We studied the effect of HLA-C matching in 515 patients after double umbilical cord blood (UCB) transplantation. After HLA matching HLA-A, -B, and -DRB1 at the allele level, we scored patients according to number of donor-recipient HLA-C matches at 4 possible loci: 2 from each donor unit, at the allele level. Given a direct interaction between HLA-A, -B, and -DRB1 matching and HLA-C score, we analyzed HLA-C matching in those receiving at least 1 2/6 to 4/6 HLA–matched unit (n = 389) versus those receiving only 5/6 or 6/6–matched units (n = 126). In those with at least 1 2/6 to 4/6 HLA–matched unit, a better HLA-C matching score was associated with significantly lower risk of death of any cause and nonrelapse mortality and better disease-free survival. There was no association with the risk of relapse, acute and chronic graft-versus-host disease, and hematopoietic recovery. In contrast, among patients receiving only allele-level 5/6 or 6/6 HLA–matched UCB units, HLA-C match had no demonstrable effect on any outcome. For patients receiving at least 1 allele-level 2/6 to 4/6 HLA–matched UCB unit, matching at HLA-C reduces nonrelapse mortality and improves survival.
Brunstein, C. G., Cutler, C. S., DeFor, T. E., Kim, H., Bejanyan, N., Garfall, A., … Ballen, K. K. (2017). Matching at Human Leukocyte Antigen-C Improved the Outcomes after Double Umbilical Cord Blood Transplantation for Recipients of Two to Four of Six Human Leukocyte Antigen–Matched Grafts. Biology of Blood and Marrow Transplantation, 23(1), 126–133. https://doi.org/10.1016/j.bbmt.2016.10.018