CXCL8 and chronic obstructive pulmonary disease: For example, the release of IL-8 and leukotriene B4 by bronchial epithelial cells [7,8] and alveolar macrophages [9]in vitro appears to be induced by acetylcholine, resulting in increased neutrophil, monocyte, and eosinophil chemotactic activities, an effect that may be enhanced in COPD.