ABSTRACT
DIAGNOSIS Autoimmune hepatitis is an unresolving inflammation of the liver of unknown cause that is associated with interface hepatitis on histologic examination, hypergammaglobulinemia, and autoantibodies. An international panel has codified the diagnostic criteria, and the definite diagnosis requires exclusion of hereditary (Wilson’s disease, genetic hemochromatosis, and alpha1-antitrypsin deficiency), viral (hepatitis A, B, or C virus infection), and drug-induced (minocycline, isoniazid, propylthiouracil, α-methyldopa, and nitrofurantoin) conditions (Table 1). The 6-month requirement to establish chronicity has been waived, and an acute, even fulminant, presentation has been recognized that may resemble acute viral or toxic hepatitis. A cholestatic form of autoimmune hepatitis is not recognized, and a marked increase (more than twofold the upper limit of normal) in the serum level of alkaline phosphatase or the presence of pruritus suggests another diagnosis. Celiac disease can be associated with a liver disease that resembles autoimmune hepatitis, and it should be excluded in patients with cryptogenic chronic hepatitis by screening for IgA antibodies to endomysium. Endomysial antibodies are more specific for celiac disease in autoimmune hepatitis than IgA antibodies to tissue transglutaminase which can be stimulated by hepatic inflammation and fibrogenesis.
