Abstract: Objective The aim of this study was to explore diagnostic performance of serum procalcitonin (PCT), interleukin-26 (IL-26) and interferon-γ (IFN-γ) levels and model for end-stage liver disease (MELD) score in predicting secondary infection in patients with hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF). Methods 71 consecutive patients with HBV-ACLF were enrolled in our hospital between January 2021 and December 2024, serum PCT level was detected by fluorescence immunochromatography, serum IL-26 and IFN-γ levels were detected by ELISA, and MELD scores were calculated. Multivariate Logistic regression analysis was applied to find risk factors, and receiver operating characteristic curve and the area under the curve (AUC) was obtained to evaluate diagnostic efficacy. Results Of the 71 patients with HBV-ACLF, secondary bacterial infection was found in 34 cases (47.9%); serum PCT, IL-26 levels and MELD score in patients with infection were (2.7±1.0)ng/mL, (223.8±74.3)pg/mL and (29.5±4.2), all significantly higher than [(0.3±0.1)ng/mL, (135.7±32.4)pg/mL and (22.3±3.6), respectively, ,P＜0.05], while serum IFN-γ level was (20.2±5.5)ng/mL, significantly lower than [(55.7±8.4)ng/mL, P＜0.05] in those without infection; multivariate Logistic regression analysis showed that serum PCT(OR=2.214, 95%CI:1.264-3.879), IL-26(OR=2.040,95%CI:1.162-3.581), IFN-γ(OR=3.854, 95%CI:1.063-13.967) and MELD score (OR=2.492, 95%CI:1.474-4.213) were all independent risk factors for secondary infection in patients with HBV-ACLF(P＜0.05); the AUC was 0.978, with sensitivity of 94.1% and specificity of 96.5%, when serum IFN-γ, PCT and IL-26, and MELD was combined for prediction of infection in patients with HBV-ACLF, much superior to any parameter did alone. Conclusion Combination of serum PCT, IL-26, IFN-γ levels and MELD score has a certain predictive efficacy for secondary infection in patients with HBV-ACLF.

Key words: Acute-on-chronic liver failure, Infection, Procalcitonin, Interleukin-26, Interferon-γ, Model for end-stage liver disease, Diagnosis