Gamma-GT – how to understand your laboratory values

You can find out what gamma-GT is, when the value is measured and what the results mean here.

Abstract

• Gamma-GT is an important enzyme in protein metabolism.
• The value is mainly used for the diagnosis of liver diseases.
• The normal values of gamma-GT are strongly dependent on age and gender.
• A healthy, balanced diet and abstaining from alcohol help to keep the value within the normal range.

What is gamma-GT?

Gamma-GT, also known as g-Gt, GGT or gamma-glutamyl transferase, is an enzyme of amino acid metabolism (protein metabolism). Gamma-G transfers amino groups and is mainly found in the liver, but also in mucosal cells of the small intestine, kidney and pancreas.

The laboratory value is mainly used to diagnose liver diseases (e.g. hepatitis).

The values for gamma-GT are obtained from blood samples, but only gamma-GT suitable for living organisms can be measured in blood serum.

What are standard values?

Like most medical laboratory values, gamma-GT values depend on age and gender.

GT values that deviate from the reference value may indicate liver disease. In general, the higher the value, the greater the supposed damage.

When is the value measured?

There are various reasons why the value of gamma-GT is considered:

• For symptoms such as jaundice, right-sided upper abdominal pain or itching, etc.
• For various liver diseases to assess the course of the disease
• If liver or bile duct disease is suspected
• If chronic alcohol abuse is suspected (can be elevated from just two glasses of wine a day)

Abstinence control: Patients who regularly consume large amounts of alcohol have higher GGT blood levels in up to 90% of cases.

Causes of altered GGT value

A low gamma-GT value is not usually an indication of a disease.

Causes of elevated GGT levels:

The GGT value alone is not sufficient to make a diagnosis. However, in conjunction with the level of other liver values, it is possible to draw conclusions about certain diseases.

Slightly elevated (in adults): Value does not rise above 120 U/l

• Uncomplicated viral hepatitis (hepatitis A, B, C, D, E)
• Fatty liver
• Chronic alcohol consumption
• Pfeiffer’s glandular fever

Moderately elevated (in adults): Value does not rise above 300 U/l

• Liver cirrhosis or alcoholic hepatitis as a result of chronic alcohol consumption
• Chronic active hepatitis
• Chronic inflammation of the bile ducts (primary biliary cirrhosis)
• Liver metastases in the context of cancer
• Diseases of the pancreas involving the liver

Highly elevated (in adults): Value rises above 300 U/l

• Bile stasis (cholestasis)
• Severe inflammation of the gallbladder or bile ducts
• Cholestatic course of viral hepatitis

What does the value say?

An elevated gamma-GT value is not enough to make a diagnosis.

Further values (e.g. ALT, AST or cholestasis parameters) are necessary for a diagnosis, but these are normally also examined as part of the diagnostic process. A suspected diagnosis can then be made on the basis of the overall picture of various values, which can then be confirmed by further examinations.

What can you do yourself?

• Follow the therapy prescribed by the doctor to treat the underlying disease (cause)
• Abstaining from alcohol and smoking
• Healthy and balanced diet
• Avoid fatty and sweet foods

Sources:

• http://www.laborlexikon.de/Lexikon/Infoframe/g/Gamma-GT.htm
• https://www.netdoktor.de/laborwerte/gamma-gt/
• https://www.netdoktor.de/laborwerte/gamma-gt/erhoeht/
• https://www.apotheken-umschau.de/laborwerte/gamma-gt-ggt