SP100 and primary biliary cholangitis: Antimitochondrial antibodies (AMA) targeting the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2) of the inner mitochondrial membrane are highly specific for PBC and are present in more than 90% of patients, while certain antinuclear antibodies, namely antiglycoprotein 210 (anti-gp 210) and anti-sp100, occur in up to 50% of AMA negative PBC patients, highlighting the complexity of PBC pathogenesis (12–14).