Gamma-glutamyl transferase (GGT) is an enzyme present throughout the body, with the highest concentrations in the liver. GGT plays a crucial role in glutathione metabolism, which is essential for antioxidant defence. It facilitates the transfer of amino acids and peptides across cell membranes. Raised GGT levels are commonly used as a marker to detect liver damage, particularly bile duct obstruction and liver conditions associated with alcohol consumption.
High GGT levels can be caused by: