Green RH, Brightling CE, Woltmann G, Parker D, Wardlaw AJ, Pavord ID. Analysis of induced sputum in adults with asthma: identification of subgroup with isolated sputum neutrophilia and poor response to inhaled corticosteroids. Thorax 2002;57:875-879.
Louis R, Schleich F, Barnes PJ. Corticosteroids: still at the frontline in asthma treatment? Clin Chest Med 2012;33:531-541.
Brusselle GG, Vanderstichele C, Jordens P, Deman R, Slabbynck H, Ringoet V, et al. Azithromycin for prevention of exacerbations in severe asthma (AZISAST): a multicentre randomised double-blind placebo-controlled trial. Thorax 2013;68:322-329.
Simpson JL, Powell H, Boyle MJ, Scott RJ, Gibson PG. Clarithromycin targets neutrophilic airway inflammation in refractory asthma. Am J Respir Crit Care Med 2008;177:148-155.
Gibson PG, Yang IA, Upham JW, Reynolds PN, Hodge S, James AL, et al. Effect of azithromycin on asthma exacerbations and quality of life in adults with persistent uncontrolled asthma (AMAZES): a randomised, double-blind, placebo-controlled trial. Lancet 2017;390: 659-668.
Simpson JL, Scott R, Boyle MJ, Gibson PG. Inflammatory subtypes in asthma: assessment and identification using induced sputum. Respirology 2006;11:54-61.
Schleich FN, Seidel L, Sele J, Manise M, Quaedvlieg V, Michils A, et al. Exhaled nitric oxide thresholds associated with a sputum eosinophil count >3% in a cohort of unselected patients with asthma. Thorax 2010;65:1039-1044.
Robroeks CM, van Berkel JJ, Dallinga JW, Jöbsis Q, Zimmermann LJ, Hendriks HJ, et al. Metabolomics of volatile organic compounds in cystic fibrosis patients and controls. Pediatr Res 2010;68:75-80.
Van Berkel JJ, Dallinga JW, Möller GM, Godschalk RW, Moonen EJ, Wouters EF, et al. A profile of volatile organic compounds in breath discriminates COPD patients from controls. Respir Med 2010;104: 557-563.
Boots AW, Bos LD, van der Schee MP, van Schooten FJ, Sterk PJ. Exhaled molecular fingerprinting in diagnosis and monitoring: validating volatile promises. Trends Mol Med 2015;21: 633-644.
Kolk AH, van Berkel JJ, Claassens MM, Walters E, Kuijper S, Dallinga JW, et al. Breath analysis as a potential diagnostic tool for tuberculosis. Int J Tuberc Lung Dis 2012;16:777-782.
van der Schee MP, Palmay R, Cowan JO, Taylor DR. Predicting steroid responsiveness in patients with asthma using exhaled breath profiling. Clin Exp Allergy 2013;43:1217-1225.
Boots AW, van Berkel JJ, Dallinga JW, Smolinska A, Wouters EF, van Schooten FJ. The versatile use of exhaled volatile organic compounds in human health and disease. J Breath Res 2012;6:027108.
Schleich FN, Dallinga JW, Henket M, Wouters EF, Louis R, Van Schooten FJ. Volatile organic compounds discriminate between eosinophilic and neutrophilic inflammation in vitro. J Breath Res 2016;10:016006.
Cohen JF, Korevaar DA, Altman DG, Bruns DE, Gatsonis CA, Hooft L, et al. STARD 2015 guidelines for reporting diagnostic accuracy studies: explanation and elaboration. BMJ Open 2016;6:e012799.
Global Initiative for Asthma. Global strategy for asthma management and prevention. 2018 [accessed 2018 Nov 14]. Available from: www.ginasthma.org.
Schleich FN, Manise M, Sele J, Henket M, Seidel L, Louis R. Distribution of sputum cellular phenotype in a large asthma cohort: predicting factors for eosinophilic vs neutrophilic inflammation. BMC Pulm Med 2013;13:11.
Stefanuto PH, Perrault K, Grabherr S, Varlet V, Focant J-F. Postmortem internal gas reservoir monitoring using GCXGC-HRTOF-MS. Separations 2018;3:24.
Dieterle F, Ross A, Schlotterbeck G, Senn H. Probabilistic quotient normalization as robust method to account for dilution of complex biological mixtures: application in 1H NMR metabonomics. Anal Chem 2006;78:4281-4290.
Garcia-Marcos L, Edwards J, Kennington E, Aurora P, Baraldi E, Carraro S, et al.; EARIP Collaboration. Priorities for future research into asthma diagnostic tools: a PAN-EU consensus exercise from the European Asthma Research Innovation Partnership (EARIP). Clin Exp Allergy 2018;48:104-120.
