Autologous mixed lymphocyte reaction in patients with Hodgkin's disease. Evidence for a T cell defect

The proliferative response of T lymphocytes cultured with autologous non-T lymphocytes is known as the autologous mixed lymphocyte reaction (MLR). This reaction can be demonstrated reproducibly in healthy individuals and has been shown to generate specific cytotoxic T cells, as well as T cells that regulate antibody synthesis and cell-mediated immunity. In this study, we demonstrate that the autologous MLR is impaired or absent in most patients with Hodgkin's disease regardless of age, sex, pathologic stage, or histologic classification. In 64 patients, the mean autologous MLR was 3,084+/-1,878 cpm compared to 16,552+/-6,532 in 29 healthy donors. A defect in autologous MLR was observed in newly diagnosed patients before the initiation of therapy, but was also found in patients without evidence of recurrent disease up to 15 yr after treatment. These findings could not be explained by abnormal kinetics or poor viability of stimulator or responder cells. The possibility that suppressor cells are responsible for the reduction of T cell autoreactivity was examined by comparing the autologous MLR of a healthy HLA-identical sibling in the presence and absence of T or non-T cells of an affected sibling. No inhibitory effects were observed. Similarly, substitution of patient plasma for pooled AB serum failed to inhibit the autologous responses of normal donors. Increasing the number of responder T cells in the culture or removing adherent cells from the stimulator population enhanced autoreactivity in some patients, indicating that the defect is not absolute. In two families, T cells of healthy HLA-A, B, and DR-identical siblings of patients responded normally to the non-T cells of their affected siblings, whereas patients' T cells failed to respond both to their own stimulator cells and those of their healthy HLA-identical siblings. These data indicate that the impairment of autologous MLR in some patients is due to a reduction or dysfunction of responder T cell activity and not to a defect of autologous stimulator cells.