Abstract: Objective This clinical trial was conducted to observe the changes of peripheral blood myeloid inhibitory cells (MDSCs), serum leukocyte differentiation antigen 38 (CD38) level and hepatic interleukin-35 (IL-35) expression in patients with autoimmune hepatitis (AIH) undergoing prednisone and azathioprine combination therapy. Methods 56 patients with AIH were recruited in our hospital between March 2017 and March 2020, and were randomly divided into control (n=28) and observation (n=28) group, receiving prednisone acetate or prednisone acetate plus azathioprine combination therapy. The regimen lasted for 6 to 36 months. Serum immunoglobulin, CD38, complement 3 (C3) and C4 levels were routinely detected. The percentage of peripheral blood MDSCs was measured by TCM, and hepatic IL-35 expression was determined by Western bloting from liver biopsy tissues. Results At the end of six month treatment, serum ALT and AST levels in the observation group were (54.6±7.1)U/L and (50.7±6.4)U/L, both significantly lower than [(90.7±11.9)U/L and (79.7±12.9)U/L, respectively, P<0.05] in the control; serum IgG, IgM, C3 and C4 levels in the observation were (11.8±1.8)g/L, (2.4±0.8)g/L, (0.5±0.2)g/L and (0.2±0.1)g/L, all significantly lower than [(19.8±3.0)g/L, (3.2±0.9)g/L, (0.7±0.3)g/L and (0.3±0.1)g/L, respectively, P<0.05] in the control; the percentage of peripheral blood MDSCs and serum CD38 level were (0.6±0.2)% and (8.6±2.5)pg/mL, both much lower than [(0.9±0.3)% and (11.5±3.8)pg/mL, P<0.05] in the control group, and the hepatic IL-35 expression became weaker as compared to that in the control, e.g., [(0.4±0.2) vs. (0.6±0.1), P<0.05]. Conclusion The combination of prednisone and azathioprine therapy in the treatment of patients with AIH could improve liver function test normal, reduce serum cytokine and complement levels, and decrease the hepatic IL-35 expression, which needs further investigation.

Key words: Autoimmune hepatitis, Prednisone, Azathioprine, Myeloid suppressor cells, Leukocyte differentiation antigen-38, Interliukin-35, Therapy