Fractions of plasma gamma-glutamyltransferase in healthy individuals: Reference values

Gamma-glutamyltransferase (GGT) activity, long used as a biomarker of liver function and excessive alcohol use, has been recently recognized to be a biomarker of future occurrence of diabetes and cardiovascular events and, either in unselected populations, or in patients with ascertained ischemic heart disease. Although the assay is widely used, highly reproducible and sensitive, it holds a poor specificity. We recently set up a novel, highly reproducible and sensitive method for differentiating and quantifying four GGT activity fractions (“big”, “medium”, “small” and “free”: b-, m-, s-, and f-GGT, respectively) in human blood, by means of molecular exclusion chromatography. We aimed to assess the clinical potential of the method by establishing reference values in healthy subjects.