COPD immune mystery: scientists probe why lungs can't clear bacteria.

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: COPD patients: * COPD patients aged 18-77 years who are GOLD Stage 1 or 2 or 3; for patients undergoing bronchoscopy already for a clinical reason. * COPD patients aged 18-77 years old who are GOLD Stage 1,2 or 3 for patients who are donating blood only. * COPD patients aged 18-69 years who are GOLD Stage 1 or 2 for patients undergoing bronchoscopy for research purposes. * COPD- Defined by radiological investigation of chest either chest X-ray or High-resolution CT scan in previous 12 months * Ability to provide informed consent Healthy volunteers: * Any healthy volunteer aged 18-77 years * Ability to provide informed consent Exclusion Criteria: COPD patients: * Individuals known to have active malignancy, immunosuppression, diabetes mellitus, chronic kidney disease or hepatic failure. * Individuals with a history of anaemia * Individuals who have donated \>250 ml of blood for any reason within the last 6 months * Individuals who are pregnant or breast feeding. * Current participation in any other clinical trial, except those directly relating to this cohort and study. * Individuals who have had a febrile illness or other symptoms of acute infectious illness (respiratory, enteric or soft tissue) within the last 2 weeks * Individuals who have received a vaccine in the past 2 weeks * Inability to communicate in English or convey willingness to participate. * For bronchoscopy - Any significant lung condition that would contra-indicate bronchoscopy including: active acute lung infection (with the exception of asymptomatic pulmonary colonisation) or malignancy, significant coexisting interstitial lung disease or additional pulmonary diagnosis in addition to COPD. Healthy volunteers: * Individuals known to have active malignancy, immunosuppression, diabetes mellitus, chronic kidney disease or hepatic failure * Individuals with anaemia on the screening full blood count (FBC) * Individuals who donated \>250 ml of blood for any reason within the last 6 months * Individuals who are pregnant or breast feeding * Current participation in any other clinical trial * Individuals who have had a febrile illness or other symptoms of acute infectious illness (respiratory, enteric or soft tissue) within the last 2 weeks. * Individuals who have received a vaccine in the past 2 weeks * Chronic or acute respiratory disease. * Any chronic medical condition or receipt of regular prescription medication other than the oral contraceptive pill. * Inability to communicate in English or convey willingness to participate * For bronchoscopy - Any active lung condition including any lung infection or asthma Any significant abnormality on CXR that would contraindicate bronchoscopy FEV1 \<65% predicted (BTS Guidelines, 2001)