Abstract: Objective The purpose of this study was to summarize the clinical and liver pathological features of patients with autoimmune hepatitis-primary biliary cholangitis overlap syndrome (AIH-PBC OS). Methods 42 patients with AIH-PBC OS were encountered in our hospital between March 2018 and March 2022, and all underwent liver biopsies and received ursodeoxycholic acid (UDCA) with or without prednisolone combination therapy for six months. Serum antinuclear antibody (ANA), anti-mitochondrial antibody (AMA), anti-mitochondrial antibody type II (AMA-M2), anti-nuclear membrane glycoprotein 210 antibody (gp210) and anti-soluble acidic phosphorylated nuclear protein (sp100) were detected. Results Among the 42 patients with AIH-PBC OS, 85.7% cases were female, and the average age of onset was (53.9±10.6) years; the abnormal rates of serum bilirubin, albumin and ALP levels were 57.1%, 60.0% and 75.7%, and the elevated serum ALT, AST and GGT levels were all more than 83.0%, and all but serum albumin, decreased greatly after six month treatment (P<0.05); the increased plasma immunoglobulin IgG, IgM and IgA levels were 69.0%, 52.3% and 33.3%; the positive rates of serum ANA, AMA, AMA2, gp210 and SP100 were 90.5%,73.5%,72.7%,47.1% and 36.7%, respectively; the common fluorescence models of ANA were cytoplasmic granules in 23 cases, centromere in 13 cases, and nuclear membrane in 8 cases; the liver histopathological examination showed the interface hepatitis, mainly mild-moderate inflammation, and mild hepatic fibrosis. Conclusion The female patients with AIH-PBC OS is more common, and the disease has the dual features of PBC and AIH. We recommend early administration of UDCA with or without steroid therapy, which might be helpful to improve the prognosis of patients with AIH-PBC OS.

Key words: Autoimmune hepatitis, Primary biliary cholangitis, Overlap syndrome, Clinical feature, Ursodeoxycholic acid, Prednisolone, Therapy