Figure 1.

The natural history of patients affected by idiopathic interstitial pneumonia has been well characterized. Clinical progression is heterogeneous, with a rate of decline in lung function that can be slowly or rapidly progressive, with a subset of patients that will develop periods of rapid decline or acute disease exacerbation. What remain poorly defined are the inciting events, disease onset, and progression from asymptomatic to symptomatic interstitial lung disease (ILD). The widespread use of high-resolution computed tomography in clinical and research settings has increased the detection of subclinical ILD in family members of affected individuals with familial pulmonary fibrosis, smokers and subjects with connective tissue disease. A better understanding of the phenotypic and molecular characteristics of subclinical ILD will increase our ability to identify at-risk populations and implement preventive strategies.