This National Jewish Health (NJH) Investigator Initiated pilot study funded by the Shah Foundation will prospectively perform a non invasive lung function test called Lung Clearance Index (LCI) to determine if 50 scleroderma patients without evidence of lung disease who have evidence of small airway inflammation or impairment to airflow are more likely to develop ILD than those with normal vales.50 subjects will be enrolled from the Rheumatology practice at NJH and followed with phone interviews or Electronic Medical Record (EMR) record review yearly times 5 to determine if they have subsequently developed evidence of ILD or pulmonary artery hypertension.