Evaluation of exhaled nitric oxide in idiopathic interstitial lung diseases

Abstract

Introduction: Exhaled nitric oxide (eNO) is a biomarker of nitrosative stress, which is involved in the pathogenesis of idiopathic interstitial pneumonias (IIP). This study evaluates eNO levels in patients with idiopathic pulmonary fibrosis (IPF) and non-specific interstitial pneumonia (NSIP). These results were correlated with pulmonary function tests (PFT) and 6-minute walking test (6MWT) parameters. Aim of the study: To investigate the role of eNO as a nitrosative stress biomarker in patients with IPF and NSIP and its potential value as a potential bioindicator of disease severity. Methods: Fractional exhaled nitric oxide (FeNO) at multiple flow rates (50-100-150 ml/s), alveolar nitric oxide (CalvNO) and maximum conducting airway wall flux (J9awNO) in 30 healthy subjects and 44 patients with IIP (32 IPF and 12 idiopathic NSIP) were evaluated. FeNO measurements were performed according to ATS/ERS guidelines. On the same day, IPF and NSIP patients underwent PFT and 6MWT. Results: IPF and NSIP patients reported higher FeNO at flow rates of 50-100-150ml/s and higher CalvNO levels than healthy controls (p Conclusions: IPF and NSIP patients showed abnormal nitric oxide pulmonary concentrations, probably due to lung fibrosis and nitrosative-mediated lung injury. CalvNO resulted a potential severity biomarker of lung fibrosis and exercise tolerance.