Clinical associations of anti-CENP-B and anti-Scl70 antibody levels measured by multiplexed fluorescent microsphere immunoassay in systemic sclerosis

The aim of this study was to assess the association between anti-CENP-B and anti-Scl70 antibody levels, measured by multiplexed fluorescent microsphere immunoassay, and the clinical features in patients affected by systemic sclerosis. Clinical evaluation of 80 scleroderma patients was performed in order to evaluate disease activity and organ involvement. Scleroderma-specific autoantibodies were detected using multiplexed fluorescent microsphere immunoassay. Unexpectedly, 11 patients resulted positive for both anti-Scl70 and anti-CENP-B antibodies; six cases showed a weak positivity for one of the two autoantibodies and a stronger positivity for the other one; five cases showed an intense positivity for both autoantibodies. This latter subgroup was excluded from the analysis of the associations between autoantibody levels and the clinical features. In the anti-CENP-B positive patients higher antibody levels were associated with a less extensive skin involvement in comparison with the cases affected by a more extensive skin involvement (521 ± 208 vs 395 ± 166 U/ml, respectively, P 0.038). In the anti-Scl70 positive patients autoantibody levels were directly correlated with skin involvement (P 0.018), showing higher levels in patients with a more extensive skin involvement in comparison with cases characterized by less extensive skin involvement (734 ± 135 vs 490 ± 183 U/ml, respectively, P 0.001). The findings of our study supports the association between autoantibody profile and disease severity in systemic sclerosis. In particular high levels of anti-Scl70 antibodies are associated with a worse cutaneous involvement, while high levels of anti-CENP-B antibodies seem to have a protective effect on skin manifestations.