This retrospective, large-scale study examined the effect of HLA match on reduced-intensity, unrelated donor transplantation. Researchers analyzed the outcomes of 2,588 transplants between 1999 and 2011 reported to CIBMTR (Center for International Blood and Marrow Transplant Research), and found that adjusted 1- and 3-year overall survival was better in 8/8 vs. 7/8 HLA-matched recipients: 54.7% vs. 48.8%, p=0.01; and 37.4% vs. 30.9%, p=0.005, respectively. They found no difference in rates of relapse and incidence of chronic GVHD between the HLA-matched and the single-locus HLA-mismatched transplants. The researchers concluded that while feasible, single-locus mismatch in reduced-intensity unrelated donor HCT is associated with inferior outcomes.
Verneris MR, et al. Biol Blood Marrow Transplant