A prognostic score for patients with acute-on-chronic liver failure treated with plasma exchange-centered artificial liver support system

Artificial liver support system (ALSS) therapy is widely used in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). We aimed to develop a predictive score to identify the subgroups who may benefit from plasma exchange (PE)-centered ALSS therapy. A total of 601 patients were retrospectively enrolled and randomly divided into a derivation cohort of 303 patients and a validation cohort of 298 patients for logistic regression analysis, respectively. Five baseline variables, including liver cirrhosis, total bilirubin, international normalized ratio of prothrombin time, infection and hepatic encephalopathy, were found independently associated with 3-month mortality. A predictive PALS model and the simplified PALS score were developed. The predicative value of PALS score (AUROC = 0.818) to 3-month prognosis was as capable as PALS model (AUROC = 0.839), R score (AUROC = 0.824) and Yue-Meng’ score (AUROC = 0.810) (all p > 0.05), and superior to CART model (AUROC = 0.760) and MELD score (AUROC = 0.765) (all p < 0.05). The PALS score had significant linear correlation with 3-month mortality (R(2) = 0.970, p = 0.000). PALS score of 0–2 had both sensitivity and negative predictive value of > 90% for 3-month mortality, while PALS score of 6–9 had both specificity and positive predictive value of > 90%. Patients with PALS score of 3–5 who received 3–5 sessions of ALSS therapy had much lower 3-month mortality than those who received 1–2 sessions (32.8% vs. 59.2%, p < 0.05). The more severe patients with PALS score of 6–9 could still benefit from ≥ 6 sessions of ALSS therapy compared to ≤ 2 sessions (63.6% vs. 97.0%, p < 0.05). The PALS score could predict prognosis reliably and conveniently. It could identify the subgroups who could benefit from PE-centered ALSS therapy, and suggest the reasonable sessions. Trial registration: Chinese Clinical Trial Registry, ChiCTR2000032055. Registered 19th April 2020, http://www.chictr.org.cn/showproj.aspx?proj=52471.