Biomarkers in Chronic Obstructive Pulmonary Disease (COPD)

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide and is characterized by fixed airflow obstruction. The cornerstone of the disease is chronic inflammation leading to narrowing of the small airways and thus impairment of lung function. Compared to spirometry, the single breath N2-washout-test is more sensitive to identify the regional heterogeneity of bronchial airflow obstruction in the small airways. The aim of this study is to evaluate whether there is a correlation between the sbN2-test, markers in exhaled air and the inflammatory cells in the small airways.