THE LONDON COPD EXACERBATION COHORT (The EXCEL Cohort)

Patients with chronic obstructive pulmonary disease (COPD) may often experience episodes of acute worsening of symptoms called exacerbations or ?attacks?. These exacerbations are an important cause of physical and mental ill-health, poor quality of life and death. Exacerbations also impose a considerable cost on the NHS, the patient and their families through time off work, hospital admissions and additional treatments. Finding the cause of these episodes is difficult because they can be due to different types of bacteria and viruses, and their timing is unpredictable so that the patient must be seen as soon as possible after the start of the infection. There is still an urgent need for more studies of COPD exacerbations but researchers need access to patients in whom exacerbations are likely to occur.

The London COPD Exacerbation Cohort (EXCEL Cohort) is a small established cohort of COPD patients recruited and specifically trained and monitored to report their attacks (exacerbations) to the research team to enable the exacerbation to be studied (and also the patient to receive treatment as quickly as possible). Our skills in running this cohort and research that we have published has gained us an international reputation and we have received both charity and industry research grants over the last 10 years. We are now seeking funding to increase the size of our cohort from 150 to 300 patients, and to study our patients in even greater detail with investigations including x-ray scanning measures of thickness of the lung airways and emphysema, state-of-the-art detection of bacteria and viruses using modern molecular methods, airway and systemic inflammation and ultrasound imaging of the heart. This will provide important information that will allow new treatments and ideas to be tested more efficiently. Our cohort has previously been involved in many studies, both on our own and in collaboration with other researchers world-wide. This proposed enlargement of our cohort has received support from multi-national pharmaceutical companies and the NHS as it provides a cost-effective resource to carry out smaller studies on specific groups of COPD patients.

Chronic obstructive pulmonary disease (COPD) exacerbations are acute episodes of worsening symptoms and an important cause of morbidity and mortality associated with the condition. They are also a major outcome measure for therapeutic intervention studies. The triggers and mechanisms of COPD exacerbations are still not clearly understood and more study of exacerbations is required if the economic and health burden of these disease is to be reduced. Exacerbations are heterogeneous in severity, occur unpredictably and must be sampled early before they are treated and resolve. Thus studies of COPD exacerbations must have access to patients who develop exacerbations and who are trained in detection and reporting of these exacerbations to the study team.

The London COPD Exacerbation Cohort (EXCEL Cohort) is an established cohort designed to study mechanisms of COPD exacerbations and their impact on health status and disease progression. Our work has contributed greatly to the understanding of COPD exacerbations. The cohort has already participated in observational studies, proof of concept studies, both grant funded and industry funded, to reduce the frequency and severity of these important events. We will utilize our existing strengths for accurately determining exacerbation frequency and severity with robust methodology previously developed by our group. Patients will be trained to monitor their symptoms electronically and detect and report exacerbations promptly, so that their exacerbations can be sampled early after symptom onset. With the specific funding, the cohort will be increased to recruit a total of 300 COPD patients, who will be phenotyped on the basis of exacerbation frequency, usual long term therapy, lung function, health status and psychological function, airway bacterial and viral infection by quantitative molecular methods. The funding requested will allow further phenotyping by CT scanning on the basis of airway wall thickness and emphysema, novel airway and systemic inflammatory markers and cardiovascular function. The exacerbation cohort will be suitable for epidemiological studies of the natural history and mechanisms of exacerbations, interventions to reduce exacerbation severity and frequency and also studies of interventions to treat individual exacerbations. Enlargement of our cohort has received support from two multi-national drug companies as it provides them with a cost-effective resource to carry out targeted proof of concept trials on specific groups of COPD patients.