Suppressor function of T lymphocytes in the acquired immunodeficiency syndrome as assessed by allogeneic mixed lymphocyte culture.

Nine patients with the acquired immunodeficiency syndrome (AIDS) were studied for suppressor cell activity utilizing an allogeneic mixed lymphocyte culture technique. The patients studied had opportunistic infections and a high incidence of intravenous drug abuse. T lymphocytes of the AIDS patients showed a consistently greater ability to suppress immunoglobulin M (IgM) synthesis by pokeweed mitogen stimulated allogeneic lymphocytes compared to controls (p less than 0.03). In 4 patients, T helper function was studied and compared to controls. Diminished helper cell function was consistently observed (p less than 0.01). All AIDS patients had leu 3a/leu 2a ratios of less than 0.9. However, a statistical correlation between the helper/suppressor cell ratio and suppressor activity was not demonstrated. Functional tests of T lymphocytes may be of value in assessing immunocompetence in patients with altered lymphocyte subset ratios.