Pretransplant Levels of Endotoxin Can Predict the Risk of Bacterial Infections and Graft Liver Function after Liver Transplantation

Abstract

Although endotoxin (Et) has been used as a biological index of bacterial infections, Et can also be used to evaluate liver functions because Et present in the portal vein blood is processed by the hepatic reticuloendothelial system. In the field of posttransplant management, it is important for liver transplant recipients to monitor the presence of posttransplant bacterial infections and graft liver functions because these results are directly correlated with a graft prognosis. Therefore, the measurement of Et during liver transplantation (LT) may be the detection of posttransplant infections and graft liver functions. This retrospective study investigated whether Et measured by the Et activity assay (EAA) in the peripheral venous blood during living donor LT (LDLT) can predict the incidence of posttransplant bacterial infections and graft liver functions. The study subjects consisted of 21 patients who underwent LDLT between April 2010 and February 2011. Et activity (EA) was measured using the EAA in peripheral venous blood samples collected 1 or 2 days before LDLT, and on postoperative days (PODs) 1, 5, 7, and 14. We included LDLT recipients with intra-abdominal infections, respiratory infections, and bacteremia in the group with posttransplant bacterial infections. The incidence rates of posttransplant bacterial infections or hyperbilirubinemia after LDLT were 57.1%. The LDLT recipients with posttransplant bacterial infections or hyperbilirubinemia had significantly higher levels of EA in comparison with patients without complications before LDLT (0.22 ± 0.10 vs. 0.07 ± 0.05, p < 0.001), but they had no statistically significant increase of EA between PODs 1 and 14. Based on a receiver operating characteristic curve analysis of pretransplant levels of EA in patients with posttransplant bacterial infections or hyperbilirubinemia, the recommended cutoff value to diagnose posttransplant bacterial infections or hyperbilirubinemia was set at 0.16 (sensitivity 83.3%, specificity 88.9%, and area under the curve 0.940). At a pretransplant level of EA greater than 0.16, patients had an augmented risk for developing posttransplant bacterial infections or hyperbilirubinemia.