The goal of this observational study is to clarify the clinical characteristics of autoimmune hepatitis (AIH) in China. The main questions it aims to answer are:

Human leukocyte antigen (HLA) gene susceptibility in Chinese AIH patients prognostic factors associated with AIH Participants will provide liver tests results and details of treatment during follow-up.

This study aims to establish a high-quality, standardized prospective cohort of AIH with regular follow-up, clarify the clinical characteristics of AIH in China, construct a prognostic model, and explore new serum markers or AIH gene susceptibility, so as to provide key clinical evidence for the prevention and treatment of AIH in China.

Inclusion Criteria:

1. ≥18 years old at the time of onset;
2. AIH simplified score ≥6 and/or AIH revised score ≥10;
3. Liver biopsy was performed and consistent with the pathological diagnosis of AIH;
4. Patents were treatment naive or who were diagnosed and treated in other hospitals but have stopped glucocorticoid/immunosuppressive therapy for more than 3 months;
5. Agree to participate in this study and sign the informed consent form.

Exclusion Criteria:

1. concomitant liver diseases: hepatotropic viral hepatitis (A, B, C, D, and E) and non-hepatotropic viral hepatitis (cytomegalovirus and Epstein-Barr virus (EBV) infection);
2. concomitant with drug-induced liver injury, primary biliary cholangitis, primary sclerosing cholangitis, alcoholic liver disease, genetic and metabolic liver diseases;
3. bone marrow or liver transplantation;
4. incomplete baseline medical history and laboratory examination results;
5. for previously diagnosed patients, immunosuppressive therapy was discontinued less than 3 months;
6. Pregnancy or lactation;
7. patients with contraindications to glucocorticoid/immunosuppressive therapy;
8. complicated with other malignant tumors;
9. complicated with mental disorders.

AIH patients who fulfilled the inclusion and exclusion criteria were enrolled in this study.