Chronic alcohol exposure appears to suppress cell-mediated immunity wh
ich may contribute to the high incidence of infections among alcohol-d
ependent patients. We measured serum neopterin, as a marker of macroph
age function and T-lymphocyte activation, in 26 alcohol-dependent pati
ents. The mean serum neopterin in these patients was significantly low
er than the mean serum neopterin in matched controls. In those who abs
tained, the mean serum neopterin at 3 weeks rose and was no longer sig
nificantly different from controls. Our findings suggest that alcohol-
dependent patients have suppressed macrophage function which may be re
versible within 3 weeks of abstention.