α-Gluthathione S-Transferase as an Early Marker of Hepatic Ischemia/Reperfusion Injury after Liver Resection

Organ dysfunction following liver resection is one of the major postoperative complications of liver surgery. The Pringle maneuver is often applied during liver resection to minimize bleeding, which in turn complicates the postoperative course owing to liver ischemia and reperfusion. Routinely, hepatocellular damage is diagnosed by, for example, abnormal aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and the prothrombin time (PT). The cytosolic liver enzyme α-glutathione S-transferase (α-GST) has recently been shown to have good sensitivity for detecting hepatic injury after acetaminophen poisoning or liver transplantation, but its role in non-transplantation liver surgery has not been assessed. In this prospective randomized clinical study, the diagnostic role of plasma α-GST following warm ischemia and reperfusion is reported. A total of 75 patients who underwent liver resection were randomly assigned to three groups: (1) without Pringle (NPR); (2) with Pringle (PR); (3) with ischemic preconditioning by 10 minutes of ischemia and reperfusion each prior to the Pringle manuever (IPC). The major findings are as follows: (1) ALT, AST, and α-GST increased upon liver manipulation as early as prior to resection, with a rapid return of α-GST values to preoperative levels, whereas ALT and AST further increased on the first postoperative day. (2) In the PR group, α-GST, but not ALT and AST, was significantly elevated compared with that in the NPR group at 15 and 30 minutes and 2 hours after resection/reperfusion. In addition, only levels of α-GST significantly correlated with the Pringle duration. (3) The ischemia/reperfusion-induced early rise in α-GST was completely prevented by ischemic preconditioning. Moreover, only α-GST concentrations (>490 μg L⁻¹) determined early after resection (2 hours) predicted postoperative liver dysfunction (24 hours PT < 60%) with a positive predictive value of 74% and a negative predictive value of 76%. Thus α-GST seems to be a sensitive, predictive marker of ischemia/reperfusion-induced hepatocellular injury and postoperative liver dysfunction.