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Clinical and technical factors affecting pH and other biomarkers in exhaled breath condensate.
Pediatr Pulmonol. 2006 Jan; 41(1):87-94.PP

Abstract

Exhaled breath condensate (EBC) pH appears to be a robust measure of asthma. However, the association between EBC pH and clinical factors and airway inflammatory markers remains unclear. The objectives of this study were to investigate the factors determining EBC pH in asthmatic children, and the reproducibility and effects of collection devices on EBC pH in nine healthy, nonsmoking adults. EBC was collected once from asthmatic children using EcoScreen, and from adults over 3 consecutive days using both RTubes and EcoScreen. EBC pH was measured immediately in non-deaerated samples by microelectrode pH meter. Concentrations of 8-isoprostane, cysteinyl leukotrienes (cys-LT), and leukotriene B4 (LTB4) were measured using enzyme immunoassay. Exhaled nitric oxide concentration (FeNO) was measured by chemiluminescence. Fifty-eight asthmatics (16 intermittent, 12 mild persistent, and 30 moderate-to-severe persistent) were recruited. EBC pH was lower among patients with moderate-to-severe persistent than intermittent asthma (P = 0.046). This marker correlated inversely with disease severity score (rho = -0.276, P = 0.036), but not FeNO or other EBC biomarkers. Bland-Altman analyses found pH but not other EBC biomarkers to be reproducible, which were confirmed by its low coefficient of variation (2.7%; range, 0.4-5.2%). There was poor correlation between pH in EBC collected by RTube and EcoScreen (rho = 0.059, P = 0.784). Factor analysis selected four factors that explained 67.5% of the total variance, and EBC pH clustered with both cys-LT and LTB4. In conclusion, our results suggest that pH in non-deaerated EBC is influenced by asthma severity in children. EBC pH measurement is reproducible, but is dependent on the collection devices used.

Authors+Show Affiliations

Department of Pediatrics, Chinese University of Hong Kong, Hong Kong SAR, China. leung2142@cuhk.edu.hkNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16292777

Citation

Leung, Ting F., et al. "Clinical and Technical Factors Affecting pH and Other Biomarkers in Exhaled Breath Condensate." Pediatric Pulmonology, vol. 41, no. 1, 2006, pp. 87-94.
Leung TF, Li CY, Yung E, et al. Clinical and technical factors affecting pH and other biomarkers in exhaled breath condensate. Pediatr Pulmonol. 2006;41(1):87-94.
Leung, T. F., Li, C. Y., Yung, E., Liu, E. K., Lam, C. W., & Wong, G. W. (2006). Clinical and technical factors affecting pH and other biomarkers in exhaled breath condensate. Pediatric Pulmonology, 41(1), 87-94.
Leung TF, et al. Clinical and Technical Factors Affecting pH and Other Biomarkers in Exhaled Breath Condensate. Pediatr Pulmonol. 2006;41(1):87-94. PubMed PMID: 16292777.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Clinical and technical factors affecting pH and other biomarkers in exhaled breath condensate. AU - Leung,Ting F, AU - Li,Chung Y, AU - Yung,Edmund, AU - Liu,Eric K H, AU - Lam,Christopher W K, AU - Wong,Gary W K, PY - 2005/11/18/pubmed PY - 2007/5/23/medline PY - 2005/11/18/entrez SP - 87 EP - 94 JF - Pediatric pulmonology JO - Pediatr Pulmonol VL - 41 IS - 1 N2 - Exhaled breath condensate (EBC) pH appears to be a robust measure of asthma. However, the association between EBC pH and clinical factors and airway inflammatory markers remains unclear. The objectives of this study were to investigate the factors determining EBC pH in asthmatic children, and the reproducibility and effects of collection devices on EBC pH in nine healthy, nonsmoking adults. EBC was collected once from asthmatic children using EcoScreen, and from adults over 3 consecutive days using both RTubes and EcoScreen. EBC pH was measured immediately in non-deaerated samples by microelectrode pH meter. Concentrations of 8-isoprostane, cysteinyl leukotrienes (cys-LT), and leukotriene B4 (LTB4) were measured using enzyme immunoassay. Exhaled nitric oxide concentration (FeNO) was measured by chemiluminescence. Fifty-eight asthmatics (16 intermittent, 12 mild persistent, and 30 moderate-to-severe persistent) were recruited. EBC pH was lower among patients with moderate-to-severe persistent than intermittent asthma (P = 0.046). This marker correlated inversely with disease severity score (rho = -0.276, P = 0.036), but not FeNO or other EBC biomarkers. Bland-Altman analyses found pH but not other EBC biomarkers to be reproducible, which were confirmed by its low coefficient of variation (2.7%; range, 0.4-5.2%). There was poor correlation between pH in EBC collected by RTube and EcoScreen (rho = 0.059, P = 0.784). Factor analysis selected four factors that explained 67.5% of the total variance, and EBC pH clustered with both cys-LT and LTB4. In conclusion, our results suggest that pH in non-deaerated EBC is influenced by asthma severity in children. EBC pH measurement is reproducible, but is dependent on the collection devices used. SN - 8755-6863 UR - https://www.unboundmedicine.com/medline/citation/16292777/Clinical_and_technical_factors_affecting_pH_and_other_biomarkers_in_exhaled_breath_condensate_ L2 - https://doi.org/10.1002/ppul.20296 DB - PRIME DP - Unbound Medicine ER -