Autoimmune liver disease diagnostic criteria primary biliary cirrhosis PBC diagnosis is based on 3 criteria: positive serum AMA, serum cholestasis, elevated enzymes for more than 6 months, and liver histopathology suggesting or supporting PBC. generally meeting 2 criteria is highly suggestive of PBC diagnosis, and meeting 3 criteria confirms the diagnosis. Diagnosis requires exclusion of other liver diseases, such as negative serum AMA and bile duct imaging to rule out primary sclerosing cholangitis. If patients have unexplained elevated alkaline phosphatase (normal bile ducts on ultrasound), PBC needs to be alerted and AMA examination can be performed. if AMA is negative, antinuclear antibody, SMA and immunoglobulin should be measured and liver biopsy histology should be performed if necessary. patients with positive AMA and normal alkaline phosphatase should be followed up and liver function tests should be performed annually. Some patients have all the typical clinical symptoms, biochemical features and histological manifestations of PBC, but are persistently negative for AMA. These patients are often described as having “autoimmune cholangitis” and require differential diagnosis from AIH. These patients may have other autoantibodies in their sera, such as anti-gp210, anti-P62 and anti-sp100 antibodies, which are now considered to be subtypes of PBC. The prognosis of PBC with positive anti-gp2l0 antibodies is relatively poor. Autoimmune hepatitis 1. Diagnostic criteria: Refer to the diagnostic recommendations of the International AIH Panel, see Table l. Confirmation of diagnosis depends mainly on the elevated level of serum gammaglobulin or IgG and the titer of anti-nuclear antibody, SMA or anti-liver and kidney microsomal Il antibody, and exclusion of other liver damage factors such as alcohol, drugs and hepatitis virus infection. In the absence of antinuclear, SMA, or antihepatorenal microsomal I-1 antibodies in the blood, the presence of perinuclear ANCA, anti-soluble liver antigen antibodies, hepatopancreatic antigen antibodies, anti-actin antibodies, anti-hepatocyte cytoplasmic type I antibodies, and anti-sialoglycoprotein receptor antibodies in the blood support the diagnosis of AIH. Liver pathology, although non-specific, is important for differential diagnosis and determination of disease severity. 2. Typing: There are 2 types according to autoantibodies. the main autoantibodies in the serum of patients with type I AIH are positive for antinuclear and/or SMA and/or anti-actin antibodies. other possible autoantibodies include perinuclear ANCA, anti-soluble liver antigen antibody/hepatopancreatic antigen antibody, the latter of which is highly specific for type I AIH. The main autoantibodies in the serum of patients with type II AlH are anti-hepatic and renal microsomal type Il antibodies and/or anti-hepatocyte cytoplasmic type I antibodies.