Carbohydrate deficient transferrin
Until recently, γ-glutamyltransferase (GGT) was considered the best biochemical marker of one of the most common causes of liver damage, alcohol abuse. Another parameter is currently being added, carbohydrate deficient transferrin (CDT).
Transferrin, as a glycoprotein, usually contains four to six sialic acid residues in its molecule. Chronic alcohol abuse (60 g of alcohol per day for at least two to three weeks) increases the proportion of transferrin lacking sialic acid (0-2 sialic acid per molecule), the so-called carbohydrate-deficient transferrin (CDT). It is considered a sign of chronic alcohol abuse if the proportion of CDT exceeds 6% of total transferrin. CDT levels remain elevated for about 2 weeks after the start of abstinence.