ACUTE ALCOHOL-INTOXICATION SUPPRESSES NATURAL-KILLER-CELL ACTIVITY AND PROMOTES TUMOR-METASTASIS

Alcohol consumption is associated with increased morbidity and mortali ty related to infectious diseases and malignancy(1-5), although immune mediation of these relationships is controversial. Specifically, the activity of natural killer (NK) cells, which are involved in the resis tance to infections and metastasis, can be suppressed in the presence of ethanol in vitro. However, acute consumption or infusion of ethanol in vivo exerts no effects on NK activity assessed in vitro thereafter . Therefore, we have developed and used a method to study the effects of ethanol on NK activity in living rats by using an NK-sensitive meta static process and selective depletion of NK cells in vivo. Acute etha nol intoxication caused a-marked suppression of NK activity in vivo an d a tenfold increase in the number of MADB106 tumor metastases. Ethano l had no effect in rats selectively depleted of NK cells or when an NK -insensitive tumor (C4047) was used. These findings suggest that even acute ethanol intoxication markedly suppresses NK activity in the livi ng organism. This suppression may underlie some aspects of the associa tion between alcoholism, infectious disease and malignancies.