HLAs and risk of acute graft-vs.-host disease after marrow transplantation from an HLA-identical sibling.

We explored the relationship between individual human leukocyte antigens (HLAs) and the risk of acute graft-vs.-host disease (GVHD) after allogeneic marrow transplantation from HLA-identical siblings. If the repertoire of polymorphic peptides encoded by minor histocompatibility loci is limited such that certain major histocompatibility complex molecules might not present any peptides that cause GVHD, then certain HLA alleles should be associated with a relatively reduced risk of GVHD and others should be associated with a relatively increased risk. Contrary to results reported in previous studies, we found no convincing evidence for associations between HLA antigens and risk of acute GVHD after HLA-identical marrow transplantation. These results are consistent with the hypothesis that the variety of minor histocompatibility antigens is not constrained by the repertoire of peptides collectively encoded by minor histocompatibility loci.