Bronchiectasis: A clinical review of inflammation

Bronchiectasis is a chronic inflammatory airway disease characterized by a self-perpetuating vortex of impaired mucociliary clearance, persistent infection, and progressive structural lung damage. While inflammation is central to disease activity and progression, targeted anti-inflammatory treatments have been limited. Understanding the different types of inflammation involved and their significant overlap is essential for effective management. This review explores key inflammation patterns, biomarkers, and available treatments across the spectrum of inflammation in bronchiectasis, with a particular focus on non-cystic fibrosis bronchiectasis in adults. Neutrophilic inflammation remains the hallmark of bronchiectasis, with promising reversible dipeptidyl peptidase-1 inhibitors reducing the activation of neutrophil serine proteases during neutrophil maturation. Eosinophilic inflammation has also gained attention, with evidence indicating that patients with this endotype may benefit from glucocorticoids and biologic therapies targeting type 2 inflammation. Additional inflammatory mechanisms discussed here include impaired epithelial function and mucociliary abnormalities, immune dysregulation, and airway inflammation triggered by infections, environmental irritants, and autoimmune conditions. Written for general clinicians, this review simplifies complex concepts, underscores key aspects of diagnostic evaluation, and discusses both conventional and emerging treatments for bronchiectasis, providing practical insights for improved personalized patient care.