GGTP

Gamma-glutamyltransferase (GGT or GGTP) is an enzyme that plays a crucial role in the metabolism of glutathione, the body's main antioxidant. It is involved in the transfer of amino acids and peptides across the cellular membrane and in glutathione metabolism, which is essential for detoxifying harmful compounds in the liver.

Function

GGTP is primarily found in the liver, but it is also present in the kidneys, pancreas, and intestines. Its main function is to catalyze the transfer of gamma-glutamyl functional groups from molecules such as glutathione to an acceptor that may be an amino acid, a peptide, or water. This process is vital for the metabolism of glutathione, facilitating the breakdown and removal of oxidized species that can be harmful to the body.

Clinical Significance

Elevated levels of GGTP are often indicative of liver damage or disease, such as hepatitis, cirrhosis, or liver cancer. It can also indicate bile duct problems and is used in the diagnosis and monitoring of these conditions. Because GGTP levels can increase with alcohol consumption, it is sometimes used to screen for excessive alcohol intake.

In addition to liver function tests, GGTP levels may be measured to assess the risk of heart disease and to monitor the treatment of patients with known liver or bile duct diseases. Its levels can be affected by drugs that induce cytochrome P-450, which is involved in drug metabolism.

Measurement

The measurement of GGTP is done through a blood test. It is often part of a liver panel or liver function test, which measures various enzymes and substances in the blood to assess the health of the liver.

Interpretation

Normal GGTP levels vary by age and sex. Elevated levels may suggest liver or bile duct damage but must be interpreted in the context of other liver function tests and clinical findings. Isolated elevation of GGTP, without changes in other liver enzymes, may not necessarily indicate liver disease and could be influenced by other factors such as alcohol use or medication.

Treatment and Management

The treatment for elevated GGTP levels focuses on addressing the underlying cause. If the elevation is due to alcohol consumption, reducing intake or abstaining from alcohol may lower GGTP levels. For liver or bile duct diseases, specific treatment will depend on the diagnosis.

Conclusion

GGTP is an important enzyme in the body's metabolism of glutathione and plays a significant role in liver function. Its measurement is useful in diagnosing and monitoring liver and bile duct diseases, as well as in assessing the impact of substances like alcohol on the liver.