Pattern of Airway Inflammation and Remodelling in Mild Persistent Atopic Asthma and in Mild Persistent Asthma Related to Gastroesophageal Reflux

Background: The increase of basement membrane thickness (BMAT) 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. Gastrooesophageal-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, FEVY1 = 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 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.