Gamma-interferon production capacity and T lymphocyte subpopulation after allogeneic bone marrow transplantation

T cell phenotypes after bone marrow transplantation (BMT) were investigated using monoclonal antibodies (moAbs) reactive to lymphocyte cell surface antigens. Patients' T cells showed decreased percentages of OKT4, 4A and 9.3-positive T cells, and increased percentages of OKT8, human Ia, and Leu-7-positive T cells. These changes in T cell phenotype persisted for a long period after BMT and had no correlation with the occurrence of graft-versus-host disease (GVHD). No lymphocyte activation antigens such as TIA (Tac) or transferrin receptor (5E9) were detected after BMT. The capacity of the patients' lymphocytes to produce gamma-interferon (IFN-gamma) was measured after incubation of lymphocytes with mitogen. Patients' lymphocytes produced significantly lower levels of IFN-gamma than the normal controls. This failure of IFN-gamma production showed no correlation with stimulation index of mitogen blastogenesis or changes of T cell population. Thus, not only T cell phenotype but also measurement of IFN-gamma production of lymphocyte may be useful in detecting immunological abnormalities in patients who receive BMT.