cell (TH1, TH2, and TH17) which will proliferate and deliver their effector function This results in localized overproduction of cytokines and recruitment of macrophages will eventually cause tissue damage or granulomas If antigen (pathogen) elimination is delayed, the activated T 40 cells and macrophages will continue producing cytokines and triggering inflammation Delayed Type IV Hypersensitivity Steps following the cytokine release Accumulation of macrophage to the site, which can transform to: giant cells – fusion of activated macrophages epithelioid cells – activated macrophages that are resembling epithelial cells, Continue to secrete cytokines Attract eosinophils to site which will degranulate and cause tissue damage Indiscriminate cytotoxicity by activated macrophages, neutrophils, NK cells, Tc cells driven by cytokines 41 Delayed Type IV Hypersensitivity Persistent antigens will result in chronic granuloma: Mass composed of giant cells, epithelioid, proliferating lymphocytes, proliferating fibroblasts and formation of fibrosis Formation of excess fibrous connective tissue in an attempt of the organism to isolate and wall off the infection, the antigen trigger, or the foreign material If the accumulated macrophages and monocytes destroy the antigen then the lesion will heal Unfortunately the more tissue is damage the more self- antigens are released and this perpetuate the reaction 42 Mechanisms of Type IV Hypersensitivity 43 Examples of Type IV Hypersensitivity Tuberculin test – Mantoux (PPD) test Injection of tuberculin to the skin to check for previous Mycobacterium tuberculosis infection Reaction is characterized by erythema and induration – reaches maximum 24-48hrs 44 Purified Protein Derivative – PPD ; Anastácio Q. SousaI,II; Margarida M.L. PompeuII; C. Jaime Araujo FilhoI; Telma R.B.S. QueirozI; J. Clementino FerreiraII ; http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702006000600015 Examples of Type IV Hypersensitivity Contact dermatitis (sensitivity) – caused by contact with small molecules, e.g. nickel, formaldehyde, poison oak, poison ivy (the hapten urushiol), hair dyes the small molecules acts as a hapten in contact with skin or other body proteins the sensitized person develops erythema, itching, eczema, blisters, or necrosis of skin with 12 – 48 hours. 45 Type IV Hypersensitivity Skin Patch Test Results are analyzed at 48h/72h 46 1) 2) https://i.ytimg.com/vi/zY26QENqe3A/maxresdefault.jpg Indian journal of dermatology; Year : 2014 | Volume : 59 ; Aeroallergen patch testing in patients of suspected contact dermatitis ; Nelee Bisen1, Shrutakirthi D Shenoi2, C Balachandran2 Delayed hypersensitivity reactions Type contact tuberculin Reaction Clinical time appearance Antigen and site 48-72 hr eczema lymphocytes, followed epidermal ( organic by macrophages; chemicals, poison ivy, edema of epidermis heavy metals, etc.) 48-72 hr local induration lymphocytes, monocytes, macrophages intradermal (tuberculin, lepromin, etc.) hardening macrophages, epitheloid and giant cells, fibrosis persistent antigen or foreign body presence (tuberculosis, leprosy, etc.) 21-28 granuloma days 47 Histology Examples of Type IV Hypersensitivity Granulomatous inflammations observed in: Sarcoidosis Crohn disease Hashimoto’s thyroiditis Allograft rejection, Graft versus Host Disease (GvHD) Diabetes mellitus type 1 Multiple sclerosis Superantigen mediated diseases (toxic shock syndrome) Ankylosing Spondylitis 48 References Basic Immunology by Abbas et al, 4th edition, 2014 Chapter 11; page 207-223 49 Ivo Boudakov, Ph.D. Ver. 2016 Autoimmunity IMMUNOLOGY (BMIC550) Learning Objectives FYI Topics and keywords to be discussed: Autoimmune diseases – T and B cell dependency. Self and non-self antigens. Central and peripheral immune tolerance. Immune tolerance failure: genetic and gender predisposition. Role of infections in autoimmunity. Review various autoimmune diseases. Antibody mediated diseases: Autoimmune hemolytic anemia; Idiopathic thrombocytopenic purpura; Goodpasture Syndrome; Cold Agglutinin Disease; Myasthenia gravis; Graves’s disease; Pernicious anemia; Systemic lupus erythematosus (SLE); Hashimoto’s thyroiditis. Cell mediated diseases: Insulin dependent diabetes mellitus; Multiple sclerosis; Autoimmune polyendocrinopathy syndrome (APS-1); Mixed diseases: Rheumatoid arthritis; Treatment. 149. Explain and link to clinical presentation central and peripheral tolerance. 150. Explain antigen sequestration as it relates to tolerance and how tolerance can be broken. 151. Define the terms molecular mimicry and cross reactivity. Explain how infectious diseases could play in the development of autoimmunity. 152. List disorders that have a known association with MHC genes (Supporting charts). 2 Learning Objectives FYI 153. For each of the disorders/disease listed in the accompanying table be able to discuss: (i) name of the disorder (ii) primary cause underlying the disorder (iii) autoantigen (if present) (iv) autoantibodies(if present) (v) characteristic features (vi) investigations (vii) mechanism of the pathology 154. For each of the disorders listed in the accompanying table, determine the immunological processes that lead to the pathology observed. 155. For each of the disorders listed in the accompanying table discuss at least one potential immunological therapy and provide a rationale for that choice. 3 Autoimmune diseases Failure of immune tolerance will cause over reaction against self antigens eventually leading to autoimmunity Many people experience an autoimmune symptoms during their lifetime but they are usually short-lived and selfresolving. The autoimmune symptoms maybe initiation by: infection tissue damage due to trauma Auto-reactive antibodies produced in most of these cases are harmless and they do not lead to serious pathology If the immune system cannot return to its resting state then chronic and debilitating autoimmunity will develop 4 Examples of Tolerance Failure Driving Autoimmunity Failure in Primary mediators Central tolerance • Autoimmune polyendocrine syndrome type 1 (APS-1), due to defect in AIRE gene function Antigen segregation Peripheral anergy • • • • • Uveitis; Multiple sclerosis (MS) Insulin-dependent diabetes mellitus (type 1); Hashimoto thyroiditis Immune-dysregulation polyendocrinopathy Regulatory cells enteropathy X-linked (IPEX) syndrome • Rheumatic fever; Antigen mimicry • Graves Disease; • Lyme arthritis 5 Prevalence of Autoimmune Diseases 1800 1700 1600 1400 1200 Reported Average Prevalence of Autoimmunity Rates per 100,000 Individuals-per-year According to Various Worldwide Studies 1100 1000 800 600 400 200 739 500 350 300 300 270 220 160 150 110 100 90 25 14 13 12 12 0 6 Compiled Studies: The Cost Burden of Autoimmune Disease: The Latest Front in the War on Healthcare Spending ; National Coalition of Autoimmune Patient Groups (NCAPG), in March 20103. 12 5 Multifactorial Disorders Autoimmune diseases are multifactorial by nature Sex hormones (e.g. gonadal sex steroids) are important modulators of the immune and autoimmune response 7 Nature Immunology 2, 777 - 780 (2001) ; Sex differences in autoimmune disease Caroline C. Whitacre; http://www.nature.com/ni/journal/v2/n9/fig_tab/ni0901-777_ft.html Gender Determined Ratio in Autoimmunity Disease Hashimoto's thyroiditis Primary biliary cirrhosis Sjogren's syndrome Systemic lupus erythematosus Chronic active hepatitis Graves' disease Rheumatoid arthritis Scleroderma Multiple sclerosis 8 Sex (Female:Male) 50:1 9:1 9:1 9:1 8:1 7:1 4:1 4:1 2:1 What Causes Breakdown of Immune Tolerance? Hormone influence/sex Autoimmune diseases are more common in women than men Severity of autoimmune diseases in women tends to ameliorate during pregnancy and they follow a relapse after giving birth Sex hormones affect the immune response by modifying the patterns of gene expression Age: Frequency of autoimmune disease increases with age Autoimmune diseases almost non existent in childhood First appearance is in the age of 20 - 40 years Failure of the immune regulatory mechanisms with age 9 advancement What Causes Breakdown of Immune Tolerance? Autoimmune diseases tend to be common among members of the same families when they share some HLA haplotypes probably due to an increased likelihood of presenting certain autoimmune antigen (hypothesis that still has to be proven) It may be possible that other genes linked with HLA genes are responsible There is direct linkage between some HLA types and the increased risk of disease occurrence compare to the general public Note: keep in mind that various literature sources have variations in the listing of HLA haplotypes linked to the same autoimmune disorders 10 Risk of Autoimmune Linked to Sex and HLA Disease Multiple sclerosis Type 1 diabetes HLA allele DR2 DQ2 + DQ8 4.8 20 10 N/A DQ6 0.2 N/A 14 25 3.7 25 4.2 3.2 N/A -1 4-5 -1 3 4-5 5.8 10-20 14.4 87.4 10 -1 0.3 <0.5 DQ8 DR3/DR4 heterozygote Graves' disease DR3 Myasthenia grads DR3 Rheumatoid arthritis DR4 Hashimoto thyroiditis DR5 Systemic lupus DR3 erythematosus (SLE) Pemphigus vulgaris DR4 Ankylosing spondylitis B27 Acute anterior uveitis B27 11 Relative risk Sex (F:M) SOURCE: modified from Janeway's Immunobiology 8th ed., 2012 Role of Infections Many autoimmune diseases follow infectious episodes Possible explanation is molecular mimicry where the pathogen is having a cross reacting antigen with the host e.g. Yersinia enterocolitica share epitopes with thyroid stimulating hormone Microbial material may serve as an adjuvant for self antigens, which will make them immunogenic Microbial materials acting as mitogens where numerous clones of lymphocyte are activated in non-specific manner causing polyclonal activation usually dormant self reacting lymphocytes can be 12 stimulated against self tissue in such instances Viruses Bacteria Table 66-2. Microbial infections associated with autoimmune diseases. ; Review of Medical Microbiology and Immunology, 13e. Warren Levinson; LANGE (NOTE: know the entries in bold font) 13 Microbe Streptococcus pyogenes Campylobacter jejuni Escherichia coli Chlamydia trachomatis Shigella species Yersinia enterocolitica Borrelia burgdorferi Hep B virus; EBV; Measels; others Hepatitis C virus Measles virus Coxsackievirus B3 (myocitic Tc damage) Coxsackievirus B4 (in mice only so far) Cytomegalovirus Human T-cell leukemia virus Autoimmune Disease Rheumatic fever Guillain-Barre syndrome Primary biliary cirrhosis Reiter's syndrome Reiter's syndrome Graves' disease Lyme arthritis Multiple sclerosis Mixed cryoglobulinemia Allergic encephalitis Myocarditis Type 1 diabetes mellitus Scleroderma HTLV-associated myelopathy Causes of Tolerance Breakdown Alteration of normal proteins Drugs or compounds from pathogens can bind to normal proteins and make them immunogenic Procainamide (antiarrhythmic agent) induces systemic lupus erythromatousus (SLE) Release of sequestered antigens Trauma or infection exposes hidden antigens to the immune system Example: anterior uveitis- primarily to the anterior segment of the eye. Causes: post-surgical (most common cause) ; trauma (second 14 most common cause) ; herpesvirus infection ; others Table 66-1. Important Autoimmune Disease, 13e. Warren Levinson; LANGE Type of Response Antibody to receptors Antibody to cell components other than receptors Cell-mediated 15 Autoimmune Disease Myasthenia gravis Graves' disease Insulin-resistant diabetes Lambert-Eaton myasthenia Systemic lupus erythematosus Rheumatoid arthritis Rheumatic fever Hemolytic anemia Idiopathic thrombocytopenic purpura Goodpasture's syndrome Pernicious anemia Hashimoto's thyroiditis Insulin-dependent diabetes mellitus Addison's disease Acute glomerulonephritis Periarteritis nodosa Guillain-Barre syndrome Wegener's granulomatosis Pemphigus IgA nephropathy Allergic encephalomyelitis and multiple sclerosis Celiac disease FYI Main Targets Acetylcholine receptor TSH receptor Insulin receptor Calcium channel receptor dsDNA, histones Joint tissue Heart and joint tissue RBC membrane Platelet membranes Basement membrane of kidney and lung Intrinsic factor and parietal cells Thyroglobulin Islet cells Adrenal cortex Glomerular basement membrane Small and medium-sized arteries Myelin protein Cytoplasmic enzymes of neutrophils Desmoglein in tight junctions of skin Glomerulus Reaction to myelin protein causes demyelination of brain neurons Enterocytes The Spectrum of Autoimmune Diseases Fig. 26.3 Autoimmune diseases may be classified as organspecific or non-organ-specific depending on whether the response is primarily against antigens localized to particular organs, or against widespread antigens. 