Superoxide dismutase 2 as a predictor in patients with hepatitis B virus-associated acute-on-chronic liver failure

The prognosis of hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) is critical in clinical management. We aimed to assess the prognostic efficacy of superoxide dismutase 2 (SOD2) for 90-day mortality in HBV-ACLF patients. The expression patterns of SOD2 in peripheral blood mononuclear cells (PBMCs) were examined in a derivation set (n = 82) by quantitative real-time polymerase chain reaction (RT-qPCR). The results were further validated in a validation set (n = 35). The expression levels of SOD2 were significantly decreased in the derivation set compared to those with chronic hepatitis B (CHB) or the healthy controls (HCs) (P < 0.001). In HBV-ACLF patients, SOD2 levels were negatively correlated with serum total bilirubin (TBIL) (rs = - 0.43, P < 0.001) and model for end-stage liver disease (MELD) scores (rs =  -  0.22, P = 0.047), but positively correlated with alkaline phosphatase (AKP) (rs = 0.23, P = 0.034). SOD2 was identified as an independent risk factor for 90-day mortality in HBV-ACLF patients (hazard ratio: 0.124, 95% confidence interval: 0.059-0.261, P < 0.001). SOD2 yielded a larger area under the receiver operating characteristic curve (AUROC) than the MELD score in predicting 90-day mortality (0.914 vs. 0.712, P < 0.001). Kaplan-Meier analysis revealed a favorable overall survival (OS) for the SOD2 high expression group compared with the SOD2 low expression group in both the derivation and validation sets (P < 0.001). SOD2 has promising potential as a predictor of 90-day mortality in patients with HBV-ACLF.