Lab Test

Gamma Glutamyl Transferase (GGT)

GGTP, GGT, Gamma Glutamyl Transpeptidase

Test Codes

EPIC: LAB85, Beaker: GGTB, Antrim: 17137

Department

Chemistry

Specimen Collection Criteria

Collect: One Gold-top SST tube. (Minimum Whole Blood: 4.0 mL)

Contact Laboratory for acceptability of other tube types.
See Minimum Pediatric Specimen Requirements for Microtainer® collection.

Physician Office/Draw Specimen Preparation

Let SST specimens clot 30-60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged SST tube within two hours of collection. (Minimum: 0.5 mL)

Preparation for Courier Transport

Transport: Centrifuged SST tube refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Rejection Criteria

  • Moderate to grossly hemolyzed specimens.
  • Red-top tubes with serum not separated from cells within two hours of collection.

In-Lab Processing

Let SST specimens clot 30-60 minutes. Centrifuge SST tubes or Microtainers® to separate serum from cells. Deliver immediately to the appropriate testing station.


Storage

Specimen Stability for Testing:

Centrifuged SST Tubes and Microtainers® with Separator Gel
Room Temperature (20-26°C or 68-78.8°F): 2-4 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Red-top Tubes and Microtainers® without Separator Gel
Room Temperature (20-26°C or 68-78.8°F): 2-4 hours
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): 2-4 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 7 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days

Laboratory

Dearborn Chemistry Laboratory
Farmington Hills Chemistry Laboratory
Royal Oak Automated Chemistry Laboratory
Troy Chemistry Laboratory

Performed

Sunday – Saturday, 24 hours a day.
Results available within 4 hours of receipt in the Laboratory.

Reference Range

Farmington Hills, Royal Oak & Troy:

Sex Age Range (U/L)
Male and Female0 -14 Days23-219
Male and Female15 Days - <1 Year8-127
Male and Female1-10 Years6-16
Male and Female11-18 Years7-21
Male and FemaleAdult Male13-60
Male and FemaleAdult Female8-39

Grosse Pointe:
Female (0 - Adult): 5-55 U/L.
Male (0 - Adult): 15-85 U/L. 

Test Methodology

Enzymatic, Spectrophotometry.

Interpretation

GGT (gamma-glutamyl transferase) is elevated in intra- and extra-hepatic biliary obstruction. It may also be elevated in primary or secondary liver tumors, in patients with chronic alcohol abuse, those taking phenobarbital or phenytoin and several other liver diseases. GGT may be low in hypothyroidism.

Clinical Utility

The quantitative determination of GGT (gamma-glutamyl transferase) aids in the diagnosis and monitoring of hepatobiliary disease. GGT is currently the most sensitive enzymatic indicator of liver disease. Normal GGT values are rarely found in the presence of clinically significant hepatic disease.

CPT Codes

82977

Contacts

Last Updated

10/28/2024

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