title: Increase in markers of airway inflammation after ozone exposure can be observed also in stable treated asthmatics with minimal functional response to ozone.
abstract: BACKGROUND
  The discrepancy between functional and inflammatory airway response to ozone has been reported in normal subjects, but few data are available for stable asthmatics regularly treated with inhaled corticosteroids.
  
  
  METHODS
  Twenty-three well controlled, regularly treated, mild-to-moderate asthmatic patients underwent two sequential randomised exposures to either filtered air or ozone (0.3 ppm for 2 hours) in a challenge chamber. Pulmonary function (PF) was monitored, and patients with FEV1 decrease greater than 10% from pre-challenge value were considered as responders. Immediately after each exposure, exhaled breath condensate (EBC) was collected to measure malondialdehyde (MDA). Six hours after each exposure, PF and EBC collection were repeated, and sputum was induced to measure inflammatory cell counts and soluble mediators (IL-8 and neutrophil elastase). The response to ozone was also evaluated according to the presence of polymorphism in oxidative stress related NQO1 and GSTM1 genes.
  
  
  RESULTS
  After ozone exposure, sputum neutrophils significantly increased in responders (n = 8), but not in nonresponders (n = 15). Other markers of neutrophil activation in sputum supernatant and MDA in EBC significantly increased in all patients, but only in nonresponders the increase was significant. In nonresponders, sputum eosinophils also significantly increased after ozone. There was a positive correlation between ozone-induced FEV1 fall and increase in sputum neutrophils. No difference in functional or inflammatory response to ozone was observed between subjects with or without the combination of NQO1wt- GSTM1null genotypes.
  
  
  CONCLUSIONS
  Markers of neutrophilic inflammation and oxidative stress increase also in asthmatic subjects not responding to ozone. A greater functional response to ozone is associated with greater neutrophil airway recruitment in asthmatic subjects.
authors.affiliation: Cardio-Thoracic and Vascular Department, University of Pisa, Pisa, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Vagaggini
authors.forename: Maria Laura E
authors.initials: ML
authors.lastname: Bartoli
authors.forename: Silvana
authors.initials: S
authors.lastname: Cianchetti
authors.forename: Francesco
authors.initials: F
authors.lastname: Costa
authors.forename: Elena
authors.initials: E
authors.lastname: Bacci
authors.forename: Federico L
authors.initials: FL
authors.lastname: Dente
authors.forename: Antonella
authors.initials: A
authors.lastname: Di Franco
authors.forename: Laura
authors.initials: L
authors.lastname: Malagrinò
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Paggiaro
mesh_terms: D000328:Adult; D001249:Asthma / Q000378:metabolism* / Q000628:therapy; D015415:Biomarkers / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology*; D008297:Male; D018375:Neutrophil Activation / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects*; D010126:Ozone / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D016207:Cytokines; D010126:Ozone