Higher Incidence of Hemorrhagic Cystitis Following Haploidentical Related Compared to Matched Related Donor Transplantation.

•Hemorrhagic cystitis occurs more frequently following haploidentical donor transplantation compared with matched related donor transplantation.•This higher frequency occurs despite the receipt of identical graft-versus-host disease prevention.•The grater susceptibility appears related to the inherent immune deficiency of HLA mismatch.