Publication Date:
2016-12-02
Description:
Cryopreserved HPC, CB products are maintained in long-term storage for future clinical use. To evaluate the impact of cryopreservation and storage over time on the quality and potency of the CBU as well as fulfill the FDA requirements for licensed products, stability studies are performed annually. These in vitro studies compare CBU stored for several years to recently processed ones with respect to HPCrecovery, potency, bacteriology, identity and integrity. This analysis summarizes the 2010-2015 annual stability evaluations including45 clinical CBU randomly selected among those processed by NCBP during the period 2006-2015 and stored inBioArchivefreezers.Pre-cryopreservation results, i.e., tests performed prior to freezing after CBU processing with the AXP system, are compared to post-thaw values of the CBU bag, and those of the CBU segment. We also present the quality assessment of segments (N=1924) of CBU processed during the same period that were released for transplantation. Methods:CBU bags were thawed and underwent albumin dextran reconstitution (dilution 1:7).Total nucleated cell (TNC) counts were measured in aSysmexXE2100 analyzer. CD45+/CD34+ counts and viability were evaluated using single platform, 3-color flow cytometry with 7-AAD, and ISHAGE gating strategy.CFU assays were evaluated using the NCBP CFU strategy (Albano et al, ASH 2008).The same assays were used for segment evaluation. Recovery was expressed as the ratio of post-thaw to pre-cryopreservation values. The segment "yield" was calculated as the ratio of segment results to the pre-cryopreservation or post-thaw bag values. Results: All CBU met acceptance criteria for identity, sterility and container integrity. Post-thaw CBU bag TNC recovery averaged 100.5% (SD: 6.2%). The range was 87%-114.5%; only one sample had recovery below 90%. TNC was not measured routinely in the segments. Average post-thaw bag CD34+ viability was 93.1% (SD: 3.2%). While the lowest value was 83.5%, 41/45 samples had viability above 90%. Segment post-thaw mean CD34+ viability was 94.7% (SD: 3.8%); 42 samples had values above 90%. The difference between segment and bag averaged 1.6% (SD: 2.5%; range: -3.1% to 7.5%). This change was statistically significant but too small to impact product quality. CD34+ and CFU recoveries (mean and SD) are shown in the Table. Post-thaw recovery of viable (v) CD34+ cells from theCBUbag ranged 60-133%, while the segment yield was 48-106%. For the 30 CBU with pre-cryopreservation CFU results, mean CBU bag recovery was 71% (range: 34%-120%) and segment CFU yield was 75% (range: 23%-125%). Segment and bag CD34+ and CFU results correlated well (p
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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