How to best diagnose patients with chronic alcohol abuse?


Key facts1

  • The harmful use of alcohol results in 2.5 million deaths each year.
  • 320 000 young people between the age of 15 and 29 die from alcohol-related causes, resulting in 9% of all deaths in that age group.
  • Alcohol is the world’s third largest risk factor for disease burden; it is the leading risk factor in the Western Pacific and the Americas and the second largest in Europe.

Alcohol is associated with many serious social and developmental issues, including violence, child neglect and abuse, and absenteeism in the workplace. ( 

Worldwide patterns of drinking score (age 15+ years) in 2010 according to WHO

Recommended maximum intake of alcoholic beverages2

Regular consumption:


  • not more than 2-3 units* of alcohol on an average day (less than 14/week)
  • at least two alcohol-free days a week


  • not more than 3-4 units* of alcohol on an average day (less than 21/week)
  • at least two alcohol-free days a week

Consumption on an occasional basis:

  • not more than 4 units* of alcohol on one occasion

Consumption of alcohol must be avoided in the following circumstances:

  • During pregnancy
  • During childhood
  • Driving
  • Operating dangerous machinery
  • When exercising responsibilities which require vigilance
  • When taking certain medications
  • People with certain chronic or acute diseases (epilepsy, pancreatitis, viral hepatitis, etc.)
  • For former alcoholics

Test principle

The Sebia CAPILLARYS CDT and MINICAP CDT assays are based on the principle of capillary electrophoresis.  Transferrin isoforms are separated by their electrophoretic mobility and the electroosmotic flow in the capillary. Proteins are directly detected at the cathodic end of the capillary. During analysis, serum transferrin isoforms are separated into five major fractions according to their sialylation level: 

  • Asialotransferrin (non-sialylated)
  • Disialotransferrin
  • Trisialotransferrin
  • Tetrasialotransferrin
  • Pentasialotranferrin

The low-sialylated isoforms of transferrin, i.e., disialotransferrin associated with asialotransferrin in some cases, constitute CDT (value calculated automatically by the system). Sebia CDT levels are interpreted as follows:

  • (1) Normal if ≤1.3%
  • (2) Non-conclusive if >1.3% and ≤1.6%
  • (3) Abnormal and indicative of alcohol abuse if >1.6%.

Test indications

Carbohydrate Deficient Transferrin (CDT) is a blood marker for chronic alcohol abuse and is based on the fact that an average daily consumption of more than 60 g of alcohol during the previous 2 weeks increases the percentage of this marker. Increased CDT levels indicate that alcohol is disrupting the normal chemistry of the liver cell. In most people, an elevated CDT will return to normal during several weeks of alcohol abstinence. It will also decrease if a person substantially reduces drinking. 

CDT is specific for heavy alcohol use; 30% reduction in CDT is consistent with a substantial reduction in alcohol intake. In many aspects, CDT has characteristics similar to HbA1c and other blood tests that change based on diet and/or therapeutical intervention. CDT increase serves as an indication that the person has returned to heavy drinking, providing an efficient and specific monitoring tool for healthcare professionals. 

SEBIA assays available for this pathology



* One unit of alcohol is 10 ml (1 cl) by volume, or 8 g by weight of pure alcohol.

1 WHO. Alcohol Fact Sheet February 2011 (

2 WHO. Problems related to alcohol consumption. Report of the expert committee. Geneva: World Health Organisation, 1980