[Interleukin-21 expression in serum of patients with acute-on-chronic liver failure and its significance].

To investigate the level of the serum IL-21 and its correlation with serum biochemical indices of liver function test in patients with acute-on-chronic liver failure. Sixty patients with acute-on-chronic liver failure (severe hepatitis group) and 18 normal cases (control group) were enrolled in the study. Peripheral blood lymphocytes were isolated and total RNA of lymphocytes was extracted by using Trizol. Real-time PCR was used to assay IL-21 mRNA level. The serum IL-21 expression level was detected by ELISA method. The correlation between IL-21 and ALT, AST, TBiL, ALB was analyzed using Pearson's correlation analysis, respectively. Serum IL-21 expression level in severe hepatitis group was higher than that of control group. Moreover, the difference between them was statistically significant (P < 0.05). Serum IL-21 level was positively correlated with serum ALT, AST, TBil, respectively (P < 0.05), but was negatively correlated with ALB, respectively (P < 0.05). Serum IL-21 expression level was increased in patients with acute-on-chronic liver failure and was associated with the severe of inflammation. We, therefore, believe that IL-21 might be involved in the pathogenesis of acute-on-chronic liver failure and might be an index of the severity of liver inflammation.