Ultrafine particles in airways: a novel marker of COPD exacerbation risk and inflammatory status.

Purpose: Ultrafine particles (UFP) are toxic due to their small size and penetration into deeper lung compartments. We aimed to evaluate the exhaled breath condensate (EBC)-UFP content as a reflection of inflammation and oxidative stress status in COPD patients and as an exacerbation risk marker.

Methods: EBC was collected by conventional methods.