Evaluation of anti-CENP reactivity in samples with centromere HEp-2 pattern and correlation with Systemic Sclerosis clinical features

Introduction/Objectives Anti-centromere antibodies are associated with limited cutaneous systemic sclerosis (lcSSc) and a more favorable prognosis. The centromere HEp-2 pattern (AC-3) suggests the presence of antibodies against CENP antigens, mainly CENP-B and A. This study analyzed the clinical and demographic associations of anti-centromere antibodies in a cohort of patients exclusively with the lcSSc form of SSc. The frequency of CENP-B and CENP-A reactivity in samples with the AC-3 pattern was also evaluated. Method Samples from 38 lcSSc patients with AC-3 were evaluated for reactivity to CENP-B and CENP-A using line-blot and ELISA. Clinical data from 68 lcSSc patients (20 AC-3 and 48 Non-AC-3) were analyzed. Results Of the AC-3 samples, 84.2% and 81.6% were reactive against CENP-B and CENP-A, respectively, by line-blot, and 92.1% were positive for CENP-B by ELISA. Concordance for CENP-B reactivity between ELISA and line-blot was 78.9%. Reactivity to both CENP-B and CENP-A was found in 68.4% of AC-3 samples, while one sample was positive only for CENP-A. Overall, 97.3% of AC-3 samples were reactive to CENP-B, and all were reactive to either CENP-B or CENP-A. Clinically, interstitial lung disease (ILD) was less frequent in AC-3 patients compared to Non-AC-3 (10.5% vs. 54.2%; p=0.001). Other organ involvement frequencies were similar. Conclusions Among lcSSc patients, anti-CENP reactivity is associated with a less severe prognosis, with ILD being less frequent in AC-3-positive patients. In addition, anti-CENP-B was the predominant autoantibody in samples yielding the AC-3 pattern, but anti-CENP-A reactivity was also prevalent and exclusive anti-CENP-A reactivity was also observed.