Anti-mitochondrial autoantibodies

Anti-mitochondrial antibodies (AMA) are a serological hallmark of primary biliary cirrhosis (PBC). The major autoantibody targets are located in the inner mitochondrial membrane, are encoded by nuclear genes and are components of the 2-oxo acid dehydrogenase complexes. Greater than 90% of PBC patients react with one or more of these autoantigens. The major epitopes have been mapped to the lipoic acid binding domain. The apparent hepatic targets of immune destruction, the apical biliary epithelial cells, express proteins that mimic these epitopes. Nevertheless, the role of AMA in biliary pathology is not clear and observed abnormalities may be due to T-cells that respond to similar epitopes. AMAs are often accompanied by autoantibodies to other intracellular components such as the nuclear pore complex, centromeres/kinetochores, and other nuclear antigens. The origin or inciting agent(s) of AMA is not known but epidemiological and immunological evidence implicates environmental agents.