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Development of Biological Reference Preparations for Blood Safety-related IVDs - WHO Strategic Plan - SoGAT XX, Warsaw, Poland 12-13 June 2007 Michael Chudy, WHO; Geneva, Switzerland 1| M. Chudy | 12 June 2007 Biological Standardization WHO is mandated by it's Member States to "…develop, establish and promote international standards for biological products." In practice, biological products cover – – – – 2| Vaccines Blood and blood products Biological therapeutics In vitro diagnostic devices M. Chudy | 12 June 2007 Quality Assurance and Safety of Biological Products WHO Norms & Standards: Expert Committee on Biological Standardization Biological Products (Vaccines, blood products, other biologicals and in vitro diagnostic devices) NSB/IVB/FCH (Vaccines, cell regulators) QSD/PSM/HTP (Blood products, in vitro diagnostic devices) Immunizations, Vaccines & Biologicals Medicines, Policy and Standards Department (IVB); Department (PSM*); Family and Community Health Cluster (FCH) Health Technology and Pharmaceuticals Cluster (HTP) (*) Expert Committee for Pharmaceutical Preparations (*) Expert Committee for Essential Medicines 3| M. Chudy | 12 June 2007 WHO Biological Reference Preparations Recommendations for the preparation, characterization and establishment of international and other biological reference standards (revised 2004) Annex 2, WHO TRS, No 932, 2005. 4| M. Chudy | 12 June 2007 WHO Biological Reference Preparations International Standard [expressed in IU] Reference Reagent International Reference Panel – Endorsed and adopted by Expert Committee on Biological Standardization (decision making body) – Catalogue on the website www.who.int/medicines www.who.int/bloodproducts/ivd/infectious_markers 5| M. Chudy | 12 June 2007 Establishment of WHO Biological Reference Preparations * 1. Selection of candidate materials 7. Characterization of final product 2. Characterization of candidate materials 8. Stability studies (incl. statistical analysis) 3. Feasibility studies 4. Inactivation (if needed) 5. Dilution of materials (dilution matrix) 6. Freeze-drying 9. International collaborative study (incl. statistical analyses) 10. Report to WHO 11. ECBS decision 12. Storage and distribution (maintenance) *Recommendations for the preparation, characterization and establishment of international and other biological reference standards (revised 2004); Annex 2, WHO TRS, No 932, 2005. 6| M. Chudy | 12 June 2007 WHO Biological Reference Preparations: IVD Strategic Plan (5 years) For blood safety-related IVDs: Serological test platforms NAT assays Other tests Meeting of the WHO Collaborating Centres for Biological Standards and Standardization (NIBSC, CBER, PEI) in Jan 2007 organized by WHO QSD/PSM 7| M. Chudy | 12 June 2007 Meeting of WHO Collaborating Centres for Biological Standards and Standardization WHO Biological Reference Preparations: Review of current situation and new proposals Role of epidemiological data worldwide New test platforms and emerging technologies Define priority projects Ways forward for collaboration (WHO CC-Network model) – Would strengthen the collaboration between the WHO CCs, and between WHO CCs and WHO – Respect interests of CCs – Synergize activities 8| M. Chudy | 12 June 2007 WHO Biological Reference Preparations: Current Situation and Proposals Pathogens with impact on blood safety √ √ √ √ HIV HBV √ Other hepatitis viruses B19V Bacteria and parasites (causative agents for syphilis, malaria, Chagas disease) Arthropod-borne agents (WNV, dengue virus) Prion agents √ √ √ √ Other blood-borne agents (bacteria, leishmania, HHV-8) √√√ √ √ , HCV √ √ √ √ , HTLV1/2, CMV √ √ √ NAT; √ Serology; √ Other 9| M. Chudy | 12 June 2007 √ Testing for Syphilitic Infection Treponema pallidum Blood screening test in many countries Anti-syphilitic serum, WHO 