Electronic nose technology (ENT) can distinguish COPD patients who are colonized with Aspergillus fumigatus from COPD patients who are not

Moniek Roe of Rohe 1, R.R. Klont*2, Marjolein Brusse-Keizer 3, Frans De Jongh 4, Paul Eduard Verweij 5, Paul Van der Valk 4.

Author address: 

1 Medisch Spectrum Twente; Medisch Spectrum Twente - Lung Department; Lung Department; 2 Laboratorium Microbiologie Twente Achterhoek; Medical Microbiology; 3 Medisch Spectrum Twente; Medical School Twente; 4 Medisch Spectrum Twente; Pulmonary Medicine; 5 Radboud University Medical Center; Medical Microbiology.


Background: Chronic pulmonary aspergillosis (CPA) in COPD patients is increasingly recognized as an
important illness with a poor clinical outcome. Positive sputum cultures are often considered
colonization and treatment is therefore seldom started. Early recognition of patients with CPA and
early initiation of antifungal therapy improves outcome. Because sputum culture is time consuming
and sensitivity is poor, an alternative tool is necessary. We investigated if the ENT could help to
identify COPD patients with Aspergillus fumigatus colonization.
Material/methods: Exhaled breath of COPD patients with (n=11) and without (n=10) a sputum
culture positive for A. fumigatus in the previous 6 months was analyzed using the Enose during
routine spirometry at an outpatient pulmonology department. Enose data were preprocessed in
MATLAB and thereafter analyzed in SPSS. Principal component analysis (PCA) was used to reduce the
data per sensor. The four principal components with the largest eigenvalue underwent an
independent t-test to compare the case with the control group. The principal components that
showed a significant difference between both groups in the t-test were used in a discriminant
analysis with internal validation using the leave-one-out method.

Results: Both the case and the control group were comparable (table 1). Only one principal
component (PCA2) showed a significant discriminating potential (p=0.001) between the Aspergillus
and the non-Aspergillus group. Another principal component (PCA3), although promising, showed no
significance (p=0,082). Both PCA2 and PCA3 were used in the discriminant analysis. The distribution
of PCA2 and PCA3 is shown in figure 1. Discriminant analysis showed a cross-validated accuracy of
90.5% between both groups. The cross-validated sensitivity and specificity were respectively 91% and

Conclusions: The results suggest that colonization with A. fumigatus leads to a distinctive breath
print in patients with COPD, and therefore the Enose might be a fast non-invasive tool to detect
A.fumigatus colonization in COPD.




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abstract No: 


Full conference title: 

27th European Congress of Clinical Microbiology and Infectious Diseases (2017, Vienna)
    • ECCMID 27th (2017)