Monitoring oxidative stress in acute‐on‐chronic liver failure by advanced oxidation protein products

Abstract

Increased oxidative stress is important in the pathogenesis of acute-on-chronic liver failure (ACLF). This study aimed to investigate whether advanced oxidation protein products (AOPP) levels can monitor oxidative stress of ACLF patients. Furthermore, we aimed to study plasma exchange (PE) treatment and determine whether it can eliminate AOPP. We measured AOPP levels in 50 ACLF patients, 30 patients with compensated liver cirrhosis (CR), 30 patients with chronic hepatitis B (CHB) and 50 healthy controls by spectrophotometric assay. AOPP concentrations were also measured before and after PE treatment in ACLF patients. As an apoptosis marker, serum cytokeratin 18 (CK18 M 30) levels were detected to investigate the relationship between AOPP and apoptosis in ACLF patients. Significantly higher AOPP levels at admission were found in patients with ACLF compared with CR, CHB and healthy controls (69.45 ± 29.04 µmol/L vs. 19.67 ± 7.02 µmol/L, 26.75 ± 5.21 µmol/L and 21.35 ± 6.15 µmol/L, respectively; P < 0.001). There was a positive relationship with total bilirubin, Child-Pugh, model for end-stage liver disease scores and CK18 M 30. In ACLF patients, AOPP levels were higher in non-survivors than survivors. An AOPP cut-off of 74.21 µmol/L was used for predicting poor prognosis. Multivariate Cox regression analysis demonstrated that AOPP were independent risk factors for prognosis. Dynamic change of AOPP levels associated with prognosis appeared earlier than total bilirubin. Following PE treatment, AOPP levels reduced to 34.65 ± 18.14 µmol/L (P < 0.001). Advanced oxidation protein products were suitable for monitoring the levels of oxidative stress in ACLF patients. Increased AOPP may serve as an important biological marker of worse outcome. In addition, PE therapy was effective in reducing AOPP.