Measurement of carbohydrate-deficient transferrin by isoelectric focusing/western blotting and by micro anion-exchange chromatography/radioimmunoassay: comparison of diagnostic accuracy.

At present, the most reliable marker of recent and heavy alcohol intake is carbohydrate-deficient transferrin (CDT). While most CDT quantitation methods (including immunofixation and micro anion-exchange chromatography [MAEC] combined with radioimmunoassay [RIA]) either lack the precision required for diagnostic usage or are not commercially available, we recently described an isoelectric focusing/Western blotting (IEF/WB) procedure that provides sensitive and specific assessment of serum CDT content. However, a modified MAEC/RIA kit, supposedly more reliable than the original, is also being advanced as suitable for widespread clinical application. Therefore, we compared this modified MAEC/RIA procedure to the IEF/WB method of CDT quantitation in the following 108 subjects; 53 alcoholics undergoing detoxification without clinical or histological evidence of liver disease, 24 recently drinking alcoholics with biopsy-proven liver disease, eight alcoholics abstinent for more than 30 days with biopsy-proven liver disease, seven non-drinking patients with non-alcoholic liver disease, and 16 healthy controls. Although CDT measurements by the two methods were correlated (r = 0.60, P < 0.01), serum CDT values obtained with IEF/WB were nearly five-fold higher than those obtained with MAEC/RIA (e.g. 140.0 +/- 58 versus 28.5 +/- 16 mg/l among the active drinkers). Of the two methods, IEF/WB exhibited significantly greater sensitivity than MAEC/RIA for detecting recent, heavy drinking (75% versus 61%, P < 0.05) and generated no false positives whereas MAEC/RIA gave falsely elevated CDT levels in 37% of the abstinent alcoholics.(ABSTRACT TRUNCATED AT 250 WORDS)