Research Advance Publication
Repeated Nitrogen Dioxide Exposures and Eosinophilic Airway Inflammation in Asthmatics: A Randomized Crossover Study
This EHP Advance Publication article has been peer-reviewed, revised, and accepted for publication. EHP Advance Publication articles are completely citable using the DOI number assigned to the article. This document will be replaced with the copyedited and formatted version as soon as it is available. Through the DOI number used in the citation, you will be able to access this document at each stage of the publication process.
Citation: Ezratty V, Guillossou G, Neukirch C, Dehoux M, Koscielny S, Bonay M, Cabanes PA, Samet JM, Mure P, Ropert L, Tokarek S, Lambrozo J, Aubier M. Repeated Nitrogen Dioxide Exposures and Eosinophilic Airway Inflammation in Asthmatics: A Randomized Crossover Study. Environ Health Perspect; http://dx.doi.org/10.1289/ehp.1307240.
Received: 18 June 2013
Accepted: 15 April 2014
Advance Publication: 18 April 2014
For materials with complex tables, EHP offers “Alt 508″ versions optimized for use with screen-reading software.
Background: Nitrogen dioxide (NO2), a ubiquitous atmospheric pollutant, has been reported to enhance the asthmatic response to allergen through eosinophilic activation in the airways. The effect of NO2 on inflammation without exposure to allergen is poorly studied.
Objectives: We investigated whether repeated peaks of NO2, at various realistic concentrations, induce changes in airway inflammation in asthmatics.
Methods: 19 nonsmoker asthmatics were exposed at rest in a double-blind, crossover study, in randomized order, to 200 ppb NO2, or 600 ppb NO2, or clean air for 1×30 min day 1, and 2×30 min day 2. The three series of exposures were separated by 2 weeks. Inflammatory response in sputum was measured 6 hours (day 1), 32 hours (day 2), and 48 hours (day 3) after first exposure and compared to baseline measured twice 10 to 30 days before.
Results: Compared to baseline, the percentage of eosinophils in sputum increased by 57% after 600 ppb NO2 (P=0.003) but did not change significantly after 200 ppb. The slope of the association between the percentage of eosinophils and NO2 exposure level was significant (p=0.04). Eosinophil cationic protein (ECP) in sputum was highly correlated with eosinophil count and increased significantly after exposure to 600 ppb NO2 (p=0.001). Lung function assessed daily was not affected by NO2.
Conclusions: To our knowledge, this is the first study on repeated NO2 peaks performed without allergen exposure that demonstrates a dose-related effect on airway eosinophilic inflammation in asthmatics.
CEHN July 2014 Article of the Month
“Outdoor Formaldehyde and NO2 Exposures and Markers of Genotoxicity in Children Living Near Chipboard Industries” (Environ Health Perspect; DOI:10.1289/ehp.1307259) has been selected by the Children’s Environmental Health Network (CEHN) as its July 2014 Article of the Month. These CEHN summaries discuss the potential policy implications of current children’s environmental health research.
Sign Up to Receive E-mail Alerts
Recent Advance Publications
- Prenatal Organochlorine and Methylmercury Exposure and Memory and Learning in School-Age Children in Communities Near the New Bedford Harbor Superfund Site, Massachusetts
- Ligand Binding and Activation of PPARγ by Firemaster® 550: Effects on Adipogenesis and Osteogenesis in Vitro
- Effects of Developmental Activation of the AhR on CD4+ T-Cell Responses to Influenza Virus Infection in Adult Mice
- Prenatal and Postnatal Serum PCB Concentrations and Cochlear Function in Children at 45 Months of Age
- Variability in Temperature-Related Mortality Projections under Climate Change
- Environmental Health Research Recommendations from the Inter-Environmental Health Sciences Core Center Working Group on Unconventional Natural Gas Drilling Operations
- Residential Greenness and Birth Outcomes: Evaluating the Influence of Spatially Correlated Built-Environment Factors
- EHPNoonNews: Pennsylania's complicated groundwater contamination http://t.co/M1eoNBJgWD @livingonearth
- EHPNoonNews: Cleaning up contaminated lands on Long Island http://t.co/qGOZgezRTg @newsday
- EHPNoonNews: Vibrio infections on the Chesapeake Bay http://t.co/HX2vf4CJGp @washingtonpost
- EHPNoonNews: CDC's Environmental Public Health Tracking Network in action http://t.co/VXJY2AtLHC @cdcgov
- Trending EHP news this week: Rethinking sterile: the hospital microbiome http://t.co/AU6rVNREbi