Document Detail


Effect of ozone exposure on airway responses to inhaled allergen in asthmatic subjects.
MedLine Citation:
PMID:  15189958     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Controlled human exposure studies have produced conflicting results regarding the effect of ozone on the early bronchoconstrictor response to inhaled allergen in specifically sensitized asthmatic subjects. Spirometric parameters do not necessarily reflect the airway inflammatory effects of inhaled ozone or allergen. OBJECTIVE: This study was designed to investigate whether exposure to ozone enhances the late airway inflammatory response, as well as the early bronchoconstrictor response, to inhaled house dust mite allergen in sensitized asthmatic subjects. DESIGN: Randomized, counter-balanced, cross-over study. SETTING: Human exposure laboratory. METHODS: Fourteen subjects were exposed to 0.2 ppm O(3) or filtered air, on separate days, for 1 h during exercise. After each exposure, the subjects were challenged with doubling doses of Dermatophagoides farinae (DF) allergen (provocative concentration of DF causing a 15% decrease in FEV(1) [PC(15)]). At 6 h after allergen challenge, bronchoscopy with BAL, proximal airway lavage (PAL), and endobronchial biopsy were performed. The second exposure/allergen challenge/bronchoscopy sequence was performed at least 4 weeks after the first sequence. RESULTS: No significant difference in cellular or biochemical markers of the late inflammatory response after allergen was found between the ozone and air exposures (although a trend toward increased neutrophils was noted after ozone exposure in the PAL fluid, p = 0.06). For the group as a whole, no significant difference in PC(15) was demonstrated after ozone exposure compared to air exposure. However, subjects with the greatest ozone-induced decrements in FEV(1) tended to have lower PC(15) values after ozone exposure. CONCLUSION: Exposure to a relatively low-level concentration of ozone does not enhance the late inflammatory or early bronchoconstrictor response to inhaled antigen in most allergic asthmatic subjects. Our results do suggest, however, that a subgroup of asthmatics may acquire increased sensitivity to aeroallergens after exposure to ozone.
Authors:
Lisa L Chen; Ira B Tager; David B Peden; Dorothy L Christian; Ronald E Ferrando; Barbara S Welch; John R Balmes
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Chest     Volume:  125     ISSN:  0012-3692     ISO Abbreviation:  Chest     Publication Date:  2004 Jun 
Date Detail:
Created Date:  2004-06-10     Completed Date:  2004-07-13     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0231335     Medline TA:  Chest     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2328-35     Citation Subset:  AIM; IM    
Affiliation:
Lung Biology Center, Center for Occupational and Environmental Health, Cardiovascular Research Institute, and Medical Service, San Francisco General Hospital, University of California, San Francisco, CA, USA.
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MeSH Terms
Descriptor/Qualifier:
Administration, Inhalation
Adolescent
Adult
Antigens, Dermatophagoides / adverse effects*
Asthma / diagnosis,  immunology*,  physiopathology*
Bronchial Hyperreactivity / immunology*
Bronchial Provocation Tests
Bronchoalveolar Lavage Fluid / cytology
Cross-Over Studies
Environmental Monitoring
Humans
Male
Organothiophosphorus Compounds
Ozone / pharmacology*
Probability
Reference Values
Respiratory Function Tests
Sensitivity and Specificity
Statistics, Nonparametric
Grant Support
ID/Acronym/Agency:
M01RR00083-41/RR/NCRR NIH HHS; R01 ES08970/ES/NIEHS NIH HHS
Chemical
Reg. No./Substance:
0/Antigens, Dermatophagoides; 0/Organothiophosphorus Compounds; 10028-15-6/Ozone; 50782-69-9/VX

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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