Diagnostic Criteria and Treatment Options for Autoimmune Hepatitis

Diagnostic Criteria

The diagnosis of autoimmune hepatitis (AIH) requires a combination of serological, biochemical, and histological findings, along with exclusion of other liver diseases, with treatment being essential for patients with moderate to severe disease to improve survival outcomes 1
AIH is characterized by hypergammaglobulinemia/elevated serum IgG, circulating autoantibodies, and a predominantly hepatitic pattern with bilirubin and aminotransferases ranging from just above normal to >50 times normal 2, 1
Female sex is a supportive feature that contributes to diagnostic scoring 1
The alkaline phosphatase (ALP) to AST (or ALT) ratio is typically <1.5 in AIH 1, 3
Elevated liver function tests and beta globulin are characteristic features reflecting hypergammaglobulinemia 3

Initial evaluation should include testing for antinuclear antibodies (ANA), smooth muscle antibodies (SMA), anti-liver kidney microsomal type 1 antibodies (anti-LKM1), and anti-soluble liver antigen (anti-SLA/LP) 4, 3, 2
Autoantibody patterns help classify AIH into Type 1 (ANA and/or SMA positive) and Type 2 (anti-LKM1 and/or anti-LC1 positive) 4

Liver biopsy is essential for diagnosis and evaluation of disease severity 2, 4, 3
Typical histological features include interface hepatitis with portal lymphocytic/lymphoplasmacytic infiltrates extending into the lobule 2

The International Autoimmune Hepatitis Group (IAIHG) scoring system includes gender, ALP:AST ratio, serum globulin/IgG levels, autoantibodies, viral markers, drug history, alcohol intake, histology, and other autoimmune diseases 1
The Simplified Scoring System (2008) includes autoantibodies, IgG or γ-globulin levels, liver histology, and absence of viral hepatitis 2

Must exclude viral hepatitis, drug-induced liver injury, Wilson's disease, alcoholic liver disease, non-alcoholic steatohepatitis, primary biliary cholangitis, and primary sclerosing cholangitis 2, 4, 3

Treatment is indicated for patients with moderate to severe AIH, young patients, symptomatic patients, and patients with cirrhosis 1, 3
Standard induction therapy includes prednisone and azathioprine 3
Treatment goals include normalization of transaminases and IgG levels, resolution of symptoms, and histological improvement with reduction of inflammation 3

Untreated moderate to severe AIH can progress to cirrhosis in 82% of patients within 5 years, with 45% mortality 1, 3
With treatment, approximately 80% of patients achieve remission 3
Regular monitoring should include liver function tests, IgG levels, screening for hepatocellular carcinoma in cirrhotic patients, and surveillance for esophageal varices in cirrhotic patients 3
Patients on immunosuppressants should receive counseling for UV-protective measures and dermatological monitoring for non-melanoma skin cancer 2