Bankova AK, Caveney J, Yao B, et al. Real-World Experience of Cryopreserved Allogeneic Hematopoietic Grafts in the COVID-19 Pandemic: A Single Center Report. Transplantation and Cellular Therapy. 2022; (doi: 10.1016/j.jtct.2022.01.010).
A single-center comparison between cryopreserved and fresh allografts in allogeneic hematopoietic cell transplantation (allo-HCT) showed the recipients of cryopreserved products had delayed engraftment and tended to be clinically inferior, leading to higher primary graft failure (GF) rates and worse overall survival (OS) and relapse-free survival (RFS) compared to fresh allograft products. Cryopreservation of allogeneic donor apheresis products was undertaken due to the COVID-19 pandemic in an effort to alleviate the challenges of both donor availability and product transport. For their retrospective study, researchers compared the outcomes of 30 patients who received cryopreserved allografts between March and August 2020 with those of 60 patients who received fresh allografts before the pandemic. Recipients of cryopreserved reduced intensity conditioning (RIC) allo-HCT saw delayed neutrophil and platelet recovery compared with fresh allograft recipients, with median times to engraftment of 24 days vs 18 days and 27 days vs 18 days, respectively. Primary GF was seen in four (13.3%) of the patients receiving cryopreserved allografts had primary GF compared and one (1.7%) of the patients who received fresh allografts. Substantially lower median total, myeloid, and T-cell donor chimerism were associated with cryopreserved RIC allo-HCT at one month. Cryograft recipients had lower OS and RFS, with hazard ratios of 2.16 and 1.90, respectively. An extended immunophenotype analysis involving 14 samples from the cryopreserved cohort and 6 prospectively collected fresh apheresis donor samples revealed lower total cell viability and significantly fewer natural killer cells (CD3-CD56+) in the cryopreserved samples.