What have we learned about systemic sclerosis from the EUSTAR database?

This review provides a timely synthesis of key findings derived from the EUSTAR (European Scleroderma Trials and Research) database, the largest international registry dedicated to systemic sclerosis (SSc), now including over 27 000 patients worldwide. As interest grows in real-world data and precision medicine in rare diseases, EUSTAR offers a uniquely rich, longitudinal dataset built over two decades of global collaboration. With sustained growth, more than 1000 new patients enrolled annually, this registry continues to inform clinical practice and research with contemporary, diverse patient data.

Analyses from EUSTAR have clarified disease phenotypes and trajectories, identified predictors of organ involvement and mortality, and validated outcome measures including the EUSTAR Activity Index. Studies have also revealed heterogeneity in treatment patterns, supported the refinement of classification criteria, and highlighted regional disparities in care. The registry has been a foundation for innovative research approaches such as emulated clinical trials, comparative effectiveness analyses, and external control arms for interventional studies.

EUSTAR has become a reference model for collaborative research in rare diseases. Its findings have directly informed guidelines and routine management of SSc. Future directions include integrating digital tools, artificial intelligence, and expanding the registry's role in clinical trial design and personalized medicine.