 The literature indicates that subjects with tobacco-induced chronic bronchitisCOPD have alveolar macrophages that have impaired function. It has been hypothesized that the impaired lung macrophage function may contribute to the increased susceptibility to infections and chronic bacterial colonization that is a central feature in subjects with chronic bronchitisCOPD. It is unknown at this time if impaired macrophage function is secondary to tobacco-induced effects, or is a central pathologic feature of chronic bronchitisCOPD. 