Early detection of bacterial airway infections in children with primary ciliary dyskinesia and cystic fibrosis by electronic nose

Early diagnosis of cystic fibrosis (CF) and primary ciliary dyskinesia (PCD)
combined with swift identification and treatment of pulmonary infections is
important for the preservation of pulmonary function, quality of life and life
expectancy. At present, the gold standard for determining pathogens in airways
of CF- and PCD-patients is culturing of sputum specimens. However, sputum
production is often minimal or absent in children and thus alternative methods
such as cough swabs and sometimes even bronchoalveolar lavage or serological
tests are used. These methods require specialized expertise, are time-consuming
and expensive, and can be rather invasive. A possible novel method that is
non-invasive and not dependent on sputum expectoration is the analysis of
exhaled breath by electronic nose. Preliminary data obtained by our group
indicates that in vitro classification of CF-derived P. aeruginosa and S.
aureus is feasible using the electronic nose.
In addition, it may be possible to identify specific smell-prints of CF- and
PCD-patients. One of the features of exhaled breath in PCD-patients, a low
nasal NO, is already being used in clinical practice to support or reject this
diagnosis. The analysis of thousands of volatile organic compounds (VOC) by
electronic nose may even have more potential and can possibly, if specific
VOC-profiles are identified, make a contribution to the initial diagnostic
work-up of children suspected of CF or PCD.

We hypothesize that expiratory VOC-analysis by electronic nose is capable of:
a.) discriminating CF-/PCD-patients with and without pulmonary infections and
b.) discriminating CF-/PCD-patients and healthy controls.

The study has a case-control, cross sectional design comparing CF and PCD
patients with healthy controls en CF and PCD patients with and without
pulmonary infections.
Cough swabs and sputum cultures will be taken as part of routine follow-up of
CF- and PCD patients at 3 monthly intervals. After informed consent has been
obtained, a breath samples will be taken and analyzed by means of discriminant
analysis on principal component reduction.

The collection of expiratory air is totally non-invasiveand thus without any
health risk.