Assessing the concordance between centromere AC-3 immunofluorescence pattern and anti-centromere protein-B antibody, and analyzing clinical correlates of dual positivity: A retrospective study.

This study evaluates the consistency between the centromere AC-3 immunofluorescence pattern and the anti-centromere protein B (anti-CENP-B) antibody test results and analyzes differences in the positive rates of potential related diseases with anti-centromere antibody (ACA) positivity. A retrospective collection of antinuclear antibody fluorescent patterns and anti-CENP-B test data from inpatients at Maanshan People's Hospital between February 2022 and February 2024 was performed. The consistency of different methods was evaluated using the kappa test and overall consistency calculation. Subsequently, the main diagnostic information of patients with ACA positivity was extracted, and the positive rates of ACAs in potential related diseases were analyzed. A total of 7893 patients were tested for both antinuclear antibody patterns and anti-CENP-B antibodies. Among them, 3959 patients were tested for ACAs using indirect immunofluorescence and Western blotting; 3936 patients were tested by indirect immunofluorescence and multiplex flow cytometric immunoassay. The consistency analysis showed that the kappa coefficients for both comparisons were >0.81, and the overall consistency was >99%, indicating that the AC-3 pattern and anti-CENP-B antibody test results were almost completely consistent. ACA positivity was observed in a variety of autoimmune diseases, with systemic sclerosis showing the highest positive rate (41.18%, 95% confidence interval: 32.12%-50.88%), followed by primary biliary cholangitis (40.00%, 95% confidence interval: 11.76%-76.93%). The positive rates of ACAs in 16 diseases were significantly higher than those in healthy control populations. There was almost complete consistency between the AC-3 pattern and the anti-CENP-B antibody test, suggesting that CENP-B is the main target antigen of the AC-3 pattern. ACA positivity was observed in various autoimmune diseases, especially systemic sclerosis and primary biliary cholangitis. This study offered useful insights for both basic and clinical investigations of ACAs.