Survival after bone marrow transplantation from cytomegalovirus seropositive sibling donors

HLA-A2-restricted T cells show peptide-specific activity against cytomegalovirus and leukaemia cells. We retrospectively analysed the influence of donor cytomegalovirus serostatus on the outcome of 103 consecutive patients who had leukaemia and who received bone-marrow transplants from HLA-identical sibling donors. We found that donor cytomegalovirus seropositivity significantly improved overall survival (p=0.02) as a result of lower relapse incidence (p=0.035) in HLA-A2-positive but not HLA-A2-negative recipients. In HLA-A2-positive recipients donor cytomegalovirus seropositivity was associated with chronic graft-versus-host disease (GVHD), but even in patients without chronic GVHD donor cytomegalovirus seropositivity significantly improved survival (p=0.0483). These preliminary data provide evidence that at least in HLA-A2-positive recipients, transplantation of bone marrow from cytomegalovirus positive, HLA-identical sibling donors seems to be associated with substantial graft-versus-leukaemia activity, and suggests a cross-reactivity of cytomegalovirus-specific donor-derived cytotoxic T cells with HLA-A2-restricted recipient minor histocompatibility antigens.