Antigen Test Boosts Detection of Primary Biliary Cirrhosis

A new enzyme-linked immunosorbent assay (ELISA) significantly increases the serological detection rate for primary biliary cirrhosis (PBC).

The assay, which is based on a designer recombinant fusion protein, provides unparalleled sensitivity for detection of autoantibodies against the mitochondrial antigen M2 (AMA-M2) in the diagnosis of primary PBC.

The novel fusion protein combines the immunogenic domains of all three relevant enzyme complexes (3E) of the M2 antigen, presenting them in a defined stoichiometric relationship. This designer antigen is used together with the classical target antigen native pyruvate dehydrogenase in the new EUROIMMUN (Luebeck, Germany) anti-M2-3E ELISA. The extended antigen spectrum and the resulting increase in diagnostic efficiency make the test a powerful new tool for PBC diagnostics.

In a study with 170 sera from clinically characterized PBC patients the new Anti-M2-3E ELISA demonstrated a 14% higher sensitivity than a conventional Anti-M2 ELISA.

The Anti-M2-3E ELISA is easy to perform and, like other EUROIMMUN ELISAs, can be fully automated on the company's Analyzer I and I-2P systems. These flexible instrument systems offer reliable automated processing of an extensive range of validated parameters for autoimmune diagnostics, infectious serology, and allergology.

PBC is an immune-mediated chronic inflammatory cholestatic liver disease of unknown etiology. Up to 94% of patients exhibit AMA-M2 and these constitute the most important serological marker. The majority of M2-specific autoantibodies are directed against the enzyme pyruvate dehydrogenase, and many commercial ELISAs are based solely on this main target antigen. However, 5-10% of patients exhibit only antibodies against the other two main autoantigens of the M2 complex, namely branched-chain 2-oxoacid dehydrogenase and oxoglutarate dehydrogenase, and are therefore not detected with conventional tests.

EUROIMMUN produces a wide range of reagents for medical laboratory diagnostics. The main focus is on test systems for antibodies in patient serum. These allow highly sensitive and specific diagnosis of autoimmune diseases, infectious diseases, and allergies.

Related Links:
EUROIMMUN