8-Isoprostane in exhaled breath condensate and exercise-induced bronchoconstriction in asthmatic children and adolescents.
BACKGROUND
Exercise-induced bronchoconstriction (EIB) in the asthmatic child is associated with persistent airway inflammation and poor disease control. EIB could arise partly from airway oxidative stress. Exhaled breath condensate (EBC) levels of 8-isoprostane (IsoP), which is a known marker of oxidative stress, might therefore be helpful for monitoring asthma noninvasively.


METHODS
We recruited 46 asthmatic children and adolescents 6 to 17 years of age (29 boys), all of whom underwent lung function testing, measurement of the fractional concentration of exhaled nitric oxide (FENO), and collection of EBCs for 8-IsoP measurement before and after exercise challenge. FENO was measured before exercise and 5 min and 20 min after exercise. Spirometry was repeated 1, 5, 10, 15, and 20 min after exercise.


RESULTS
Baseline 8-IsoP levels (but not baseline FENO levels) correlated with the fall in FEV(1) 5 min after exercise (r = - 0.47; p = 0.002). 8-IsoP levels measured after exercise remained unchanged from baseline levels; conversely, FENO levels decreased in parallel with the decline in FEV(1) at 5 min (r = 0.44; p = 0.002). The mean baseline 8-IsoP concentrations were higher in patients with EIB (n = 12) than in those without EIB (n = 34; 44.9 pg/mL [95% confidence interval (CI), 38.3 to 51.5] vs 32.3 pg/mL [95% CI, 27.6 to 37.0], respectively; p < 0.01). No difference was found in the mean baseline FENO between groups (with EIB group: 38.7 ppb; 95% CI, 24.5 to 61.1; without EIB group: 29.1 ppb; 95% CI, 22.0 to 38.4).


CONCLUSIONS
Increased 8-IsoP concentrations in EBC samples of asthmatic children and adolescents with EIB suggest a role for oxidative stress in bronchial hyperreactivity.
Barreto
Mario
M
Department of Pediatrics, Sant'Andrea Hospital, II Faculty of Medicine, University "La Sapienza," Rome, Italy. Electronic address: mario.barreto@uniroma1.it.
Villa
Maria Pia
MP
Department of Pediatrics, Sant'Andrea Hospital, II Faculty of Medicine, University "La Sapienza," Rome, Italy.
Olita
Carla
C
Department of Pediatrics, Sant'Andrea Hospital, II Faculty of Medicine, University "La Sapienza," Rome, Italy.
Martella
Susy
S
Department of Pediatrics, Sant'Andrea Hospital, II Faculty of Medicine, University "La Sapienza," Rome, Italy.
Ciabattoni
Giovanni
G
Department of Drug Sciences, School of Pharmacy, University "G. D'Annunzio," Chieti, Italy.
Montuschi
Paolo
P
Department of Pharmacology, Faculty of Medicine, Catholic University of the Sacred Hearth, Rome, Italy.