The association of de novo anti-HLA-DPB1 donor-specific antibody formation and primary graft failure after allogeneic hematopoietic cell transplantation.

Despite advances in HLA matching, graft failure remains a serious complication after allogeneic hematopoietic cell transplantation (HCT). Pre-formed anti-HLA donor-specific antibodies (DSAs) have been associated with graft failure, but the impact of newly developing (de novo) anti-HLA antibodies on HCT outcomes remains unknown. Here, we present the first reported case of graft failure associated with de novo anti-HLA-DPB1 DSA after a 10/10 matched unrelated donor HCT. Based on this observation, testing for DSA should be considered in case of unexplained pancytopenia after allogeneic transplantation, especially after reduced intensity conditioning.