[The clinical laboratory in the diagnosis of autoimmune liver diseases]

The mechanism of production of autoimmune diseases is a loss of tolerance to autoantigens, which in turn produces a destruction of target organs. We review two autoimmune liver diseases which are non-organ specific: autoimmune chronic active hepatitis and primary biliary cirrhosis. The former is classified in three types according to its' profile of autoantibodies: type 1, in which anti smooth muscle and antinuclear autoantibodies are found in high titers; type 2, is characterized by the presence in serum of anti liver/kidney and anti cytosolic 1 autoantibodies; in type 3 anti soluble liver antigen antibody is present, results in this last type of autoimmune hepatitis await confirmation. In primary biliary cirrhosis the most important advance in the serologic diagnosis has been in the classification of anti mitochondrial antibodies. Up to now 9 different types of these antibodies are known, 4 of which are found in this disease: anti M2, anti M4, anti M8 and anti M9. Anti M2 and/or anti M9 are associated with a benign course of the disease, whereas anti M2, anti M8 and anti M8 are associated with a progressive course.