RT Journal Article
SR Electronic
T1 Repeated breath profiling by eNoses identifies asthma exacerbations and airway eosinophilia
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P4051
VO 44
IS Suppl 58
A1 Niki Fens
A1 Marianne A. van de Pol
A1 Paul Brinkman
A1 Marije G. Gerritsen
A1 René Lutter
A1 Peter J. Sterk
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/P4051.abstract
AB IntroductionAsthma exacerbations are hallmarked by increased airway inflammation. Exhaled metabolites are associated with biomarkers of inflammation (Fens ERJ '11; Ibrahim Thorax '11). We investigated whether profiles of exhaled biomarkers (breathprints) measured by electronic noses (eNoses) are associated with loss of control/exacerbation after ICS withdrawal.Methods23 patients (6 male; 28±10 yr) with moderate to severe persistent asthma on ICS (≥500 µg fluticasone) were included. Exhaled metabolites (VOCs), FeNO and sputum cell counts were measured at baseline (T1), during loss of control or exacerbation (Reddel AJRCCM '09) (T2) and after recovery (T3=T2 + 4 weeks). VOCs were measured by eNose platform (158 sensors; metal oxide, polymer, quartz microbalance, IMS). Breathprints were created from sensor values by principal component (PC) analysis. Mixed model and correlation analysis were used.Results22 patients experienced a loss of control. Breathprints changed significantly between T1 and T2 (PC8 p=0.038; PC9 p=0.020), as did FeNO (p<0.01) and sputum eosinophils (p<0.01). No differences were found between T1 and T3 for all parameters. PC8 was correlated with sputum eosinophils at T3 (p=0.04, R=0.49), but not at T1 and T2.ConclusionUsing an integrated eNose platform for the assessment of exhaled metabolites, it is possible to discriminate between stable periods and periods with loss of control or exacerbation of asthma. The eNose breathprint was correlated with sputum eosinophils in stable condition, whereas it was not during exacerbation. This indicates that eNose captures a more comprehensive biomarker signal than merely identifying sputum eosinophils during unstable asthma episodes.