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. 2023 Mar 20;9(2):00427-2022.
doi: 10.1183/23120541.00427-2022. eCollection 2023 Mar.

Validation of volatile metabolites of pulmonary oxidative injury: a bench to bedside study

Dominic Fenn  1   2 , Thijs A Lilien  2   3 , Laura A Hagens  4 , Marry R Smit  4 , Nanon F L Heijnen  5   6 , Anita M Tuip-de Boer  2 , Anne H Neerincx  1 , Korneliusz Golebski  1   7 , Dennis C J J Bergmans  5   6 , Ronny M Schnabel  5 , Marcus J Schultz  4 , Anke H Maitland-van der Zee  1 , Paul Brinkman  1 , Lieuwe D J Bos  1   2   4
Affiliations

Validation of volatile metabolites of pulmonary oxidative injury: a bench to bedside study

Dominic Fenn et al. ERJ Open Res. .

Abstract

Background: Changes in exhaled volatile organic compounds (VOCs) can be used to discriminate between respiratory diseases, and increased concentrations of hydrocarbons are commonly linked to oxidative stress. However, the VOCs identified are inconsistent between studies, and translational studies are lacking.

Methods: In this bench to bedside study, we captured VOCs in the headspace of A549 epithelial cells after exposure to hydrogen peroxide (H2O2), to induce oxidative stress, using high-capacity polydimethylsiloxane sorbent fibres. Exposed and unexposed cells were compared using targeted and untargeted analysis. Breath samples of invasively ventilated intensive care unit patients (n=489) were collected on sorbent tubes and associated with the inspiratory oxygen fraction (F IO2 ) to reflect pulmonary oxidative stress. Headspace samples and breath samples were analysed using gas chromatography and mass spectrometry.

Results: In the cell, headspace octane concentration was decreased after oxidative stress (p=0.0013), while the other VOCs were not affected. 2-ethyl-1-hexanol showed an increased concentration in the headspace of cells undergoing oxidative stress in untargeted analysis (p=0.00014). None of the VOCs that were linked to oxidative stress showed a significant correlation with F IO2 (Rs range: -0.015 to -0.065) or discriminated between patients with F IO2 ≥0.6 or below (area under the curve range: 0.48 to 0.55).

Conclusion: Despite a comprehensive translational approach, validation of known and novel volatile biomarkers of oxidative stress was not possible in patients at risk of pulmonary oxidative injury. The inconsistencies observed highlight the difficulties faced in VOC biomarker validation, and that caution is warranted in the interpretation of the pathophysiological origin of discovered exhaled breath biomarkers.

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Conflict of interest statement

Conflict of interest: D. Fenn has nothing to disclose. Conflict of interest: T.A. Lilien has nothing to disclose. Conflict of interest: L.A. Hagens has nothing to disclose. Conflict of interest: M.R. Smit has nothing to disclose. Conflict of interest: N.F.L. Heijnen has nothing to disclose. Conflict of interest: A.M. Tuip-de Boer has nothing to disclose. Conflict of interest: A.H. Neerincx has nothing to disclose. Conflict of interest: K. Golebski has nothing to disclose. Conflict of interest: D.C.J.J. Bergmans has nothing to disclose. Conflict of interest: R.M. Schnabel has nothing to disclose. Conflict of interest: M.J. Schultz has nothing to disclose. Conflict of interest: A.H. Maitland-van der Zee has received research grants outside the submitted work from GSK, Boehringer Ingelheim and Vertex; she is the principal investigator of a P4O2 (Precision Medicine for more Oxygen) public–private partnership sponsored by Health Holland involving many private partners that contribute in cash and/or in kind (Boehringer Ingelheim, Breathomix, Fluidda, Ortec Logiqcare, Philips, Quantib-U, Roche, Smartfish, SODAQ, Thirona, TopMD and Novartis); and she has served in advisory boards for AstraZeneca, GSK and Boehringer Ingelheim, with money paid to her institution. Conflict of interest: P. Brinkman has nothing to disclose. Conflict of interest: L.D.J. Bos reports grants from the Dutch Lung Foundation (Young investigator grant), grants from the Dutch Lung Foundation and Health Holland (Public–Private Partnership grant), grants from the Dutch Lung Foundation (Dirkje Postma Award), grants from IMI COVID19 initiative, and grants from Amsterdam UMC fellowship, outside the submitted work; he has also served in advisory capacity for Santhera and Janssen with money paid to his institution.

Figures

FIGURE 1
FIGURE 1
a) Interleukin (IL)-8 and b) lactate dehydrogenase (LDH) release shown for a549 cells treated for 24 h (T24) with or without 1 mM hydrogen peroxide (H2O2). Values expressed relative to untreated control cells (T0) and p-value calculated using Mann–Whitney U test.
FIGURE 2
FIGURE 2
Previously identified in vivo volatile organic compounds observed in in vitro cellular headspace, split per treatment group, A549 cells in Roswell Park Memorial Institute (RPMI) media (n=22) and 1 mM hydrogen peroxide (H2O2)-treated a549 cells (n=23). Differences between experimental groups evaluated using Mann–Whitney U test. a) Cyclohexane; b) decane; c) heptane; d) hexane; e) octane; and f) undecane.
FIGURE 3
FIGURE 3
a) Volcano plot of all volatile organic compounds significantly released by a549 cells (fold change ≥1, p<0.05) either treated or not treated with hydrogen peroxide (H2O2) (n=45). b) Differences in experimental groups for the identified volatile organic compound, 2-ethyl-1-hexanol (p<0.001).
FIGURE 4
FIGURE 4
a–c) Spearman's rank correlation analysis showed no association between identified volatile organic compounds (VOCs) (decane, hexane and octane) in patients’ exhaled breath (n=489) and the fraction of inspired oxygen (FIO2). d) Equally, compounds showed poor discriminative power for pulmonary oxidative injury when comparing individual VOCs as predicator variables for whether patients had a FIO2 ≥0.6 (n=489). AUC: area under the curve.
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References

    1. Chow CW, Abreu MTH, Suzuki T, et al. . Oxidative stress and acute lung injury. Am J Respir Cell Mol Biol 2003; 29: 427–431. doi:10.1165/rcmb.F278 - DOI - PubMed
    1. Holguin F. Oxidative stress in airway diseases. Ann Am Thorac Soc 2013; 10: Suppl., S150–S157. doi:10.1513/AnnalsATS.201305-116AW - DOI - PubMed
    1. Betteridge DJ. What is oxidative stress? Metabolism 2000; 49: 2 Suppl. 1, 3–8. doi:10.1016/S0026-0495(00)80077-3 - DOI - PubMed
    1. van de Kant KDG, van der Sande LJTM, Jöbsis Q, et al. . Clinical use of exhaled volatile organic compounds in pulmonary diseases: a systematic review. Respir Res 2012; 13: 117. doi:10.1186/1465-9921-13-117 - DOI - PMC - PubMed
    1. Park HS, Kim SR, Lee YC. Impact of oxidative stress on lung diseases. Respirology 2009; 14: 27–38. doi:10.1111/j.1440-1843.2008.01447.x - DOI - PubMed

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