Carbohydrate Deficient Transferrin (CDT)
Chemical Pathology
Notes
- Serum transferrin, an iron-transporting glycoprotein, occurs in isoforms with different levels of sialylation.
- In individuals with chronic or recent elevated alcohol intake the asialo, mono and disialo isoforms occur in higher levels. Together, these isoforms are collectively referred to as carbohydrate-deficient transferrin (CDT).
- CDT provides a marker of chronic alcoholism with a half-life of approximately 2 weeks.
- CDT is unsuitable for screening the general population for short-term increases in alcohol consumption and binge drinking.
Indication for testing:
- Chronic alcoholism and alcohol avoidance compliance.
Sample requirements
Please note: this test is not routinely available and all requests should be discussed with the Duty Biochemist before venepuncture. Suggest request alternate markers γGT, MCV, ALT, AST in the first instance.
For adults, blood taken into a 5mL gold top tube (or rust top for the Acute Unit)
Storage/transport
Send at ambient temperature to the laboratory. If unavoidable, samples can be stored refrigerated overnight.
Required information
Relevant clinical details including reason for the test.
Turnaround times
Samples are sent to a referral laboratory for analysis with results expected back within 3 weeks.
Reference ranges
Appropriate reference ranges are supplied with results reported by the analysing laboratory.
Studies have shown that alcoholics who consume greater than 50g of ethanol/day for at least one week will have an increase in serum CDT levels.
Both false positive and false negative results can occur - refer to reference below for more details. Because of this CDT should be interpreted along with other investigations (γGT, MCV, ALT, AST) as well as the clinical status of the individual and use of suitable questionnaires.
Page last updated 22/02/2024