Systemic sclerosis (SSc) is a heterogeneous systemic autoimmune disease with distinct prognosis according to patients. In patients with systemic sclerosis, interstitial lung disease (ILD) concerns almost 50 % of patients and represents the main cause of mortality. Disease course in SSc-ILD is highly variable: patients can experience stable disease, slow or fast progression. Prevention of ILD progression now represents a key objective of SSc-ILD management. The understanding of the course and patterns of SSc-ILD progression is necessary, as reliable prediction tools that allow the stratification of the risk of progression. We aimed to identify the longitudinal trajectories of ILD in SSc patients using latent class mixed models and to examine their associations with SSc characteristics.

Inclusion Criteria:

• Patients with systemic sclerosis according to 2013 ACR/EULAR criteria
• Patients with interstitial lung disease on HRCT chest
• Patients with PFT at ILD diagnosis and at least 1 PFT evaluation during follow-up

Exclusion Criteria:

• Patients with an alternative diagnosis of SSc-associated ILD (silicosis, sarcoidosis, lung cancer or other significant lung abnormalities)

Patients with systemic sclerosis-interstitial lung disease