16 SOURCE: Immunology ; 6th Edt. ; Ivan Maurice Roitt, Jonathan Brostoff, David K. Male ; 2001 Organ specific FYI Hashimoto's thyroiditis Primary myxoedema Thyrotoxicosis Pernicious anaemia Autoimmune atrophic gastritis Addison's disease Premature menopause (few cases) Insulin-dependent diabetes mellitus Stiff-man syndrome Goodpasture's syndrome Myasthenia gravis Male infertility (few cases) Pemphigus vulgaris Pemphigoid Sympathetic ophthalmia Phacogenic uveitis Multiple sclerosis (?) Autoimmune haemolytic anaemia Idiopathic thrombocytopenic purpura Idiopathic leucopenia Primary biliary cirrhosis Active chronic hepatitis (hbsag negative) Cryptogenic cirrhosis (some cases) Ulcerative colitis Atherosclerosis(?) Sjogren's syndrome Rheumatoid arthritis Dermatomyositis Scleroderma Mixed connective tissue disease Anti-phospholipid syndrome Discoid lupus erythomatosus Systemic lupus erythomatosus (SLE) Non-organ specific Examples of Type II Cytotoxic Hypersensitivity Goodpasture syndrome: antibodies against glomerular basement membrane (GBM) antigen {collagen alpha-3 (type IV) protein; gene COL4A3} present in lung and kidney. Symptoms: coughing blood (lung) and burning sensation during urination. Leads to lungs and kidney failure. Treatment is based on immunosuppressant (corticosteroids and cyclophosphamide) Rheumatic fever (note: this is not rheumatoid arthritis) Antigens from the cell wall of Streptococcus can induce cross- reacting auto-antibodies against myocardial antigens Causes myocarditis, rheumatoid arthritis, inflammation 17 Examples of Type II Cytotoxic Hypersensitivity Autoimmune hemolytic anemia Self generated antibody against ones own RBC causes destruction and very short half life of the RBCs Etiology is not clearly known, but drugs have been implicated Symptoms include: fatigue, fever, jaundice, splenomegaly, and anemia Idiopathic thrombocytopenia purpura: Self made anti-platelets antibodies which will cause bleeding spots in skin petechiae; purpura bleeding in various organs: gums, gasterointestianl tract, genitourinary tract 18 Examples of Type II Cytotoxic Hypersensitivity Drugs can also induce thrombocytopenia and it is known as drug-induced-thrombocytopenia: hundreds of various drugs: sulfonamides, antihistamine drugs, NSAIDs, etc. Cold (hem) agglutinin disease: Infection triggers: Mycoplasma pneumonaie, EBV, CMV, etc. Auto-antibodies target RBC only at temp. lower than 37 C Destruction of RBC noted mostly in the arms and legs Unless the production of new RBC keeps up with the rate of destruction, the person will suffers of anemia Cold agglutinins – cross reacting IgM antibodies against RBC Coombs test could be false negative if not properly performed: 19 because IgM are raised, react, and activate compliment only at low temperature against glycophorin on RBC. Drug Known to Induce Type II Hypersensitivity Some drugs will act as hapten when combine with cell surface structures, inducing production of antibodies as a result the cells are destroyed following complement fixation, cell lysis, or opsonization Sedormid (a sedative drug) binds to platelets and will induce antibody production This results in platelet destruction (thrombocytopenia) and leads to purpura – bleeding Chloramphenicol – binds to white blood cells, Results in agranulocytosis (decreased WBC count) Chlorpromazine (tranquilizer) or phenoacetin (analgesic): Bind to RBC and causes hemolytic anemia 20 Glomerulonephritis – Type III Glomerulonephritis (glomerular nephritis, GN): a renal disease linked to inflammation of the glomeruli (small blood vessels in the kidneys). Circulating immune complex is frequently prerequisite for glomerulonephritis usually follows skin infection by group A streptococci and it appears about 10 days after infection, e.g. post-streptococcal acute glomerulonephritis The inflammatory process damages the basement membrane causing linkage of serum proteins – proteinuria 21 Systemic lupus erythematosus (SLE)- Type III It is initiated by immune-complex hence type III Auto-antibodies against double stranded DNA and other part of the cell nucleus: histones, nuclear protein Systemic, multi-organ inflammation affects kidney, skin, joints, muscles, lungs 22 Systemic lupus erythematosus (SLE)- Type III Specific etiology is not always known although that in some cases a link is established with some drugs (>30): Most prominent are procainamide (antiarrhythmic agent), hydralazine (high blood pressure), isoniazid (antibiotic) Symptoms: Prominent skin erythematous rash around the nose and cheeks – butterfly rush Mixed connective tissue involvment overlapping with rheumatoid arthritis Renal involvement Central nervous system involvement (50%): depression, psychoses, seizures 23 HLA Association with SLE Varies Between FYI Different Ethnic Groups The disease mainly affects women: age of 20-60 years old and is associated with various HLA markers / ethnicities Author Caucasian Arnett Fernades et al. Reivelle et al. Rudwaleit et al. Barron et al. Rudwalet et al. and Hong et al. Hashimoto et al. and Doherty et al. Wilson et al. Liphaus et. al. 24 Ethnic Groups Black Asian Mixed HLA-DR2/DR3 - - - HLA-DR2 - - - - HLA-DR2 - - - HLA-DR2 - - HLA-DR2 - - HLA-DR3 - - HLA-DR9 - - - HLA-DR15 (2) - - - HLA-DR1/DR4 HLA-DR7 HLA-DR15 (2) HLA-DR8 HLA-DR7 SOURCE: http://www.scielo.br/pdf/rhc/v57n6/a06v57n6.pdf / REV. HOSP. CLÍN. FAC. MED. S. PAULO 57(6):277-282, 2002 / Bernadete de L. Liphaus, Anna Carla Goldberg, Maria Helena B. Kiss and Clovis A. A. Silva ; ANALYSIS OF HUMAN LEUKOCYTE ANTIGENS OF CLASS II-DR IN BRAZILIAN CHILDREN AND ADOLESCENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS Rheumatoid arthritis – Type III / IV During the active phase of the disease patients have high level of rheumatoid factor and low level of complement is observed Anti-citrullinated protein antibodies (ACPAs) are relatively new highly sensitive and specific markers that are superior alternative of the rheumatoid factor (RF) for predicting and monitoring the disease progression 25 Rheumatoid arthritis – Type III / IV Chronic inflammatory autoimmune disease of primarily affecting small joints of the hands and feet and associated with HLA-DR4 Common among women between 30-50 years of age Etiology is not completely understood and may also be infectious leading to degradation of cartilage and bone erosion. Synovial membrane of the inflamed joint is infiltrated with T cells (CD4), plasma cells, macrophages, synovial fluid with high level of cytokines: TNF, IL-1 (type IV) Individuals with this disease form “rheumatoid factor” which are IgM and IgG antibodies against the Fc region of normal autologous IgG antibodies Deposition of immune complex on blood vessels and synovial 26 membrane will activate complement (type III) Type 1 Diabetes Mellitus – Type IV Diabetes mellitus type 1 also known as juvenile diabetes or insulin dependent diabetes mellitus (IDDM) Destruction of pancreatic beta cells in the islets of Langerhans due to auto-reactive T cell mediated cytotoxicity there is no synthesis of insulin causing insulin dependency Auto-antibodies area also produced that may serve as disease monitoring markers, but their direct role in the disease outcome is not clear: Anti- islet cell; enzyme glutamic acid decarboxylase; insulin Epidemiology: Affects 1 in 500 people in the US ; childhood onset but also 27 happens in early 30s and 40s; associated with HLA-DR3, DR4, DQ2, DQ8 haplotypes Type 1 Diabetes Mellitus – Type IV Viral infection seems to play role and often precedes the onset of IDDM. Probably this s the case of Antigenic mimicry linked to Mumps; Cytomegalovirus, Influenza, Coxsackievirus There is a similarity between 6-amino acid sequence of coxsackievirus protein and glutamic acid decarboxylase Isolated coxsackievirus B4 strain from IDDM patient causes IDDM in mouse animal models Similarly mumps and coxsackievirus can destroy islet cells in vitro 28 Multiple sclerosis – Cell Mediated Type IV Affects the nervous system by demyelination of the white matter in brain Symptoms include motor weakness, ataxia, impaired vision, mental aberrations Mediated by auto-reactive T cells and activated macrophages. Viral infection may also play role: Multiple sclerosis patients have high elevated level of anti measles antibodies T cell clones derived from a MS patient reacted against both myelin basic protein and Epstein Barr virus 29 Autoimmune polyendocrinopathy syndrome (APS-1) – Type IV Multiple autoimmune diseases are linked to APS-I: Present with hypothyroids, hypogonadism, and infertility Candidiasis, vitiligo (skin depigmentation), alopecia (baldness) Addison’s disease (pernicious anemia): symptoms include chronic adrenal insufficiency and hypocortisolism In the absence of functional AIRE it would be no self tolerance to peripheral tissue antigens An autosomal recessive disorder mapped to AIRE gene on chromosome 21 with >42 known mutations 30 Autoimmune polyendocrinopathy syndrome (APS-1) – Type IV AIRE is a transcription factor capable of regulating the expression of various tissue specific proteins in thymus its expression tissue within the thymic medullary epithelial cells leads to negative selection hence it directs development of central T cell tolerance during T cell development that takes place in the thymus. Treatment- targets individual disease present in APS patents: Endocrine: levothyroxine for hypothyroids, fludrocortison for Addinson’s disease Anti-infectious treatment during candidiasis outbreaks 31 Treatment of Autoimmune Diseases Each disease has an individual approach In organ specific autoimmune disease the target will be the organ and treating for a metabolic correction/control: Treated with insulin for IDDM Anti-thyroid drugs for Graves’ disease Replacing damaged tissue - stem cell research Immunotherapy Monoclonal antibodies against certain cytokines Anti TNF antibodies or use of soluble receptors for TNF (as decoy) for rheumatoid arthritis 32 Treatment Chemotherapy Suppression of the immune response to reduce symptoms, but this increases the risk of opportunistic infections Anti-inflammatory drugs Corticosteroids: control inflammatory lesion by inhibiting the influx of neutrophils and other phagocytic cells Immunosuppresive drugs Cyclosporin: inhibits cytokine synthesis by T cells Other drugs such as azathioprine – nucleoside analogue that inhibits DNA synthesis: prevent proliferation of lymphocytes 33 References Basic Immunology by Abbas et al, 4th edition, 2014 Chapter 11; page 207-223 34 Ivo Boudakov, Ph.D. Ver. 2016 Autoimmunity IMMUNOLOGY (BMIC550) Learning Objectives FYI Topics and keywords to be discussed: Primary and secondary immunodeficiencies. B cell and antibody deficiencies: Bruton’s disease (X – linked infantile agammaglobulinemia) ; Transient hypogammaglobulinemia; Common variable hypogammaglobulinemia; Selective immunoglobulin deficiencies; Immunoglobulin deficiency with increased IgM; Selective IgA deficiency. T cell deficiencies: DiGeorge Syndrome, Chronic mucocutaneous candidiasis, Duncan’s Syndrome; X-linked (IPEX) Syndrome. Combined T & B cell deficiencies: Severe combined immunodeficiency syndrome (SCID- XSCID, ADA, JAK3), WiskottAldrich syndrome, Ataxia telangiectasia. Phagocytic deficiencies: Chronic granulomatous disease, Chediak Higashi; Leukocyte adhesion deficiency syndrome (LAD-I), Cyclic Neutropenia. IFN- receptor deficiency. Complement deficiency: Paroxysmal nocturnal hemoglobinuria; Hereditary angioedema; C3; 5-9 complement deficiency. 156. Explain the difference between congenital (primary) versus acquired immunodeficiency. 157. Learn examples of acquired immunodeficiencies and their causes. List the extrinsic factors that lead to immunodeficiencies. 158. 2 Recall the immunological abnormalities associated with HIV infection. Learning Objectives FYI 159. For each of the primary immunodeficiencies listed in the accompanying chart, learn (i) name of the disorder (ii) defect in the disorder (iii) how the disorder manifests (iv) mechanism of pathology (v) characteristic features (vi) immunological treatment 160. Explain why, or why not, gene therapy could be used as a therapeutic intervention for each of the disorders. 161. Explain the defect in (a) SCID and (b) X-SCID and why these defects lead to dysfunction in both T cell and B cell immunity. Identify the cytokines that signal via CD132. 162. Explain the role of JAK kinases and STAT proteins in signal transduction as well as the role of adenosine deaminase. 3 Learning Objectives FYI 163. Compare and contrast Bruton’s agammaglobulinemia, (X-linked agammaglobulinemia/ hypogammaglobulinemia), Transient Hypogammaglobulinemia of Infancy, and Common Variable Immunodeficiency with respect to features in the attached table. 