MedWire News: Molecular profiling of exhaled breath using an “electronic nose” can accurately distinguish patients with asthma from those with chronic obstructive pulmonary disease (COPD), say Dutch researchers.
Niki Fens (University of Amsterdam) and colleagues explain: “The diagnoses of COPD and asthma are based on the presence of characteristic symptoms and lung function measurements.
“However, similar clinical and physiological features can be observed in both conditions, which can hamper the clinical distinction of these diseases.”
The researchers therefore investigated whether “breathprints” of volatile organic compounds (VOCs) produced by patients can help distinguish between the two disorders.
For their study, the team enrolled 30 patients with COPD aged an average 61.6 years, 20 patients with asthma aged an average 35.4 years, 20 nonsmoking controls aged an average 56.7 years, and 20 smoking controls aged an average 56.1 years. The participants’ mean FEV1 values were 1.72 l, 3.32 l, 3.44 l, and 3.58 l, respectively.
After breathing for 5 minutes through an inspiratory VOC filter, an expiratory breath sample from each participant was collected in a Tedlar bag and analyzed using an electronic nose.
The researchers found that VOC breathprints distinguished patients with asthma from those with COPD with an accuracy of 96.0%. Breathprints also distinguished patients with asthma from nonsmoking and smoking controls with an accuracy of 95.0% and 92.5%, respectively.
Exhaled breath profiles of patients with COPD partially overlapped with those of asymptomatic smokers, resulting in a discriminatory accuracy of just 66.0%.
The findings were repeatable and reproducible, the team notes in the Journal of Respiratory and Critical Care Medicine.
Fens and team conclude: “Our study shows that fingerprinting of exhaled air by electronic nose can adequately distinguish between patients with COPD and patients with asthma.
“This indicates that the VOC profiles in the exhaled breath differ between two inflammatory airways diseases, warranting further diagnostic validation of electronic noses in COPD and asthma.”
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