Diseases of the airways (bronchi) of the lungs include asthma and chronic obstructive pulmonary disease (COPD), which are leading causes of reduced quality of life, loss of work, hospital admissions and deaths and result in a major economic burden to the patient and society. Worsening (exacerbation) of these conditions is common and is frequently due to viral or bacterial infection, which causes inflammation in the bronchi, i.e. bronchitis. Ways to objectively measure the inflammation are needed to improve diagnosis, cause and severity and to guide treatment. The investigators also need to understand changes in the body's defense (immune) mechanisms that make some patients have more frequent infective bronchitis.