The effect of acute alcohol ingestion on Fc-receptor-mediated clearance of IgG-tagged erythrocytes by the reticuloendothelial system in humans.

To help elucidate the pathogenesis of bacterial infections in alcoholics we documented reticuloendothelial system (RES) function in 14 healthy adults (9 males, 5 females, age: 22 +/- 2.6 years) prior to and following acute alcohol intoxication. Autologous erythrocytes were labelled with Cr51 isotope, tagged with anti-Rh IgG antibody, and infused into the systemic circulation. Blood samples were drawn at specific time intervals over a 2-h period and the radioactivity in each sample was used to develop computer-generated clearance curves from which half-lives (T1/2) were derived. Each study was carried out in the same individual on two separate occasions at least two weeks apart, once when sober and again one hour after ingestion of an intoxicating amount of alcohol (1 gm/kg over 1 h). Eleven of 14 participants showed no appreciable change in RES clearance capacity following alcohol ingestion. In the remaining three individuals alcohol prolonged the T1/2 by 38%, 38%, and 74% from when sober. These individuals were similar to other participants in terms of age, blood alcohol levels, pre- and postalcohol liver biochemistry, and hematologic and immunologic findings. Two of the three were HLA Dr5 positive, as compared to none of the 11 with unimpaired clearances. The results of this study suggest that perhaps a small subset of the population exists in whom acute alcohol intoxication impairs Fc-receptor-mediated RES clearance of IgG-tagged erythrocytes from the systemic circulation. This depression of RES function could contribute to the increased frequency and severity of bacterial infections reported in some alcoholics.