Abstract: Objective To evaluate plasma IL-21 levels in patients with alcoholic liver diseases and the effects of recombinant IL-21 on proliferation and activation of LX-2 hepatic stellate cells in vitro. Methods The plasma levels of IL-21 in patients with alcoholic hepatitis（n=17）,patients with alcoholic liver cirrhosis（n=51）,and healthy controls（n=20） were measured by ELISA;the LX-2 hepatic stellate cells were subjected to recombinant IL-21 at the concentration of 1 ng/ml or 10 ng/ml for 24 or 48 hours,then the cell proliferation and expression of α-smooth muscle actin were determined by CCK-8 and by FACs,respectively. Results Plasma levels of IL-21 were significantly elevated in patients with alcoholic hepatitis and cirrhosis as compared to that in healthy controls（P<0.05）,however,no significant difference was observed between patients with alcoholic hepatitis and patients with alcoholic cirrhosis,and no significant difference was found among cirrhotic patients with different Child class either;Incubation of LX-2 hepatic stellate cells with IL-21 at 1 ng/ml or 10 ng/ml for 24 or 48 hours did not affect cell proliferation,but significantly increased the expression of α-smooth muscle actin in the cells（P<0.05）. Conclusion IL-21 might contribute to the fibrogenesis in alcoholic liver diseases though induction of activation of hepatic stellate cells.

Key words: Alcoholic liver disease, LX-2 cells, Liver fibrosis, Hepatic stellate cells, Interleukin-21