In the previous study, we found serum thymosin β4 (Tβ4) levels were associated with mortality in liver failure patients. In this study, we try to evaluate the prognostic value of Tβ4 in acute-on-chronic liver failure (AoCLF) patients by comparing with the Child-Pugh (CTP) and Model for End-Stage Liver Disease (MELD) scores.

Serum Tβ4 levels were measured by enzyme-linked immunosorbent assay (ELISA), and the CTP and MELD scores were calculated for each patient.

Serum Tβ4 levels of AoCLF patients [0.4120 (0.2447–0.7492)μg/mL] were lower than healthy controls [9.2710 (5.1660–13.2485)μg/mL] (P<0.001). AoCLF patients were divided into survival and death group. Compared to survivors, lower Tβ4 concentrations, higher CTP and MELD scores (P<0.001, respectively) were observed in AoCLF patients who died. There were negative correlations between Tβ4 levels and CTP scores (P<0.001), MELD scores (P<0.001). A CTP score of 11.5, a MELD score of 21.63 and a Tβ4 concentration of 0.3840μg/mL were identified as the cut-off values for the stratification of AoCLF patients. MELD≥21.63 combined with Tβ4<0.3840μg/mL can more exactly discriminate between the patients who would survive and die.

Serum Tβ4 concentration has appreciable value to evaluate the short-term prognosis of AoCLF patients, although Tβ4 is not superior to MELD. The combination of Tβ4 and MELD scores are more effective in assessing the prognosis of AoCLF patients.