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Test ID: GGT
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GGT
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Useful For
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To evaluate for a possible liver disease or bile duct disease and to differentiate between liver and bone disease. Used as a screening test for alcohol abuse.
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Method name and description
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Enzymatic colorimetric assay
γ-glutamyltransferase transfers the γ-glutamyl group of L-γ-glutamyl-3-carboxy-4-nitroanilide to glycylglycine.
Enzymatic colorimetric assay performed on the Roche cobas c-systems. γ‑glutamyltransferase transfers the γ‑glutamyl group of L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to glycylglycine. The amount of 5‑amino‑2‑nitrobenzoate liberated is proportional to the GGT activity in the sample. It is determined by measuring the increase in absorbance photometrically.
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Clinical information
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γ‑glutamyltransferase is used in the diagnosis and monitoring of hepatobiliary diseases. Enzymatic activity of GGT is often the only parameter with increased values when testing for such diseases, and is one of the most sensitive indicators known. γ‑glutamyltransferase is also a sensitive screening test for occult alcoholism. Elevated GGT activities are found in the serum of patients requiring long‑term medication with phenobarbital and phenytoin. (Roche Cobas γ-Glutamyltransferase ver.2 package insert ; Roche Diagnostic Corp., Indianapolis, IN)
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Aliases
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Gamma-Glutamyl Transferase, GGT
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Specimen type / Specimen volume / Specimen container
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Specimen type: Serum, Plasma
Minimum volume of sample: 1 mL
Serum: Plain tube (red or yellow top)
Plasma: Li‑heparin tube
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Collection instructions / Special Precautions / Timing of collection
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Collect blood by standard venipuncture techniques as per specimen requirements. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
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Storage and transport instructions
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Storage: 7 days at 15 – 25°C
7 days at 2 – 8°C
1 year at (- 15 to - 25°C)
Transport: 2-25°C
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Specimen Rejection Criteria
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Grossly hemolyzed, icteric and lipemic samples, wrong collection container, insufficient sample.
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Biological reference intervals and clinical decision values
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Patient Sex Age Range Range (U/L)
Female 0 Mins To 182 Days 15 - 132
Female 182 Days To 1 Y 1 - 39
Female 1 Y To 12 Y 4 - 22
Female 12 Y To 18 Y 4 - 24
Female >18 Y 6 -42
Male 0 Mins To 182 Days 12-122
Male 182 Days To 1 Y 1 - 39
Male 1 Y To 12 Y 3 - 22
Male 12 Y To 18 Y 2 - 42
Male >18 Y 10 - 71 |
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Turnaround time / Days and times test performed / Specimen retention time
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Daily (24/7)
Turn-around time:
Routine: One working day
Specimen Retention: 4 days
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