Impact of pretransplant donor-specific anti-HLA antibodies on cord blood transplantation on behalf of the Transplant Complications Working Group of Japan Society for Hematopoietic Cell Transplantation.

Graft failure (GF) remains a major complication of cord blood transplantation (CBT). Although the presence of pretransplant, donor-specific anti-HLA antibodies (DSA) was reported to be associated with an increased risk of GF after CBT, data are still limited. Thus, we conducted a retrospective analysis of recipients of single-unit CBT with pretransplant anti-HLA antibodies using the database of Japan Society for Hematopoietic Cell Transplantation (JSHCT). Data for recipients of single-unit CBT with pretransplant anti-HLA antibodies from 2010 to 2014 were obtained. In total, 343 patients who received CBT and who had detailed information about anti-HLA antibodies were included. The median age was 51 years (range, 0-71). Regarding DSA, 25 patients had a mean fluorescence intensity (MFI) ≥ 1000 (DSA-positive group) and 318 patients had a MFI <1000 (DSA-negative group). The cumulative incidence of neutrophil engraftment at 60 days after CBT was 75.7% (95% CI, 70.6-80.1) in the DSA-negative group and 56.0% (95% CI, 34.1-73.1) in the DSA-positive group (P = 0.03). In conclusion, pretransplant DSA with a MFI ≥ 1000 was associated with an increased risk of GF in single-unit CBT.