Primary and secondary autoimmunity in hepatology

Primary autoimmune liver diseases can be hepatitic or cholestatic in nature. Autoimmune hepatitis, more often diagnosed in women, is characterized by biochemical and histological activity, with polyclonal hypergammaglobulinemia as a frequent feature. Antinuclear and anti-smooth muscle antibodies are the serological hallmarks of type 1 autoimmune hepatitis, whereas liver-kidney microsomal antibody type 1 and liver cytosol antibody type 1 designate the type 2 form. Response to immunosuppression is usually excellent. The most frequent cholestatic autoimmune disease is primary biliary cirrhosis, characterized by anti-mitochondrial antibody positivity and typical bile duct lesions observed on liver biopsy. Treatment with biliary acids improves the biochemical picture, may alleviate pruritus, and delays the development of end-stage liver disease. Primary sclerosing cholangitis occurs more frequently in men and affects both the intra- and extrahepatic biliary trees, determining the typical "beading" appearance. Associated inflammatory bowel diseases are often observed. To date, no medical therapy is able to modify the course of this disease. Autoimmune cholangitis is an anti-mitochondrial antibody-negative cholestatic disease with most of the features of primary biliary cirrhosis. "Overlap" syndromes where autoimmune hepatitic and cholestatic features coexist in the same patient, have also been reported. Autoimmune phenomena secondary to hepatitis C virus-related liver disease such as the occurrence of antinuclear, anti-smooth muscle antibodies and liver-kidney microsomal antibody type 1 are often observed.