The following is a summary of “Aggregated eosinophils and neutrophils characterize the properties of mucus in chronic rhinosinusitis,” published in the May 2024 issue of Allergy & Immunology by Miyabe, et al.

Airway obstruction due to viscous mucus is a significant pathophysiologic feature of persistent inflammation, which can lead to organ damage. For a study, researchers sought to test the hypothesis that the biophysical properties of accumulating granulocytes impact the clinical characteristics of mucus.

Nasal mucus samples were surgically collected from patients with eosinophilic chronic rhinosinusitis and neutrophil-dominant, noneosinophilic chronic rhinosinusitis. These samples were analyzed for computed tomography (CT) density, viscosity, water content, wettability, and protein composition. Human eosinophils and neutrophils were isolated and stimulated to form extracellular traps and aggregates. The physical properties of these aggregates were also examined.

Mucus from patients with eosinophilic chronic rhinosinusitis exhibited significantly higher CT density, viscosity, dry weight, and hydrophobicity than patients with noneosinophilic chronic rhinosinusitis. The physical properties of mucus correlated with levels of eosinophil-specific proteins. Aggregates formed from eosinophils and neutrophils displayed similar physical and pathological characteristics to those of mucus. Treatment with deoxyribonuclease and heparin, which breaks down the structure of eosinophil extracellular traps, effectively reduced the viscosity and hydrophobicity of both eosinophil aggregates and eosinophilic mucus.

The study shed light on the pathogenesis of mucus stasis involving infiltrated granulocyte aggregates from a novel perspective. The findings inform the development of new treatment strategies for eosinophilic airway diseases.

Reference: jacionline.org/article/S0091-6749(24)00002-2/abstract