The Variant Forms of Autoimmune Hepatitis

OBJECTIVES: To review the diagnostic criteria for autoimmune hepatitis, to characterize the variant forms of autoimmune hepatitis, and to indicate appropriate therapies for this condition. DATA SOURCES: A MEDLINE search (1990 to 1995) of the English-language literature, review of a personal library of journals and reprints (1975 to 1995), and review of references selected from the bibliographies of identified articles. Terms used in the MEDLINE search included the names of all autoimmune liver diseases, viral hepatitis and autoimmunity, cryptogenic hepatitis, and overlap syndromes. STUDY SELECTION: All articles that discussed atypical clinical features, mixed diagnostic findings, and variations in treatment response were selected. DATA EXTRACTION: Data were selected from 548 articles. DATA SYNTHESIS: Standardized criteria permit the confident diagnosis of autoimmune hepatitis, but they exclude many patients who have features suggesting autoimmunity. Such patients have findings indicative of both autoimmune hepatitis and another disorder (overlap syndromes) or findings that are inconsistent with the classic definition of autoimmune hepatitis (outlier syndromes). Overlap syndromes include combinations of autoimmune hepatitis and primary biliary cirrhosis, primary sclerosing cholangitis, or chronic viral hepatitis. Treatment of these syndromes requires identification of the predominant disorder and selection of the most appropriate drug regimen. Outlier syndromes include autoimmune cholangitis and cryptogenic chronic hepatitis. Corticosteroids or ursodeoxycholic acid are treatment options for patients with autoimmune cholangitis; corticosteroids can also benefit patients with cryptogenic chronic hepatitis. Grading each clinical feature and developing a composite score can permit comparison of the variants and a determination of the similarity between the variants and autoimmune hepatitis. CONCLUSIONS: Variant forms of autoimmune hepatitis are common. Recognition of them is important in assessing common pathogenic mechanisms, developing effective treatment strategies, and refining classification schemes.