The M2 antibodies belong to the group of Anti-Mitochondrial Antibodies (AMA) and are strongly associated with PBC. At least 9 distinct AMA have been identified, which have been classified M1-M9 according to their antigen specificity and disease association. Of these, only the M2 subtype approaches absolute specificity for PBC. Indeed, about 95 % of PBC patients have M2 autoantibodies and, conversely, about 90 % of asymptomatic individuals who are found to be M2-positive on routine screening can be shown to have underlying PBC on further investigation.

The target antigens of M2 antibodies have been identified as components of the 2-Oxo-Acid Dehydrogenase Complex, the immune-dominant epitopes being located on the E2 subunits of Pyruvate Dehydrogenase Complex (M2/PDC-E2), Branched-Chain Oxo-Acid Dehydrogenase Complex (M2/ BCOADC-E2) and Oxo-Glutarate Dehydrogenase Complex (M2/OGDC-E2). In most patients, anti-M2 antibodies are directed against various combinations of different epitopes/antigens. Particular cases are however regularly documented where they recognize a single epitope, either linear, conformational or cryptic, on a single subunit. This induces discordances between tests, depending on the antigen used. Indeed, high correlation with IFA results is obtained by using native PDC (M2/nPDC) alone. Highest sensitivity and information levels are obtained by using the whole spectrum of separated native and recombinant antigens.


Antigen used by D-tek

Recombinant, full-length, human, expressed in Baculovirus-infected Sf9 cells (for more information on our antigens click here)