164. Describe the defect in DiGeorge Syndrome and explain why these individuals are particularly prone to viral and fungal infections. 165. Describe the features of selective IgA deficiency and explain why IvIG is not suitable as therapy. Explain why IvIG could actually be detrimental to the patient. 166. Describe the defect in LAD-1 (leukocyte adhesion defect-1) and what is the consequence. 167. Describe the consequences and clinical manifestation of a defect in (a) C3 and (b) C5-C9. 168. Describe the defect in Hereditary Angioneurotic Edema (HANE)/ Hereditary Angioedema (HAE), effect on complement function, and clinical manifestations 4 Learning Objectives FYI 169. Describe the defect in paroxysmal nocturnal hemoglobinuria (PNH), the effect of the complement function, and the clinical manifestation. 170. Explain why aging leads to acquired immunodeficiency. 5 Immunodeficiency Primary immunodeficiencies can be grouped based on the type of defect: B cell development and function deficiency (~50%) T cell development and function deficiency (~30%) Combined B cell and T cell deficiency Phagocytes deficiency (~18%) Complement deficiency (~2%) Primary deficiencies are usually hereditary (congenital) Secondary deficiencies are acquired complication following another diseases, e.g. HIV infection, nutritional abnormalities, or medications / medical treatments 6 Immunodeficient Diseases B cells & Antibody deficiencies X – linked infantile agammaglobulinemia (Bruton agammaglobulinemia) Transient hypogammaglobulinemia Common Variable Immune Deficiency (CVID) or Common Var. Hypogammaglobulnemia Selective immunoglobulin deficiencies DiGeorge Syndrome (Congenital Thymic Aplasia) Chronic mucocutaneous candidiasis Duncan’s Syndrome (X – linked-lymphoproliferative syndrome ) Hyper-IgM syndrome (failure in class switch) IL-12 receptor deficiency (IL-12 induces Th1 differentiation /proliferation) Combined T & B cell deficiencies T cells deficiencies Type Severe combined immunodeficiency syndrome (SCID) Wiskott-Aldrich syndrome Phagocytes deficiency Ataxia telangiectasia Chronic granulomatous disease (CGD) Chediak-Higashi syndrome Job’s syndrome (hyper-IgE syndrome) Leukocyte adhesion deficiency syndrome Cyclic Neutropenia – low neutrophil count Myeloperoxidase deficiency Interferon gamma receptor (IFN-g receptor) deficiency Hereditary angioedema Complement Paroxysmal nocturnal hemoglobinuria deficiency Recurrent infections and autoimmune diseases 7 Disorders linked to C1-C9 complement component deficiencies B cell or Antibody Deficiencies B cells Deficiency Patients with B cell deficiencies have increased susceptibility to extra cellular bacterial infection and failure to neutralize viruses Especially encapsulated bacterial infections due to their resistance to phagocytosis therefore highly dependent on B cell immunity and intact antibody synthesis Immunoglobulin impairment is directly linked to major problems with opsonization and complement fixation T cell mediated immunity is normal T cell deficiency is linked to viral and other intracellular pathogens (Herpes simplex virus, Mycobacterium, and Listeria), fungal and protozoa infections 8 B cells Deficiency Bruton disease (X- linked hypo-gamma-globulinemia) Described in 1952 by Ogden Bruton. Other names: X-linked agammaglobulinemia; X-linked hypogammaglobulinemia; Bruton type agammaglobulinemia, Sex-linked agammaglobulinemia Sex linked with frequency 1 in 50,000 to 100,000 new-borns Female carriers are immunologically normal, but at homozygous stage they will be B cell deficient as well Cell mediated immunity (CMI) is normal Pre-B cells are present but fail to mature leading to almost no detectable mature B cell in the peripheral blood: Low levels of all immunoglobulin (IgG, IgA, IgM, IgD, IgE) 9 B cells Deficiency Bruton disease (X- linked hypo-gamma-globulinemia) First symptoms appear in childhood (>6 months) with clearance of the protective maternal antibodies This patient presented with recurrent otitis and areas of cellulitis in the diaper area. Pseudomonas aeruginosa and Staphylococcus aureus were isolated from the skin lesions. Symptoms include otitis media, bronchitis, septicemia, pneumonia, arthritis, etc. Most commonly associated pathogens are: Haemophilus influenzae & Streptococcus pneumonia Intestinal protozoa - Giardia lamblia causing malabsorption 20% of the children develop arthritis most probably because of joint infections 10 B cells Deficiency Bruton disease (X- linked hypo-gamma-globulinemia) Mutation is in of Bruton tyrosine kinase (Btk, located at Xq21to Xq22) regulatory genes needed for pre B cells differentiation Diagnosis is based on no blood circulating CD19 or CD20 cells by fluoro-cytometric assays (FACS) detection or low levels of all antibody immunoglobulin classes Treatment is by passive immunization with periodic injections of large amounts of IgG (IVIG) maintains a person for 20 – 30 years Antibiotics treatment to infections could be use but frequently with poor response or no response 11 Transient Hypogammaglobulinemia B cells Deficiency Delayed onset of normal IgG production around fifth to sixth month of life. Transient deficiency of IgG that can last few months to as long as 2 years. All other immunoglobulins are normal expressed Deficiency in various functions of T helper cell influences IgG diminishing class switch Specific treatment is not offered unless there is a recurrent infections which handled with antibiotics IVIG (400-800 mg/kg) can be offered, but this has been 12 linked to delay in the long term resolution of the transient hypogammaglobulinemia status B cells Deficiency Common Variable Immune Deficiency (CVID) {Hypogammaglobulinemia} It is relatively common (1 in 25000) with high variability of Ig production – can be either low or high levels of Igs Usually it appears during adulthood in 30s or early 40s, but in 20% of the cases can be childhood disease It is a relatively slow onset that take few years to develop with first sings to be frequent and/or unusual infections There is no clear genetic correlation although that few genes have been proven involved in the symptomatics. The nature of defects in B cells ranges from: Absence of B cells proliferation in response to antigen Normal proliferation of B cells but only IgM production 13 B cells Deficiency Common Variable Immune Deficiency (CVID) {Hypogammaglobulinemia} Both male & females are equally affected with some having decrease only in IgG and IgA; others have decrease in all three major types of immunoglobulins (IgG, IgA and IgM) Patients have higher risk of pyogenic bacterial infection and in many cases risk of developing autoimmune diseases: hemolytic anemia, thrombocytopenia (low platelets), systemic lupus erythematousus (SLE) Treatment Antibiotic treatment for infections Combined with passive low doses of IVIG injections 14Patients can live up to 70-80 years with this deficiency Selective Immunoglobulin Deficiencies (and IgA Deficiency) B cells Deficiency Low levels of one of the five classes of antibody and normal levels for other immunoglobulins IgA deficiency is the most common primary antibody deficiencies (1 in 500 Caucasian) compare to IgG and IgM deficiencies In some patients with IgA deficiency some of the IgG sub- classes maybe also low (usually IgG2 and/or IgG4) Although that IgM and IgG deficiencies are rare they are more serious than IgA 15 Selective Immunoglobulin Deficiencies (and IgA Deficiency) B cells Deficiency IgA deficiency is linked with: recurrent sinus and lung infections Allergic reactions, and autoimmunity probably due to the recurrent triggers by mucosal infections Risk of anaphylactic shock during blood transfusion due to reaction against donor IgA Treatment Wide spectrum antibiotics Passive immunity for IgA deficiency does not exist 16 because the antibody delivery is required in the mucus membrane T cells deficiency T cells Deficiency Patients with T- cell defects have recurrent viral, protozoa, and fungal infections Since B cell function largely dependent on T cell therefore the humoral immunity is also hampered Diseases common linked to T cell deficiencies are: Infections Allergy Lymphoid malignancies Autoimmune disease 17 DiGeorge Syndrome (Congenital Thymic Aplasia). T cells Deficiency Has been linked to a deletion on chromosome 22 (22q11.2) but has not been linked to a single gene. Defect in the embryological development of 3rd and 4th pharyngeal pouches is linked to Failure of both thymus and parathyroids development, thymic aplasia - defective or absence of thymus Some improvement with age is probably due to development of small amounts of thymic tissue that will support T cells Hypoparathyroidism leads to cardiovascular abnormalities Could be hereditary or congenital (present at birth) with variation in the phenotype even within the same family 18 DiGeorge Syndrome (Congenital Thymic Aplasia). T cells Deficiency Large variation in presentation spectrum: congenital heart disease, defects in the palate, neuromuscular problems with closure (velo-pharyngeal insufficiency), learning disabilities, mild differences in facial features, recurrent infections. Completely absent or few abnormal T cells B cell, plasma cells, and serum immunoglobulins levels are detected but in subnormal levels Most common among patients are intracellular infections (viruses) and yeast infections such as Candida albicans and Pneumocystis carinii , but patient they should be able to cope with most common bacterial infections Should never be immunized with live attenuated viral vaccines 19 DiGeorge Syndrome (Congenital Thymic Aplasia). T cells Deficiency CATCH 22- Cardiac defects, Abnormal faces, Thymus underdevelopment, Cleft palate, Hypocalcaemia, and chr.22 20 DiGeorge Syndrome (Congenital Thymic Aplasia). T cells Deficiency Prognosis is very poor in untreated patients. Treatment: Antibiotic for infections and other supportive medicine Thymic transplantation for DiGeorge syndrome infants may restore the functionality of T cells but not the other defects Transplantation of donor tissue either from infants less than 6 months of age or fetal thymus (less than 14 wk of gestation) this is to avoid graft-versus-host (GvHD) reaction. Donor thymus provides sufficient number of thymic epithelial cells allowing successful development of T cells from the recipient bone marrow. 21 Chronic Mucocutaneous Candidiasis T cells Deficiency It is not a specific disorder but a heterogeneous group of disorders presenting with recurrent or persistent superficial skin infections, usually Candida albicans. Affects the skin, mucous membranes, and nails. Selective defect in functioning of T cells (TH1 and TH17) against C.albican. Usually normal cellular response towards other pathogens and normal B cell functions. Can be inherited and affects equally males and females Other complications may include adrenal and parathyroid deficiencies. 22 SOURCE: http://emedicine.medscape.com Treatment is very difficult. T cells Deficiency Duncan syndrome (X-linked lymphoproliferative syndrome) It is a very rare disease linked to two different X-linked genes, therefore two different forms of this syndrome (XPL1 and XPL2) Disease is present in males with mothers being carriers Patient do not present with major symptoms until they are infected with Ebstein-Barr virus (EBV) XPL1 has been mapped in 1998 to Xq25 (1998) mutation of SH2 domain on SAP signaling protein (128-amino acid coding SH2D1A gene) impairing activation of T and NK cells Such deficiency leads to functional suppression of T cells that renders them unable to kill EBV-infected B cells Inability to kill causes T-cell proliferation leading to increased 23 risk of lymphoma or other lymphoproliferative diseases T cells Deficiency Duncan syndrome (X-linked lymphoproliferative syndrome) Symptoms are fulminant infectious mononucleosis (EBV); hypogammaglobulinemia; lymphoma; hemophagocytic lymphohistiocytosis (too many activated immune cells) Low prognosis where most of the patients (60-70%) will not surviving to 10 years of age. The median age of onset is 3-5 years with 1-2 months median survival The only cure is allogeneic stem cell transplantation Preemptive treatment to block B cells with anti-CD20: (rituximab) until EBV is reduced has been proven effective (Milone MC; Blood. 