title: Biomarker reproducibility in exhaled breath condensate collected with different condensers.
abstract: Optimal collection and analysis of exhaled breath condensate (EBC) are prerequisites for standardisation and reproducibility of assessments. The present study aimed to assess reproducibility of EBC volume, hydrogen peroxide (H(2)O(2)), 8-isoprostane and cytokine measurements using different condensers, including a newly developed glass condenser. At four points in time, 30 healthy subjects performed sequential EBC collections randomly using the following four condensers: glass, silicone, EcoScreen (Erich Jaeger GmbH, Hoechberg, Germany) and an optimised glass condenser. In small EBC samples, H(2)O(2) was measured by spectrophotometer, 8-isoprostane by enzyme immunoassay, and cytokines by multiplexed xMAP technology (Luminex Corporation, Austin, TX, USA). The optimised glass condenser yielded significantly more EBC volume (median 2,025 microL, interquartile range 1,600-2,525). The reproducibility of EBC volume, yielded by the new glass condenser, was comparable with EcoScreen (19-20 coefficients of variation (CV)%), but was significantly better compared with silicone and glass (29-37 CV%). The new condenser was associated with significantly more detections of H(2)O(2), 8-isoprostane, interleukin-2, -4, -5 and -13, and tumour necrosis factor-alpha. Isoprostane concentrations were significantly higher using the new condenser, whereas H(2)O(2) and cytokine concentrations were not. Reproducibility of biomarkers was equally variable for all condenser types. In conclusion, significantly more exhaled breath condensate volume and biomarker detections were found using the optimised glass condenser, including higher 8-isoprostane levels. However, biomarker reproducibility in exhaled breath condensate in healthy adults was not influenced by the type of condenser.
authors.affiliation: Dept of Paediatric Pulmonology, Caphri Research Institute, University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands. p.rosias@orbisconcern.nl
authors.forename: P P
authors.initials: PP
authors.lastname: Rosias
authors.forename: C M
authors.initials: CM
authors.lastname: Robroeks
authors.forename: A
authors.initials: A
authors.lastname: Kester
authors.forename: G J
authors.initials: GJ
authors.lastname: den Hartog
authors.forename: W K
authors.initials: WK
authors.lastname: Wodzig
authors.forename: G T
authors.initials: GT
authors.lastname: Rijkers
authors.forename: L J
authors.initials: LJ
authors.lastname: Zimmermann
authors.forename: C P
authors.initials: CP
authors.lastname: van Schayck
authors.forename: Q
authors.initials: Q
authors.lastname: Jöbsis
authors.forename: E
authors.initials: E
authors.lastname: Dompeling
mesh_terms: D000328:Adult; D015415:Biomarkers; D001944:Breath Tests / Q000295:instrumentation* / Q000379:methods; D015237:Dinoprost / Q000031:analogs & derivatives / Q000032:analysis; D045853:Exhalation; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis; D007378:Interleukins / Q000032:analysis; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000295:instrumentation* / Q000379:methods; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D015415:Biomarkers; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost; D006861:Hydrogen Peroxide