Improving P. Aeruginosa Detection With Breath-based Diagnostics (IMPACT-Breath)

AIM 1: Refine and validate volatile biomarkers in the breath of adult and pediatric CF patients for detecting established P. aeruginosa lung infections. For each expectorating subject (n ≥ 288; 5 centers), the diagnostic accuracy of the volatile biomarker panel will be tested, with sputum culture as the standard. AIM 2: Quantify intra-subject breath variability of the target pediatric population. We will collect longitudinal breath samples for two years from P. aeruginosa-negative subjects (n ≥ 58; \~60% non-expectorating) at 4 pediatric CF clinical centers. We will measure intra-subject variance in the breath signatures of expectorating and non-expectorating subjects, with the latter being the target population for the clinical trial. Two to 8 breath samples will be collected per patient.