Matching for TNF microsatellites is strongly associated with matching for other non-HLA MHC sequences in unrelated bone marrow donor-recipient pairs

The use of unrelated donors for bone marrow transplantation is associated w ith an increased morbidity and mortality when compared with HLA identical s iblings. We have demonstrated previously that matching of unrelated donors and recipients for TNFa microsatellites is correlated with lower CTLp frequ encies. Matching of unrelated donors and recipients for other non-HLA seque nces in thr major histocompatibility complex has been reported to result in less graft-versus-host disease and improved survival. It has been argued t hat matching for non-HLA sequences in the MHC in addition to the HLA genes themselves results in matching for the entire MHC and is therefore the equi valent of providing an HLA identical sibling donor. In order to test this h ypothesis we have examined TNFa microsatellites of unrelated donor recipien t pairs in whom matching for HLA loci, non-HLA sequences near HLA B (beta-b lock markers) and non-HLA sequences near DRB1 (delta-block markers) had bee n det ermined. All 17 patients who were matched for HLA and non-HLA markers were also matched for TNF microsatellites. This data supports the idea tha t matching for HLA genes and non-HLA markers results in matching at all oth er loci in the MHC. (C) American Society for Histocompatibility and Immunog enetics, 1999. Published by Elsevier Science Inc.