The role of proteinases in the pathogenesis of chronic bronchitis

Proteinases have been implicated in the pathogenesis of many acute and chronic destructive lung diseases. Their role has been implied by a combination of genetic deficiency of their inhibitors and/or their ability to induce lung disease in animal models that resemble the human counterpart. However, identification of proteinases in lung tissue has proven difficult, with the exception of airway secretions, which often contain excessive and varied enzyme activity. Recent studies have focused on the role of these enzymes in the pathogenesis of airway diseases. This article reviews the evidence for their role in chronic bronchitis, the implications of this role, and new approaches to therapy based on the pathogenic mechanisms involved.