Soluble ST2 Serum Concentration Predicts Efficacy of Artificial liver support system in Acute-on-chronic liver failure
Authors: Qiang Rui , Zhu Li , Xu Jun-Chi , Chen Hui , Li Ming , Zhu Chuan-Wu , Xu Ping 
Published: April 2022

Abstract
Background & Objective: It has been proven that artificial liver support system (ALSS) treatment can reduce the short-term mortality rate of acute-on-chronic liver failure (ACLF) by 30% and increase the long-term survival rate of ACLF patients by 50%. However, at present, there are poor specificity and sensitivity of a single index for predicting the efficacy of ALSS treatment. Therefore, it is found that the biological detection indexes with higher sensitivity and specificity will further improve and simplify the evaluation system of ALSS treatment. Studies related to sST2 and ACLF showed that sST2 is inversely proportional to the survival time of patients, and sST2 can be used as an index to judge the prognosis of ACLF. However, the existing studies have not explored the relationship among sST2, ACLF and ALSS, and whether sST2 can be an independent biological index for predicting the efficacy of ALSS treatment remains to be further verified.Methods: In this study, ACLF patients from October 2017 to July 2021 in the Affiliated Infectious Disease Hospital of Soochow University were selected. The residual sera of ACLF patients were collected within 30 days after ALSS treatment, and the content of sST2 in serum was determined by ELISA method, Survival curve, ROC curve and other statistical methods were used to analyze the relationship between sST2 and the efficacy of ALSS treatment.Results: This study found that similar to other independent influencing factors (TBIL, ALT, AST, PT, PTA and INR), the expression of sST2 in peripheral blood of ACLF patients after ALSS treatment decreased significantly, which was positively correlated with the levels of inflammatory injury index ALT (P < 0.0001) and coagulation indexes PT (P < 0.0001) and INR (P < 0.0001), and negatively correlated with PTA (P < 0.0001). Further survival curve analysis showed that after ALSS treatment, the short-term mortality (30 days) of patients with high sST2 value was higher than that of patients with low sST2 value, and the survival time was lower. After 20 days, the survival rate was lower than 50%, with statistically significant difference (Log-rank P=0.0023) and the statistical difference was greater than that of known biological indexes such as TBIL (Log-rank P=0.0385), PT (Log-rank P=0.0357) and INR (Log-rank P=0.0138). ROC curve analysis also showed that the AUC value of sST2 was significantly higher than other indexes, and its cut-off value was 312,500.00 pg/ml, and its sensitivity and specificity were 78.3% and 59.9%, respectively. Based on the time axis curve, it was that the level of sST2 in the survival group was significantly lower than that in the death group (P=0.0244) from the 4th day, and the difference between the survival group and the death group widened with the passage of time, suggesting that sST2 is less affected by time.Conclusions: In this study, the relationship between sST2 and the efficacy of ALSS treatment on ACLF is analyzed for the first time, and it is found that sST2 is an independent factor for predicting the efficacy of ALSS treatment. Compared with traditional indicators TBIL, ALT, AST, PT, PTA and INR, sST2 has better predictive value, higher sensitivity and specificity, which is less affected by time factors. The results of this study provide more accurate, sensitive and earlier biological indicators for predicting the efficacy of ALSS treatment.