What is Carbohydrate-Deficient Transferrin?
Transferrin is a plasma glycoprotein synthesised by the liver that carries iron and is normally decorated with branched oligosaccharide chains terminating in sialic acid residues. Chronic heavy alcohol consumption interferes with the glycosylation machinery in hepatocytes, resulting in undersialylated (carbohydrate-deficient) isoforms — predominantly asialo- and disialo-transferrin. These isoforms rise after sustained alcohol intake over several days to weeks and fall with a half-life of approximately two weeks after cessation, making CDT a marker of the chronicity and quantity of drinking rather than a snapshot of recent intake.