Systemic sclerosis-associated interstitial lung disease in the EUSTAR database: analysis by region

Objectives: The prevalence and characteristics of systemic sclerosis-associated interstitial lung disease (SSc-ILD) vary between geographical regions worldwide. The objectives of this study were to explore the differences in terms of prevalence, phenotype, treatment, and prognosis in patients with SSc-ILD from predetermined geographical regions in the EUSTAR database. Methods: Patients were clustered into seven geographical regions. Clinical characteristics and survival of patients with SSc-ILD were compared among these pre-determined regions. Results: For baseline analyses, 9260 SSc patients were included, with 6732 for survival analyses. The prevalence of SSc-ILD in the overall population was 50.2%, ranging from 44.0% in "Western Europe & Nordic countries" to 67.5% in "Eastern European, Russia & Baltic countries". In all regions, anti-topoisomerase antibodies were associated with SSc-ILD. Management also significantly differed; mycophenolate mofetil was prescribed at baseline in 31.6% of patients with SSc-ILD in "America (North & South)" and 31.7% in "Middle East" but only 4.3% in "Asia & Oceania" (P < 0.0001). Patients from "America (North & South)" and "Middle East" had the highest survival rate at the end of follow-up (85.8% and 85.2%, respectively). Conclusion: Our study highlights key differences among regions in terms of clinical presentation and prognosis of SSc-ILD. This work also demonstrates that the management of SSc-ILD is highly variable among the different regions considered, suggesting that efforts are still needed for the standardisation of medical practice in the treatment of this disease. Keywords: Interstitial lung disease; autoantibodies; lung fibrosis; scleroderma; systemic sclerosis