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Carbohydrate-deficient transferrin (CDT) in serum/plasma (24-hour collection)

Published: August 9, 2026Updated: August 16, 2026

This test measures a form of transferrin protein that may be missing important sugar molecules, which can help identify long-term alcohol use.

Quick summary

["CDT helps doctors check for heavy alcohol consumption over weeks or months."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
101583-3
Short code
ESBL cft to cft-clav IC rto Bd Pos Imp
Synonyms
ESBL cft to cft-clav IC rto Bd Pos Imp
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
based-on-lab-data
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why is this test done?

Your doctor may order a CDT test if they suspect you’ve been drinking alcohol excessively. It’s often used alongside other tests to monitor alcohol abuse or withdrawal, especially in patients with liver concerns or those recovering from alcohol dependence.

How is the test performed?

You’ll collect your blood sample in the morning after fasting for at least 8 hours. The test measures CDT levels in your serum or plasma, which are analyzed using an immunoassay method to detect the specific protein variant.

What does the result mean?

CDT levels above normal can indicate chronic alcohol misuse, though they don’t confirm alcohol alone as the cause. Higher levels may also appear in other conditions, so results are interpreted alongside clinical findings and patient history.

What are common causes of abnormal results?

Elevated CDT is most strongly linked to long-term alcohol consumption, but other factors—such as certain liver diseases, malnutrition, or medications—can also affect it. Your doctor will consider these when evaluating your results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CDT Screening

Frequently asked questions

Will I need to prepare for this test?
Yes, you’ll need to fast for 8 hours before your blood draw to ensure accurate results. Avoid alcohol for at least 48 hours before testing, as it may interfere with the test’s sensitivity.
How long will I wait for results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will discuss them with you during your follow-up visit.
Can CDT test detect acute alcohol intoxication?
No, CDT measures long-term alcohol exposure, not recent drinking. For acute alcohol levels, tests like ethanol or carboxyhemoglobin are used instead.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy