A large-scale study of 8,003 unrelated donor myeloablative transplants between 1999 and 2011 has demonstrated that high-resolution matching at HLA-A, -B, -C, -DRB1 yields optimal survival. This retrospective study analyzed adult and pediatric HCT recipients with AML, ALL, CML, or MDS whose outcomes were reported to CIBMTR (Center for International Blood and Marrow Transplant Research). A single or double HLA mismatch (6/8 or 7/8) resulted in significantly increased risk for grade II-IV and III-IV acute GVHD, chronic GVHD, transplant-related mortality, and overall mortality compared to HLA-matched cases (8/8). The authors noted, however, that 7/8 matched donors should be considered an acceptable option for patients without 8/8 matched donors.
High-Resolution HLA-A, -B, -C, -DRB1 Matching Yields Optimal Survival in Unrelated HCT