Abstract
Background: Outdoor air pollution contributes to asthma exacerbations and development; yet its effects on airway pathology have not been defined, especially in children. To investigate the effects of pollution on airway pathology we examined retrospectively the effect of environmental exposure on pathological changes in bronchial biopsies (BB) in 99 children undergoing a clinically indicated bronchoscopy (age5.3±2.9yrs;53wheezing/46non-wheezing).
Methods: Structural and inflammatory changes (Basement Membrane-BM thickness, epithelial loss, eosinophils, neutrophils, macrophages, mast-cells, lymphocytes) were quantified in BB by immunohistochemistry. PM10, NO2 and SO2 levels were obtained from monitoring stations closest to child home in the 90 days preceding BB. The association between average levels of pollutants and biopsy findings was evaluated using a Generalized Additive Model with negative binomial family to allow for overdispersion, adjusted for atmospheric pressure, temperature, humidity.
Results: SO2 exposure was negligible while high levels of exposure were recorded for PM10 (46[33-60]μg/m3) and NO2 (40[31-48]μg/m3). BM thickness increased with increasing levels of PM10 (Relative Risk, RR90days1.34,CI1.0-1.7), particularly in wheezing children. Exposure to PM10 reduced neutrophilic inflammation (RR90d0.46,CI0.2-0.8), particularly in non-wheezing children. Short-term exposure to NO2 also reduced neutrophils (RR3d0.61,CI0.4-0.95).
Conclusions: Chronic exposure to PM10 affects BM thickness in wheezing children, suggesting that it can contribute to asthma development by promoting airway remodeling. Exposure to NO2 and PM10 was associated to reduced neutrophilic inflammation, possibly unravelling impaired innate immunity.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 4084.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020