title: Monitoring oxidative stress in acute-on-chronic liver failure by advanced oxidation protein products.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors: Tianjin Third Central Hospital, The Third Central Clinical College of Tianjin Medical University, Tianjin Key Laboratory of Artificial Cell, Tianjin Institute of Hepatobiliary Disease, Tianjin, China.
authors: Hua
authors: H
authors: Liu
authors: Tao
authors: T
authors: Han
authors: Jie
authors: J
authors: Tian
authors: Zheng-Yan
authors: ZY
authors: Zhu
authors: Ying
authors: Y
authors: Liu
authors: Yan
authors: Y
authors: Li
authors: Shi-Xiang
authors: SX
authors: Xiao
authors: Ying
authors: Y
authors: Li
authors: Yu-Ying
authors: YY
authors: Feng