PDC and primary biliary cholangitis: AMA, the hallmark of PBC, can be detected in approximately 90% of patients with PBC.[2] AMA recognizes the 2-oxo-acid dehydrogenase complex located in the inner membrane of the mitochondria, which mainly comprises the pyruvate dehydrogenase complex E2 subunit (PDC-E2), the 2-oxo-glutaric acid dehydrogenase complex E2 subunit (OGDC-E2), and the branched-chain 2-OADC E2 subunit (BCOADC-E2).[4] As the most disease-specific autoantibodies, AMA serves as a serological marker for diagnosing PBC.