Pattern of airway inflammation and remodelling in mild persistent atopic asthma and in mild persistent asthma related to Gastroesophageal Reflux

SUMMARY

Background: The increase of basement membrane thickness (BMT) represents a structural feature described as commonly characterizing airway remodelling in asthma, even if the non-atopic condition had been investigated only episodically from this point of view. Gastroesophageal-reflux is a pathological condition which can frequently cause and/or sustain asthma in non-atopic individuals. Objectives: The aim of the study was to measure BMT; some inflammatory mediators in BAL; cys-leucotrienes (LTE4) in urine; e-NO, and BHR to Methacholine (MCh) in mild atopic and in mild non-atopic, GER-related asthma. Methods: After their informed consent, 25 mild atopic (40.9 years ± 13.1 sd, FEV1=95.9% pred. ± 12.9 sd) and 39 non-atopic, GER-related asthmatics (57.3 years ± 14.2 ds, FEV1=101.3% pred. ± 12.2 sd), nonsmoker and of a comparable asthma duration, underwent measurements of basal lung function and bronchial response to MCh (PD20 FEV1); endobronchial biopsies and BAL (in the right middle lobe), and a 24-h gastroesophageal pHmetry. Results: Atopic and GER-related asthma showed two distinct patterns of airway inflammation. The eosinophilic contribution to airway inflammation was systematically prevailing in the former group, such as: EOS=10.7% ±13.4 sd vs 2.0% ± 2.8 sd, p=0.001; ECP=344.9 mcg/l ± 635.9 sd vs 59.2 mcg/l ± 75.1 sd, p=0.001. Conclusions: Data from the present study are suggesting that persistent mild atopic and mild GER-related asthma seem to represent two distinct phenotypes of asthma in terms of airway remodelling, and in particular of BMT involvement.