Abstract: Objective The aim of this study was to compare the clinicopathological features between patients with autoimmune hepatitis (AIH) and drug-induced liver injury (DILI). Methods 62 patients with AIH and 104 patients with DILI were encountered in our hospital between January 2018 and March 2022, and all underwent liver biopsies. The hepatic inflammation and fibrosis was evaluated by Ishak scores. Results The percentage of female cases in patients with AIH was 75.8%, much higher than 53.8% in patients with DILI (P<0.05); serum AST and immunoglobulin G levels in patients with AIH were 134(58, 312)U/L and 17.4(12.8, 20.4)mg/dL, significantly higher than [57(32, 135)U/L and 13.6(10.9, 15.7)mg/dL, respectively, P<0.05], while serum albumin level was 37.0(32.4, 40.6)g/L, significantly lower than [(42.2(36.8, 44.3)g/L, P<0.05] in patients with DILI; the incidence of interfacial hepatitis, plasma cell infiltration, rosette formation and lymphocyte infiltration in patients with AIH were 91.9%, 71.0%, 62.9% and 51.6%, all significantly higher than 16.3%, 29.8%, 21.1% and 17.3%, respectively, in patients with DILI (P<0.05); the incidences of fibrosis score 0, 1, 2, 3, 4, 5 and 6 in patients with AIH were 6.4%, 6.4%, 9.7%, 50.0%, 14.5%, 8.1% and 4.8%, significantly different compared to 25.0%, 35.6%, 29.8%, 7.7%, 1.9%, 0.0% and 0.0% in patients with DILI (P<0.05), suggesting more severe fibrosis in patients with AIH. Conclusion There are differences as respect to blood biochemistry, plasma immunoglobulin, and liver histopathology between patients with AIH and DILI, and among them, the liver tissue changes in patients with AIH is characterized by interfacial hepatitis, portal inflammation and liver fibrosis, which might help differentiate them.

Key words: Autoimmune hepatitis, Drug-induced liver injury, Immunoglobulin, Interfacial hepatitis, Liver fibrosis