Airway Differentiation for Eosinophilic Diseases

Non-asthmatic eosinophilic bronchitis (NAEB) may result from in situ airway differentiation of eosinophil progenitor cells (EoPs).

To better understand the immunologic processes that promote eosinophilic inflammation in the airways of patients with NAEB and eosinophilic asthma, researchers used flow cytometry to measure the levels of EoPs and CD34+ hematopoietic progenitor cells (HPCs) in the induced sputum and peripheral blood of these patients.

Researchers compared these results for 15 patients with NAEB with the levels of 15 patients with eosinophilic asthma and 14 healthy controls. They then repeated these measurements after 1 month of treatment with inhaled corticosteroids (ICS) in patients with NAEB and after 1 month of treatment with ICS plus long-acting beta-agonists in patients with eosinophilic asthma.

At baseline, compared with healthy controls, patients with NAEB or eosinophilic asthma both had greater numbers of HPCs and EoPs in sputum (P < .05) but not in blood. After 1 month of budesonide, 200 μg, twice daily, cough considerably improved in patients with NAEB, although decreases in HPCs and EoPs in their sputum were not significant. This finding indicated that in situ differentiation of EoPs may mediate airway eosinophilia in patients with NAEB.

“Controlling in situ airway differentiation of EoPs may control airway eosinophilia and provide long-term resolution of symptoms in NAEB,” researchers concluded.

—Ellen Kurek

Reference:

Zhan C, Xu R, Li B, et al. Eosinophil progenitors in patients with non-asthmatic eosinophilic bronchitis, eosinophilic asthma, and normal controls. Front Immunol. 2022;13:737968. doi:10.3389/fimmu.2022.737968