Evaluating the diagnostic efficacy of anti-M2-3E, anti-gp210, and anti-sp100 antibodies in primary biliary cirrhosis.

Abstract

Introduction: The diagnosis of primary biliary cholangitis (PBC) relies on the detection of specific antibodies, yet there is variability in the diagnostic accuracy and efficiency among the different diagnostic methods. We aimed to assess the individual diagnostic performance of these markers using different detection methods.

Methods: A total of 112 participant-54 with PBC and 58 acting as disease controls-were enrolled. The levels of anti-M2-3E, anti-gp210, and anti-sp100 antibodies were measured using immunoblot tests from Euroimmun, flow cytometry-based multiplex bead immunoarray (MBIA [Tellgen]), and multiplex magnetic barcode encoding (MMBCE [Livzon]) assay. The 6 antigens used in the MBIA assay included recombinant E2 subunits of the pyruvate dehydrogenase complex, branched-chain 2-oxo acid dehydrogenase complex, and 2-oxoglutarate dehydrogenase complex, which together represent the M2-3E epitope group. In addition, recombinant gp210, sp100, and centromere protein B were included for the detection of antinuclear antibodies. Each antigen was covalently bound to a uniquely fluorescence-coded microsphere to allow multiplexed antibody detection in a single sample.

Results: Anti-M2-3E and anti-gp210 antibodies showed much higher positivity rates in the PBC group than among control individuals. Quantitative levels of the antibodies were markedly elevated in patients with PBC. The area under the curve for the combined markers was consistently high (0.825-0.837) across platforms, indicating robust diagnostic accuracy. The logistic regression analysis revealed a substantial advantage in combining multiple markers, with anti-sp100 showing the highest odds ratio for PBC diagnosis.

Discussion: The study demonstrated consistent diagnostic performance across the immunoblot, MBIA, and MMBCE detection methods for PBC markers. These findings underscore the potential of a multimarker approach to enhance PBC assessments in clinical settings.

Trial registration: This study received retrospective approval from the Ethical Committee of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (institutional review board No. TJ-IRB202308129, dated August 12, 2023).