Serum gamma-glutamyl transpeptidase: its clinical significance.

Serum gamma-glutamyl transpeptidase (gamma-GT) level was estimated in 132 patients with different liver diseases (chronic persistent and chronic active hepatitis, postnecrotic cirrhosis, chronic alcholic hepatitis and alcoholic cirrhosis, cholestasis syndrome, fatty liver, Gilbert disease) and malignancies with and without liver involvement. The gamma-GT levels were compared with the values for serum bilirubin, transaminases (GOT, GPT) and alkaline phosphatase in the same patients. gamma-GT values were normal in chronic persistent hepatitis and increased in chronic active hepatitis. Very high activities were measured in chronic alcoholic cirrhosis in contrast to postnecrotic cirrhosis. gamma-GT proved to be more sensitive than alkaline phosphate as an index of cholestasis and liver involvement in malignancies. It is suggested that gamma-GT activity offers valuable aid in differential diagnostics of liver-diseases. gamma-GT being an inducible enzyme, its activity may be raised by enzyme inducing drugs also in subjects without liver disease.