Neutrophil elastase

Class

Elastase inhibitor

Neutrophil elastase is a serine protease stored in the granules of neutrophils, a type of white blood cell central to innate immune defense. When neutrophils are activated at sites of infection or tissue injury, they release elastase to help break down bacteria and damaged tissue matrix, including elastin, collagen, and other structural proteins. Under normal conditions, this activity is tightly balanced by circulating protease inhibitors such as alpha-1 antitrypsin. When neutrophil activation is excessive or chronic, or when the natural inhibitor is deficient or overwhelmed, unchecked elastase activity can damage lung tissue and other structures, contributing to conditions such as chronic obstructive pulmonary disease, alpha-1 antitrypsin deficiency, bronchiectasis, cystic fibrosis, and acute lung injury. Pharmacological inhibition of neutrophil elastase aims to restore this protease-antiprotease balance, limiting ongoing tissue destruction while leaving the broader immune response largely intact. This approach is of particular interest in chronic inflammatory lung diseases where progressive loss of elastin-rich tissue drives irreversible decline in lung function. Elastase inhibitors are typically administered as small molecules designed to bind the enzyme's active site and block its proteolytic activity.