Morphologic and immunohistochemical studies at the electron microscopic level were made of elastic fibers in lung of four patients with pulmonary emphysema. Abnormal elastic fibers were observed which were interpreted as resulting from: 1) hydrolytic damage by elastase and 2) abnormal synthesis of new elastic fibers in areas of pulmonary remodeling. These observations emphasize the critical importance of alterations of elastic fibers in the pathogenesis of pulmonary emphysema.
