RELATIONSHIP BETWEEN ALCOHOL INTAKE AND IMMUNOGLOBULIN-A IMMUNOREACTIVITY WITH ACETALDEHYDE-MODIFIED BOVINE SERUM-ALBUMIN

Acetaldehyde, the main metabolite of ethanol, is a highly reactive spe cies that reacts with macromolecules to produce unstable and stable ad ducts. Acetaldehyde-modified proteins are immunogenic and have been de tected in the liver and blood of alcoholics. Furthermore, antibodies r eactive with acetaldehyde-modified proteins have been detected in the plasma of social drinkers and alcoholics. However, the class distribut ion of immunoglobulins reactive with modified proteins was different i n the two groups, being predominantly immunoglobulin (Ig)M in social d rinkers, but IgM and IgA in alcoholics. In this study, we demonstrate that heavy drinkers (alcohol intake >130 g/week for females and 150 g/ week for males) also exhibit IgA reactivity with acetaldehyde-modified proteins. The IgA adduct-specific reactivity (IgA reactivity with ace taldehyde-modified bovine serum albumin-reactivity with native bovine serum albumin) showed a moderate correlation with self-reported alcoho l intake, but did not correlate with markers such as plasma transamina se, gamma-glutamyltransferase activity, or mean corpuscular volume. Ig A adduct-specific reactivity had similar specificity to the convention al tests of alcohol abuse, but had higher sensitivity than the other t ests, especially with heavy drinkers. Data presented herein demonstrat e that elevated IgA reactivity with acetaldehyde-modified epitopes is associated with heavy drinking and is a potential marker for high alco hol intake.