Childhood-onset versus adult-onset Sjögren Syndrome: Clinical phenotype, disease activity, and predictors of organ damage in a national multicenter cohort.
Abstract
Objectives
To compare the clinical, immunological, and diagnostic characteristics of childhood-onset (coSS) versus adult-onset Sjögren syndrome (aoSS), assess disease activity and damage accrual, and identify independent predictors of organ damage.
Methods
This national, multicenter retrospective cohort included 197 patients, 115 (58.4%) with coSS and 82 (41.6%) with aoSS. Clinical, laboratory, and outcome data were compared between groups. Disease activity and damage were evaluated using the ESSDAI and SSDDI, respectively. Damage was defined as SSDDI ≥1. Logistic regression analyses were used to identify independent predictors of damage.
Results
Female predominance was more pronounced in aoSS (93.9% vs 84.3%, p=0.04), while diagnostic delay was significantly longer in coSS (8.1 vs 5.4 months, p=0.001). Fulfillment of the 2016 ACR/EULAR criteria at baseline was lower in coSS (73.0% vs 98.8%, p<0.001). coSS was characterized by more symptomatic parotitis, cervical lymphadenopathy, constitutional symptoms, and Raynaud phenomenon, whereas sicca symptoms, anti-Ro and RF positivity, leukopenia, lymphopenia, and pulmonary involvement were more frequent in aoSS. Baseline ESSDAI was higher in coSS (9.3 vs 5.0, p<0.001), whereas SSDDI at last visit was lower (p=0.002). Older age at symptom onset (OR=1.044, p<0.001), higher baseline ESSDAI (OR=1.121, p=0.002), and leukopenia (OR=2.657, p=0.046) independently predicted damage, while RF positivity was protective (OR=0.343, p=0.008).
Conclusion
coSS displays a distinct clinical phenotype and higher initial disease activity than aoSS, yet accrues less damage over time. These results highlight the need for pediatric-specific classification criteria and underscore the importance of baseline disease activity, leukopenia, and RF positivity as key predictors for guiding damage-oriented risk stratification across the SS spectrum.