Abstract: Objective The aim of this study was to observe the efficacy of combination of ursodeoxycholic acid (UDCA) and prednisone and azathioprine in the treatment of patients with autoimmune hepatitis (AIH).Methods 120 AIH patients were recruited in the Department of Gastroenterology in our hospital between February 2017 and December 2019, and were randomly divided into control and observation groups with 60 cases in each group. The patients in the control received prednisone and azathioprine, while those in the observation group received UDCA at base of prednisone and azathioprine therapy. The regimen lasted for 21 months. Serum complement 3 (C3), C4, as well as immunoglobulin were detected.Results At the end of the treatment, serum alanine aminotransferase level in the observation group was (55.2±6.9)U/L, significantly lower than 【(91.2±12.8)U/L, P<0.05】, serum aspartate aminotransferase level was (59.7±7.5)U/L, significantly lower than 【(101.5±13.5)U/L, P<0.05】, serum alkaline phosphatase level was (122.4±15.7)U/L, much lower than 【(138.9±15.2)U/L, P<0.05】, and serum glutamyl transpeptidase level was (120.7±10.1)U/L, significantly lower than 【(161.5±20.7)U/L, P<0.05】 in the control; serum C3 level in the observation was (0.6±0.1)g/L, significantly lower than 【(0.8±0.2)g/L,P＜0.05】, and serum C4 level was (0.1±0.1)g/L, significantly lower than 【(0.2±0.1)g/L, P＜0.05】 in the control; serum IgG level in the observation group was (12.5±2.0)g/L, significantly lower than 【(20.4±2.7)g/L, P＜0.05】, and serum IgM level was (2.7±0.9)g/L, significantly lower than 【(3.4±1.1)g/L, P＜0.05】 in the control.Conclusion The administration of ursodeoxycholic acid at base of prednisolone and azathioprine combination in the treatment of patients with AIH could effectively reduce serum C3 and C4 levels, improve immune functions and alleviate liver injury, which needs further investigation.

Key words: Autoimmune hepatitis, Ursodeoxycholic acid, Prednisone, Azathioprine, Complement C3, Complement C4, Therapy