A1256656608edNmr

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Reentry for Donors DeferredBased on Anti-HBc
Test Results
November 3, 2005 BPAC Meeting FDA/CBER/OBRR/DETTD
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Issue

• FDA would like to update the Committee on a
  proposed algorithm that would allow reentry of
  donors deferred for testing repeatedly reactive
  (RR) for antibodies to hepatitis B core antigen
  (anti-HBc) on more than one occasion.

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Donor Screening for Anti-HBc September
10, 1991 Guidance

• Donations for transfusion should be tested for
  anti-HBc. Only negative units should be
  transfused.
• Donors should be indefinitely deferred when they
  test RR more than once.
• Donor reentry algorithm not recommended at that
  time because there was no supplemental
  (additional, more specific) tests for anti-HBc.

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Consequences of anti-HBc screening

• Although anti-HBc donor screening has
  contributed to blood safety, many donors have
  been indefinitely deferred because of potentially
  false positive (FP) anti-HBc results.

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Considerations

• Reentry permitted only on the premise that
• i) historical tests for anti-HBc were false
  positives
• and
• ii) there is no evidence for past or present
  hepatitis B virus infection.

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December 1998 BPAC Meeting

• FDA and AABB presented to BPAC similar reentry
  algorithms based on negative test results for
  HBsAg, anti-HBc, anti-HBs.
• The Committee did not recommend reentry because
  ARC data showed that some HBsAg and anti-HBc
  negative samples were HBV DNA reactive using an
  experimental NAT.

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October 2004 BPAC Meeting

• FDA presented to BPAC the following reentry
  algorithm based on negative test results for
  HBsAg, anti-HBc, and HBV NAT.
• The Committee did not vote on the proposed
  re-entry algorithm because of lack of data to
  validate its use.

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Proposed Anti-HBc Re-entry algorithm

• A donor who has been indefinitely deferred
  because of having tested repeatedly reactive for
  anti-HBc on more than one occasion may be
  reentered
• if,

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Proposed Anti-HBc Re-entry algorithm

• a) after a minimum of 8 weeks subsequent to
  the last repeatedly reactive anti-HBc test, a new
  sample is collected from the donor, and this
  sample tests negative for HBsAg, anti-HBc, and
  HBV NAT (sensitivity of 95 detection at lt10
  copies/mL) in FDA licensed assays.
• and

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Proposed Anti-HBc Re-entry algorithm

• b) when a donor presents at a blood center to
  donate, subsequent to the negative tests for
  HBsAg, anti-HBc and HBV NAT, all donor
  suitability criteria for donors of Whole Blood
  and components are fulfilled.

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Recent Developments

• FDA licensed in April 2005 the Roche Cobas
  AmpliScreen HBV NAT for screening donations in
  minipool and individual donation (ID) format.
  Roche presented data showing that its is possible
  to enhance the sensitivity of the ID test.

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Recent Developments

• FDA licensed in October 2005 the Abbott PRISM
  anti-HBc test for screening donations. This
  test uses different technology than other
  currently licensed assays and could be used in
  the re-entry algorithm.

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Request for Data

• The FDA is looking forward to reviewing data to
  validate the proposed reentry algorithm for
  anti-HBc repeat reactive donors