Gamma-Glutamyltransferase (GGT)

Test Code

GGT

Alias/See Also

Epic: LAB2298

Preferred Specimen

Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 3 mL

Minimum Volume

0.25 mL

Other Acceptable Specimens

Specimen Type: Plasma
Collection Container: Green top (Lithium heparin)

Instructions

Centrifuge and separate cells after clot formation and within 1 hour of collection.

Transport Container

Plastic vial

Specimen Stability

Room temperature: 7 days
Refrigerated: 7 days
Frozen: 1 year

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Unlabeled, mislabeled, wrong tube type, QNS, hemolyzed.

Methodology

L-gamma-glutamyl-3-carboxy-4-nitroanalide Substrate

Setup Schedule

Daily

Report Available

Same day

Limitations

Bilirubin and Hemolysis can decrease GGT results by as much as 12-17%. Intralipid can increase GGT results by as much as 3%.

Reference Range

Males
11 - 88 U/L

Female
10 - 70 U/L

Clinical Significance

Renal tissue has the highest level of GGT, but is elevated in many forms of liver disease. GGT is elevated earlier and is more pronounced in obstructive jaundice and metastatic jaundice. It may reach 5 to 30 times normal levels in intra- or post hepatic biliary obstruction. GGT is also sensitive to alcohol use.

Performing Laboratory

Inova Laboratories

2832 Juniper Street

Fairfax, VA 22031

Last Updated: March 28, 2023
Last Review: N. Wolford, March 28, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.