Anti mitochondrial antibody is typically seen in: March 2005

Ans. D: Primary biliary cirrhosis 90% of patients with primary biliary cirrhosis (PBC) have autoantibodies in their blood that react with the inner lining of mitochondria. These autoantibodies are called antimitochondrial antibodies (AMA). AMA specifically react against a component of this multienzyme complex called E2. In PBC, AMA preferentially react with the E2 component of one of the multienzymes that is called the pyruvate dehydrogenase complex (PDC). Accordingly, the antigen is designated as PDC-E2. The practical impoance of all of this is that the PDC-E2 antigen is now used,in a diagnostic test for PBC. The PDC-E2 antigen is also referred to as M2, a term introduced to designate it as the second mitochondrial antigen. P-ANCA (Perinuclear antineutrophil cytoplasmic antibody). It is positive in about 65% of patients with Primary sclerosing cholangitis (PSC).