Correlation of FeNO, Blood Eosinophils, Bronchoalveolar Lavage Findings and Bronchial Epithelium Histopathology in Patients With Chronic Obstructive Pulmonary Disease and Asthma

This is a multicenter prospective trial. Enrollment will continue until 150 patients with chronic obstructive pulmonary disease and 50 patients with severe asthma have been entered into this trial and have completed bronchoscopic evaluation. In this trial, the following parameters are to be evaluated: * Blood eosinophils (absolute and relative) * FeNO * Eosinophils in bronchoalveolar lavage * Tissue eosinophilia (protected specimen brush sampling, endobronchial biopsy)