1st IS (#HS) nearly exhausted Proposal for replacement: – – – – 10 | IgG preparation (plasma pool of samples from latent syphilis patients) IgM/IgG preparation (plasma pool of samples from acute syphilis patients) Collaborative study is completed Report to ECBS in October 2007 M. Chudy | 12 June 2007 Testing for Malarial Infection Plasmodium falciparum, P. malariae, P. ovale, P. vivax Endemic in more than 100 countries Donor testing to reduce the deferral period/loss of donors (non-endemic areas) Direct parasite detection – – Giemsa- or Wright's-stained thick and thin blood film (gold standard method) Time expensive, need experienced hands Antigen detection – No sufficient sensitivity NAT testing – Pro and cons (e. g. DNA vs RNA!) Antibody testing – – 11 | 1st IS P. falciparum DNA, #04/176 (ECBS 2006) Antibody Reference Panel (proposal) Effective indicator of infection Negative result no guarantee that donor is not infected M. Chudy | 12 June 2007 Chagas Disease American Trypanosomiasis Protozoan parasite Trypanosoma (T.) cruzi First described by Carlos Chagas in 1909 Morphologically distinct stages – Insect-stage: epimastigote – Host-stage: Trypomastigote/amastigote >100 strains classified into two groups (T. cruzi I and T. cruzi II) Chronic asymptomatic carrier state in infected individuals Endemic in Latin America Non-endemic areas: issue due to emigration (e.g. USA, Spain, France) 16–18 million infected cases; >80 million people at risk T. cruzi DNA detected in mummies from Chile and Peru (7050 BC-1050 AD) 12 | M. Chudy | 12 June 2007 T. cruzi Infection Main routes of parasite transmission By bloodfeeding bugs (sub-family Triatominae); the faeces of the insects contain parasites which can enter the wound left after the bloodmeal, usually when it is scratched or rubbed Transfusion with infected blood (whole blood and components); Tissue and organ transplantations Congenital (from infected mother to fetus) 13 | M. Chudy | 12 June 2007 Testing for T. cruzi Infection Diagnosis is complex due to low parasitemia in later stages Microscopic examination of T. cruzi in blood, lymph fluid, cerebrospinal fluid Xenodiagnosis (uninfected bugs are fed on an individual suspected of having the disease; investigation of blood smear microscopically several weeks later) PCR (limited sensitivity due to low T.cruzi level in chronic stages) Serological tests detecting antibodies are well-suited 14 | M. Chudy | 12 June 2007 Testing for T. cruzi Infection: Serological Tests for Detecting Antibodies Screening tests (initial tests) – Indirect hemagglutination assay (IHA) – Enzyme-linked immunosorbent assay (ELISA) Confirmatory tests (supplemental tests) – Indirect immunoflourescence assay (IFA) – Radio-immuno-precipitation assay (RIPA) – Immunoblot/Western blot Rapid tests Antigens used for ELISA tests – – – – 15 | Whole parasite lysates or semipurified antigenic fractions (epimastigote stage) Trypomastigote excretory-secretory antigens (TESAs; major component trans-sialidase) Cocktail of recombinant proteins Synthetic peptides M. Chudy | 12 June 2007 Testing for T. cruzi Infection: Blood Donation Screening Endemic areas – In most counties for more than 10 years – Prevalence of T. cruzi-infected blood is higher than of HIV, HBV and HCV – Transfusion-transmitted rest-risk differs from country to country Non-endemic areas – USA • >12 million immigrants from endemic regions • ARC pilot studies since end of Jan 2007 with ORTHO test – Spain • Recommendation to test donors from endemic regions (not for excl. source plasma) • To reduce the deferral period/loss of donors – France • Evaluation of screening tests (blood centre in Tours) 16 | M. Chudy | 12 June 2007 Testing for T. cruzi Infection Problems with serological tests – Indeterminate results and false-positive results • Other T. spec • Other infectious diseases: