GGT: Not Just a Marker of Alcohol Use

From a liver test to a redox sensorFor many decades, a raised serum gamma-glutamyl transferase (GGT) was interpreted in only one of two ways, with the elevation being attributed either to excessive alcohol intake or to a disorder of the liver or biliary tract.Although the test is regarded as sensitive, it has long been considered notoriously non-specific.However, what has actually been altered is not the assay itself but the manner in which its results are understood.Increasingly, GGT is being viewed by researchers as a dynamic indicator of glutathione turnover rather than as a passive index of hepatic injury, and much of what can be learned from the enzyme is reorganized by that single conceptual shift.1,