The Study On The Expression Of Interleukin-33/ST2 Pathway And Its Potential Role In HBV-related Acute-on-Chronic Liver Failure

Objective To investigate the dynamic changes of Interleukin(IL)-33/ST2 axis in HBV-related acute-on-chronic liver failure(HBV-ACLF),and determine the value of serum IL-33/soluble ST2(s ST2)as a novel prognostic biomarker and its possibility as a potential therapeutic target.Methods Serum levels of IL-33 and s ST2 in HCs,CHB and HBV-ACLF patients were detected by ELISA,and clinical data were collected.The ALF murine model was set up by intraperitoneal injection of D-Gal N(900mg/kg)/LPS(10ug/kg),with confirmation of histopathology and biochemistry.Dynamic expression profiles of intrahepatic IL-33 and its receptor ST2 L were investigated by Real-time PCR and Western-blot at different time points.Cellular source of intra-hepatic IL-33 in ALF model was examined by immunohistochemistry stain.Oxidative stress(OS)was induced by H2O2 in L02 cells,and the impact of IL-33 on cytotoxicity from OS was estimated by CCK-8.Results ELISA data showed an indiscriminately low level of serum IL-33 in HC,CHB and HBV-ACLF groups.But the levels of serum s ST2 in the three groups were so different:the CHB(34.00±4.55 ng/ml)and HBV-ACLF groups(82.19±7.61 ng/ml)had much higher levels of serum s ST2 than HC(9.86±1.10ng/ml),particularly the level of serum s ST2 in HBV-ACLF group being the highest.Then,HBV-ACLF patients were divided into survivors and nonsurvivors based on the follow-up outcomes,and we found serum s ST2 level of nonsurvivors was significantly higher than that of survivors at baseline(101.07±13.30 vs 63.59±6.13 ng/ml)(p<0.01).With the disease progression,serum s ST2 level of non-survivors remained almost unchanged and stayed at a high level(p>0.05),whereas serum s ST2 level of HBV-ACLF survivors drastically declined from week 1 to 4(p<0.001).Eventually,the gap of serum s ST2 level between HBV-ACLF survivors and non-survivors widened further over time(p<0.001).Furthermore,the correlations between serum s ST2 level and novel ACLF prognostic scoring systems were evaluated.It was observed that serum s ST2 level was positively correlated with CLIF-C OF,CLIF-C ACLF scoring systems and ACLF grades.By the analysis of ROC curves,it was proved that serum s ST2 had a good diagnostic accuracy for predicting 6-month mortality in HBV-ACLF patients,comparable to these prognostic scoring systems.Finally,HBV-ACLF patients were stratified into two groups by the cut-off point of serum s ST2 76ng/ml at baseline or 53 ng/ml at week 4.Compared with those below the cut-off point,HBV-ACLF patients with serum s ST2 above the cut-off point had a statistically higher mortality.In ALF murine model,we found that the m RNA level of intra-hepatic IL-33 continuously increased with the progression of ALF,and peaked at the last time point 7h.Intra-hepatic ST2 L protein level was up-regulated at 3h,but subsequently reduced to the lowest at 7h.Immunohistochemistry stain confirmed that intra-hepatic IL-33 was mainly located in the nucleus of endothelial cells and sinusoidal cells in ALF mice,which was the same to healthy mice.When oxidative stress(OS)was induced by H2O2 at concentration of 800 umol/L in L02 cells,treatment by IL-33 protein ranging from 10 ng/m L to 400 ng/m L for 24 hours didn't have a significant effect on cytotoxicity from OS.Conclusions IL-33/ST2 axis is indeed involved in the progression of HBV-ACLF.Furthermore,serum s ST2 may act as a novel promising biomarker to assess severity and predict prognosis of HBV-ACLF,providing reliable reference for promptly making treatment decisions.