Use of cryopreserved hematopoietic stem cell grafts during the onset of the COVID-19 pandemic had no impact on patient overall survival (OS) compared with fresh grafts during the first year after transplant, according to research published in Blood Advances.

“At the outset of the [COVID-19 pandemic], substantial risks arose with the use of fresh donor products,” the study authors explained. “The National Marrow Donor Program, along with several other global donor registries, imposed a temporary requirement for cryopreservation of most unrelated donor products during the first six months of the pandemic.”

The researchers used the Center for International Blood and Marrow Transplant Research (CIBMTR) outcomes database to assess the impact of cryopreserved allografts on patients receiving hematopoietic cell transplantation (HCT) at US transplant centers during the first 6 months of the COVID-19 pandemic. The primary endpoint was 1-year OS following HCT.

Continue Reading

The analysis compared 1543 recipients of cryopreserved allografts (median age, 58 years; range, 0-82) and 2499 recipients of fresh allografts (median age, 55 years; range, 0-79).

Multivariable regression analysis showed no significant difference between recipients of cryopreserved allografts compared with recipients of fresh allografts in OS (hazard ratio [HR], 1.12; 95% CI, 0.98-1.28; P =.09), nonrelapse mortality (HR, 1.01; 95% CI, 0.84-1.22; P =.89), acute graft vs host disease (GVHD; Grade II-IV: HR, 1.11; 95% CI, 0.99-1.24; P =.064; Grade III-IV, 0.93; 95% CI, 0.76-1.13; P =.45), or GVHD-free, relapse-free survival (HR ,1.03; 95% CI 0.93-1.14; P =.58).

However, the analysis also revealed lower disease-free survival (DFS) in the group receiving cryopreserved allografts (HR, 1.18; 95% CI, 1.05-1.33; P =.006) due to a higher risk of relapse (HR, 1.21; 95% CI, 1.04-1.41; P =.01). It also showed that primary graft failure was higher (odds ratio, 1.48; 95% CI, 1.10-2.00; P =.01) and the risk of chronic GVHD was lower (HR, 0.65; 95% CI, 0.50-0.84; P =.001) with cryopreserved allografts.

“[The findings] indicate that fresh grafts should be the first choice given the negative impact of cryopreservation on hematopoietic engraftment, relapse, and DFS as well as the small risk that donor grafts may go unused. However, cryopreservation is a reasonable alternative to a fresh donor product when safety and logistical challenges may dictate the decision for one versus the other,” the researchers wrote in their report.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of authors’ disclosures. 


Devine SM, Bo-Subait S, Kuxhausen M, et al. Clinical impact of cryopreservation of allogeneic hematopoietic cell grafts during the onset of the COVID-19 pandemic. Blood Adv. Published online April 10, 2023. doi:10.1182/bloodadvances.2023009786