Abstract
INTRODUCTION: Barcelona Cord Blood Bank (BCBB) program started for CB units (CBU) donations in 1991. In 2002, Automated Volume-Reduced method was introduced applying the closed System (Sepax®, Cytiva). In order to ensure the quality of cryopreserved units after long-term storage, CBB programs evaluate cell recovery, progenitor cells functionality such as viability and Colony forming unit (CFU), and myeloid recovery after cord blood transplant (CBT). OBJECTIVES: This retrospective study investigated quality parameters of CBUs stored for 1-20 years processed by automated volume-reduced and cryopreserved and stored in Bioarchive® system, (Thermogenesis) showing the effect of cryopreservation on variables measured both pre- and post-thaw. Additionally, we analyzed engraftment after CBT transplantation according to CBU time storage. METHODS: CBUs used for transplantation between2002 to 2022 were included in the study. To evaluate the influence of long-term storage of cryopreserved CBUs, Kruskal-Wallis correlation test between quality variables was performed. We studied correlation between pre-cryopreservation and post-thaw values (recovery) of TNC and CD34+ counts, CD45+ and CD34+ viability, CFU and CFU-FM counts. Additionally, myeloid engraftment was evaluated categorizing whole population in 3 groups according CBU storage duration: short-term (≤ 2 years), medium-term (> 2 and ≤ 5 years) and long-term (> 5 years). RESULTS: A total of 1577 CBUs with a median of 3.9 (range 1.3-20 years) of cryopreservation storage were evaluated. The median of TNC and CD34+ recovery, CD45+ and CD34+ recovery, CFU and CFU-GM recovery were 81.7%, 79.9%, 54.4%, 73.3%, 58.2% and 26.5%, respectively. Analysis demonstrated a non-significance decreased in CD34+ counts recovery, infused CD34 + 7AAD-viability and CFU-GM counts (P = 0.12, P = 0.28 and P = 0.96, Figure 1), respectively. Neutrophil engraftment at 42 days after CBT was found significantly faster for short-term stored CBUs (98%; CI95%, 96-99%, P = 0.015, Figure 1). No significance difference was found in platelet engraftment at 60 days between CBUs storage time groups (P = 0.5). DISCUSSION: Most quality parameters results evaluating CBUs demonstrated no significance decrease up to 20 years of cryopreservation meaning likely successful clinical transplantation of CBUs following long-term storage. Long-term cryopreserved CBUs continue to fulfil release FACT-Netcord requirements. [Image: see text]