Is there a place for anti-nucleosome antibody assessment in scleroderma?

Introduction. The hallmarks of systemic sclerosis (SSc) include microangiopathy, autonomic dysfunction, as well as immune disturbance and the widespread fibrosis of the skin and visceral organs. While the significance of SSc-specific autoantibodies such as anti-centromere and anti-topoisomerase I has long been demonstrated, the clinical relevance of non-specific autoantibodies remains a matter of debate. Our primary objective was to assess the relationships between non-SSc-specific antibody titers and the clinical characteristics of scleroderma patients. Secondary objectives included a comparison between SSc, SLE and healthy controls (HC) with respect to autoantibody values, as well as the analysis of the immune disturbance in elderly individuals in the 3 groups. Material and method. We conducted a cross-sectional study in which we recruited 67 adult patients with SSc, 67 age and gender-matched individuals with SLE and healthy controls (HC). Biological samples (venous blood) were collected in order to determine the levels of anti-SSA/Ro, anti-SSB/La, anti-U1RNP and anti-nucleosome antibodies (ELISA). We recorded the presence of digital ulcers (DUs), ILD (thoracic X-rays), and PAH (Doppler echocardiography) in the scleroderma cohort. Results. The frequency of anti-nucleosome antibody positivity in the scleroderma group exceeded our expectations, resembling that of lupus patients. Moreover, our findings indicate an association between serum anti-nucleosome antibody titers and SSc-related cardiopulmonary involvement. Anti-U1RNP antibodies were linked to PAH. We did not identify a notable relationship between the 4 autoantibodies studied and DUs. However, the latter were significantly more frequent in male patients. Although elderly individuals with scleroderma did not demonstrate a significantly decreased autoantibody production, lupus patients over 60 years of age exhibited a decline in anti-nucleosome antibody titers. Discussions. Earlier research reported an association between anti-nucleosome and anti-U1RNP antibodies with SSc-related cardiopulmonary impairment. Moreover, male gender is currently regarded as an important risk factor for the development of scleroderma DUs. Conclusions. Recent research provides new insights on the pathogenic processes of autoimmune rheumatic diseases, in an attempt to identify potential risk factors for organ involvement. Our study confirms the link between anti-nucleosome antibodies and cardiopulmonary involvement in the SSc population. Moreover, the impact of immunosenescence on the dynamics of autoantibody production in connective tissue diseases remains in need of further investigation.