Severe T lymphocyte immunodeficiency associated with hypogammaglobulinemia: defective lymphokine secretion but enhanced autologous mixed lymphocyte reaction.

The multiparameter immunologic study of T cells of a patient with acquired hypogammaglobulinemia was investigated, since he had a normal B-cell number and function. His peripheral blood lymphocytes were found to contain predominant CD4+ CD45R+ T cells with a clear deficiency of CD4+ CDw29+ as well as CD8+ T cells. His T cells proliferated in response to phytohemagglutinin (PHA) and pokeweed mitogen (PWM), but no immunoglobulin was secreted in PWM-induced patient's T-cell and normal B-cell differentiations. His T cells were also found to possess concanavalin A (Con A)-induced suppressor function when cocultured with normal T cells, as well as IgG-, IgA-, and IgM-specific suppressor function on PWM-induced normal T- and B-cell differentiations. The patient's T cells were found to secrete elevated amounts of interleukin-2 but failed to secrete two important B-cell stimulating factors, B-cell growth factor and B-cell differentiation factor, in response to PHA. An investigation of immunoregulatory T-cell function in the autologous mixed lymphocyte reaction (AMLR) and allogeneic mixed lymphocyte reaction (MLR) indicated that the patient's T cells produced an enhanced AMLR but were deficient in MLR. These results suggest that the abnormalities we have identified in this patient with hypogammaglobulinemia reflect an intrinsic defect of T cells in the humoral immune response to produce three major immunoglobulins.