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SoGAT XX, Warsaw, Poland 12-13 June 2007 Michael Chudy, WHO; Geneva, Switzerland

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. Biological Standardization.

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SoGAT XX, Warsaw, Poland 12-13 June 2007 Michael Chudy, WHO; Geneva, Switzerland

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  1. Development of Biological Reference Preparations for Blood Safety-related IVDs - WHO Strategic Plan - SoGAT XX, Warsaw, Poland12-13 June 2007Michael Chudy, WHO; Geneva, Switzerland

  2. 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 • Vaccines • Blood and blood products • Biological therapeutics • In vitro diagnostic devices

  3. Quality Assurance and Safety of Biological ProductsWHO Norms & Standards: Expert Committee on Biological Standardization Immunizations, Vaccines & Biologicals Department (IVB); Family and Community Health Cluster (FCH) Medicines, Policy and Standards Department (PSM*); Health Technology and Pharmaceuticals Cluster (HTP) (*) Expert Committee for Pharmaceutical Preparations (*)Expert Committee for Essential Medicines

  4. 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.

  5. 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

  6. Establishment ofWHO 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.

  7. 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

  8. Meeting of WHO Collaborating Centres forBiological 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

  9. WHO Biological Reference Preparations:Current Situation and Proposals Pathogens with impact on blood safety • HIV • HBV , HCV • Other hepatitis viruses • B19V , HTLV1/2, CMV • 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) √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ NAT; √ Serology; √ Other

  10. Testing for Syphilitic Infection • Treponema pallidum • Blood screening test in many countries • Anti-syphilitic serum, WHO 1st IS (#HS) nearly exhausted • Proposal for replacement: • 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

  11. 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 • Effective indicator of infection • Negative result no guarantee that donor is not infected 1st IS P. falciparum DNA, #04/176 (ECBS 2006) Antibody Reference Panel (proposal)

  12. 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)

  13. 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)

  14. 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

  15. 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 • Whole parasite lysates or semipurified antigenic fractions (epimastigote stage) • Trypomastigote excretory-secretory antigens (TESAs; major component trans-sialidase) • Cocktail of recombinant proteins • Synthetic peptides

  16. 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)

  17. 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

  18. Epidemiological InformationWHO 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)

  19. New Tests and Emerging TechnologiesWHO 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

  20. Priority Projects for Biological Reference Preparations WHO Collaborating Centres' Meeting (29-30 January 2007) Consultation Feasibility studies Collaborative study *IS **Panel 1two panels for HBsAg- and NAT-tests;

  21. Future Projects for Biological Reference Preparations WHO Collaborating Centres' Meeting (29-30 January 2007) • New proposals (ECBS endorsement is needed): • Anti-HTLV-1/2 antibody panel • Anti-Plasmodium species antibody panel • For further discussion: • 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

  22. Ways Forward for CollaborationWHO 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

  23. Meeting of WHO Collaborating Centres forBiological 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

  24. 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. 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,…

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