Abstract: Objective The purpose of this study was to investigate the changes and implication of polyreactive IgG (pIgG)levels in patients with autoimmune hepatitis (AIH). Methods 48 patients with AIH were recruited in our hospital between September 2022 and June 2024, all patients underwent liver biopsy and were treated with standardized immunosuppressive therapy for six months. Serum pIgG level was assayed and calculated. Results Serum ALT, AST, bilirubin and pIgG levels at baseline in 29 patients with severe degree of liver activity were (152.8±35.2) U/L, (128.3±32.6)U/L, (73.1±23.5)μmol/L and (83.5±23.2)mg/L, all significantly higher than [(72.5±15.6) U/L, (68.3±16.8)U/L, (27.8±6.3)μmol/L and (45.4±15.8)mg/L, respectively, P<0.05] in 19 patients with mild to moderate degree, while there was no significant difference as respect to serum IgG levels between them (P>0.05); serum pIgG level in 31 patients with liver histoactivity of G3/G4 was (84.6±25.0)mg/L, much higher than [(44.5±16.3)mg/L, P<0.05] in 17 patients with G1/G2; by end of six-month immunosuppressive therapy, complete biochemical response (CR) was obtained in 38 cases (79.2%), and 10 patients (20.8%)didn’t; serum pIgG level in patients with CR was (42.0±11.7) mg/L, much lower than [(81.8±17.2)mg/L, P<0.05] in non-responders, while there was no significant difference as respect to serum IgG levels between the two groups (P>0.05). Conclusion Serum pIgG level might serve as a novel biomarker for assessing disease activity and predicting treatment response in patients with AIH, which warranted further clinical investigation.

Key words: Autoimmune hepatitis, Standardized immunosuppressive therapy, Polyreactive IgG, Therapy