Scleroderma Lung: Role of Gastroesophageal Reflux, Microaspiration and Cough

Inclusion Criteria: * Adult patients ≥ 18 years old. * Fulfilling the American College of Rheumatology criteria for SSc. * For ILD subgroup (n=6): * An upright chest-roentgenogram (chest x-ray) is abnormal and compatible with an interstitial lung disease. * HRCT of the chest confirms the presence of bilateral reticular, ground glass, and/or honeycomb abnormalities that is otherwise unexplained by an alternative process * The HRCT fibrosis score must be ≥ 7. * The total lung capacity (TLC, measured by body plethysmography) and/or the diffusing capacity of the lung for carbon monoxide (DLCO) is below the predicted normal. * The forced vital capacity (FVC) is reduced below the predicted normal. * The patient is symptomatic (i.e. dyspnea and/or a chronic cough) for more than 8 weeks that is otherwise unexplained by an alternative mechanism. * For No ILD subgroup (n=6): * No radiographic evidence of ILD on plain chest x-ray. * The HRCT fibrosis score, when performed) must be \< 7 * The TLC and FVC are within their predicted normal. * The DLCO is within the predicted normal, except when reduced in isolation by pulmonary hypertension. Exclusion Criteria: * Active smoking within the 6 months. * Pneumonia or bronchitis in past 4 weeks. * Active acute illness such as uncontrolled heart failure, infection, or asthma. * Use of more than 3 liters per minute (LPM) of oxygen by nasal cannula at rest. * Coordinator, investigator, or clinician concerns on the patient's compliance, safety, or in ability to complete study requirements. * Morbid condition not expected to live more than 1 year. * Alternative cause or diagnosis for the patient's ILD besides SSc. * Pregnancy. * Obstructive lung disease with an FEV1 (forced expiratory volume in 1 second) to FVC ratio less than 0.7, nor radiographic evidence of emphysema on CT. * Planned therapeutic procedures involving the esophagus (e.g. dilation, surgery) prior to completion of study tests