2005) 24 Severe Combined Immunodeficiency Disease Combined T and B cells (SCID) NOTE: this condition(s) will be discussed in a form of small groups clinical case active learning approach Failure of stem cells to differentiate into T and/or B cells Various gene defects will cause similar clinical SCID type of presentation that usually affects T, B and/or NK cells: XSCID – deficiency in common gamma (c) chain which affects cytokine receptors: IL-2R, IL-4R, IL-7R, IL-9R, IL-15R, IL-21R Bare lymphocyte syndrome (type 2) defect in MHC class II Absent TCR and BCR – defects in RAG1 and RAG2 genes Defect in adenosine deaminase (ADA) Defect in JAK-3 kinase 25 Severe Combined Immunodeficiency Disease Combined T and B cells (SCID) (a) T. B. and NK cells are differently affected in different types of SCID depending on the genes involved RAG1; RAG2; Artemis, LIG4 ADA (b) Defective gene frequency in SCID patients Many genes Common gamma chain (c) {XSCID} and JAK3 kinase 1. T cells are driven by IL7 2. NK cells are driven by IL15 26 SOURCE: Harald Mikkers, Karin Pike-Overzet, & Frank J.T. Staal, Pediatric Research (2012) 71, 427–432 doi:10.1038/pr.2011.65 Severe Combined Immunodeficiency Disease Combined T and B cells (SCID) SCID patients should not receive live vaccine, and are highly prone to viral, bacterial, fungal and protozoal infections: Cytomegalovirus, Pneumocystis carinii, and Candida. Treatment: Bone marrow transplantation with histocompatible tissue Partially HLA matched (haplotype) bone marrow transplantation with eliminated mature donor T cells. Gene therapy – year 2000 trials were successful (10 patients) until the retroviral vector insertion triggered a proto-oncogene resulting in death of 4 patients due to leukemia 27 Ataxia-Telangiectasia Combined T and B cells Ataxia telangiectasia (ATM) gene codes for serine/threonine protein kinase involved in DNA repair an autosomal (chromosome 11) recessive gene with various mutations (nonsense, missense) causing variability in this disease severity It is a neurodegenerative disorder: ataxia – uncoordinated muscle movement Telangiectasia - dilation of small blood vessels (more noticeable in the facial area, eye): spider veins Other symptoms: high incidence of malignancy (particularly leukemias), chromosomal instability; raised alpha-feto-protein levels 28 Ataxia-Telangiectasia Combined T and B cells Immunodeficiency linked to defect in repair of double stranded DNA brakes during V(D)J recombination and class switch. This affects: T-cells and their functions are reduced to various degrees. B cell numbers with IgM concentrations are normal to low. Significantly reduced IgG, IgE and IgA (in 70% of the cases) Low number of blood lymphocytes Ataxia-Telangiectasia outcome and treatment: Only symptomatic and supportive treatment no definitive cure treatment exists Highly variable life expectancy – patients frequently 29 die in their teens or early 20s Wiskott-Aldrich Syndrome Combined T and B cells Presents in boys as a triad pyogenic infection severe eczema - first month of life thrombocytopenia – petechia and bleeding due to defective platelets Parents have poor response to polysaccharide antigen; increased risk of severe autoimmune disease and malignancy Various mutations are mapped to an X-linked gene (WASp) that is expressed in hematopoietic stem cells responsible for actin cytoskeleton rearrangement and possibly signaling in lymphocytes and platelets. 30 Wiskott-Aldrich Syndrome Combined T and B cells The Immunological defects are due to inability of T cells to become polarized which consistently gets worse and decreased antibody production Antibody profile is variable: Reduced IgM concentrations Both IgA and IgE levels are elevated. Normal, elevated or reduced IgG levels Supporting therapy: anti inflammatory drugs; IvIG; bone marrow transplant may be helpful 31 Chronic Granulomatous Disease (CDG) Phagocyte Deficiencies Defect in the phagosome oxidative microbicidal killing function by neutrophils and monocytes. Pathogens are phagocytosed but not kill. Impaired function of NADPH oxidase, which is required for generation of peroxidase and superoxides Mutations include: deletions, frame-shift, nonsense, and missense in either X-linked (protein p91-PHOX) or autosomal recessive gene (CYBA and NCF1) all linked to NADPH 1 in 200,000 people (in US), with ~20 new cases per year. The intracellular survival of pathogens results in the formation of a granuloma, which can become large enough to cause obstruction of the stomach, esophagus, or bladder. 32 Chronic Granulomatous Disease (CDG) Phagocyte Deficiencies Case: A 12-year-old boy | fever, chills, sweats, productive cough, nausea, and vomiting | Recurrent pneumonias since the age of 5 years | On physical examination febrile, tachycardic, and tachypneic; diffuse rhonchi were heard in both lungs. The patient also had finger clubbing, splenomegaly, and massive lymphadenopathy in the cervical, axillary, and preauricular areas (Panel A) and the epitrochlear and inguinal areas (Panel B) of his body. Blood cultures grew Staphylococcus aureus. A chest radiograph (Panel C) and computed tomography of the chest revealed multiple bilateral abscesses in both lungs. Successfully treated with trimethoprim– sulfamethoxazole, levofloxacin, and voriconazole, with nearly complete resolution of symptoms. 33 SOURCE: Chronic Granulomatous Disease | Mohsen Esfandbod, M.D., and Maryam Kabootari, M.D. | N Engl J Med 2012; 367:753August 23, 2012 Chronic Granulomatous Disease (CDG) Phagocyte Deficiencies Most of patients are males with symptoms appearing during first 2 years of life. CDG patient are very susceptible to opportunistic infection and most common are : Staphylococcus aureus ; certain Gram negative bacilli; fungi – Aspergillus fumigatus and Candida Diagnoses is done by Nitroblue Tetrazolium test (NBT) where defective phagocytes take-up the salt, but cannot oxidize it. Positive (normal) results 34 SOURCE: The Journal of Infectious Diseases 2003; Severe Clinical Forms of X91 CGD; Marie Jose´ Stasia et. al. have violet precipitates. Treatment: Chronic Granulomatous Disease (CDG) Phagocyte Deficiencies Chemotherapy: Aggressive therapy with wide spectrum antibiotics and antifungal agents. Immunotherapy Administration of interferon gamma (IFN-) – stimulate the production of superoxide in phagocytic cells Bone marrow transplant from HLA matching donor Gene therapy: The disease is a result of a single gene defect which allows for a correction strategy by gene therapy. Transfer of functional gene in bone marrow stem cells isolated 35 from the patient gives some encouraging results Leukocyte Adhesion Deficiency Type I (LAD-I) Syndrome Phagocyte Deficiencies An autosomal recessive mutation in β2 (beta-2) integrin (CD18) which takes part in LFA-1 and other integrin structures LFA-1 mediate adhesion of T-cells, B-cells, macrophages and neutrophils to the endothelial cells As a result of the defect neutrophils and other cells cannot emigrate through the vessel wall to the infected site Patients are highly susceptible to pyogenic infections with variable severity Delayed separation of the umbilical cord is the earliest sign of LAD-1 Figure 1: Skin lesions in LAD-1 SOURCE: Journal of Clinical Neonatology Year : 2014 | Volume : 3 | Issue : 2 | Page : 109-111 ; Unusual neonatal presentation of type I LAD ; Bonny B Jasani et. al. 36 Treatment by bone marrow transplant, various stem cell technologies combined with possible gene therapy for CD18. Interferon-gamma Receptor Deficiency Phagocyte Deficiencies Chemotherapy: Aggressive therapy with wide spectrum antibiotics and antifungal agents. Immunotherapy Administration of interferon gamma (IFN-) – stimulate the production of superoxide in phagocytic cells Bone marrow transplant from HLA matching donor Gene therapy: The disease is a result of a single gene defect which allows for a correction strategy by gene therapy. Transfer of functional gene in bone marrow stem cells isolated 37 from the patient gives some encouraging results Chediak-Higashi Syndrome Phagocyte Deficiencies Mutation in LYST (Lysosomal Trafficking Gene Regulator) gene causes accumulation of large cytoplasmic granules which cannot fuse with lysosomes and affects phagocytes, TC and NK cells This results in inability to destroy targets, leading to; Increase of bacterial, viral, and fungal infections Reduction in skin and eye pigmentation causing: silver hair, partial albinism, and photophobia Treatment: Antibacterial and antifungal drugs Bone marrow transplantation as long term option 38 SOURCE: 1) http://www.medicalrealm.net/what-is-genetic-disorder---chediak-higashi-syndrome.html 2) http://cursoenarm.net/UPTODATE/contents/mobipreview.htm?20/9/20628 ; Robert L Baehner, MD. Cyclic neutropenia Phagocyte Deficiencies Low neutrophil count (neutropenia), less than 200/ul for the duration of 3 to 5 days repeated in cycles of 21 days Autosomal dominant mutation in the neutrophil elastase (ELANE) gene is responsible for short lived neutrophils that makes it for a period of low count One of the rarest types of neutropenia: 1 in every 106 people, compare to other forms neutropenia (congenital and idiopathic) which more common with 1in 2x105 frequency Symptoms: only during neutropenic stage patients are susceptible to life-threating bacterial infection and usually Seems that the condition improves after puberty. Treatment includes G-CSF (granulocyte colony stimulating 39 factor) Phagocyte Deficiencies Job Syndrome (Autosomal Dominant Hyperimmunoglobulin E (IgE) There is a typical facial features presented with prominent forehead, deepset eyes, broad nasal bridge Typical triad presentation with eczema, eosinophilia, recurrent skin and pulmonary infections with average survival age of 27 Symptoms start from early childhood with Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae It is common to have skin abscesses with Staph. Aureus Treatment is predominantly focused on pharmacotherapy to reduce morbidity symptomatic and prevent complications 40 SOURCE: http://emedicine.medscape.com/article/886988-overview Phagocyte Deficiencies Job Syndrome Cytokines and JAK-STAT3 Signaling Various mutations in STAT3 gene will influence the JAK- STAT signaling pathway and will result in increase of IL-6; TGF- and decrease in IFN- ; IL-12; TNF-α upon cytokine stimulation 41 Interferon-gamma Receptor Deficiency Phagocyte Deficiencies Mutation in the receptor gene encoding either the ligand- biding portion or the signal transducing portion of the receptor for interferon gamma. Symptoms are associated with increased infections especially mycobacterial infections due to macrophage failure Individuals with this defect should not be immunized with BCG ( live attenuated vaccine) 42 Secondary/Acquired Immunodeficiency The secondary are more frequent that that the primary immunodeficiencies. They result as secondary complications to a prior change of the physical or health status of the patient. Infection Malignancies Malnutrition Liver damage Aging Therapeutic agents such as radiation or drugs 43 Secondary/Acquired Immunodeficiency Infection: Viral: measles infection, HIV Bacterial: S. pneumonia, H. influenzae, M. leprae Protozoan: malaria parasite Therapeutic agents X rays Cytotoxic drugs/ cancer therapy Immunosuppressive drugs used in transplantation; Corticosteroids Other diseases can be a prerequisite for secondary immunodeficiency: sickle cell anemia, diabetes mellitus, burns, rheumatoid arthritis, renal malfunction, etc. 44 Secondary/Acquired Immunodeficiency Malnutrition reduces the supply of amino acid for the synthesis of Ig, complement, and other products Liver damage due to infection or alcohol consumption might affect components of the innate humoral immunity such as complement protein synthesis / acute phase proteins Aging is linked to complex changes of many parts of the immune system resulting in increased infections Increased production of pro-inflammatory cytokines: TNF-, IL-1/6 is linked to age related diseases: such as Alzheimer’s, Parkinson’s, Atherosclerosis Decreased production of IL-2 hampers T cell activities Increased B cell activity with aging is associated with 45 increase of autoimmune diseases Age Related Changes to the Immune System Table 9.1 Immune deficiencies observed in normal elderly individuals. 