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Test ID: CDTA Carbohydrate Deficient Transferrin, Adult, Serum

Reporting Name

Carb Def Transferrin, Adult, S

Useful For

Indicating chronic alcohol abuse


This test is not appropriate for screening patients for congenital disorders of glycosylation.

Specimen Type


Ordering Guidance

This test is for evaluation of alcohol abuse. If the ordering physician is looking for congenital disorders of glycosylation, order CDG / Carbohydrate Deficient Transferrin for Congenital Disorders of Glycosylation, Serum.

Necessary Information

1. Patient's age is required.

2. Reason for testing is required if patient is younger than 21 years of age.

Specimen Required

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 0.1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.

Specimen Minimum Volume

0.05 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 45 days
  Refrigerated  28 days
  Ambient  7 days

Reference Values


0.11-0.12 (indeterminate)

Day(s) Performed


Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
CDTA Carb Def Transferrin, Adult, S 53803-3


Result ID Test Result Name Result LOINC Value
31714 Mono-oligo/Di-oligo Ratio 35469-6
31715 Interpretation 59462-2

Clinical Information

Chronic alcoholism causes a transient change in the glycosylation pattern of transferrin where the relative amounts of disialo- and asialotransferrin (carbohydrate deficient transferrin: CDT) are increased over the amount of normally glycosylated tetrasialotransferrin. This recognition led to the use of CDT in serum as a marker for chronic alcohol abuse.


CDT typically normalizes within several weeks of abstinence of alcohol use. However, it is important to recognize that there are other causes of abnormal CDT levels, which include congenital disorders of glycosylation and other genetic and nongenetic causes of acute or chronic liver disease.


CDT testing alone is not recommended for general screening for alcoholism; however, when combined with other methods (ie, gamma-glutamyltransferase, mean corpuscular volume, patient self-reporting, ethylglucuronide analysis), clinicians can expect to identify the majority of patients who consume a large amount of alcohol.


Patients with chronic alcoholism may develop abnormally glycosylated transferrin isoforms (ie, carbohydrate deficient transferrin: CDT >0.12). CDT results from 0.11 to 0.12 are considered indeterminate.


Patients with liver disease due to genetic or nongenetic causes may also have abnormal results.

Clinical Reference

1. De Giovanni N, Cittadini F, Martello S: The usefulness of biomarkers of alcohol abuse in hair and serum carbohydrate-deficient transferrin: a case report. Drug Test Anal. 2015 Aug;7(8):703-707

2. Fleming MF, Anton RF, Spies CD: A review of genetic, biological, pharmacological, and clinical factors that affect carbohydrate-deficient transferrin levels. Alcohol Clin Exp Res. 2004;28(9):1347-1355

3. Gough G, Heathers L, Puckett D, et al: The Utility of Commonly Used Laboratory Tests to Screen for Excessive Alcohol Use in Clinical Practice. Alcohol Clin Exp Res. 2015 Aug;39(8):1493-1500

4. Shibamoto A, Namisaki T, Suzuki J, et al: Clinical significance of gamma-glutamyltranspeptidase combined with carbohydrate-deficient transferrin for the assessment of excessive alcohol consumption in patients with alcoholic cirrhosis. Medicines (Basel). 2021 Jul 19;8(7):39

5. Torrente MP, Freeman WM, Vrana KE: Protein biomarkers of alcohol abuse. Expert Rev Proteomics. 2012 Aug;9(4):425-436

Report Available

7 to 10 days

Method Name

Affinity Chromatography/Mass Spectrometry (MS)


If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.

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