Hematopoietic cell transplantation with cryopreserved grafts for severe aplastic anemia

Eapen, Mary; Zhang, Mei-Jie; Tang, Xiao-Ying; Lee, Stephanie J.; Fei, Ming-Wei; Wang, Hai-lin; Hebert, Kyle M.; Arora, Mukta; Chhabra, Saurabh; Devine, Steven M.; Hamadani, Mehdi; D'Souza, Anita; Pasquini, Marcelo C.; Phelan, Rachel; Rizzo, J. Douglas; Saber, Wael; Shaw, Bronwen E.; Weisdorf, Daniel J; Horowitz, Mary M.

The COVID-19 pandemic and the ensuing barriers to the collection and transport of donor cells, it is often necessary to collect and cryopreserve grafts before initiation of transplant conditioning. The effect on transplant outcomes in non-malignant disease is unknown. This analysis examined the effect of cryopreservation of related and unrelated donor grafts for transplantation for severe aplastic anemia in the US during 2013-2019. Included are 52 recipients of cryopreserved grafts who were matched for age, donor type, and graft type to 194 recipients who received non-cryopreserved grafts. Marginal Cox regression models were built to study the effect of cryopreservation and other risk factors associated with outcomes. We recorded higher 1-year rates of graft failure (HR 2.26, 95% CI 1.17 – 4.35, p=0.01) and of 1-year overall mortality (HR 3.13, 95% CI 1.60 – 6.11, p=0.0008) after transplantation of cryopreserved compared to non-cryopreserved grafts with adjustment for sex, performance score, comorbidity, cytomegalovirus serostatus, and ABO blood group match). Acute and chronic GVHD did not differ between groups. Adjusted probabilities of 1-year survival were 73% (95% 60 – 84) and 91% (95% CI 86 – 94) with cryopreserved and non-cryopreserved grafts, respectively. These data support the use of non-cryopreserved grafts, when possible, for severe aplastic anemia.