The Neutrophil and Its Special Role in Chronic Obstructive Pulmonary Disease

This chapter provides an overview of the role of the neutrophil in chronic obstructive pulmonary disease (COPD), starting with neutrophil maturation and structure. Cytokines and chemoattractants, which are important in neutrophil activation and recruitment, will be discussed and neutrophil migration into lung and neutrophil apoptosis have been outlined, with particular reference to COPD. Neutrophils have a characteristic multilobed nucleus and abundant storage granules in their cytoplasm. The mature neutrophil has three chemically distinct granule types, which appear at different stages of maturation. There is strong evidence supporting the belief that the neutrophil is central to the pathogenesis of COPD. The neutrophil is the only cell that has been shown to be able to cause all of the pathological changes of the disease including emphysema, mucus hypersecretion, epithelial destruction, and reduced ciliary beating. Based upon current evidence it appears likely that the neutrophil and in particular, NE is associated with at least the initial lung damage seen in COPD although macrophages appear necessary either to initiate the acute neutrophilic response and/or sustain the subsequent inflammatory response causing initiation and progression of emphysema. Neutrophils are present at both the bronchial and alveolar level in COPD, and therefore it is likely that neutrophil migration occurs from the bronchial and pulmonary circulation.