Effects of Inhaled Corticosteroids on Sputum Bacterial Load in COPD

Exacerbations are important events in the natural history of chronic obstructive pulmonary disease (COPD). Beside the acute (and prolonged) clinical impact, there is evidence that exacerbations negatively affect the natural history of the disease; e.g. lung function decline is accelerated in patients with frequent exacerbations. Bacteria are considered the most relevant cause of exacerbations, but there is evidence that viral infections are equally contributing. Either alone or in combination with viruses, airway bacterial load in stable COPD correlates with both the frequency of exacerbations and the decline in lung function. A long-term clinical trial recently showed that the regular treatment with inhaled corticosteroids (ICS) increases the risk of infectious events such as pneumonia, whereas it reduces the frequency of acute COPD exacerbations in COPD. In a recent study it was found that airway bacterial load increases over time (1 yr follow up) in stable COPD. In this study, virtually all patients (93%) were treated with ICS. This study is designed to evaluate whether long-term (1 year) ICS treatment increases viral and/or bacterial load in the sputum of COPD patients.