Hemosiderin in sputum macrophages may predict infective exacerbations of chronic obstructive pulmonary disease: A retrospective observational study

Infective exacerbations of COPD are common and are accompanied by neutrophilic bronchitis in sputum. Increased respiratory iron content has been associated with respiratory tract infection, though it is unclear if this represents a predisposing factor for infection or the sequelae of inflammation.