Alternate Names : GGT, Gamma-Glutamyltranspeptidase, GGTP
Gamma-glutamyltransferase, also known as GGT, is an enzyme
that is found mainly in the liver. But it may also be found in the:
Who is a candidate for the test?
GGT levels are measured when a doctor suspects there is damage
or disease in the liver or the biliary system.
How is the test performed?
In order to measure the amount of GGT in the blood, a blood
sample is taken from a vein on the forearm or hand. First, the skin over the vein
is cleaned with an antiseptic. Next, a rubber tube called a tourniquet is tied
around the upper arm. This enlarges the veins in the lower arm by restricting
blood flow through them. A fine needle is gently inserted into a vein, and the
tourniquet is removed. Blood flows from the vein through the needle and is
collected in a syringe or vial for testing in the laboratory. After the needle is
withdrawn, the puncture site is covered for a short time to prevent bleeding.