High-resolution typing for unrelated donor transplantation: how far do we go?

For best results with unrelated donor transplantation of acute myeloid leukaemia (AML) patients, high-resolution typing should be completed for human leucocyte antigens (HLAs) A, B, C and DR. In the absence of an HLA-identical sibling, an unrelated adult donor, fully matched or with a single mismatch at these loci, should be used. If such a donor is not available in a timely manner, cord blood mismatched at one or two loci may be used. Data also suggest that peripheral blood transplantation may be more permissive of HLA mismatching than bone marrow transplants. Transplant decisions should be based on several factors, including availability of matched donors, as well as patient age, performance status and disease stage.