The Carbohydrate Deficient Transferrin (CDT) Blood Test is a specialized test used to evaluate chronic alcohol consumption and assess liver function. Transferrin is a protein that transports iron in the bloodstream, and when someone consumes excessive alcohol over an extended period, the carbohydrate content of transferrin decreases. The CDT test is often used to detect alcohol abuse, monitor treatment progress, and help diagnose related health issues.

What Is Carbohydrate Deficient Transferrin (CDT)?

Transferrin is a glycoprotein that helps transport iron throughout the body. In healthy individuals, transferrin has a certain amount of carbohydrate chains attached to it. However, chronic heavy alcohol consumption can alter this structure, resulting in carbohydrate-deficient transferrin (CDT). Elevated CDT levels in the blood can be an indicator of alcohol abuse, particularly when other tests for alcohol consumption are inconclusive.

Why Is the CDT Test Performed?

The CDT test is commonly used for:

  • Detecting chronic alcohol abuse or heavy drinking patterns, especially when other markers (such as liver enzymes) do not provide clear answers.
  • Monitoring alcohol cessation or treatment progress in individuals undergoing recovery from alcohol dependence.
  • Assessing liver function and identifying potential liver damage or cirrhosis linked to long-term alcohol consumption.
  • Differentiating alcohol-related liver damage from other causes of liver dysfunction, such as hepatitis or fatty liver disease.

Symptoms That May Lead to a CDT Test

Your doctor may recommend a CDT test if you have:

  • Liver issues, such as jaundice, swelling, or abdominal pain
  • Chronic alcoholism or a history of heavy drinking
  • Alcohol dependence or withdrawal symptoms
  • Unexplained changes in liver enzyme levels

How Is the Test Conducted?

  1. Sample Collection: A healthcare provider will draw a blood sample, usually from a vein in your arm.
  2. Lab Analysis: The sample is tested to measure the level of carbohydrate-deficient transferrin in the blood.
  3. Results Interpretation:
    • Normal CDT Levels: Low or absent CDT levels suggest that the individual is not a chronic heavy drinker.
    • Elevated CDT Levels: High CDT levels may indicate excessive alcohol consumption, typically over the course of several weeks.

What Do Abnormal CDT Levels Mean?

  • Elevated CDT Levels: Elevated levels typically indicate chronic alcohol abuse or long-term heavy drinking. The higher the CDT level, the more likely it is that the person has a history of alcohol misuse.
  • Normal or Low CDT Levels: A normal result suggests that the individual does not have a history of heavy alcohol use or that alcohol consumption is not a contributing factor to liver issues.

Common Conditions Linked to Elevated CDT Levels

  • Alcohol Abuse or Dependence: Long-term heavy alcohol consumption is the most common cause of elevated CDT levels.
  • Liver Disease: Chronic alcohol abuse can lead to liver damage, including cirrhosis and fatty liver disease.
  • Pancreatitis: Chronic alcohol consumption can also contribute to inflammation of the pancreas.

Preparation and Risks

  • Preparation: No special preparation is usually required for the CDT test. However, your doctor may ask you to avoid alcohol for 2–3 days prior to the test to ensure accurate results.
  • Risks: As with any blood test, there is a small risk of bruising or discomfort at the needle site.

To book please use the link below or call our friendly team on 01443 303003.

Back to Blood Tests