Particles in exhaled air (PExA): Non-invasive phenotyping of small airways disease in adult asthma

This study quantified surfactant protein A and albumin in exhaled aerosol particles in 115 adult asthmatic patients (discovery cohort, n=83; replication cohort, n=32) and 21 healthy volunteers. In the discovery cohort, spirometry was performed using a Vitalograph Alpha spirometer.