High-performance liquid chromatography improves diagnostic efficiency of carbohydrate-deficient transferrin

Carbohydrate-deficient transferrin (CDT) is considered a useful biochemical marker of regular high alcohol intake. CDT was measured in the sera of 51 alcohol abusers, 20 patients with non-alcoholic liver disease and 30 healthy controls with an alcohol intake of < 30 g/day. The mean CDT levels of these three groups respectively were determined with high-performance liquid chromatography (HPLC; 4.6 +/- 5.2%; 0.7 +/- 0.2%; 0.7 +/- 0.2%) and with a radioimmunoassay after microcolumn anion-exchange chromatography (MAEC/RIA; 34.2 +/- 26.9 U/l; 16.9 +/- 3.8 U/l; 18.0 +/- 5.7 U/l). CDT levels in patients with severe alcohol abuse (161.6 +/- 96.4 g/day) were significantly higher than in the two other groups under investigation (P < 0.0001). In heavily drinking subjects, the mean daily alcohol intake correlated with aspartate aminotransferase levels (ASAT) but not with the CDT levels determined either with HPLC or MAEC/RIA. With both methods, the CDT levels were slightly higher in patients with an ASAT concentration > 30 U/l, which may indicate an advanced liver damage (P < 0.05). Analysis of receiver-operating characteristic (ROC) plots demonstrated that the diagnostic accuracy of the HPLC method, which determines the relative amount of CDT, was significantly higher than the established MAEC/RIA method, which measures the absolute amount of CDT (area under the ROC curve: 0.95 +/- 0.02 vs 0.73 +/- 0.05; P < 0.0001). At a specificity of > 95%, the sensitivity of CDT determined with HPLC and MAEC/RIA was 80 and 47%, respectively. In addition, HPLC may be a useful and reliable method for the determination of this important biochemical marker, since the HPLC chromatogram is a visible document of the successful isotransferrin separation and measurement.