Identification of exhaled volatile organic compounds (VOCs) associated with loss of asthma control

Rationale: Asthma exacerbations are linked to increased airway inflammation. Exhaled metabolites are associated with biomarkers of inflammation [Fens ERJ911; Ibrahim Thorax911]. We investigated whether VOCs measured by GC/MS are correlated to markers of asthma control. Aim: To identify exhaled VOCs suitable for monitoring asthma control. Methods: Patients with moderate to severe asthma prospectively withdrew ICS (≥500µg FP) and followed up for 14 weeks. Exhaled VOCs were measured by GC/MS at baseline, loss of control [Reddel AJRCCM909] and dose restoration. Questionnaires, blood, sputum, FENO and lung function were collected. Pearson correlation between GC/MS compounds and clinical variables for each patient was done by univariate analysis. Compounds with the highest median were selected compounds of interest (COI). Results: 22 of 23 included patients (6 males; age 28±10; 21 atopic) had loss of asthma control. COIs had median correlations with clinical variables between 0.48 and 0.88 (Table). Conclusions: This study revealed VOCs associated with clinical and inflammatory changes during steroid withdrawal, suggesting that breath analysis qualifies for non-invasive monitoring of asthma control.