Anti-Ro/SS-A antibody is associated with worse pulmonary outcome and reduced overall survival in systemic sclerosis.

OBJECTIVE: We sought to determine the association of anti-Ro/SS-A antibody with organ involvement and disease outcome in patients with systemic sclerosis (SSc). METHODS: A retrospective, long-term study of a cohort of incident patients diagnosed with SSc and continuously followed at our rheumatology clinic during 1990-2018. RESULTS: Included were 105 patients with known anti-Ro/SS-A antibody status, 92.4% female, mean age at diagnosis 52.0 ± 15.6 years, and median follow-up of 10 years; 64% were diagnosed with limited cutaneous SSc, 18% with diffuse cutaneous SSc, and 18% had SSc siné scleroderma or undetermined disease type. Anti-Ro/SS-A antibody tested positive in 21% of patients. In univariate analysis, anti-Ro/SS-A antibody positivity was significantly associated with SSc overlap with Sjögren's syndrome (p < .001). Predicted forced vital capacity deterioration at last encounter was significantly associated with anti-Ro/SS-A antibody positivity. In multivariate regression for anti-Ro/SS-A antibody-positive SSc patients and disease outcome [adjusted for age > 50 years, smoking, and baseline predicted forced vital capacity (pFVC) < 80%], positive anti-Ro/SS-A antibody was significantly associated with a higher all-cause mortality rate (HR 5.17, CI 95%, 1.18-22.67, p = .029), and greater deterioration of pFVC defined as a decrement of last available pFVC compared to first available pFVC of ≥10% (HR 3.65, CI 95%, 1.07-12.38, p = .038). CONCLUSIONS: Anti-Ro/SS-A antibody is an independent risk factor for worse pulmonary outcome and higher all-cause mortality in patients with SSc.