The autologous mixed lymphocyte reaction in systemic lupus erythematosus

The autologous mixed lymphocyte reaction (AMLR) represents the proliferation of T cells in response to signals from autologous non-T cells. Fractionation of the non-T population into B enriched and macrophage enriched cells demonstrated that both could serve as effective stimulator cells in the AMLR. Cytolytic treatment of both populations with a macrophage specific, monoclonal antibody abrogated stimulation of the macrophage but not the B cell population. Utilizing a series of negative selection procedures - cytolysis with T cell specific monoclonal antibody, metabolic suicide with 5-bromo-2-deoxyuridine (brdU) and light - it could be demonstrated that T cells responding to autologous macrophage were distinct from those responsive to autologous B cells. Studies of the AMLR reactivity to B cells and macrophage in a small number of patients with active systemic lupus erythematosus (SLE) demonstrated that although reactivity to both populations was diminished, the response to autologous B cells was reduced more than the response to autologous macrophage. These studies suggest that the AMLR represents the sum reactivities of two responder T cells. Moreover, they suggest that a relatively selective deficiency in only one of these cells may occur in SLE.