Anti-DNA topoisomerase II α autoantibodies in Japanese patients with systemic sclerosis

Abstract

The pathogenesis and etiology of systemic sclerosis (SSc) remain unknown, but the presence of several autoantibodies is recognized as one of its prominent features. The clinical significance of anti-DNA topoisomerase II α antibody (anti-topo II α Ab) remains unknown in Japanese patients with SSc. To determine the prevalence and clinical correlation of anti-topo II α Ab in Japanese patients with SSc. Serum samples were obtained from 103 Japanese patients with SSc. Control serum samples were obtained from 43 healthy Japanese volunteers. Anti-topo II α Abs were determined by enzyme linked-immunosorbent assay.IgG anti-topo II α Ab levels were significantly increased in SSc patients (n=103) compared to normal controls (n=43; P<0.005). IgG or IgM anti-topo II α Ab was detected in 19% (20/103) of SSc patients when absorbance values higher than the mean+2SD of control serum samples were considered positive. By contrast, IgG or IgM anti-topo II α Ab was observed in only 7% (3/43) of healthy individuals. The presence of pulmonary fibrosis was more frequently detected in SSc patients with IgG anti-topo II α Ab than those without the Ab (P<0.05). Moreover, % DLco and % VC were significantly decreased in SSc patients with anti-topo II α Ab relative to those without the Ab (P<0.05 and P<0.01, respectively). The elevated levels of both erythrocyte sedimentation rate and C-reactive protein were also more frequently observed in SSc patients positive for IgG anti-topo II α Ab (P<0.005). The results of the present study indicate that anti-topo II α Ab represent one of the autoantibody specificities detected on SSc patients and may be regarded a serological marker of pulmonary fibrosis in Japanese patients with SSc.