46 NEUTROPHILS Decreased phagocytic activity Decreased microbicidal activity CELL-MEDIATED IMMUNITY Decreased CD3+ cells Increased Th2 subset and decreased Thl subset Decreased lymphocyte proliferation Decreased CD28 expression Decreased delayed type hypersensitivity Increased production of proinflammatory cytokines HUMORAL IMMUNITY Increased autoantibodies Decreased ability to generate primary immune responses NATURAL KILLER CELLS Increased percentage Decreased cytotoxic activity Malignancies - Acquired Immunodeficiency Monoclonal gammopathies, e.g. Waldenstrom macroglobulinemia cancer of B cell, resulting in overproduction of antibdies with monoclonal nature, mainly IgM antibodies Multiple myeloma – cancer cells that originate from plasma cells Bence-Johes proteins – a mareker for multiple myeloma – monoclonal globulin protein or immunoglobulin light chain Hodgkin's disease Lymphoma (cancer of the lymphatic system, lymph nodes, 47 etc. ) where they for a abnormal giant neoplastic cells known as Reed-Steinberg Hereditary Angioedema C1 Inhibitor Deficiency Complement Deficiencies Autosomal dominant deficiency of C1-esterase inhibitor gene with a frequency of about 1/50,000 - 1/150,000 people In the absence of one of the two copies of C1-INH inhibitor is sufficient to dysregulate three different cascades and cause the observed symptoms: Complement – classic (C1) and MBL (MASP-2) pathways Coagulation – factor XI and XII leading to fibrin buildup Contact cascade – resulting in increased bradykinin levels Patients experience recurrent episodes of angioedema of skin and the mucosa of gastrointestinal tract upon a trigger There is absence of urticaria or rush that distinguishes HAE 48 from allergic reaction Hereditary Angioedema C1 Inhibitor Deficiency Complement Deficiencies Functional deficiency of C1-INH will allow anyone of those three pathways to run to be dysregulated and presents with the underlined hereditary angioedema symptomsMorgan BP. N Engl J Med 2010;363:581-583. 49 Hereditary Angioedema C1 Inhibitor Deficiency Complement Deficiencies May cause airway obstruction due to leakage of vasoactive proteins and fluid in the larynx Treatment: Purified C1-inhibitor, fresh frozen plasma (FFP), kallikrein inhibitor; but not anti-allergic drugs 50 Paroxysmal Nocturnal Hemoglobinuria Complement Deficiencies Hematopoietic stems cell have a anchor (GPI – glycosyl phosphatidylinositols) that mounts a set of regulatory proteins on the cell surfaces to protect them from unwanted complement attack Some of those regulatory proteins involve decay accelerating factor (DAF; CD55) membrane inhibitor of reactive lysis (MIRL; CD59) The main defect is due to various mutations in the X-linked phosphatidylinositol glycan A (PIGA) enzyme which takes part in formation of GPI. Hence absent protection of the cell 51 surfaces from the complement mount attacks Paroxysmal Nocturnal Hemoglobinuria Complement Deficiencies Most prominent complement mediated cell lyses is for the red blood cells, but also in other cells like platelets are also affected Most obvious symptoms are the episodes of black urine (hemolysis) particularly in early morning hours. RBCs are lyse 24/7 , but at night there is a concetration of urine which marks the significant color change Treatment is mostly supportive with anti-hemolytic drugs, iron for the anemia, recombinant erythropoietin or androgens to stimulate erythropoiesis, anticoagulants for thrombosis 52 Paroxysmal Nocturnal Complement Deficiencies Hemoglobinuria – Symptoms and Prognosis Anemia that impairs quality of life Disabling fatigue (80%) ; Abdominal (44%) and Chest Pain (33%) ; Dyspnea ; (64%) ; Hemoglobinuria (62%) ; Renal impairment (14%) Poor physical functioning Thrombosis venous ; liver, mesenteric, dermal, cerebral ; arterial; myocardial infarction ; cerebral vascular accident PNH is a rare disease with annual rate of 1-2 cases per million Median survival rate is 10-20 years from the time of diagnosis without disease-modifying and supportive treatment 53 SOURCE: http://geneticdiseasesforlife.blogspot.com/2010/10/paroxysmal-nocturnal-hemoglobinuria.html Deficiencies in C1-C9 Proteins Complement Deficiencies Depending on which part of the complement components (C1- C9) are deficient this can lead to either susceptibility to pathogenic infections and/or severe autoimmune reactions Classical pathway deficiencies (C1, C4, C2) is linked to: recurrent bacterial infections in C2 deficiency autoimmune diseases (SLE, atherosclerosis) due to inability to clear the immune complexes after antibody formation MBL pathway members also includes C2, C4 and are linked to: recurrent bacterial infection, mainly in the childhood Alternative pathway deficiency (properdin, factor B and factor D) causes: pyogenic and Neisseria spp. infections, but NOT immune 54 complex disease Complement Deficiencies 55 Source: Advanced Diagnostic Laboratories National Jewish Health Complement Deficiencies Deficiencies in C1-C9 Proteins Complement Deficiencies C3 deficiency- infection with pyogenic bacteria and Neisseria spp. sometimes immune-complex disease membrane attack complex (MAC) deficiencies (C5-C9) (terminal path) mostly Neisseria spp. infections Leiner's disease – early infancy systemic disorder deficiency of C5 (also reported with C3 and C4 deficiency). chronic diarrhoea, seborrhoeic dermatitis; recurrent infections Deficiencies of the complement regulatory protein autoimmune disorders 56 References Basic Immunology by Abbas et al, 4th edition, 2014 Chapter 11; page 207-223 57 Ivo Boudakov, Ph.D. Ver. 2016 Transplantation Immunology IMMUNOLOGY (BMIC550) Learning Objectives FYI Topics and keywords to be discussed: Transplantation: autograft, isograft:, allograft, xenograft. Cellular and humoral graft rejection. Chronic, acute, and hyperacute graft rejection. Minor antigens. HLA compatibility. Immunosuppressive drugs and graft survival. GvHD. Fetus as an allograft. 183. Understand the terms autograft, isograft, allograft, and xenograft in Transplantation. 184. Compare and contrast hyperacute, acute, and chronic graft rejection. 185. Recall that the major molecular target in graft rejection is the alloMHC/allo peptide. 186. Explain differences between major and minor MHC antigens. 187. Explain why graft survival is dependent on the inhibition of T cells. 188. Explain the immunological processes in Graft versus Host Disease (GvHD) and contrast it with Host versus Graft Disease HvGD. 189. Describe the immune properties of (i) the recipient who receiving the tissue and (ii) the donor tissue, under conditions that lead to graft versus host. 2 Learning Objectives FYI 190. Describe tissue differences in clinical transplantation and their prognosis. 191. Explain three potential problems of immunosuppression for transplant patients and what would be the consequences if immunosuppression is not giving. 3 Terminology in Transplantation Immunology Transplantation is the act of transferring cells, tissues, or organs from one site to another Depending on the transplanted tissue or organ (also known as graft) there are different types of transplantations: Autograft: transfer of an individual’s own tissue to another body site Isogeneic (syngeneic) graft: transfer of tissue between genetically identical individuals, like monozygotic twins or inbreed strain (e.g. lab mouse strain) Allogeneic graft: graft between genetically different members of the same species. Xenogeneic graft: transfer of tissue between different 4 species (human and pig grafts) 5 Graft Rejection 2 1 3 3 6 Graft Rejection Adaptive immune response (not the innate response) is responsible for graft rejection Autografts and isografts (syngeneic grafts) are easily accepted as the graft is recognized as self tissue Allograft and xenograft are usually rejected as they are recognized by the adaptive immune system as non-self Allografts are acutely or chronically rejected unless a mistake is made to avoid ABO antigen rejection Xenografts are more frequently rejected due to hyperaccute rejection mechanism because of preformed natural antibodies against xeno-antigens 7 Comparisons Between Accepted and Rejected Grafts 8 Allograft Transplant Rejection Without immunosuppressant drugs allografts are rejected First set of allogeneic graft rejection: the first time an allograft is done it seems to be initially accepted with blood vessels getting reconstituted the graft seems morphologically and functionally healthy for only about a week. Around day 7 a post-transplantation inflammation becomes evident and the graft is invaded by lymphocytes and macrophages – cellular immunity The blood vessels within the graft undergo necrosis resulting in reduction of circulation 9 Allograft Transplantation and Rejection With time the necrosis extends within the initial graft which assumes a scab like appearances and sloughs off by the end of the second week. Clearly this is T- cell mediated reaction and the main cause is cellular based immune rejection Second set of allograft rejection from the same donor Second graft from the same donor is much more rapidly and vigorously rejected than the first graft The vascularization process quickly gets interrupted by the inflammatory response and infiltration of lymphocytes and macrophages Necrosis sets early, the graft sloughs off by the 6th day 10 due to the immune memory Graft Rejection: Host Versus Graft Disease (HvGD) Histological examination of the rejection site shows: T - lymphocytes (both CD4 and CD8) Monocytic cells (monocytes/macrophages) Because the second rejection is faster and more aggressive than the first rejection the site contains memory cells. Individual that lack thymus (T cell deficient) do not reject graft B cell deficient individuals normally reject grafts this shows the role of cell mediated immune response Rejection slows or does not occur in immunocompromised 11 individuals Mechanism of Graft Rejection HLA antigens play a major role in graft rejection leading to acceptance or rejection The more MHC alleles are shared between the donor and the recipient, the slower the rejection process would be Both MHC classes (I and II) are involved Most tissues have MHC class I antigen responsiveness DR locus of MHC class II is of significant importance There is a direct graft recognition where recipient T cells directly recognize the donor HLAs as foreign to reject There is an indirect graft recognition where recipient T cells recognize processed and presented alloantigens on 12 the surface of recipient APC inside the grafted organ Direct and Indirect Recognition of Donor Graft Recipient CTLs attack on the graft tissue activated by donor APC It is currently believed that this is the more common mechanism during acute graft rejection 13 Indirect Recognition of Donor Graft Recipient APC can digest and present alloantigens (such as donor MHCs) on the surface of recipient MHCs Due to cross-presentation mechanisms donor APCs will be capable of presenting to both CD4 and CD8 recipient’s T lymphocytes as foreign and stimulate immune response this will result in cytokine release and inflammation in the grafted organ/tissue The current believe is that indirect recognition has a more prominent role in the chronic graft rejection Even complete matching at all MHC loci will not ensure 100% graft survival due to other antigens known as minor histocompatibility antigens (MiHA) 14 Minor Histocompatibility Antigens (MiHA) Essentially any allelic variation between the donor and the recipient that is different from HLA polymorphism is considered minor antigen that may trigger graft rejection Minor antigens that can cause incompatibility are H-Y antigen (a mediator of testicular organization; Smcy, gene): encoded on the Y chromosome and present only in all normal male tissues HA-2 minor histocompatibility antigen derived from the contractile protein myosin Blood group antigens Minor antigens have important clinical implication in blood 15 transfusion and in boon marrow transplantation Hyper-acute Type of Graft Rejection Occurs within minutes to few hours after transplantation Hyper-acute rejection is fully preventable with proper match of blood type allogeneic donor tissue 16 Hyper-acute Type of Graft Rejection It is mediated by preformed natural antibodies that quickly attack the donor tissue when they bind to the donor vascular endothelium, they fix the complement and cause endothelial damage coagulation blocks blood supply to the grafted tissue It is prominent in xenograft transplantation, because humans have natural antibodies to several animal antigens In allograft it is common with blood type incompatibility ABO type antibodies bind to all tissues, not just RBCs, cause blood clotting, endothelial cell damage by complement. 