Patients with the acquired immunodeficiency syndrome (AIDS) are susceptible to a variety of opportunistic pathogens which require intact cellular immunity for control and eradication. We evaluated interleukin 1 and 2 production in 12 homosexual men without AIDS but with evidence of altered cell-mediated immunity and serologic evidence of infection with human T-cell lymphotrophic virus type III (HTLV-III), the etiologic agent of AIDS and found production of both factors diminished compared to heterosexual controls. Therafectin (SM-1213) is a new agent which selectively activates macrophages and stimulated interleukin 1 production in vitro. Therafectin was administered to these same 12 patients in a double-blind, placebo controlled trial. We failed to find any significant changes in their immunologic status including interleukin 1 or 2 production.