Mechanisms and Impact of Bacterial Colonisation in COPD

COPD is a leading cause of lung disease and a common cause of hospitalisation, time off work and death. Smoking is the major factor associated with development of COPD. Nevertheless why some people develop COPD while others, including many smokers do not, is poorly understood. A central feature of COPD is accumulation of a particular type of white blood cell, the neutrophil, which is a key component in defence against bacterial infection in the lung airway. As disease progresses the small airways of many patients with COPD start to accumulate bacteria, which are normally lacking in the small airways of healthy individuals or smokers who lack COPD. The accumulation of bacteria in the smaller airways of many patients with COPD may be important to the development of the disease. Researchers will test if blood cells, which normally ingest and kill bacteria, have a reduced ability to perform this function in patients with COPD and whether the clearance of these blood cells after they have performed their role in protecting against infection is impaired. Researchers will relate these findings to the clinical features of COPD in a well-defined group of patients who have had extensive characterisation of their disease. In particular, researchers will relate this defect to the presence of frequent flares of disease, which lead to symptoms of wheezing and shortness of breath. Comparison will be made between blood cells obtained from the lung and from he blood to determine if the alterations are specific to the lung. Researchers will identify particular molecular alterations in the way these blood cells respond to bacteria and determine whether they can correct these alterations using agents, which are used to treat a range of different medical conditions, but which they predict might correct these alterations in function. The aim of this programme of work is ultimately to identify new ways in which to treat COPD and the agents, which the researchers demonstrate have the great