[The proteolytic etiopathogenesis of pulmonary emphysema]

Laennec and later workers attributed the aetiopathogenesis of emphysema to mechanical causes. This view has been superseded by the current proteolytic theory. It is now believed that the destruction of the pulmonary parenchyma in emphysema occurs when the homeostatic equilibrium between cellular proteases (polymorphonucleates and macrophages) and serum antiproteases (primarily alpha-1-antitrypsin) which protects the respiratory ways, is disturbed. This imbalance not only produces idiopathic emphysema due to alpha-1-antitrypsin but also post-bronchitic forms due to increased protease release.