Carbohydrate-deficient Transferrin (CDT), Adult

Test ID: 


CPT code:



•Transferrin Isoforms

Clinical Use:

An indicator of chronic alcohol abuse

Additional Test Information:

CDT testing can be an effective tool for the early diagnosis of chronic alcohol misuse, for the detection of patients addicted to alcohol, and for the follow-up of treatment and diagnosis of alcohol relapse. CDT quantitation is useful in detecting abusive alcohol consumption (defined as ethanol consumption >40 mL per day for at least two weeks) and a more specific marker for alcohol exposure than other available markers, such as γ-glutamyl transferase (GGT). It enables early detection of alcohol misuses and follow-up of alcoholic patients. On stopping alcohol consumption, the CDT level goes back to normal after two to four weeks. If the patient starts drinking after withdrawal, CDT increases in a few days. Transferrin is an 80-kDa serum glycoprotein produced by the liver. Its function is to carry iron around an organism mediated by iron-binding properties. Transferrin comprises a single polypeptide chain with two polysaccharide chains ended by a sialic acid residue. There are several isoforms of human transferrin with different levels of sialylation. Carbohydrate-deficient transferrin (CDT), defined by 2 sialo and 0 sialo isoforms, is a marker of chronic alcohol abuse.

Specimen Type:

Serum, frozen

Requested Volume: 

1 mL

Minimum Volume: 

0.75 mL

Container Type: 

Red-top tube or gel-barrier tube


Serum should be separated from cells within two hours of venipuncture. Send serum frozen in a plastic transport tube. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions:


Stability Requirements



Room temperature

2 days


2 days


7 days

Freeze/thaw cycles

Stable x3


Rejection Criteria

Fibrinogen present in sample; hemolyzed specimen; aged and improperly stored specimen; anticoagulated specimen (citrate, EDTA); presence of genetic variants of transferrin.

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MCI Diagnostic

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7018 South Utica Avenue

Tulsa, Oklahoma 74136

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Sun: 7AM-3PM

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Sun: 7AM-3PM


Mon – Sat: 7AM-11PM

Sun: 7AM-3PM

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