Clinical characteristics of carbohydrate-deficient transferrin (%disialotransferrin) measured by HPLC: sensitivity, specificity, gender effects, and relationship with other alcohol biomarkers.

AIMS: The sensitivity and specificity of the relative disialotransferrin amount (%DST), considered the primary single target for measurement of the alcohol biomarker carbohydrate-deficient transferrin (CDT), were compared with the absolute CDT amount determined by the CDTect assay and with GGT and AST.

METHODS: Serum samples (n = 1387) were collected within the WHO/ISBRA Study on State and Trait Markers of Alcohol Use and Dependence. The subjects had been classified as "nondrinkers" (26%), "light/moderate drinkers" (50%), or "heavy drinkers" (24%) by use of the WHO/ISBRA Interview Schedule. An HPLC candidate reference method for CDT was used to quantify individual transferrin glycoforms.

RESULTS: No gender difference in %DST was noted for nondrinkers, but light/moderate and heavy drinking males had significantly higher levels than females. Of the alcohol biomarkers examined, %DST showed the strongest correlation with self-reported alcohol intake, except for female heavy drinkers. The area under the %DST ROC curve for male (0.83) and female (0.82) heavy drinkers was significantly higher compared with CDT by CDTect (0.68) and GGT (0.69). At the 40, 60, or 80 g ethanol/day thresholds, %DST showed lower test sensitivity in women but there was no significant gender difference in overall accuracy according to ROC curve analysis.

CONCLUSIONS: %DST measured by HPLC showed overall higher sensitivity for "heavy drinking" and better correlation with recent high alcohol intake, compared with the absolute CDT amount, and GGT and AST. The observation that several "light/moderate drinkers" had elevated %DST levels and some also a measurable asialotransferrin indicated misclassification with the WHO/ISBRA Interview Schedule and emphasize the limitations of self-reports of drinking.