e.g. leishmaniasis, malaria, syphilis • Autoimmune disorders – Lack of sensitivity of some assays No global reference materials for serological tests available Need for establishing of appropriate BRPs/already ECBS endorsed WHO Consultation on 2-3 July 2007, WHO/HQ Geneva Reference Preparations for both screening and clinical diagnostics 17 | M. Chudy | 12 June 2007 Epidemiological Information WHO Collaborating Centres' Meeting (29-30 January 2007) Points for discussion Changes of prevalence data of infectious agents (variability, new variants, mutants) Emerging/re-emerging agents: investigation to assess the relevance on blood and blood product safety Coordination and information exchange between the WHO CCs and with other groups (e.g. WP-TTID/ISBT) 18 | M. Chudy | 12 June 2007 New Tests and Emerging Technologies WHO Collaborating Centres' Meeting (29-30 January 2007) New generations of ELISA systems/platforms New NAT approaches Emerging technologies: – Chip technology (microarray) – Nanotechnology-based assays Suitability of existing WHO Biological Reference Preparations 19 | M. Chudy | 12 June 2007 Priority Projects for Biological Reference Preparations WHO Collaborating Centres' Meeting (29-30 January 2007) 2007 2008 2009 ECBS HCV RNA (3rd)* 2007 Anti-syphilitic (2nd)* 2007 Anti-HBs (2nd)* 2008 Anti-HBc* 2008 HIV-1 gt (2nd)** 2009 HIV-2 RNA* 2009 HBV gt1** 2009 Anti-HCV** 2009 Anti-T. cruzi** 2009 1two 20 | panels for HBsAg- and NAT-tests; M. Chudy | 12 June 2007 Consultation Feasibility studies Collaborative study *IS **Panel Future Projects for Biological Reference Preparations WHO Collaborating Centres' Meeting (29-30 January 2007) New proposals (ECBS endorsement is needed): – – For further discussion: – – – – – – – – – – 21 | Anti-HTLV-1/2 antibody panel Anti-Plasmodium species antibody panel HIV-2 genotype panel HCV genotype panel B19V genotype panel Anti-CMV antibody standard WNV RNA preparation/pan panel for arthropod-borne flaviviruses RNA HCV core antigen preparation Preparations for anti-HHV-8 antibodies and HHV-8 DNA TSE blood preparations Blood-borne bacteria panel Anti-Leishmania antibody panel M. Chudy | 12 June 2007 Ways Forward for Collaboration WHO Collaborating Centres' Meeting (29-30 January 2007) To monitor progress – Annual face-to-face meetings – Teleconferences Need to establish a network of WHO CCs for IVD-related biological standardization representing all the WHO Regions – To ensure complementary and focused expertise at global level Master form sheet for future BRP proposals 22 | M. Chudy | 12 June 2007 Meeting of WHO Collaborating Centres for Biological Standards and Standardization Meeting Report: Development of WHO Biological Reference Preparations for blood safety-related in vitro diagnostic tests Shortly on the website: www.who.int/bloodproducts/ivd/infectious_markers 23 | M. Chudy | 12 June 2007 24 | M. Chudy | 12 June 2007 WHO Biological Reference Preparations Validation, quality control and comparability of IVD tests (analytical sensitivity) Tool for identifying unsuitable diagnostic kits Tool for global regulation and harmonization in the IVD area Tool for regulatory bodies, manufacturers, product users (physicians/scientists) to communicate in a "common language" Underpin the appropriate diagnoses of the disease 25 | M. Chudy | 12 June 2007 WHO Collaborating Centres for Biological Standards and Standardization WHO CCs: NIBSC, CBER, PEI WHO CCs represent the greatest know how and experience in establishing global measurement standards – – – – Characterization of source materials Freeze-drying procedure Organizing collaborative studies Custodian/distribution of reference materials In collaboration with manufacturers, regulatory bodies, blood transfusion services, WHO CCs involved in diagnostics of blood-borne infections, scientific experts,… 26 | M. Chudy | 12 June 2007