Measurement of Exhaled Hydrocarbons

Oxidative stress is implicated in the pathogenesis and progression of asthma (1 ,2 ), chronic obstructive respiratory disease (COPD) (3 ), and cystic fibrosis (4 ). Reactive oxygen species (ROS) are unstable compounds with unpaired electrons, capable of initiating oxidation. Several of the inflammatory cells which participate in the inflammatory response, such as macrophages, neutrophils, and eosinophils release increased amounts of ROS (1 ,5 ) exceeding the already reduced tissue antioxidant defences of asthmatic and COPD patients (2 ).