Autoimmune liver diseases

Autoimmune-type chronic active hepatitis (AI-CAH) and primary biliary cirrhosis (PBC) are the two main autoimmune liver diseases. Although the etiologic agents of autoimmune liver diseases are unknown, a loss of tolerance against self antigens is regarded to be responsible for target cell destruction, that is, hepatocytes in AI-CAH and bile duct epithelia in PBC. AI-CAH is heterogeneous, and at least three different subgroups of AI-CAH can be distinguished by circulating autoantibodies including antinuclear antibodies (ANA), liver membrane autoantibodies (LMA), liver kidney microsomal antibodies (LKM), and antibodies to a soluble liver antigen (SLA). This has clinical relevance, because only autoimmune-type CAH seems to profit from immunosuppressive therapy. These serologic diagnostic markers may help to distinguish AI-CAH from CAH due to non-A, non-B virus infection. Antimitochondrial antibodies (AMA) and their PBC-specific subtypes characterize PBC, a chronic progressive cholestatic liver disease. Despite numerous therapeutic trials in the past, an effective medical treatment is not available. However, good results have been observed with orthotopic liver transplantation in end-stage PBC. This article has characterized autoimmune liver diseases, dealing with clinical, histologic, and immunopathologic aspects and concentrating on immune phenomena leading to their diagnosis. This has therapeutic consequences.