GGTP - Gamma-Glutamyl Transpeptidase Test

GGTP test

It is a simple blood test used to detect the blood levels of GGTP (Gamma-glutamyl transpeptidase) enzyme. GGTP is also called Gamma-glutamyl transferase. Enzymes are those proteins which take part in certain chemical reactions in your body. This enzyme is found in certain organs like liver and bile duct (mainly) and in other organs like kidney, pancreas, heart and brain in mild amount. Whenever there is damage to these organs this enzyme leaks in blood and hence its level increases.

This test is usually used to detect liver disorders. If the blood levels of GGTP is normal it shows that there is no liver disease. But it is a nonspecific test since it cannot tell the cause of liver damage .for finding the cause of liver damage other tests is required.

The common symptoms of liver disorder can be:

• Jaundice-yellow discolouration of skin and eyes
• Extreme tiredness

• Appetite loss

• Abdominal pain

• Nausea and vomiting

• Clay coloured stool

• Dark yellow urine

Why is GGTP test prescribed?

​Your health care provider may prescribe this test to detect certain conditions in which its level increases such as:

• Diabetes

• Chronic Alcohol abuse

• Heart failure

• Liver tumours

• Hepatitis

• Liver cirrhosis

• Diseases of pancreas

• Cholestasis (stagnation of bile due to blockage of bile duct)

• Drug overdose

This test is also done as a part of routine health check up to assess liver function especially if there is history of prolonged use of liver toxic medications.

 It may also be prescribed in those individuals having symptoms and signs of liver disease as mentioned above.

This test also helps to differentiate between liver disorder and bone disease when it is done along with ALP test.  

What are the components of GGTP test?

This test is usually done along with other liver function tests such as ALT (alanine aminotransferase), AST (aspartate aminotransferase), ALP (alkaline phosphatase) and bilirubin to differentiate between various liver diseases and bile duct disorders.

Procedure and prerequisites

The sample for Gamma-glutamyl transpeptidase test is taken from blood by inserting small needle into vein of your arm. A small amount of blood is then collected in a test tube or vial. You may feel some pain due to needle prick. Certain drugs can alter the level of this enzyme like acetaminophen, alcohol, antiepileptic like phenytoin, carbamazepine and birth control pills.

Reference range

Normal range-5 to 40 U/L

This reference range may vary from laboratory to laboratory