Causes, Characteristics and Mechanisms of Infective Exacerbations in Subjects With Asthma and Chronic Obstructive Pulmonary Disease (COPD)

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. At present, sputum cell counts are able to identify different types of bronchitis, their severity and may be able to differentiate viral from bacterial infection. Other measurements in sputum, exhaled breath, blood and urine are also available to measure this inflammation. Measurement of immune cells in the blood gives us an idea about the working capacity of the immune system of the body. The investigators plan to study patients with asthma or COPD at the time of worsening of their condition to identify, 1. To what extent viral or bacterial bronchitis can be diagnosed from tests of inflammation? 2. How clearing of infection relates to clearing of inflammation? 3. What are the changes in the body's defense mechanisms that make a patient more prone to frequent infective bronchitis? 4. How do the measurements in sputum, exhaled breath, blood and urine relate to viral and bacterial bronchitis? 5. What are the differences in the measurements in sputum, exhaled breath, blood and urine in asthma and COPD?