Donor Characteristics Affecting Graft Failure, Graft-versus-Host Disease, and Survival after Unrelated Donor Transplantation with Reduced-Intensity Conditioning for Hematologic Malignancies

We examined the effect of donor characteristics on graft failure (<5% donor chimerism within 3 months after transplantation), acute and chronic graft-versus-host disease (aGVHD, cGVHD), and survival after unrelated donor reduced-intensity conditioning (RIC) transplantation in 709 patients with hematologic malignancies. Donor recipient pairs were HLA typed at HLA-A, -B, -C, and -DRBI (allele-level). A total of 501 patients were >95% donor chimerism, 145 patients were 5% to 95%, and 63 patients were <5%. The only donor characteristic associated with transplantation outcome was donor recipient HLA matching. One- or 2-loci mismatched transplants led to higher grade 2-4 (relative risk [RR] = 1.27, P =.035) and grade 3-4 (RR = 1.85, P <.001) aGVHD and 2-loci mismatched transplants higher mortality (RR = 2.22, P <.001). Graft failure was higher after transplantation of bone marrow (RR = 2.33, P =.002). Donor age, parity, and donor sex match were not associated with transplantation outcome. Donor recipient HLA matching is the only donor characteristic predictive for survival after RIC regimens for hematologic malignancies. Biol Blood Marrow Transplant 17: 1869-1873 (2011) (C) 2011 American Society for Blood and Marrow Transplantation