Abstract: Objective To evaluate the value of serum complement C3 and C4 in the diagnosis of autoimmune hepatitis patients. Methods From October 2011 to May 2017,87 patients with autoimmune hepatitis were treated with 44 cases of remission and 43 cases of active.Biochemical indicators of liver function in two groups by automatic biochemistry analyzer for detection of complement C3,C4,IgA,IgG,IgM,by turbidimetry was detected in peripheral blood,and detect liver biopsy. Results The levels of ALT,AST,TBIL,DBIL,GGT,ALP and IgG in patients with autoimmune hepatitis were significantly higher than those in patients with autoimmune hepatitis remission （P<0.05）. The level of autoimmune hepatitis （P<0.05）. The expression of C3 in all patients was significantly lower than that in patients with autoimmune hepatitis remission （P<0.05）. The expression of C3 in all patients was negatively correlated with AST,TBIL and DBIL （P<0.05）. There was no significant correlation between the expression of C3 and the levels of ALT,AST,TBIL,DBIL,GGT and ALP （P>0.05）. There was no significant correlation between ALT expression,ALT,ASTG,DBIL,GGT and ALP levels. The expression of C4 in 19 patients with autoimmune hepatitis was negatively correlated with （Histological activity index） HAI score （P<0.05）. Conclusion The levels of C3 and C4 in serum of patients with autoimmune hepatitis were significantly decreased,which provided a reliable basis for early diagnosis and early treatment.

Key words: Serum complement C3, Serum comple ment C4, Autoimmune hepatitis, Disease assessment, Clinical value