Spanish researchers found that almost half of patients with COPD identified in the study carried potentially pathogenic bacteria (PPMs) in their airways. These bacteria contribute to airway inflammation and can exacerbate symptoms.
The presence of these bacteria was linked to darker sputum samples - suggesting that sampling sputum could be a simple way of tracking COPD severity.
In the study, researchers studied 119 patients with COPD and assessed sputum samples provided over the course of one year.
They found bacterial colonisation in 49% of cases. More than 80% of darker sputum samples yielded PPMs when cultured, compared to just 44.7% of lighter coloured samples.
The presence of PPMs was also associated with increased degree of dyspnoea.
The authors concluded: ‘The identification of patients colonised by PPMs using a non-invasive and relatively inexpensive technique such as the analysis of sputum may play an important role in the management of severe and very severe COPD.'