Carbohydrate Deficient Transferrin (CDT)

General Information

Carbohydrate deficient transferrin (CDT) is used to test for compliance of alcohol avoidance in chronic alcoholism.

Transferrin is a glycoprotein which contains up to nine terminal sialic acid residues on its carbohydrate side chains. Alcohol appears to inhibit the glycation of several glycoproteins, including transferrin, and in subjects consuming excessive amounts of alcohol, plasma transferrin often lacks up to four of these sialic acid residues. This results in asialo-, monosialo-and disialotransferrins which are collectively termed carbohydrate deficient transferrin (CDT. Consumption of more than 80 g of alcohol per day leads to a increase in plasma CDT concentration, irrespective of any liver disease. CDT returns to normal concentrations within two weeks of abstinence.

The sensitivity and specificity of CDT is superior to GGT as a biomarker of continuous alcohol consumption.

False positives may occur in the presence of medical complications such as primary biliary cirrhosis, hepatocellular carcinoma and viral liver cirrhosis.