Chemokine regulation of angiogenesis

Angiogenesis is increasingly being recognized for its role in promoting the pathogenesis of inflammatory diseases and tumorigenesis. Newly formed blood vessels have abnormal walls, causing them to be susceptible to disruption and extravasation of blood elements. Indeed, patients with inflammatory pulmonary diseases and lung cancer often develop a life-threatening massive hemoptysis (1). Hemoptysis in the vast majority of patients originates from systemic, rather than the pulmonary vasculature, and the bronchial vessels are almost universally involved (2,3). Numerous anatomical and radiological studies have shown that the bronchial vasculature, in contrast to the pulmonary vasculature, has a remarkable capacity for proliferation in various experimental and clinical lung disorders. Besides the bronchial vasculature, other systemic arteries surrounding the lung frequently contribute to the perfusion of lesions responsible for hemoptysis. The presence of systemic angiogenesis in the lung makes lung resection more difficult and increases the risks of major intraoperative hemorrhage.