Impaired autologous and allogeneic mixed lymphocyte reaction in human marrow transplant recipients

The autologous and allogeneic mixed lymphocyte reactions of enriched T to non-T cells from 54 allogeneic marrow recipients were studied. Reactivity of cells from almost all patients was severely impaired when compared with those from their marrow donors. There were no differences between lymphocyte responses of patients with and without graft-versus-host disease. However, in the autologous mixed lymphocyte reaction the impairment was more severe in cells from short-term than in those from long-term patients. Coculture experiments using enriched T or non-T cells from patients mixed with T or non-T cells from their respective marrow donors indicated that the impairment resided primarily in the responding T cells, partially in stimulating non-T cells, and perhaps also in the interactions of T and non-T cells. In the allogeneic mixed lymphocyte reaction, T cells from patients showed defective responses to normal allogeneic non-T cells. Their non-T cells, however, often had normal allogeneic stimulating capacity.