Impaired antibody-dependent cell-mediated cytotoxic activity in patients with the acquired immunodeficiency syndrome

Since the acquired immunodeficiency syndrome (AIDS) is characterized by opportunistic infections and malignancies indicative of a profound suppression in cell-mediated immunity, we investigated the antibody-dependent cell-mediated cytotoxicity (ADCC) of peripheral blood mononuclear cells of patients with AIDS against chicken red blood cells (CRBC). A marked decrease in ADCC-CRBC activity was observed from patients with AIDS as compared to healthy controls. Furthermore, suppression in ADCC activity was seen when mononuclear cells from healthy subjects were assayed using media containing 25% or 40% sera from AIDS patients. Two of two patients with AIDS and impaired ADCC-CRBC activity were also found to have in vivo impaired reticuloendothelial system Fc-specific clearance of 51Cr-labelled, anti-Rho (D) IgG-sensitized autologous erythrocytes. These data provide further evidence of monocyte-macrophage dysfunction in AIDS and help explain the widespread occurrence of opportunistic pathogens in AIDS.