Dallinga JW, Robroeks CM, van Berkel JJ, Moonen EJ, Godschalk RW, Jöbsis Q, et al. Volatile organic compounds in exhaled breath as a diagnostic tool for asthma in children. Clin Exp Allergy 2010;40: 68-76.
Fens N, Zwinderman AH, van der Schee MP, de Nijs SB, Dijkers E, Roldaan AC, et al. Exhaled breath profiling enables discrimination of chronic obstructive pulmonary disease and asthma. Am J Respir Crit Care Med 2009;180:1076-1082.
Schleich F. Diagnosis and clinical interest of asthma inflammatory phenotypes [accessed 2018 Nov 14]. Available from: http://bictel.ulg.ac.be/ETD-db/collection/available/ULgetd01152015-163140/unrestricted/Schleichthesis.pdf.
Dragonieri S, Brinkman P, Mouw E, Zwinderman AH, Carratú P, Resta O, et al. An electronic nose discriminates exhaled breath of patients with untreated pulmonary sarcoidosis from controls. Respir Med 2013;107:1073-1078.
Hothorn LA. How to deal with multiple treatment or dose groups in randomized clinical trials? Fundam Clin Pharmacol 2007;21: 137-154.
Ulanowska A, Kowalkowski T, Trawińska E, Buszewski B. The application of statistical methods using VOCs to identify patients with lung cancer. J Breath Res 2011;5:046008.
Montuschi P, Santonico M, Mondino C, Pennazza G, Mantini G, Martinelli E, et al. Diagnostic performance of an electronic nose, fractional exhaled nitric oxide, and lung function testing in asthma. Chest 2010;137:790-796.
Brinkman P, Wagener AH, Hekking PP, Bansal AT, Maitland-van der Zee AH, Wang Y, et al.; U-BIOPRED Study Group. Identification and prospective stability of electronic nose (eNose)-derived inflammatory phenotypes in patients with severe asthma. J Allergy Clin Immunol 2019;143:1811-1820.
de Vries R, Dagelet YWF, Spoor P, Snoey E, Jak PMC, Brinkman P, et al. Clinical and inflammatory phenotyping by breathomics in chronic airway diseases irrespective of the diagnostic label. Eur Respir J 2018;51:1701817.
Ibrahim B, Basanta M, Cadden P, Singh D, Douce D, Woodcock A, et al. Non-invasive phenotyping using exhaled volatile organic compounds in asthma. Thorax 2011;66:804-809.
Louis R, Godinas L, Schleich F. Induced sputum: towards normal values. In: Non invasive assessment of airways inflammation in asthma and COPD. Athens, Greece: Paschalidis Medical Publications; 2011. pp. 113-123.
Gibson PG, Simpson JL, Saltos N. Heterogeneity of airway inflammation in persistent asthma: evidence of neutrophilic inflammation and increased sputum interleukin-8. Chest 2001;119: 1329-1336.
Buszewski B, Ulanowska A, Kowalkowski T, Ciesliński K. Investigation of lung cancer biomarkers by hyphenated separation techniques and chemometrics. Clin Chem Lab Med 2011;50: 573-581.
Carpagnano GE, Palladino GP, Lacedonia D, Koutelou A, Orlando S, Foschino-Barbaro MP. Neutrophilic airways inflammation in lung cancer: the role of exhaled LTB-4 and IL-8. BMC Cancer 2011;11: 226.
Hicks LC, Huang J, Kumar S, Powles ST, Orchard TR, Hanna GB, et al. Analysis of exhaled breath volatile organic compounds in inflammatory bowel disease: a pilot study. J Crohn's Colitis 2015;9: 731-737.
Li J, Peng Y, Liu Y, Li W, Jin Y, Tang Z, et al. Investigation of potential breath biomarkers for the early diagnosis of breast cancer using gas chromatography-mass spectrometry. Clin Chim Acta 2014;436: 59-67.
Jareño-Esteban JJ, Muñoz-Lucas MA, Carrillo-Aranda B, Maldonado-Sanz JA, de Granda-Orive I, Aguilar-Ros A, et al.; Study Group. Volatile organic compounds in exhaled breath in a healthy population: effect of tobacco smoking. Arch Bronconeumol 2013;49: 457-461.
Demarche S, Schleich F, Henket M, Paulus V, Van Hees T, Louis R. Detailed analysis of sputum and systemic inflammation in asthma phenotypes: are paucigranulocytic asthmatics really noninflammatory? BMC Pulm Med 2016;16:46.
Schleich FN, Chevremont A, Paulus V, Henket M, Manise M, Seidel L, et al. Importance of concomitant local and systemic eosinophilia in uncontrolled asthma. Eur Respir J 2014;44:97-108.