17 Acute Type of Graft Rejection It is a result of cellular mediated adaptive immunity Occurs about 10 days to few weeks after the graft is transplanted Graft is rejection by a recipient who has not previously been sensitized to the graft from the same donor Histological examination shows infiltration of lymphocytes and macrophages due to MHC graft mismatch and insufficient immunosuppressive treatment 18 Chronic Type of Graft Rejection Occurs months to years after tissue transplantation has assumed normal function and survival It is mediated by both cellular (T lymphocytes and macrophages) and humoral immunity Allogeneic antibody-antigenic complexes are detectable at 19 the site of rejection Chronic Type of Graft Rejection The main pathologic feature is vascular injury resulting in atherosclerosis TH cellular immune response plays an important role by releasing pro-inflammatory cytokines and causing inflammation, leading to graft atherosclerosis (narrowing of blood vessels) and fibrosis formation Currently chronic graft rejection is the main type of graft rejection, while acute rejection is successfully managed by immunosuppressive prophylaxis and graft MHC match 20 HLA/MHC Typing Finding the closes match between the recipient and the donor maximum of 12 MHCs loci is done in different ways Mixed lymphocyte reaction (a relatively old way) Serology –complement fixation test using antibodies DNA technology – the molecular techniques are more specific and sensitive by using either PCR detection of gene sequencing Tissue typing and correct matching is usually limited to 3 most important loci (paternal and maternal) HLA-A, HLA-B, and HLA-DR The following three loci are of lesser importance: HLA-C, 21 HLA-DP, and HLA-DQ HLA/MHC Typing Mixed leukocyte reaction (MLR): mix of lymphocytes from two unrelated individuals will recognize and stimulate each other as foreign causing cell culture proliferation More cell proliferation – high antigenicity Less cell proliferation – lower antigenicity Serological testing is using a panel of antibodies specific to the different HLA antigens Cells from donor or recipient are mixed with specific sera Complement is added Cells bearing HLA antigens to a particular sera will be lysed by the complement 22 Graft Versus Host Disease (GvHD) Bone marrow or hematopoietic stem cell (from donors blood) transplantation is becoming a widely used approach in leukemia treatment or correction of inherited defects (e.g. SCID, etc.) The recipient bone marrow is removed to allow adoption of new hematopoietic system The danger is that donor T cell will react against the recipient tissues causing Graft Versus Host Disease (GvHD) This is relatively common with immunocompromised recipient and insufficient HLA match with the donor alloantigens Can be avoided by depleting donors tissue of donor’s T cells by using anti T cell monoclonal antibody Even with a sufficient HLA match there is still risk of GvHD due 23 to the existence of the minor histocompatibility antigens Graft Versus Host Disease (GvHD) Symptoms Sever immunodeficiency till the donor graft is established Acute GvHD warning signs: Skin: very faint to severe sunburn-like rashes, or blisters Stomach and intestines: nausea, loss of appetite, vomiting, diarrhea, abdominal discomfort, abdominal bloating, blood Liver: jaundice, dark urine, Chronic GvHD warning signs: in addition to the above signs the skin texture thickens, join arthritis like pain, dry eyes changes, mucosal irritation linked to pain in the mouth, genitals, lungs. 24 SOURCE: http://bestpractice.bmj.com/best-practice/images/bp/en-gb/946-1-hlight default.jpg Prevention of Graft Rejection Although find the closet HLA match is important, the need for it has been reduced with the advancement in the immunosuppressive therapies in bone marrow only finding a match is still of great importance for successful transplantation Immunosuppressive agents have systemic action which will cause complications such as Susceptibility to infections or development of cancers Two approaches in immunosuppression: Chemical immunosuppressants Monoclonal antibodies against 25 TCR, CD3, CD8, CD4, CD40; IL-2 receptor (CD25) Drugs Acting on Suppression of the Cell Cycle 26 FROM: Roitt's Essential Immunology 12th ed. - P. Delves, et. al., (Wiley-Blackwell, 2011) Drug Mechanism of action Block DNA synthesis Prevent correct DNA replication through formation of phosphoramide mustard Cyclophosphamide metabolite: which creates crosslinks between and within DNA strands leading to cell death Blocks DNA replication by virtue of its Mycophenolate conversion into a purine analog mycophenolic mofetil acid; It also suppresses CD25; CD154 (CD40L); CD28 Azathioprine It is a purine analog that inhibits an enzyme Methotrexate Inhibits the metabolism of folic acid Reduces inflammation by blocking expression of cytokines: TNF-α, IFN-, IL-1, IL-2, IL -6; Inhibition Corticosteroids of neutrophil adherence to endothelial cells, Suppression of monocytes/macrophages functions Blocks lymphocyte proliferation by inhibiting IL-2R Rapamycin signaling 27 ADAPTED from: Basic Immunology by Abbas et al, 5th edition, 2016 Drug Cyclosporine and tacrolimus Mechanism of action Blocks T cell cytokine production by inhibiting the phosphatase calcineurin and thus blocking activation of the NFAT transcription factor and production of cytokines (IL-2) Binds to and depletes T cells by promoting Anti-thymocyte phagocytosis or complement-mediated lysis (used to globulin treat acute rejection) Inhibits T cell proliferation by blocking IL-2 binding; Anti-IL-2 receptor (CD25) may also opsonize and help eliminate activated IL-2R expressing T cells antibody CTLA4-Ig (belatacept) Anti-CD52 (alemtuzumab) 28 Inhibits T cell activation by blocking B7 co-stimulator binding to T cell CD28 Depletes lymphocytes by complement-mediated lysis ADAPTED from: Basic Immunology by Abbas et al, 5th edition, 2016 Unadjusted One- and Five-Year Patient Survival by Organ Organ Transplanted 1-Year Survival 5-Year Survival Kidney Deceased Donor 94.8% 80.6% Living Donor 98.0% 90.3% Pancreas alone 96.7% 88.1% Pancreas after kidney 96.6% 83.9% Kidney-pancreas 95.0% 86.1% Liver Deceased donor 86.9% 73.6% Living donor 90.6% 76.1% Intestine 81.0% 53.6% Heart 87.8% 74.4% Lung 84.0% 52.6% Heart-Lung 75.0% 49.7% Source: 2007 OPTN/SRTR Annual Report, Table 1.13. 29 Unadjusted One- and Five-Year Graft Survival by Organ Organ Transplanted 1-Year Survival 5-Year Survival Kidney Deceased Donor 90.0% 67.5% Living Donor 97.3% 80.2% Pancreas alone 80.1% 50.6% Pancreas after kidney 78.5% 58.1% Kidney-pancreas (kidney) 92.9% 77.9% Kidney-pancreas (pancreas) 86.2% 72.5% Liver Deceased donor 82.3% 67.6% Living donor 84.1% 68.6% Intestine 73.4% 36.9% Heart 87.3% 73.2% Lung 82.3% 49.7% Heart-Lung 75.0% 73.2% Source: 2007 OPTN/SRTR Annual Report, Table 1.13. 30 The Fetus is a De Facto Tolerated Allograft A fetus carries paternal as well as maternal MHC antigens The paternal MHCs are foreign to the mother and should act as allograft Fetus is not reject by the mother Several tolerogenic mechanism have been suggested 31 FROM: Kenneth Murphy-Janeway's immunobiology 8th ed.2012 Mechanisms of Fetal Tolerance Maternal T cells do not interact with the placenta because: Cells on the outer layer do not express classical MHC antigens. Presence of complement inhibitory proteins on the placental outer layer Mothernal T cell have tolerance to parental MHC antigens (in murine experiments) during pregnancy Local nonspecific 32 immunosuppression at the outer layer of the placenta – by inhibitory cytokine production FROM: Roitt's Essential Immunology 12th ed. - P. Delves, et. al., (Wiley-Blackwell, 2011) Regulation of Tolerance is Happening at the Developmental Stage Burnet’s Hypothesis:(1949) During the development of the immune system in neonatal stage the antigens are recognized as self. Immune system becomes tolerant to these antigens by clonal deletion Medawar proved Burnet’s Hypothesis by inducing tolerance in experimental animals. Together Burnet & Medawar have won Nobel Prize in 1960 for their work. 33 34 Regulation at the Developmental Stage Evidence from Dizygotic cattle twins (Dr. Ray Owen 1945) Same mother (C) was mated with two different bulls (A and B) to produce dizygotic twin calves (d and e) which have shared the blood supply in utero Therefore the calves will also share each others alloantigens Once the calves grow (D and E) they can accept graft from each other without rejection Antigen tolerization should happen before full development of the immune system at early embryo or neonatal stage. Dr. Owen observations led to Burnet's clonal hypothesis and the experiments on the induced unresponsiveness by Dr. Medawar 35 Experimentally Induced Unresponsiveness (Medawar) Acquisition of tolerance in early stages of life Mice that are injected with an antigen at an early stage of development will be tolerized as adults for this antigen 36 References Basic Immunology by Abbas et al, 4th edition, 2014 Chapter 10; page 196-204 37 Ivo Boudakov, Ph.D. Ver. 2016 Tumor Immunology Immunology IMMUNOLOGY (BMIC550) Learning Objectives FYI Topics and keywords to be discussed: Selected tumors and the relationship with their host. Tumor associated antigens: Oncofetal antigens: alpha-fetoprotein (AFP), carcino-embryonic antigen (CEA ). Immunity to tumors and mechanisms of escaping the immune response. Immunotherapy. 171. Compare and contrast benign and malignant tumors. 172. Describe the patient populations in which the incidence of malignancy increased. 173. List the particular malignancy(ies) that arise in immunosuppressed patients or in patients that are using immunosuppressive drugs. 174. List the particular malignancy(ies) that arise in patients infected with (i) Epstein Barr virus, (ii) human immunodeficiency virus (HIV). 175. List one tumor specific antigens and the malignancy with which it is associated. 176. Explain the term “tumor associated antigen”. 177. Define “oncofetal” (tumor associated) antigens. List three malignancies associated with oncofetal antigens. 2 Learning Objectives FYI 178. Explain the relevance of oncofetal antigens in clinical practice for diagnosis and or monitoring recurrence. 179. Discuss tumor markers play a role in tumor immunology. List four tumor markers and the malignancy with which each is associated as well as their role in diagnosis. 180. Describe three ways in which monoclonal antibodies are used to effect a therapeutic “magic bullet effect”. 181. Compare and contrast the different tumors of the immune system (leukemia, lymphoma, plasma cell). Where possible characterize unique features of each. 182. Differentiate between Waldenstrom’s macroglobinemia and multiple myeloma. 3 Benign vs. Malignant Tumors Benign tumors have the cells grow as a compact mass and remain at their site of origin Malignant tumors present with uncontrolled cells growth which can spread into surrounding tissue and to distant body sites Benign tumors are diploid, low number of mitotic cell counts with normal mitosis, and retain their specialization Malignant tumors are genetically “weird”: polyploidy, abnormal mitosis with high mitotic count, loss of 4 specialization, wide range of structural differentiations Malignancy Naming Carcinomas are epithelial cell tumors (e.g. breast, colon, pancreas, and others) Leukemias are tumors of circulating blood cells Lymphomas are solid tumors in lymph nodes Myelomas are tumors of bone marrow cells Sarcomas are tumors of the soft tissue, or connective and supportive tissue (e.g. bone, cartilage, fat, muscle, blood vessels) 5 Link Between Cancer Development and Immune Surveillance Immune surveillance theory states that there will be more tumors in individuals whose immune system is suppressed Examples of the immune surveillance role against cancer immunodeficient individuals have an increased rate of some types of tumors (eg. Kaposi sarcoma in AIDS) high rate of skin cancer among immuno-compromised patients living in high sunshine regions patient on immuno-suppressive drugs have high risk of developing certain cancer – mainly viruses induced blocking inhibitory receptors for various therapeutic reasons, such as PD-1 and CTLA-4, will leads to tumor remission 6 Link Between Cancer Development and Immune Surveillance Examples of the immune surveillance role against cancer Certain age groups (elderly people) have an increased occurrence of tumors, due to the fact that this age groups often have less effective immune system. Animal experiments supporting the immune surveillance concept immunocompetent animals will actively reject transplanted tumors if they have been previously immunized against the same tumor antigens immunity can be adoptively transferred from an animal, in which a tumor has regressed, to a naïve animal by injection of lymphocytes (T cells) 7 Tumor Immunosurveillance The same immune response that is mounted against virally infected cells is also acting against tumors APC pickup a tumor antigen and present it on MHC II as well as cross-presentation on MHC I. This triggers CTL (CD8 TC) activation 8 Tumor Immunosurveillance CTLs play an important role in immunological surveillance but first time when they are activated they would need help from TH (CD4) cells as well Cross-presentation is important to allow dendritic cells (APC) present not just to TH (CD4) but also to TC (CD8) 9 which eventually turn into CTLs Tumor Immunosurveillance 10 Variety of Tumor Antigens 11 Tumor Immunosurveillance The current knowledge of the individual players in tumor surveillance is still evolving Adaptive immunity mostly employs CTLs mediated cytotoxicity through the mechanisms of activating apoptosis and cytokine production: e.g. TNF-α (tumor necrosis factor) Role of innate immunity involves NK cells can be further activated in presence of IL-2 into Lymphokine Activated Killer cells (LAK) which are highly lethal to tumor cells, even to NK resistant tumors Activated macrophages can kill tumors by: by producing reactive oxygen intermediates production of TNF-α (tumor necrosis factor) 12 Tumor – Host Relationship Most of human tumors are spontaneously developing tumors and they might not be immunogenic These are tumors developed by mutations Their progression is not necessarily associated with failure of the immune system To be recognized by immunosurveillance, tumor cells must have antigens that are recognized as foreign, such as: Altered antigens Abnormal antigens The anti-tumor immune response is used for diagnosis, prophylaxis, and immunotherapy 13 Tumor Genes Altered expression of normal self genes could be a result of gene mutation by chemical, physical, or other means may promote tumor growth Silencing of tumor suppressor genes like p53 or RB Up-regulated expression of proto-oncogene to make them behave as oncogenes that are otherwise silent or under control: RAS, WNT, MYC, ERK, others Oncogenic viruses are known to induce tumorigenesis upon infection as a result of the following mechanisms: Carrying their own viral oncogenes Integration and disruption of host cell genome at a site that alters normal host gene expression 14 Variety of Tumor Antigens Spontaneous tumors cause by mutation are very different from virus induced tumors in their extreme antigenic heterogeneity. two tumors induced by the same chemical, in the same animal will rarely share common tumor specific antigen Tumor specific antigens (TSA) only found on specific tumors and never on normal cells which gives a great potential for tumor specific targeting Tumor associated antigens (TAA) these are not unique to tumors and can also be present on normal cells in various circumstances Tumors can also be monitored by overexpression levels of 15 otherwise normal self proteins Abnormal Cancergene testis expression antigens Antigens Nature of Antigen Tumor Type Caspase 8 Regulator of apoptosis Squamous cell carcinoma Surface immunoglobuli Specific antibody alter gene Lymphoma ns (IgG) / rearrangements in B cell clone Idiotype 1. MAGE-1 2. MAGE-3 3. NY-ESO-1 Normal testicular proteins in 1. Melanoma male germ cells 2. Breast (heterogeneous re-expression 3. Glioma in many different tumors) HER-2/neu Receptor tyrosine kinase Oncoviral protein Tumor Specific Antigens (TSA) or tumor suppressor Ag Some Tumor Antigens 1. HPV type 16 2. E6 and E7 Viral transforming gene product proteins 16 1. Breast 2. Ovary Cervical carcinoma ADAPTED FROM: Kenneth Murphy-Janeway's immunobiology 8th ed.2012 Tumor Associated Antigens (TAA) TAA are antigens that appear in various tumors and are not specifically linked to a single tumor type The cannot be used as targets for anti-tumor treatment, but a good monitoring markers for tumor progression and remission Example of such markers are oncofetal antigens: these are genes that are normally expressed during embryonic stage and supposedly kept silent during adult life during oncogenesis the oncofetal antigens are up-regulated Alpha-fetoprotein (AFP) Carcinoembryonic antigen (CEA) Beta-chorionic gonadotropin (β-HCG) 17 Oncofetal Antigens Antigens Associated Tumors Notes 1. Most patients with liver cancer; Used as a diagnostic as well as prognostic index Alpha-fetoprotein 2. Some cases of nonafter chemotherapy or (AFP) seminomatous testicular surgery cancer High level of CEA is linked to Carcinoembryonic 1. Colon and rectal carcinoma; antigen (CEA) 2. Pancreatic, breast, lung, stomach, and prostate cancer 1. Ovarian germ cell tumors; Beta-chorionic 2. Gestational trophoblastic gonadotropin (βdisease (hydatidiform mole and HCG) choriocarcinoma); 3. Testicular tumors 18 It is a glycoprotein involved in cell adhesion and used to monitor recurrence and treatment It is normally detected in early pregnancy but it is abnormal for nonpregnant women, man, or late pregnancy Carcino-embryonic Antigen (CEA ) The production of CEA is happening in the fetal gut, liver and pancreas and usually stops after birth. It can be also present in alcoholic cirrhosis patients, smokers, as well as chronic obstructive pulmonary diseases (COPD) 19 SOURCE: https://www.fascrs.org/patients/disease-condition/colon-and-rectal-cancer-follow-care Alpha-fetoprotein (AFP) The antigen is normally expressed by fetal liver, yolk sac, and gastrointestinal cells In addition to the liver and testicular cancer it maybe detected in numerous other cases: pancreatic, gastric, lung tumors in liver cirrhosis of viral and alcoholic origin It has immunosupressant activity Healthy Liver Fibrotic Liver Cirrhotic Liver Liver Cancer A healthy liver Continuous liver Scar tissue replaces normal, Formation of a inflammation (e.g. Hepatitis healthy tissue, blocks blood malignant tumor in B) can lead to fibrosis – a flow and obstructs normal the liver. formation of liver scar tissue functionality 20 SOURCE: http://livercancertreatment.club/wp-content/uploads/2016/02/level-4-liver-cancer-wDrL.jpg Beta-Human Chorionic Gonadotropin (β-hCG) Normal protein expressed by trophoblastic epithelium of the placenta and can be used for pregnancy test as well. Ovarian cancer and GTD, but in rare cases it can also be seen in hepatic, breast, pancreatic, and gastric cancers 21 SOURCE:https://www.youtube.com/watch?v=NrTRPohUq6U How Tumors Evade Immunosurveillance? 1. Tumor cells – suppress antigen presentation Due to lack of co-stimulatory molecules such as B7 the TC cells are not able to be activated and become anergic (anergy) Lack or reduced expression of MHC class I avoids recognition of tumors by TC cells back-up mechanism - such cells became susceptible to NK 2. Tumors may release of immunosuppressive cytokines TGF-β affects many mediators and has an inhibitory effect on TC cell differentiation 22 How Tumors Evade Immunosurveillance? 3. Release of cytokines that induce suppressor TREG lymphocytes 4. Tumor cells might masking 23 their antigen by covering them with mucin (substance found in mucus secretion) 5. Some tumors may shed their unique antigens which block antibodies and T cells away from malignant cells surface. 6. Tumor cells may express the necessary marker to induce apoptosis of TC cells How Tumors Evade Immunosurveillance? 7. Antigen concentration Early tumor development the amount of antigen may be too small to stimulate the immune system Later due to the rapid proliferation of malignant cells, the immune system is quickly overwhelmed with too high antigen concentration. 8. Tumors in the immunological privileged sites will not be attacked by immune response (cornea of the eye) 9. Tumors may develop into low antigen variant, that does not stimulate the immune response. 24 Immunotherapy Immunotherapy in treating cancer Enhance the immune system by active and passive means which can be either specific or non-specific induction Active immunotherapy is when there is a direct induction of the immunosurveillance in the patient: Non-specific immunization with BCG (Bacillus Calmette- Guerin); extracts of BCG, Corynebacterium parvum or Corynebacterium diphtheriae , viral antigens with adjuvant, killed tumor cells or their extract, or recombinant antigens. Cytokines can be actively induced by immunization Passive immunotherapy is when the immunosurveillance is not directly induced but rather transferred into the patient as a passive recipient such as adoptive transfer method. 25 Passive Immunotherapy (Adoptive Transfer) Cytokines can be non-specific and passively administered, unfortunately this is known to cause various side effects IL-2 and TNF have been tried but are strong induction of fever and toxic shock syndrome Interferon, IFN alpha and IFN beta – promising results with certain cancer types Dendritic cell vaccines (Engineered Antigen-Presenting Cells) the patient’s cells are specifically trained outside his body to recognize the tumor antigens and transferred back to the patient 26 Passive Immunotherapy (Adoptive Transfer) IL-2 activated killer cells “ex-vivo” Patients own killer cells are activated by IL-2 in-vitro and given back to the patient: results have wide variations Use of tumor specific monoclonal antibodies Anti-tumor antigen specific monoclonal antibodies could be linked to a killer drug such as: toxin (diphtheria toxin), ricin, radioisotopes, anti-tumor drugs Specific antibodies targeting: Tumor markers: Anti-HER2; Anti-CD30; Anti-EGFR (receptor for colorectal cancer) Antibodies that will modulate the immune response through either immunosuppressive or immunostimulatory 27 receptors. Immunotherapy on The Works 28 Immunotherapy on The Works 29 Immunotherapies 30 B and T cell Malignancies B-cell malignancies are diverse set of diseases, clinically divided into indolent (slow growth) and aggressive malignancies: Leukemias (e.g CLL – chronic lymphocytic leukemia – 95% is from B cells origin) Lymphomas: Hodgkin (Reed-Sternberg cells) lymphomas and most of non-Hodgkin lymphomas (NHL) Myelomas (plasma cell neoplasms) T cell malignancies (neoplasms) are more uncommon 10%-15% of all non-Hodgkin's lymphomas T cell acute lymphoblastic leukemia (T-ALL) ; 5% of the CLL (Chronic Lymphocytic Leukemia) is T cell based Adult T cell leukemia / lymphoma (ATLL) caused by HTLV-1 (human T lymphocyte virus) 31 Monoclonal Gammopathies A group of disease with abnormal proteins found in the blood and produced by plasma cells (Ab producing B cells) Variable symptoms: Anemia; Fatigue ; Weakness, Pain in the bones or soft tissues; Tingling in the feet or the hands, Infections, Bleeding, Weight loss, Headache, Mental changes, etc. Diagnoses of monoclonal gammopathies is usually based on the type of abnormal proteins in the blood. 32 SOURCE: Mayo clinic ; Br J Haematol. 2006 Sep;134(6):573-89. Monoclonal gammopathy of undetermined significance. Kyle RA Differential Diagnosis: Multiple Myeloma vs. Waldenström Macroglubulinemia Both malignancies cause Rouleaux formation of RBCs which looks like a stack of coins due to the high abnormal concentration of immunoglobulins Hepatospleenomegaly Lymphadenopathy Hyperviscosity Bence Jones proteins in urine Positive Coomb's test Bony Lesions M-protein type 33 Waldenström Multiple Myeloma Macroglubulinemia --+ --+ --+ More common Less common Less common More common More common Less Common light chain only, Monoclonal IgM IgG, IgA, IgD Differential Diagnosis: Multiple Myeloma vs. Waldenström Macroglubulinemia Light immunoglobulin chains (or Bence Jones protein) are small enough to be excreted with the urine: More frequently associated with multiple myeloma or AL amyloidosis. Whole immunoglobulins –usually called "M- spike protein" ("M" stands for monoclonal) when in high levels can cause aggregates of polymers from where the name macroglobulinemia is derived in case Waldenström Macroglubulinemia this can cause the blood to become too viscous Heavy chains production only is also possible. 34 Case Study: HIV with Multiple Myeloma A 45-year-old white man presented with an acute retroviral illness characterized by fever, rash, lymphadenopathy, headache, and sore throat. Shortly thereafter, he tested positive for HIV infection, with an initial CD4+ cell count of 475/µL (normal, 460/µL or more) and an HIV viral load of more than 800,000 copies/mL. He began an antiretroviral regimen of nelfinavir, stavudine, and lamivudine. Seven months later, his CD4+ cell count dipped below 400/µL in the setting of a persistently detectable HIV viral load. Consequently, his regimen was changed to hydroxyurea, zidovudine, didanosine, saquinavir, and ritonavir. One year later, his hematocrit, which had previously been in the normal range, fell to 30% despite with nondetectable HIV viral load and a CD4+ cell count of 600/µL. Two months later the patient complained of worsening fatigue and dyspnea on exertion. Serum protein electrophoresis (SPEP) showed an increased M spike. Thalidomide-Based Treatment for HIV-Associated Multiple Myeloma: A Case Report ; David M. Aboulafia, MD ; AIDS 35 SOURCE: Read. 2003;13(8) M Spike Protein in Multiple Myeloma Chart A presents serum protein electrophoresis of a patient with multiple myeloma, where M spike of more than 5 g/dL. the M spike is a monoclonal paraprotein production by the malignant cells Chart B is the same patient after 9 months of combinatory anti-myeloma regiment showing a significant reduction of M spike. 