Alcohol test – CDT
CDT stands for carbohydrate-deficient transferrin, i.e. desialylated transferrin. Transferrin is the iron-carrying glycoprotein found in serum in several forms, including forms deficient in their carbohydrate chains (asialo, monosialo and disialo isoforms). This change has been found in the serum of people who abuse alcohol.
In the following years, CDT therefore attracted great attention as a
sensitive and specific laboratory marker of excessive alcohol consumption. The
mechanism behind the rise in CDT in people with alcoholism is the inhibition of protein glycosylation caused by ethanol and acetaldehyde. Serum CDT is thought to rise when more than 60 g of alcohol a day is consumed for at least 7-10 days. A period of 2-3 weeks is needed before CDT returns to normal in people who have stopped drinking.
Clinical significance
CDT values rise after at least 7 days of drinking 50-80 g of alcohol a day and stay raised for at least 15-20 days. As for how long it takes for CDT to fall, during abstinence the value returns to normal with a half-life of 14-17 days.
The main advantage of this marker is its good sensitivity, in any case higher than that of GGT and MCV, and above all its precision (over 90%), so that when CDT is raised it is practically certain that the person is a heavy drinker. The test is also independent of age, medication and other diseases, and the rise is seen in people who abus
How it is done
It is a simple blood test. For these tests it is advisable to fast from the evening before.