A modified method for the assay of carbohydrate-deficient transferrin (CDT) in serum.

CDT has been shown to be a good marker of regular high alcohol intake. It has been measured principally by isoelectric focusing or pH-based anion exchange chromatography. The present assay was developed to improve the technical stability of the latter method. It is based on anion exchange of serum using ionic strength instead of pH followed by a transferrin in RIA of isotransferrins with pI > 5.7. Two hundred and fifty-one individuals were examined. With the exception of a new inborn error of glycoprotein metabolism, the sensitivity for alcohol abuse was 94% and the specificity was 98%. The values correlated with the total amount of alcohol recently consumed and normalized with a mean t1/2 of 15 days.