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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. Biological Standardization.

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development of biological reference preparations for blood safety related ivds who strategic plan
Development of Biological Reference Preparations for Blood Safety-related IVDs - WHO Strategic Plan -

SoGAT XX, Warsaw, Poland12-13 June 2007Michael Chudy, WHO; Geneva, Switzerland

biological standardization
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
slide3

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

who biological reference preparations
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.
who biological reference preparations5
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

establishment of who biological reference preparations
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.

who biological reference preparations ivd strategic plan 5 years
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

meeting of who collaborating centres for biological standards and standardization
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
who biological reference preparations current situation and proposals
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

testing for syphilitic infection
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
testing for malarial infection
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)

chagas disease
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)
t cruzi infection
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)
testing for t cruzi infection
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
testing for t cruzi infection serological tests for detecting antibodies
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
testing for t cruzi infection blood donation screening
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)
testing for t cruzi infection17
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
epidemiological information who collaborating centres meeting 29 30 january 2007
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)
new tests and emerging technologies who collaborating centres meeting 29 30 january 2007
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
slide20
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;

slide21
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
ways forward for collaboration who collaborating centres meeting 29 30 january 2007
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
meeting of who collaborating centres for biological standards and standardization23
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

who biological reference preparations25
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
who collaborating centres for biological standards and standardization
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,…