Cytomegalovirus immunity and T lymphocytes in bone marrow donors and acute graft-versus-host disease.

T lymphocyte subset numbers in bone marrow grafts were correlated with the cytomegalovirus (CMV) antibody status of the donors and with the occurrence of acute graft-versus-host disease (GVHD) in their recipients. We studied whether or not the (previously reported) association between donor CMV antibodies and GVHD could be explained by CMV-related changes in T cell subsets in the marrow grafts. There were no significant correlations between any of the T cell subsets in the marrow grafts and the occurrence of grades II-IV GVHD. A particular subset of CD8+ T cells carrying the HNK1 marker was significantly increased in the marrow grafts of CMV-seropositive donors. Although recipients of marrow from CMV-seropositive donors received an average of five times more CD8+ HNK1+ T cells than those with CMV-seronegative donors, that situation was not associated significantly with the development of GVHD.