Diagnostic value of alpha-glutathione S-transferase as a sensitive marker of increased risk for hepatocellular damage in hepatitis C virus (HCV) infection: relation to HCV viraemia.

Hepatitis C Virus (HCV) infection is a disease characterized by a silent evolution, a wide fluctuation of transaminase activities, and the potential presence of significant histological lesions in patients with normal concentrations of transaminases. Alpha-Glutathione S-transferase (alpha-GST) is a class of enzymes responsible for cellular detoxifying processes. Its wide hepatic distribution, high cytosolic concentration, and short in vivo plasma half-life of this enzyme are properties, which may make monitoring this enzyme more clinically useful than conventional biochemical liver function tests as a marker of hepatocellular damage. This work was designed to study whether determining alpha-GST compared to other biochemical parameters might improve the assessment of patients with HCV infection, and to determine whether the increase in alpha-GST concentrations could reflect HCV viraemia. A total of 68 HCV infected patients along with 20 anti-HCV negative healthy subjects were enrolled in this study. HCV infected patients were tested for the presence of HCV RNA in their sera by polymerase chain reaction and evaluated with conventional liver biochemistry (ALT, AST and gamma-GT). Alpha-GST concentrations were determined in all cases and control subjects included in the study using an enzyme immunoassay. HCV viraemia was found in 36/68( 52.9%) seropositive patients. Alpha-GST levels were markedly elevated in HCV infected subjects compared to healthy controls (P < 0.001). Alpha-GST values were significantly higher than the cut off value in the 36 HCV viraemic patients compared to 81.3% of the HCV RNA-negative subjects (P < 0.05). The estimated alpha-GST concentrations were significantly above the cut off value in 91.2% of HCV infected subjects compared to 4.4% for ALT, 17.6% for AST and 41.2 % for gamma-GT (P < 0.001). In conclusion, measurement of alpha-GST levels in HCV infected patients could reflect liver injury more than biochemical markers. Therefore, it is possible that in combination with the other traditionally used liver markers; alpha-GST determination could provide another parameter, which may play a complimentary role in the assessment of hepatocellular damage caused by HCV.