title: EIA and GC/MS analysis of 8-isoprostane in EBC of children with problematic asthma.
abstract: Asthmatic airways are characterised by enhanced oxidative stress, which can be studied by measuring biomarkers, such as 8-isoprostane. The aims of the present study were: 1) to measure the concentrations of 8-isoprostane in exhaled breath condensate (EBC) and urine of children with problematic and well-controlled asthma; 2) to compare the concentrations of 8-isoprostane measured by gas chromatographic/negative ion chemical ionisation mass spectrometry (GC/NICI-MS) and by an enzymatic immunoassay (EIA). We recruited 20 asthmatic allergic children, 13 with well-controlled asthma and seven with problematic asthma. They underwent exhaled nitric oxide measurements and spirometry, and both EBC and urine samples were collected. 8-isoprostane was measured in EBC by GC/NICI-MS and EIA. 8-isoprostane concentrations in EBC were significantly higher in children with problematic asthma than in children with well-controlled asthma (p = 0.01). An acceptable reproducibility emerged between GC/NICI-MS and EIA (coefficient of reproducibility 11.5 pg x mL(-1)). 8-isoprostane levels measured in urine did not correlate with those measured in EBC. We showed that 8-isoprostane in EBC was significantly increased in children with problematic asthma, suggesting a role for oxidative stress in this asthma phenotype. In addition we found an acceptable reproducibility of EIA compared to GC/NICI-MS, even if the latter method had higher accuracy.
authors.affiliation: Dept of Paediatrics, Respiratory Medicine and Allergy Unit, University of Padova, Via Giustiniani 3, 35128 Padova, Italy. silvia.carraro.1@unipd.it
authors.forename: S
authors.initials: S
authors.lastname: Carraro
authors.forename: P E
authors.initials: PE
authors.lastname: Cogo
authors.forename: I
authors.initials: I
authors.lastname: Isak
authors.forename: M
authors.initials: M
authors.lastname: Simonato
authors.forename: M
authors.initials: M
authors.lastname: Corradi
authors.forename: V P
authors.initials: VP
authors.lastname: Carnielli
authors.forename: E
authors.initials: E
authors.lastname: Baraldi
mesh_terms: D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism*; D001944:Breath Tests / Q000379:methods*; D002648:Child; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000378:metabolism / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods* / Q000592:standards; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods* / Q000592:standards; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology; D015203:Reproducibility of Results; D013147:Spirometry
chemical_list: D018927:Anti-Asthmatic Agents; D015415:Biomarkers; C075750:8-epi-prostaglandin F2alpha; D009569:Nitric Oxide; D015237:Dinoprost