Autoimmune hepatitis (AIH) is a form of chronic hepatitis due to autoimmune mechanisms which are not entirely clear. The disease occurs more commonly among females and in Caucasians and is characterized clinically by a wide range of presentations from asymptomatic patients to those with acute, fulminant disease. AIH also commonly occurs with other autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, thyroiditis, inflammatory bowel disease etc. Within the liver, the disease may also occur in so-called "overlap syndromes" with primary sclerosing cholangitis or primary biliary cholangitis.

Patients with AIH also typically have positive autoantibodies and elevated levels of IgG. AIH typically responds to treatment with immunosuppressive agents such as steroids and azathioprine. End stage liver disease due to AIH may be treated with liver transplantation.

The liver biopsy in this case shows features of severe hepatitis with marked interface and lobular activity featuring marked lymphoplasmacytic inflammation. As seen on the accompanying trichrome stain, early fibrosis is also present but mild. The marked degree of necroinflammatory activity and collapse of parenchyma in this case may mimic cirrhosis and careful examination of the trichrome stain will help to distinguish this from true fibrosis.

While this pattern of inflammation is not specific, correlation of these findings with the clinical history (with the exclusion of viral, drug, or other etiologies) and positive serology are supportive of AIH.

This slide shows H&E stain. See Related Content for Trichrome stain.