IgAs against acetaldehyde-modified red cell protein as a marker of ethanol consumption in male alcoholic subjects, moderate drinkers, and abstainers.

Background: Alcohol abuse has been shown to result in the production of antibodies against acetaldehyde-modified epitopes in proteins. However, as yet, only limited information has been available on the clinical usefulness of such responses as markers of hazardous drinking.

Methods: We developed an ELISA to measure specific IgAs against acetaldehyde-protein adducts. This method was evaluated in cross-sectional and follow-up studies on male heavy drinkers with a current ethanol consumption of 40 to 540 g/d (n=40), moderate drinkers consuming 1 to 40 g/d (n=25), and abstainers (n=16). The clinical assessments included detailed interviews on the amounts and patterns of ethanol consumption and various biochemical markers of alcohol abuse and liver function.

Results: The mean antiadduct IgAs (198+/-28 U/L) in the alcohol abusers were significantly higher than those in the moderate drinkers (58+/-11 U/L, p<0.001) or abstainers (28+/-8 U/L, p<0.001). The values of moderate drinkers were also higher than those in abstainers (p<0.05). The amount of ethanol consumed during the period of 1 month preceding blood sampling correlated strongly with antiadduct IgAs (r=0.67, p<0.001). The sensitivity (73%) and specificity (94%) of this marker were found to exceed those of the conventional laboratory markers of alcohol abuse in comparisons contrasting heavy drinkers with abstainers although not in comparisons contrasting heavy drinkers with moderate drinkers. During abstinence, antiadduct IgAs disappeared with a mean rate of 3% per day. In additional analyses of possible marker combinations, antiadduct IgAs, together with CDT, were found to provide the highest sensitivity and specificity.

Conclusions: Measurements of antiadduct IgAs may provide a new clinically useful marker of alcohol abuse, providing a close relationship between marker levels and the actual amounts of recent ethanol ingestion.