Elderly-onset systemic sclerosis defines a distinct clinical subset: analysis from the SPRING registry of the Italian Society for Rheumatology

bjective: Elderly-onset systemic sclerosis (SSc) is relatively uncommon, and its clinical phenotype and prognostic implications remain poorly characterized, with conflicting evidence regarding disease course and outcomes. Methods: Within the Italian SPRING (Systemic Sclerosis PRogression INvestiGation) registry, we compared demographic and clinical characteristics of patients with elderly-onset SSc (≥70 years at the time of the first non- Raynaud’s manifestation) to those with younger onset. Cross-sectional analyses, multivariable logistic regression, and unsupervised cluster analysis were conducted to identify features associated with elderly-onset SSc. Longitudinal analysis was performed to assess mortality risk within SSc patients and compared to the general Italian population. Results: Elderly-onset accounted for 8.5 % (160/1893) SSc cases in SPRING. These patients exhibited fewer peripheral vascular complications (digital ulcers: 13 % vs. 23 %; p =0.016), higher prevalence of anticentromere antibodies (60 % vs. 39 %; p =0.007), a lower prevalence and likelihood of diffuse skin subset (OR 0.40; 95 % CI 0.19–0.83) but an increased risk of pulmonary arterial hypertension confirmed on right-heart catheterization (OR 14.1; 95 % CI 3.68–54.5) at multivariate analysis. As expected, patients with elderly onset SSc had an increased risk of death compared to younger-onset individuals. Compared with the age-, sex-, and calendar year- matched general Italian population, patients with SSc showed a fivefold increased mortality, with a trend toward a higher risk in young-onset (SMR 6.3; 95 %CI 4.1–9.1) compared with elderly-onset (SMR 4.5; 95 %CI 2.4–7.7) cases. Conclusions: Elderly-onset identifies a distinct clinical subset of SSc, mainly characterized by mild cutaneous and peripheral vascular involvement, but showing a greater burden of pulmonary vascular disease and increased mortality compared to the age-matched general population.