Pos1320 anti-ro/ssa ‑ positive systemic sclerosis - commonly associated clinical and serological features independently from the underlying disease

Background The significance of anti-Ro antibodies in systemic sclerosis (SSc) is still unclear as their presence could represent an epiphenomenon of the strong immune response in severe visceral involvement or directly participate in tissue damages in SSc patients. Recent data suggest that the presence of anti-SSA/Ro antibodies is an independent risk factor for worse pulmonary outcome and higher all-cause mortality in patients with SSc [1] . Objectives To determine the frequency of anti-SSa/Ro antibodies in a cohort of SSc patients and its association with clinical, serological features and survival, in order to analyze the diagnostic utility of their separate detection. Methods This was a single-center retrospective study of a SSc cohort followed over a 10-year period in our rheumatology department. Duration of disease progression, symptoms and parameters related to a specific organ involvement according to MEDS evaluation sheets, were evaluated in all patients. Results 270 SSc patients were selected, from which we identified a final population of 28 (10%) anti-Ro-positive patients. The anti-SSA/Ro group included more women (26/28) with a mean age of 47.9 ± 13.7 years, most of them with diffuse subset (16/30). The presence of anti-SSA/Ro antibodies was positively correlated with presence of anti-Scl 70 antibodies (p=0.012), elevated modified Rodnan score (p=0.041), myositis (p=0.013), and lower DLCO (p=0.019). Moreover, associations were strongest for elevated CRP levels (p<0.001) and calcinosis cutis (p<0.001). Compared to non-anti-SSa/Ro patients, both groups were similar regarding demographic data, age at diagnosis, disease duration and type of skin involvement. As expected, the anti-SSa/Ro group had significantly more frequent erosive synovitis (p=0.002), myopathy (p=0.010), gastrointestinal involvement and interstitial lung disease (ILD) (p=0.001). No statistically significant differences were found regarding frequencies of Raynaud’s phenomenon, pulmonary hypertension, renal, vascular and cardiac involvement, nor neoplasia. There was a greater proportion of digital ulcers and calcinosis in the anti-SSa/Ro group (42% vs 17% and 58% vs 14%), but without statistical significance. Again, among those patients, a much higher proportion (64% vs 42%) was treated with immunosuppressive agents. No differences in mortality were found between the groups. Conclusion Anti-SSA/Ro antibodies seem to characterize a distinct group of SSc patients who are almost exclusively female, express elevated CRP levels, have a high prevalence of ILD, myositis, joint involvement and calcinosis, and commonly receive immunosuppressants. Reference [1]Meridor K, et al Anti-Ro/SS-A antibody is associated with worse pulmonary outcome and reduced overall survival in systemic sclerosis. Mod Rheumatol. 2022 Oct 15;32(6):1086-1093 Acknowledgements: NIL. Disclosure of Interests None Declared.