Anticentromere-A and anticentromere-B antibodies show high concordance and similar clinical associations in patients with systemic sclerosis

Objective. To determine the diagnostic sensitivity and specificity and the clinical usefulness of parallel anticentromere-A and anticentromere-B antibody (anti-CENP-A and anti-CENP-B) testing in patients with systemic sclerosis (SSc). Methods. Sera from 280 consecutive patients with SSc and 259 controls were tested for the presence of anti-CENP-A and anti-CENP-B antibodies by a monospecific line immunoblot assay (LIA) with recombinant human centromere proteins A and B as well as by indirect immunofluorescence (IIF). Crossreactivity and possible associations with clinical manifestations were studied. Results. Both antibodies revealed a diagnostic sensitivity of 36.8% and a specificity of > 97% for SSc, with a high concordance rate of 94.3% despite different amino acid sequences of the antigens and absence of crossreactivity. There was a significant correlation of the antibody levels measured by LIA. Both antibodies were associated with similar clinical manifestations and identified patients with limited disease and rather mild skin sclerosis. Conclusion. Detected by LIA, anti-CENP-A and anti-CENP-B antibodies show high concordance in patients with SSc and share significant associations to clinical manifestations, but are not completely identical. Detection of both antibodies in parallel may slightly increase the diagnostic sensitivity for SSc. The Journal of Rheumatology