The Gamma Glutamyl Transferase assay is useful for diagnosing liver diseases, such as hepatitis, cirrhosis and some forms of cancer.
The values found are often compared with those of the alkaline phosphatase.
of leukotrienes and in that of glutathione. and in the treatment of liver and biliary tract diseases, such as cirrhosis, cholestasis and primary and secondary liver tumors.
Although Gamma glutamyl transferase is found in the cell membranes of many tissues - including kidney, pancreas, spleen, heart, brain and demining vesicles - its serum concentrations appear to depend mainly on the health of the hepatobiliary system. For this reason, high levels of GGT in the blood are commonly found in all diseases of the liver and biliary tract.
The clinical importance of serum Gamma Glutamyl Transferase is however diminished by the low specificity; a particularly high value of gamma GT indicates the probable presence of liver damage, but does not give any information on its origin. Therefore, the plasma dosage of this enzyme it provides very little additional information compared to that deriving from the determination of transaminases, alkaline phosphatase and bilirubin.
The simultaneous dosage of glutamyl transferase and alkaline phosphatase (ALP), tells us if the "increase of the latter" is of hepatic origin (both values are increased) or if it is due to a bone tissue problem (only increases the phosphatase alkaline).