8-Isoprostane in Exhaled Breath Condensate: A Systematic Review in Adult Asthma

Adam Peel, Christina-Jane Crossman-Barnes, Jonathan C Y Tang, Yoon Loke, Gwyneth Davies, Stephen J. Fowler, Andrew Wilson

Research output: Contribution to conferencePoster

Abstract

Background: The potential of exhaled breath condensate (EBC) as a non-invasive indicator of airways disease has been studied for over thirty years. 8-isoprostane is a product of lipid peroxidation detectable within EBC, and a potential objective indicator of oxidative stress in asthma.
Aim: To assess the evidence for the use of 8-isoprostane in EBC as a biomarker in adult asthma.
Methods: We searched a number of online databases (including PubMed, Embase and Scopus) in January 2016. We included studies of adult non-smokers with EBC collection and asthma diagnosis conducted according to recognised guidelines. We aimed to pool data using random effects meta-analysis and assess heterogeneity using I2. Study quality and risk of bias was assessed using QUADAS-2 and GRADE.
Results: We included twenty studies, the findings from which were inconsistent. Seven studies (n = 329) reported 8-isoprostane concentrations in asthma to be significantly higher than that of control groups, whilst six studies (n = 403) did not. Only four studies had results appropriate for inclusion in a random effects meta-analysis of mean difference between asthma and controls. This found a statistically significant between-groups difference of +22pg/ml in asthma. Confidence in the result is limited by the small number of studies; substantial methodological and statistical heterogeneity; and inability to assess the risk of bias in key domains.
Conclusion: The clinical value of EBC 8-isoprostane as a quantitative assessment of oxidative stress in asthma remains unclear due to variability in results and methodological heterogeneity. It will be essential to develop accurate, reliable and standardised methods of both EBC collection and 8-isoprostane analysis if its use as a biomarker in asthma is to be evaluated.
Funding: University of East Anglia and the Asthma UK Centre for Applied Research.
Original languageEnglish
Publication statusPublished - 9 Nov 2016
EventAsthma UK Centre for Applied Research Annual Scientific Meeting - Edinburgh, United Kingdom
Duration: 9 Nov 201610 Nov 2016

Conference

ConferenceAsthma UK Centre for Applied Research Annual Scientific Meeting
CountryUnited Kingdom
CityEdinburgh
Period9/11/1610/11/16

Keywords

  • Asthma
  • Exhaled breath condensate
  • Biomarker
  • systematic review and meta-analysis

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