A Study to Obtain Normal Values of Inflammatory Variables From Healthy Subjects

Smoking induces an inflammatory reaction in the airways which can ultimately result in persistent damage and the development of a Chronic Obstructive Pulmonary Disease (COPD). However, not all subjects who smoke end up with COPD. After long-term smoking, approximately 20% of subjects develop COPD. At this time, it is unclear why some subjects develop COPD, whereas others maintain a normal lung function. In addition, smoking has important consequences in asthma. Patients with asthma who smoke have a more severe asthma and more often experience an asthma exacerbation. In addition, it has been shown that inhaled corticosteroids are less effective in smoking asthmatics. With this research project, the researchers will investigate the effects of smoking on the airways. To this end, the researchers will compare markers of airway inflammation, lung function and symptoms between healthy smokers and non-smokers of varying age. In addition, the researchers will compare those healthy subjects with patients with asthma and COPD which are characterized in earlier studies.