COPD is highly prevalent in primary care. It is associated with tobacco smoke or toxic occupational exposure. Some COPD patients will experience a faster decline in quality of life and lung function. There is currently no prognostic marker allowing to identify those patients at higher risk of fast lung function decline. Recent data suggest that fibrocytes are involved in COPD's physiopathology. A higher blood fibrocytes level during an acute exacerbation has been associated with higher mortality in COPD patients at a late stage of the disease. In mice, fibrocytes role in lung function decline has been demonstrated at an early stage. To date, association between blood fibrocytes during an exacerbation and lung function decline has not been evaluated at the early stage of COPD in humans.
This study aims to estimate the association between blood fibrocytes measured during a suspected exacerbation and 3-year decline in forced expiratory volume in one second (FEV1), in patients with COPD in primary care, with a history of smoking, independently of the number of exacerbations and of tobacco or occupational exposure.
In this study, blood fibrocytes during a suspected exacerbation will be measured at inclusion. The lung function (FEV1) will be assessed at follow-up visits at 2 months, 12 months and 36 months after inclusion. COPD-related health status and severity of dyspnea will be assessed with COPD Assessment test (CAT) and the modified Medical Research Council dyspnea scale (mMRC) at follow-up visits at 2 months, 12 months and 36 months after inclusion.
