Interleukin 2 production and responsiveness in individuals with acquired immunodeficiency syndrome and the generalized lymphadenopathy syndrome.

Proliferative responsiveness to, and production of, interleukin 2 (IL-2) was determined in 9 homosexually active men with the acquired immunodeficiency syndrome (AIDS) and in 28 homosexually active men with the persistent generalized lymphadenopathy syndrome (PGL). All were seropositive for antibody to human T-lymphotrophic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV). Purified T lymphocytes from individuals with AIDS and PGL had a significantly decreased (P less than 0.01) proliferative response to a saturating amount of exogenous, purified IL-2 as compared to seronegative male controls. Similarly, T4+-enriched T lymphocytes also had a significantly decreased proliferative responsiveness to IL-2 (AIDS, P less than 0.05; PGL, P less than 0.005). T8+-enriched T lymphocytes from individuals with AIDS or PGL did not suppress the IL-2-induced proliferation of autologous T4+ T lymphocytes. In addition, production of IL-2 was significantly decreased in the AIDS group (P less than 0.01) and the PGL group (P less than 0.005) with median values of IL-2 produced being 0.1 and 1.0 U/ml, respectively, compared to 9.9 U/ml for control. These findings demonstrate that substantial quantitative and qualitative abnormalities of the IL-2-T-lymphocyte system exist in patients with AIDS as well as in relatively healthy individuals with PGL. These defects are likely important contributing factors to the depressed T-lymphocyte functions commonly observed in HTLV-III/LAV-associated diseases.