Inhibition of antibody-dependent cell-mediated cytotoxicity by ethanol.

Ethanol has been shown to inhibit spontaneous cell-mediated cytotoxicity and antibody-dependent cell-mediated cytotoxicity in vitro in a dose-dependent manner. The effect was observed under differing assay conditions such as incubation time and effector: target cell ratio. Acetaldehyde, the primary metabolite of ethanol, did not inhibit these functions of the immune system. A mixture of ethanol and acetaldehyde showed no interaction with respect to spontaneous and antibody-dependent cell-mediated cytotoxicity. These observations may help to explain the apparently increased incidence of infection for individuals who chronically ingest large amounts of alcoholic beverages.