Role of elastases in the pathogenesis of chronic obstructive pulmonary disease: Implications for treatment

Neutrophil elastase, metalloproteinases, and their inhibitors play an important role in the development of chronic obstructive pulmonary disease (COPD), resulting in extensive tissue damage and malfunctioning of the airways. Nearly fifty years after the protease-antiprotease imbalance hypothesis has been suggested for the cause of emphysema, it is still appealing, but it does not explain the considerable variation in the clinical expressions of emphysema. However, there are many recent research findings to support the imbalance hypothesis as will be shown in this review. Although limited, there might be openings for the treatment of the disease.