Abstract: Objective To investigate the changes of serum adenosine deaminase（ADA） levels in patients with autoimmune hepatitis（AIH） and its correlation to hepatic activity index and response to steroid therapy. Methods 70 patients with AIH were enrolled in our hospital between April 2013 and May 2016,all patients received liver biopsies under US guidance and serum ADA levels were detected by ELISA. The area under ROC was applied to evaluate the efficacy of every parameter for the diagnosis of hepatic interfacial inflammation and the influencing factors for non-response to steroid therapy was made by Logistic analysis. Results Serum ADA levels in 53 patients with active AIH,17 at remission and 38 healthy persons were （30.2±7.1）U/L,（16.5±4.3）U/L and （12.9±2.2） U/L,and the differences were significant （P<0.05）;serum ADA levels in 17 patients with mild,21 with moderate and 32 with severe hepatic interfacial inflammation were（16.5±4.3） U/L,（26.0±4.7） U/L and （32.9±7.2） U/L,and the differences were statistically significant（P<0.05）;the AUC for serum ADA to diagnose the interfacial inflammation was 0.867（95%CI：0.764-0.936）,the cut-off-value was 22.1 U/L,the sensitivity and specificity were 100.0% and 63.2%;univariate analysis showed that female,serum ADA,ALT,AST,TBIL,GGT,ALP,IgG,IgM,anti-gp210 positive and cirrhosis were related to non-response to steroid therapy and the Logistic analysis demonstrated that serum ADA,ALP and liver cirrhosis were the independent factors for failed steroid therapy. Conclusion Serum ADA levels in patients with AIH is closely related to hepatic activity index, which might be helpful in predicting the response of patients with AIH to steroid therapy.

Key words: Autoimmune hepatitis, Adenosine deaminase, Hepatic activity index, Steroid therapy, Response