Anti-Proteases and Alpha-1 Antitrypsin Augmentation Therapy.

Alpha-1 antitrypsin deficiency is a genetic disease that first highlighted the importance of protease balance in normal lung homeostasis. Proteases such as neutrophil elastase are important in many pulmonary diseases. However, the first commercially licensed anti-protease therapy was used for emphysema in alpha-1 antitrypsin deficiency. The 4 commercial alpha-1 protease inhibitor preparations in the United States are currently given intravenously to augment the serum and alveolar epithelial lining fluid concentrations of alpha-1 antitrypsin. Since the discovery of alpha-1 antitrypsin deficiency in 1963, many genetic polymorphisms of the SERPINA1 gene have been discovered. Because neutrophilic inflammation is the hallmark of usual COPD, anti-protease therapy also has been explored in this disease. Further trials with different dosing schema, inhaled therapy, and in different disease states are all ongoing. These studies would be facilitated by having COPD outcomes that are independent of measurement of air flow and achievable in smaller populations over a short period of time.