Gamma-glutamyl transpeptidase (GGT)

Test performed from the blood to determine the level of gammaglutamyltranspeptidase.

Test performed from the blood to determine the level of gammaglutamyltranspeptidase
Measurement of gamma-glutamyltransferase activity is used in the diagnosis and treatment of biliary hepatitis. GGTP is an enzyme found in the kidney and liver.


An increase in activity is observed in:

• intrahepatic and extrahepatic cholestasis,
• biliary tract inflammation,
• hepatitis,
• alcoholic disease,

GGTP what is it?

GGTP (gamma-glutamyltranspeptidase) is an enzyme found in the cells of many organs.

GTP testing is used mainly in the diagnosis of liver and biliary tract diseases. PGD, the level of which is tested in blood serum, is mainly derived from the biliary tract and liver.

The level of PGD in the blood serum is mainly derived from the bile ducts and liver.

Testing the level of PGD is one part of a panel that is liver tests. Usually, for a comprehensive assessment of liver status, in addition to this test, it is necessary to determine - the level of aminotransferases and alkaline phosphatase (ALP).

The level of aminotransferases and alkaline phosphatase (ALP)

When is PGD tested - indications for the test?

Increased levels of PGD can be a symptom of liver disorders or developing gallbladder stones.

Otherwise, it may indicate cholestasis, or bile stasis in the bile ducts. Cholestasis is a serious health condition because the acids in the bile cause damage to liver cells and digestive disorders.

Overall, cholestasis is a serious health condition

An abnormal level of PGD is also found in people with liver cancer, who develop alcoholic disease or have developed hepatitis infection. In suspicion of all of these diseases, a doctor may recommend testing the PGD level.

The GGT test may also be performed to determine the cause of elevated alkaline phosphatase (ALP) levels - biliary or liver disease, or from bone disease.

How does a GGT test look like?

The level of PGD is tested in blood serum, during the test the nurse takes a small sample of blood from the elbow vein. Before collection, the skin at the puncture site is disinfected and a tourniquet is applied to the patient. The blood is collected in a tube, and after the collection is completed, the puncture site should be pressed with gauze for a few minutes - this will prevent bruising. The entire test, including preparation, takes only a few minutes.

GGTP - how to prepare for a blood test?

For the test, you should prepare properly. Blood should be taken on an empty stomach. What does this mean? You should refrain from eating and drinking beverages other than water for 8 to 12 hours before the blood is drawn. This recommendation applies to all tests from a blood sample, because the consumption of a meal can affect the result, and possible deviations from the norm or changes in the proportions and levels of the parameters tested are difficult to predict.

The day before the test, you should avoid very fatty, hard-to-digest, fried meals and foods. It is also inadvisable to consume even small amounts of alcohol (2-3 days before the test). Smoking can also increase GGT levels.

On the day of the test, you can drink a small amount of water, so that the collection will be easier. Blood should be drawn in the morning, but in most cases this is not a problem - collection centers are open at times to suit the requirements of drawing blood for the test. Before the test, rest in a sitting position for about 10-15 minutes, it is advisable to come to the collection point early enough to avoid rushing and ensure your comfort while taking care of the test result.

In patients on chronic medication, consult with your doctor regarding taking the morning dose of medication on the day of the intake.

Also inform your doctor if you are taking medications or herbal preparations.

Decision on how to prepare for the test is up to the doctor in each case.