Abstract
Sputum transcriptomic analysis of air pollutant signatures: link to asthma severity and phenotype
Background: Air pollution could increase the risk of asthma exacerbations but those who are most at risk remain undefined.
Aim: To determine the prevalence of gene signatures induced by exposure to components of air pollution in sputum transcriptomics of the U-BIOPRED cohort.
Methods: Enrichment scores(ES) in sputum cells from 61 non-smokers severe asthma(SAns), 20 mild-moderate asthma(MMA) patients and 16 healthy-volunteers(HV) were analyzed for published signatures after ozone, SO2, NO2, NOx, PM2.5, and PM10 exposure(acute:<24 hours, short-term:1-21 days, mid-term:3 weeks-6 months or chronic:6 months-5 years). Using gene set variation analysis(GSVA), we calculated ES across severity, inflammatory phenotype, exacerbation frequency(≥3/year), and airflow limitation(FEV1/FVC<0.7).
Results: Most pollutant gene signatures were enriched in SAns vs MMA/HV with significant differences for acute exposure to ozone and SO2(all p<0.02), mid-term exposure to ozone and PM2.5(all p<0.03) and chronic exposure to PM2.5 and NOx(all p<0.04).Acute and mid-term exposures were associated with a mixed/neutrophilic inflammation(all p<0.02), whereas chronic exposure with mixed/eosinophilic phenotypes(all p<0.01).No pollutants were associated with an exacerbation-prone phenotype. Only acute exposure to ozone and chronic exposure to PM2.5 or NOx were associated with airflow limitation(all p<0.03).
Conclusions: Chronic exposure to constituents of air pollution may be linked to the development of more severe asthma, both neutrophilic as well as eosinophilic inflammation and to airflow obstruction, but not to exacerbations.
Footnotes
Cite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA1783.
This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.
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 2021