Association between plasma level of superoxide dismutase and survival of patients with acute-on-chronic liver failure

BACKGROUND: Fewer than 50% of patients with acute-on-chronic liver failure (ACLF) recover spontaneously, and ACLF has high mortality without liver transplantation. Oxidative stress has been shown to mediate hepatic inflammation during acute liver failure (ALF). We wanted to see if a biomarker for oxidative stress might be used to measure the severity and prognosis of ACLF patients. METHODS: A retrospective cohort of 124 ACLF patients, as well as healthy individuals, liver cirrhosis and ALF patients, was studied between January 2015 and September 2018. The levels of plasma superoxide dismutase (SOD) were detected using an ELISA commercial kit, and the Kaplan–Meier method was used for survival analysis. RESULTS: Patients with ACLF had statistically higher plasma SOD levels than the controls did (healthy controls and liver cirrhosis patients); however, the levels did not differ from those in patients with ALF. The plasma SOD level may be an inexpensive, easily accessible, and significant independent prognostic index for mortality on multivariate analysis (HR = 1.201, 95% CI 1.001–1.403, P < 0.01) as well as the model for end-stage liver disease (MELD) score. A level of SOD > 428 U/mL was linked to a statistically significant increase in the likelihood of death or liver transplantation in ACLF patients. Combination of plasma SOD levels and MELD scores improved performance in measuring the severity and prognosis of ACLF patients. CONCLUSION: Patients with ACLF can be classified into high-risk and low-risk groups based on their plasma SOD levels at the time of admission to the hospital. The patient outcome is more closely connected with the combination of SOD level and MELD score than either value alone. This approach might be used to predict patient prognoses and prioritize liver transplant candidates.