title: Oxidative stress and airway inflammation after allergen challenge evaluated by exhaled breath condensate analysis.
abstract: BACKGROUND
  Allergen exposure may increase airway oxidative stress, which causes lipid membrane peroxidation and an increased formation of 8-isoprostane.
  
  
  OBJECTIVE
  The aim of the study was to investigate oxidative stress induced by allergen challenge in mild asthmatics, by measuring 8-isoprostane in exhaled breath condensate (EBC), and to examine their relationship with mediators derived from arachidonic acid. Methods 8-isoprostane, cysteinyl leukotrienes (cys-LTs) and prostaglandin E2 (PGE(2) ) concentrations in EBC were measured at baseline and after allergen challenge in 12 patients with mild allergic asthma sensitized to cat allergen.
  
  
  RESULTS
  At 24 h after allergen challenge, compared with baseline values, EBC 8-isoprostane increased [48.64 pg/mL (44.14-53.61) vs. 21.56 pg/mL (19.92, 23.35), P<0.001], cys-LTs increased [27.37 pg/mL (24.09-31.10) vs. 13.28 pg/mL (11.32, 15.57), P<0.001] and PGE(2) decreased [18.69 pg/mL (12.26, 28.50) vs. 39.95 pg/mL (34.37, 46.43), P<0.001]. The trend of increasing 8-isoprostane after allergen challenge was significantly correlated with the trend of increasing cys-LTs (R(2) =0.85, P<0.001) whereas the trend of decreasing PGE(2) after allergen challenge was significantly correlated with the trend of increasing cys-LTs (R(2) =0.52, P=0.001).
  
  
  CONCLUSIONS
  The increase in EBC 8-isoprostane observed after allergen challenge indicates that allergen exposure increases airway oxidative stress in allergic asthma. The strict correlation between cys-LTs and 8-isoprostane underlines the relationship between allergic inflammation and oxidative stress. A shift of arachidonic acid metabolism towards lipoxygenase pathway is induced by the allergen challenge. Airway oxidative stress occurs after allergen challenge even in patients with mild intermittent allergic asthma.
authors: Department of Biomedical Sciences and Human Oncology, Allergy and Clinical Immunology, University of Torino & AO Mauriziano Umberto I, Largo Turati 62, Turin, Italy.
authors: L
authors: L
authors: Brussino
authors: I
authors: I
authors: Badiu
authors: S
authors: S
authors: Sciascia
authors: M
authors: M
authors: Bugiani
authors: E
authors: E
authors: Heffler
authors: G
authors: G
authors: Guida
authors: A
authors: A
authors: Malinovschi
authors: C
authors: C
authors: Bucca
authors: G
authors: G
authors: Rolla
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000485:Allergens / Q000008:administration & dosage*; D000818:Animals; D001249:Asthma / Q000175:diagnosis / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D015415:Biomarkers / Q000378:metabolism; D001944:Breath Tests; D016022:Case-Control Studies; D002415:Cats; D015237:Dinoprost / Q000031:analogs & derivatives / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D045853:Exhalation; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D015289:Leukotrienes / Q000378:metabolism; D015227:Lipid Peroxidation; D008168:Lung / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D012720:Severity of Illness Index; D013997:Time Factors; D055815:Young Adult
chemical_list: D000485:Allergens; D015415:Biomarkers; D015289:Leukotrienes; C075750:8-epi-prostaglandin F2alpha; D009569:Nitric Oxide; D015237:Dinoprost; D015232:Dinoprostone