Nasal mucosal response to repeated challenges with pollen allergen

Area of Science:

• Immunology
• Otorhinolaryngology
• Cell Biology

Background:

• Allergic rhinitis involves complex cellular responses in the airway mucosa.
• Understanding these dynamics is crucial for managing seasonal allergies.

Purpose of the Study:

• To investigate the cellular and symptomatic responses of the nasal mucosa to controlled daily allergen exposure in patients with seasonal allergic rhinitis.
• To correlate symptom severity with morphologic changes in the nasal mucosa.

Main Methods:

• Nine patients with birch pollen-allergic rhinitis underwent daily allergen challenges for seven days.
• Nasal symptoms, including blockage measured by peak flow meter, were recorded.
• Cell samples were collected via mucosal imprints, brush samplings, and nasal lavage for light microscopy and histamine measurement.

Main Results:

• Patients exhibited increased nasal symptoms, worsening between Days 2 and 7.
• Light microscopy showed an immediate and sustained increase in eosinophils in nasal lavage (2.3% to 13.1%) and brush specimens.
• A strong correlation was observed between lavage and brush sampling methods for cellular analysis.

Conclusions:

• Repeated allergen exposure leads to a progressive increase in nasal symptoms and eosinophilic inflammation in allergic rhinitis.
• Nasal lavage and brush sampling are reliable methods for assessing cellular changes in allergic rhinitis.
• The findings provide insights into the dynamics of airway mucosal response to allergens.