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Original Article
 

Inflammatory Asthma Phenotype Discrimination Using an Electronic Nose Breath Analyzer
 

Plaza V1, Crespo A1*, Giner J1, Merino JL2, Ramos-Barbón D1, Mateus EF1, Torrego A1, Cosio BG3, Agustí A4, Sibila O1

1Department of Respiratory Medicine, Hospital de la Santa Creu i Sant Pau; Institut d’Investigació Biomédica Sant Pau (IIB Sant Pau): Universitat Autònoma de Barcelona, Department of Medicine; Barcelona Respiratory Network (BRN), Barcelona, Spain
2RFic group. École Polytechnique Fédérale de Lausanne, Switzerland
3Department of Respiratory Medicine, Hospital Son Espases, Palma de Mallorca; CIBER Enfermedades Respiratorias (CIBERES), Spain
4Thorax Institute, Hospital Clinic, IDIBAPS, University of Barcelona; FISIB, CIBER Enfermedades Respiratorias (CIBERES); Barcelona Respiratory Network (BRN), Barcelona, Spain
*This paper is part of the doctoral thesis of AC.

J Investig Allergol Clin Immunol 2015; Vol. 25(6): 431-437
 

 Abstract


Background and Objective: Patients with persistent asthma have different inflammatory phenotypes. The electronic nose is a new technology capable of distinguishing volatile organic compound (VOC) breath-prints in exhaled breath. The aim of the study was to investigate the capacity of electronic nose breath-print analysis to discriminate between different inflammatory asthma phenotypes (eosinophilic, neutrophilic, paucigranulocytic) determined by induced sputum in patients with persistent asthma.

Methods: Fifty-two patients with persistent asthma were consecutively included in a cross-sectional proof-of-concept study. Inflammatory asthma phenotypes (eosinophilic, neutrophilic and paucigranulocytic) were recognized by inflammatory cell counts in induced sputum. VOC breath-prints were analyzed using the electronic nose Cyranose 320 and assessed by discriminant analysis on principal component reduction, resulting in cross-validated accuracy values. Receiver operating characteristic (ROC) curves were calculated.

Results: VOC breath-prints were different in eosinophilic asthmatics compared with both neutrophilic asthmatics (accuracy 73%; P=.008; area under ROC, 0.92) and paucigranulocytic asthmatics (accuracy 74%; P=.004; area under ROC, 0.79). Likewise, neutrophilic and paucigranulocytic breath-prints were also different (accuracy 89%; P=.001; area under ROC, 0.88).

Conclusion: An electronic nose can discriminate inflammatory phenotypes in patients with persistent asthma in a regular clinical setting. ClinicalTrials.gov identifier: NCT02026336.

Key words: Asthma. Electronic nose. Inflammation. Volatile organic compounds.