Abstract: Objective The aim of this study was to investigate implication of serum macrophage migration inhibitory factor (MIF) and interleukin-21 (IL-21) level changes in patients with autoimmune hepatitis (AIH). Methods 61 consecutive patients with AIH were encountered in our hospital between December 2017 and November 2022, and all received standardized immunosuppressive therapy by prednisone and azathioprine combination. Liver biopsies were performed and serum MIF and IL-21 levels were assayed by ELISA at presentation. Results Serum MIF and IL-21 levels in 17 patients with clinically determined severe liver injury were (2.5±0.9)μg/L and (321.5±34.2)pg/mL, both much higher than [(1.5±0.5)μg/L and (174.7±20.5)pg/mL, respectively, P<0.05] in 44 patients with mild to moderate liver injury; serum MIF and IL-21 levels in 26 patients with histo-pathologicall proved G3-G4 inflammatory activity were (2.6±1.1)μg/L and (332.9±35.4)pg/mL, both much higher than [(1.5±0.6)μg/L and(170.8±25.4)pg/mL, respectively, P<0.05] in 35 patients with G1-G2 inflammatory activity; of our series, 54 patients (88.5%) responded biochemically to standardized immunosuppressive therapy, and serum MIF and IL-2 levels in 19 patients responded late after six months were(2.9±1.5)μg/L and (334.5±40.6)pg/mL, significantly higher than [(1.5±0.3)μg/L and (194.8±19.5)pg/mL, respectively, P<0.05] in 22 patients who responded less than six months or [(0.9±0.2)μg/L and (100.6±9.2)pg/mL, respectively, P<0.05] in 23 patients who responded less than three months. Conclusion Serum MIF and IL-21 levels in patients with AIH elevate, which might influence liver injury and response to immunosuppressive therapy, and warrants further investigation.

Key words: Autoimmune hepatitis, Standardized immunosuppressive therapy, Macrophage migration inhibitory factor, Interleukin-21, Response