FDA Approves Mini-Pool Testing of Certain HCT/Ps for HIV/HCV NAT

FDA approved the HIV and HCV NAT testing assays manufactured by Roche Molecular Systems and Gen-Probe Inc. for mini-pool testing of certain human cells, tissues, and cellular and tissue-based products (HCT/Ps), eventually clearing the way for facilities to begin mini-pool testing of hematopoietic stem/progenitor cells (HPCs) sourced from bone marrow, peripheral blood or cord blood as well as donor lymphocytes for infusion (DLIs). Testing can occur in mini-pools — comprised of equal aliquots from individual donor specimens — as well as individual donation testing. The pool size for testing has not changed from the originally approved pool size for each manufacturer. Updated manufacturer package inserts will be posted on the FDA Web site once available.

To reflect this change, FDA has removed the “note” from its Web site stating that HCT/Ps must be tested individually.

This development creates some questions regarding previously tested products addressed in the guidance document Certain Human Cells, Tissues, and Cellular and Tissue-Based Products (HCT/Ps) Recovered From Donors Who Were Tested For Communicable Diseases Using Pooled Specimens or Diagnostic Tests, which was published by FDA in January. FDA is currently discussing this issue internally and will provide further direction at a later date. AABB will post updates on the AABB Web site as they become available.

Background: AABB became aware that collection facilities and testing laboratories were interpreting manufacturer’s instructions in package inserts for HIV-1 and HCV NAT for HCT/P donors differently than FDA. As a result of these differing interpretations, some samples from donors of HCT/Ps were tested by individual sample, and others were tested in pooled samples. To address this issue, AABB partnered with other stakeholders in the field and sent a letter to FDA in November 2005 outlining their concerns.

The stakeholder organizations and testing laboratories worked together to collect and analyze testing data that could be used to compare infectious disease prevalence rates of HPC donors to donors of other blood components, which are already tested in pools. The goal of the project was to support the performance of pooled NAT prospectively/retrospectively. During the January 2006 FDA Liaison Meeting for Cellular Therapy, the data summary was presented to FDA representatives. After incorporating additional details and clarifications, this data analysis was completed and submitted to FDA by the test kit manufacturers.