title: Exhaled breath condensate: determination of non-volatile compounds and their potential for clinical diagnosis and monitoring. A review.
abstract: Exhaled breath condensate is a promising, non-invasive, diagnostic sample obtained by condensation of exhaled breath. Starting from a historical perspective of early attempts of breath testing towards the contemporary state-of-the-art breath analysis, this review article focuses mainly on the progress in determination of non-volatile compounds in exhaled breath condensate. The mechanisms by which the aerosols/droplets of non-volatile compounds are formed in the airways are discussed with methodological consequences for sampling. Dilution of respiratory droplets is a major problem for correct clinical interpretation of the measured data and there is an urgent need for standardization of EBC. This applies also for collection instrumentation and therefore various commercial and in-house built devices are described and compared with regard to their design, function and collection parameters. The analytical techniques and methods for determination of non-volatile compounds as potential markers of oxidative stress and lung inflammation are scrutinized with an emphasis on method suitability, sensitivity and appropriateness. The relevance of clinical findings for each group of possible non-volatile markers of selected pulmonary diseases and methodological recommendations with emphasis on interdisciplinary collaboration that is essential for future development into a fully validated clinical diagnostic tool are given.
authors.affiliation: Bioanalytical Instrumentation, CEITEC - Central European Institute of Technology, Masaryk University, Veveri 97, 602 00 Brno, Czech Republic. Electronic address: petr.kuban@ceitec.muni.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Kubáň
authors.forename: František
authors.initials: F
authors.lastname: Foret
mesh_terms: D000388:Air / Q000032:analysis; D015415:Biomarkers / Q000032:analysis* / Q000378:metabolism; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007118:Immunoassay; D008171:Lung Diseases / Q000175:diagnosis* / Q000378:metabolism; D026361:Reactive Nitrogen Species / Q000032:analysis / Q000378:metabolism
chemical_list: D015415:Biomarkers; D026361:Reactive Nitrogen Species
keywords: 3-NT; 3-nitrotyrosine; 5-HPETE; 5-LO; 5-hydroperoxyeicosatetraenoic acid; 5-lipoxygenase; 8-IP; 8-isoprostane; ALF; Analytical techniques; BAL; CF; COPD; COX; EBC; Exhaled breath condensate (EBC); FDA; GSH; GSSG; INF-γ; Ions; LT; Metabolites; NMR; PCA; PE; PG; PLS; PLS-DA; PP; PTFE; Proteins; ROS; RS–NO; S-nitrosothiols; SI; TNF-α; U.S. Food and Drug Administration; VOC; airway lining fluid; bronchoalveolar lavage; chronic obstructive pulmonary disease; cyclooxygenase; cystic fibrosis; exhaled breath condensate; glutathione; glutathione disulfide; interferon γ; leukotriene; nuclear magentic resonance; partial least squares; partial least squares discriminant analysis; polyethylene; polypropylene; polytetrafluoroethylene; principal component analysis; prostaglandin; reactive oxygen species; sputum induction; tumor necrosis factor α; volatile organic compounds