36 SOURCE: http://www.medscape.com/viewarticle/460735 2 Next generation of immunotherapy for melanoma. J Clin Oncol. 2008;26:3445-3455 FYI 37 Next generation of immunotherapy for melanoma. J Clin Oncol. 2008;26:3445-3455 References Basic Immunology by Abbas et al, 4th edition, 2014 Chapter 11; page 189-196 38 Ivo Boudakov, Ph.D. Ver. 2016 Tumor Immunology Immunology IMMUNOLOGY (BMIC550) Learning Objectives FYI Topics and keywords to be discussed: Passive and active vaccination. Live (attenuated) and killed vaccines. Toxoid, subunit vaccines, adjuvants, antiserum.. 192. Explain the concept of (i) recombinant vaccines and (b) DNA vaccines. 193. Describe the “prime / boost approach” to immunization. 194. Explain the terms: herd immunity, passive natural immunity, passive artificial immunization, active immunization. 195. Explain the term “gamma globulins” and why it is passive artificial immunization. 196. List advantages and disadvantages of live versus killed vaccine and explain the differences in effectiveness. 197. Discuss the role of adjuvants in immunization and list some examples. 198. List vaccines that can be administered to immunosuppressed patients, and explain why. 199. Discuss advantages and disadvantages of the oral live (Sabin) and killed (Salk) polio vaccines. 2 Learning Objectives FYI 200. Name two bacterial toxoid vaccines and explain the principles underlying these vaccines. 201. Define tetanus toxin, tetanus toxoid, heterologous antiserum, homologous antiserum. 202. Describe the causative agent of tetanus, the mechanism of infection and consequence. Explain how “neonatal tetanus” can occur. Explain why natural immunity to tetanus is not possible. 203. Explain the various clinical approaches to treating patients infected with C. tetani spores. 3 Immunology: Prevention at Work (US Data) Disease Total cases Diphtheria 206,939 Measles 894,134 Mumps 152,209 Pertussis 265,269 Poliomyelitis 21,269 Rubella 57,686 Tetanus 1,560 Year Cases in 1994 % Change 1921 2 -99.9% 1941 963 -99.9% 1968 1537 -99.9% 1934 4617 -99.9% 1952 0 -100% 1969 227 -99.9% 1923 51 -99.9% The number of cases of illness in the U.S. in a representative year (either before a vaccine was available or before it came into widespread use) with the number of cases reported in 1994. (Modified: Abbas et. all; Basic Immunology; 2016) 4 Acquired Immunity Naturally Acquired Active Antigens enter body naturally; produce antibodies and specialized lymphocytes 5 Passive Antibodies from mother transferred to the fetus Artificially Acquire Active Antigens in vaccines; body makes antibody & specialized lymphocytes Passive Preformed antibody in immune serum introduced by injection Various Types of Vaccinations Live vaccines Small pox (variola vaccine) BCG (Bacille de Calmette–Guerin); Typhoid oral Live Attenuated vaccine (Salmonella typhi); Typhus (Rickettsia sp.); Plague Vaccines (Yersinia pestis); Oral polio (Sabin vaccine); Yellow fever virus; Measles; Mumps; Rubella; Intranasal Influenza; Cholera; Typhoid (Salmonella typhi); Pertussis (whooping Killed cough, Bordetella pertussis); Plague; Rabies; Salk polio; Inactivated Intra-muscular influenza; Japanese encephalitis vaccines Toxoids Diphtheria; Tetanus Meningococcal polysaccharide vaccine; Subunit Vaccines Pneumococcal polysaccharide vaccine; Hepatitis B polypeptide vaccine Conjugated Meningococcal conjugate; Pneumococcal conjugate; Haemophilus influenzae type B (Hib) conjugate vaccines Recombinant Hepatitis B vaccine vaccines 6 Live vs. Live Attenuated Vaccines Live cowpox virus was used to prevent from smallpox virus infections as described by Edward Jenner in 1798. A vaccination campaign using live vaccinia virus (not to be confused with cow- or small-pox virus) succeeded in worldwide eradication of smallpox (1980) under the WHO lead. the origin of vaccinia virus has not be clearly identified Live, attenuated vaccines are usually contagions strains that have been weakened in the lab and can’t cause disease frequently achieved by extensive multiple passages in various animal species to get strains with diminished virulence Main limitations: cannot be given to immunocompromised patients; in isolated cases the vaccines can revert and induce full-blown diseases ( live Sabin polio vaccine is known to 7 cause isolated cases of paralysis) Live Attenuated vs. Killed Vaccines Live, attenuated vaccines are the closes to the natural active immunization: requires only single or maximum of two doses to achieve lifelong immunity elicit strong cellular and humoral (Ab) immune responses Inactivated (killed) vaccines are produced by heat, chemical, or radiation treatment of live pathogens. Advantage is their prolonged shelf life with minimum maintenance requirements at room temperature. The disadvantage of inactivated (killed) vaccines is that they: Require multiple boosting (injections) Elicit weaker immune response which in many cases is mainly humoral (Ab) immunity activation 8 Toxoid Vaccines Toxoid vaccines are used when the main phonology is due to the toxins entering the body instead of damage doe to bacterial growth tetanus toxin and diphtheria toxin are both exotoxins exotoxins are proteins which can be neutralized by chemical treatment with formaldehyde such inactivated “toxoids” are very effective inducers of humoral immunity which generates neutralizing defensive antibodies 9 Tetanus and Tetanus Toxoid Vaccines Tetanus toxin is a extremely potent neurotoxin which works in very low concentration such low concentration is below the limits of natural immunogenicity and cannot lead to development functional immune response In case that the mothers does not transfer tetanus protective antibodies to the newborn infant there is a risk of acquiring “neonatal tetanus” This is usually observed when the umbilical cord is not properly healed or when non-sterile scissors are used to cut the umbilical cord 10 Subunit Vaccines Instead of live or killed pathogen, individual structures (antigens) from the pathogen are isolated and mixed in a form of vaccine It may contain anywhere between 1 to 20 antigens which may target humoral (B cells) and/or cellular (T cells) immunity The individual antigens (epitopes) can be either isolated from the actual pathogens, or produced in a lab through DNA recombination technologies Such vaccines are safe because there is no danger of reversing back to virulent pathogen strains 11 Conjugate Vaccines Conjugate vaccines are special (sub-) type of subunit vaccines Young children are lacking the capacity of the developed adult immune system and therefore they frequently do not respond to polysaccharide antigens such as bacterial capsules Way around of resolving such lack of immunogenicity is to link (conjugate) the polysaccharide antigen with a protein which will elicit strong T cell dependent B cell response 12 DNA Vaccines vs. Recombinant Vaccines Recombinant vaccines are produced using DNA recombination technologies and delivered in two ways: inserted in a carrier vector (attenuated virus or bacteria) that is given as a live organism to the person to be vaccinated – recombinant vector vaccines inserted in a model organism (like yeast) that is be used for production of the corresponding antigens as vaccine subunits DNA vaccines are naked DNA molecules inserted in a suitable DNA vector that will allow for expression in human cells host cells. The DNA construct is introduced by: Injection Needleless technology using high-pressure DNA gun to deposit gold particles coated with DNA in the tissue 13 Naked DNA Vaccines They are considered safe Current test although have still not produced an approved for clinical use naked DNA vaccine, they have proven to be Inducing strong immune response both cellular and humoral Principle has been demonstrated working in human subjects Most of the current clinical studies are focused on using cancer markers during vaccination by naked DNA vaccines This is still largely work in-progress 14 Herd Immunity “Vaccine refusal helped fuel Disneyland measles outbreak, study says” “The measles outbreak traced to Disneyland has led to 22 cases of the disease in California and several in other states.” The LA Times 15 Herd Immunity is Population Immunity Vaccines are safe as and the benefits for the population outnumber the isolated negative cases due to potential pathogenicity If 75% of children are immunized against diphtheria the disease disappears in the population 16 Immunoprophylaxis by Passive IgG transfer Passive transfer of immunity - transfer of Ig, immune sera Sera collected from previously infected humans Sera collected from laboratory infected animals, e.g. horse Transfer of primed cytotoxic T lymphocytes Passive immunization with immunoglobulin is recommended for : For prophylaxis/treatment of various infections or toxins Long-standing immunodeficiency 17 Steroid treatment Immunotherapy – Passive Immunity INFECTION Tetanus Diphtheria Botulism; Gas gangrene; Snake or scorpion bite Varicella zoster Rabies Hepatitis B Hepatitis A Measles Cytomegalovirus 18 ANTIBODY SOURCE HORSE HUMAN USE X X Prophylaxis Treatment X — Treatment — — — — — X X X X X — X Treatment immunodeficiency Post-exposure to vaccine Treatment Prophylaxis (Travel) Treatment Prophylaxis in patients receiving immunosuppression Table 14.1. Passive immunotherapy with antibody. Passive Immunity with IvIG Intravenous immunoglobulin infusions (IvIG): empirically discovered blood product of pooled IgG extracted from the plasma of over one thousand blood donors IvIG is used in treatment for: Primary immune deficiencies (plasma protein replacement therapy at low dose: 100 to 400 mg/kg every 3 to 4 weeks) Autoimmune diseases (high dose ≈1-2g/kg of body wt; for 6 months, followed by low dose maintenance therapy ) Acute Infections IvIG is very expensive product: at well over $50/g which can go up to $8,000 for a single dose (average body weight of 80 kg person at 2g/kg) 19 Mode of IvIG Action Mechanism of actual is not completely understood especially in suppressing the autoimmune diseases Anti-infectious action is primarily conducted through neutralization, opsonization, ADCC, complement activation Anti-inflammatory IvIG action is believed to be linked to Anti-idiotypic network regulation Activation of regulatory feedback loop from low affinity FcRIIB receptors 20 21 Off-label Anti-inflammatory (high-dose) therapy Replacement (low-dose) therapy) Licensed Table 1. Examples of the clinical use of IVIG Primary immunodeficiencies (CVID and others); HIV infection; Bone marrow transplantation; B cell lymphocytic leukemia; Multiple myeloma Idiopathic thrombocytopenia purpura (first historically approved therapy in 1981); Guillain-Barre syndrome; Kawasaki disease; Chronic inflammatory demyelinating polyneuropathy (CIDP) Autoimmune neutropenia; Autoimmune hemolytic anemia; AntiFactor VIII autoimmune disease; Multiple sclerosis; Myasthenia gravis; Stiff person syndrome; Multifocal neuropathy; Systemic vasculitis (ANCA positive); Polymyositis; Dermatomyositis; Rheumatoid arthritis; Systemic lupus erythematosus; Antiphospholipid syndrome; Toxic epidermal necrolysis; Autoimmune skin blistering diseases; Steroid-dependent atopic dermatitis; Graft-vs-host disease; Sepsis syndrome Other Immunotherapies Adoptive transfer of predominantly of autologous ex-vivo modified immune cells (e.g. TC cells; Dendritic cells) currently this has limited application especially of it is allograft due to MHC restriction and class match Non-specific immunotherapy: non specific therapeutic stimulation or down regulation of the immune system: Non-specific stimulation by microbial products or triggers e.g. Aldara (Imiquimod): activates immune cells through the toll-like receptor 7 (TLR7) for genital warts (HPV) Use of cytokines To stimulate the immune response 22 Down regulate the immune response Active agent Action cytokines filtered bacterial used by Coley (1909) against tumors Microbial cultures products BCG some activity against tumors effective in chronic: hepatitis B; hepatitis C; herpes zoster; wart virus IFNα (HPV); prophylactic against common cold (also some tumors) effective in some cases of: chronic IFN granulomatous disease; lepromatous leprosy leishmaniasis (cutaneous) IL-2 leishmaniasis (cutaneous) bone-marrow restoration after G-CSF cytotoxic drugs TNF antagonists septic shock Cytokine IL-1 antagonists; inhibitors severe (cerebral) malaria? IL-10 23 References Numerous various sources; please use this lecture as main learning tool 24