Airway neutrophilic inflammation

Airway neutrophilic inflammation is a pathological phenotype characterized by the excessive recruitment and activation of neutrophils within the respiratory tract, often identified by sputum neutrophilia (sputum neutrophils ≥ 61–65%). Unlike eosinophilic inflammation, which is typically responsive to corticosteroids, neutrophilic inflammation is a hallmark of steroid-resistant conditions such as chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), and severe neutrophilic asthma. The process involves the release of potent mediators, including neutrophil elastase (NE), matrix metalloproteinases (MMPs), and reactive oxygen species (ROS), which contribute to tissue damage, airway remodeling, and mucus hypersecretion. Therapeutic strategies aim to modulate this response by targeting neutrophil recruitment (e.g., CXCR2 antagonists like navarixin), inhibiting protease activation (e.g., DPP1 inhibitors like brensocatib), or using immunomodulatory agents like macrolides. However, a significant therapeutic challenge is the risk of compromising the host's innate immune defense, as neutrophils are critical for pathogen clearance.

Other names

Neutrophilic airway inflammationSputum neutrophiliaNeutrophilic bronchitisNon-eosinophilic airway inflammation

Dipeptidyl peptidase 1 (DPP1) inhibition, neutrophil elastase inhibition, CXCR2 antagonism, macrolide immunomodulation, and phosphodiesterase inhibition.