Natural variability in the disease course of SSc-ILD: implications for treatment

Interstitial lung disease (ILD) affects approximately 50% of patients with systemic sclerosis (SSc) and is the leading cause of death in SSc. Our objective was to gain insight into the progression of SSc-associated ILD (SSc-ILD). Using data from longitudinal clinical trials and observational studies, we assessed definitions and patterns of progression, risk factors for progression, and implications for treatment. SSc-ILD progression was commonly defined as exceeding specific thresholds of lung function worsening and/or increasing radiographic involvement. One definition used in several studies is decline in forced vital capacity (FVC) of >= 10%, or >= 5-10% plus a decline in diffusing capacity of the lung for carbon monoxide >= 15%. Based on these criteria, 20-30% of patients in observational cohorts develop progressive ILD, starting early in the disease course and progressing at a highly variable rate. Risk factors such as age, FVC, extent of fibrosis and presence of anti-topoisomerase I antibodies can help predict progression of SSc-ILD, though composite risk scores may offer greater predictive power. Whilst the variability of the disease course in SSc-ILD makes risk stratification of patients challenging, the decision to initiate, change or stop treatment should be based on a combination of the current disease state and the speed of progression.

Automated summary

Through longitudinal clinical trials and observational studies, researchers assessed definitions, progression patterns, risk factors, and implications for treatment of SSc-associated ILD. Approximately 20-30% of patients develop progressive ILD early in the disease course, with risk factors such as age, FVC, extent of fibrosis, and presence of anti-topoisomerase I antibodies contributing to predicting progression.