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Updated: Aug 13, 2026
A Reversible, Non-invasive Method for Airway Resistance Measurements and Bronchoalveolar Lavage Fluid Sampling in Mice
Published on: April 13, 2010
Early decrease in nasal eosinophil proportion after nasal allergen challenge correlates with baseline bronchial
M Silvestri1, E Battistini, A C Defilippi
1Pulmonary Dept, G Gaslini Institute, Genoa, Italy.
Background:
Allergic rhinitis is induced by an IgE mediated inflammation after allergen exposure of the membranes lining the nose which, in predisposed individuals, may constitute a risk factor for the occurrence of asthma.
Objective:
To detect early changes in nasal inflammation after allergen exposure, 11 children [9.0 (7, 11) yrs], sensitized to house dust mites (HDM), with rhinoconjunctivitis and asthma and an age- and gender-matched control group (Ctr) were studied.
Methods:
The following parameters were evaluated: i) pulmonary function; ii) bronchial reactivity to methacholine (MCh), expressed as Pd20MCh; iii) nasal brushing (NB) 'at baseline' and, on a separate day, 30 min after nasal allergen challenge (NAC). On NBs, the following markers of inflammation were evaluated: a) neutrophil and eosinophil proportion, b) 'intact to degranulated eosinophil' ratio, and c) expression of intercellular adhesion molecule (ICAM)-1 and HLA-DR by nasal epithelial cells.
Results:
'At baseline', allergic children showed elevated nasal eosinophilia and increased ICAM-1 and HLA-DR expression (p<0.05), as compared to Ctr. In allergic children, nasal eosinophilia correlated with Pd20MCh (p=0.002). The significant decrease in nasal eosinophilia observed after NAC (p=0.002) was associated with a significant decrease in the 'intact to degranulated eosinophil' ratio (p=0.001). Interestingly, correlations were still present between Pd20MCh and 'post NAC' eosinophilia (p=0.004) or the NAC-induced decrease in eosinophilia (p=0.010).
Conclusions:
In children sensitized to HDM, experimental allergen exposure is followed by an early depletion of nasal eosinophils. The correlation between allergen-induced changes in nasal eosinophilia and bronchial reactivity to MCh further supports the concept of a tight link between upper and lower respiratory tract involvement in respiratory allergy.
