Healthy non-smoking subjects:
All normal volunteers will meet the following criteria:
Age 21-75 years. No history of respiratory or allergic disease. Normal baseline spirometry as predicted for age, sex and height. Non-smokers. No history of upper respiratory tract infection in the preceding six weeks. Not taking regular medication
COPD is diagnosed according to American Thoracic Society, European Respiratory Society and British Thoracic Society guidelines by the doctors in Professor Barnes' COPD clinic.
All COPD volunteers will meet the following criteria:
Age between 35-75 years. A smoking history of at least 10 pack years. ( 1 pack year = 20 cigarettes per day for 1 year) FEV1:FVC ratio of <0.7, post-bronchodilator FEV1 of <85% predicted, reversibility with inhaled beta2-agonist of <15% of predicted FEV1: all three criteria are required.
Subjects will not included in this study if they meet any of the following exclusion criteria:
Clinically significant findings in the medical history or on physical examination other than those of COPD in the COPD group.
Pregnant women or mothers who are breastfeeding. Subjects who are unable to give informed consent.-