Transferrin and mitochondrial aspartate aminotransferase in young adult alcoholics

Two recently proposed biochemical markers of alcoholism, namely, quantitation of plasma transferrin variant (Tf5.7) and the ratio of plasma mitochondrial aspartate aminotransferase (m-AspAT) to total AspAT (t-AspAT), were tested for their ability to detect young adult alcoholics. Another commonly used biochemical test, namely, activity of plasma gamma glutamyltransferase (GGT) was included as a comparison. Although mean values of GGT, TF5.7, total transferrin (Tftot), m-AspAT and t-AspAT in alcoholics were significantly higher than those in controls, there were too many overlapping values in each test between alcoholics and controls to render any of these tests suitable as a marker for young adult alcoholics. Depending on cut-off limits, the sensitivity of each test ranged from 0-52% and the specificity ranged from 80-97%. Moreover, the m-AspAT/t-AspAT and Tf5.7/Tftot ratios were not significantly different between alcoholics and controls. A stepwise linear discriminant function analysis of all the variables resulted in a slight increase in classification sensitivity (66%) but a decrease in specificity (77%). The relatively short duration (mean = 5.6 years) of heavy alcohol intake and the time elapsed (mean = 5.8 days) since the alcoholics last consumed alcohol very likely contributed to the low sensitivity. Young adults might also be more resilient with regard to the damaging biochemical effects of ethanol. Abnormal biochemical values might reverse to normal values much more quickly in young adult alcoholics than in those who are older and have more years of alcohol abuse.