The enzyme Gamma-Glutamyl Transpeptidase (γ-GT, EC 2.3.2.2.) is distributed
widely throughout the body, highest activities being present in the kidney, followed by
pancreas, liver, spleen, and brain. It catalyses transfer of the gamma-glutamyl group
from gama glutamyl peptides to other peptides or any of the common amino acids
except proline.
Since a group of Polish investigators first reported elevated γ-GT activity in sere of
Patients with hepatic disease, a number of reports have appeared describing the
conditions in which there is an elevated serum γ-GT activity. The level of γ-GT has
been shown to be raised mainly in patients with hepato-biliary disease and to a lesser
extent in a number of other conditions as Pancreatic, heart, neurologic, and renal
diseases.
As the Department of Clinical Pathology, Yonsei University Medical College, has
recently purchased the autoanalyzer System 5 (Gilford Instrument Laboratories, Inc.), the
rapid and_accurate determination of serum γ-GT activity has ben made possible. The
author measured he activity in sera from the patients with a variety of diseases and 30
normal controls comprised of healthy medical students by using System 5.
The results are as follows.
1. The average values of γ-GT for normal controls were 19.2 IU/L (range 8-33 IU/L)
in male, and 16.5 IU/L (range 6-28 IV/L) in female, respectively.
2. Patients with all forms of hepato-biliary diseases had elevated serum γ-GT level.
The highest activity was noted in patients with cholecystits or cholelithiasis. .
3. Patients with primary hepatocellular and metastatic carcinomas had significantly
elevated serum γ-GT level and higher increase rate than those of. any other enzyme
tests. This may suggest the value of γ-GT as a screening test for neoplastic diseases
of the liver.
4. Of all the patients studied, patients with carcinoma of pancreas revealed highest γ
-GT values.
5. Patients with carcinomas except hepatocellular and pancreatic carcinomas did not
reveal significant elevation of serum γ-GT activity.
6. In patients with bone diseases, γ-GT levels were within normal range in contrast to
elevated alkaline phosphatase activities.
7. A portion of patients with neurologic diseases showed slightly elevated γ-GT level
No significant change of γ-GT activity was noted in patients with renal failure.
8. In spite of the lack of specificity, it appears that the determination of γ-GT can
indicate hepato-biliary dysfunction, especially used with other tests.
9. When the level of γ-GT is increased abruptly during the follow-up of a liver
cirrhosis patient, the measurement of γ-GT may indicate the progress of liver cirrhosis
or complication of hematoma, especially in a country like Korea which has a high
incidence of liver
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