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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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Item Value
Available Stat? Yes
Test code GGT
Performed by? Chemistry
Sendout? no
Price range $
In House Availability Routine: 7 days
Principle GGT catalyzes the transfer of the gamma-glutamyl moiety of L-gamma-glutamyl-3-carboxy-4 nitroanilide to glycyglycine, simultaneously producing 5-amino-2-nitro-benzoate. The rate change in absorbance at 410 NM is measured and used to calculate the enzyme activity of GGT.

L-gamma-glutamyl-p-nitroanilide       GGT         5-amino-2-nitro-benzoate
                +                     <->                      +
       glycylglycine                              gamma-glutamyl glycyglycine

Interpretation Serum GGT is a sensitive indicator of hepatobiliary disease and is useful in the diagnosis of obstructive jaundice, chronic alcoholic liver disease, follow-up of chronic alcoholics undergoing treatment, and in the detection of hepatotoxicity. GGT is more responsive to biliary obstruction than AST, ALT or ALKP. GGT is also increased in hepatoma, carcinoma of the pancreas, carcinoma metastatic to the liver, and in patients taking enzyme inducing drugs such as phenytoin and phenobarbital.
Container type gel tube (gold or green top)
Amount to Collect 2 mL
Sample type Blood
Normal range
Male: 15-73 U/L Female: 12-43 U/L
Synonyms GGT;LAP (Leucine Amino Peptidase);Leucine Amino Peptidase (LAP);
Stability Serum is stable at 2-8°C for one month and at -20°C for one year
References 1. Bayer(TM) Clinical Methods GGT (55) B01-4138-01 Advia 1650 Operator's Guide. PN 073-5001-09. Last accessed June 2003. Siemens Medical Solutions Diagnostics, Malvern, PA.

2. Evans, D.S., Kringle, R.O.: gamma-Glutamyltransferase: Response Surface Co-optimization of Reaction Conditions with gamma-Glutamyl-3-carboxy-4-nitroanilide as the Substrate. Clin Chem, 27:1036, 1981.

3. Young, D.S. Effects of Drugs on Clinical Laboratory Tests ed. 4. Washington D.C.: AACC Press; 1995.

4. Friedman, R.B., Young, D.S.: Effects of Disease on Clinical Laboratory Tests, Washington D.C.; AACC Press, 1997.
CPT coding 82977
Last Updated 8/19/2009 8:07:03 AM
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