Electronic nose in discrimination of children with uncontrolled asthma

Measuring biomarkers (e.g. volatile organic compounds [VOCs]) in exhaled breath is an attractive approach to monitor airway inflammation in asthma and other lung diseases. Olfactive technology by electronic nose (e-Nose) has been applied to identify VOCs in exhaled breath. We compared e-Nose respiratory patterns in a pediatric cohort with asthma classificate children with different asthma control. This cross-sectional study involved 38 children: 28 with asthma and 10 healthy controls . The asthmatic patients were categorized as having controlled (AC), partially controlled (APC) or uncontrolled asthma (ANC) based on level of asthma symptom control according to Global Initiative for Asthma (GINA). Clinical exams, exhaled breath collection for generating e-Nose VOC profiles, and spirometry were performed. Exhaled breath samples were obtained using a commercial electronic nose (Cyranose 320; Smith Detections, Pasadena, CA, USA). The discriminative ability of breathprints were investigated by principal component analysis and penalized logistic regression. The e-Nose was able to discriminate between the CON (controls) + AC and the ANC + APC group with an area under the curve [AUC] of 0.85 (95% confidence interval [CI] 0.72 to 0.98) and a cross-validated AUC of 0.80 (95% CI 0.70 to 0.85). Sensitivity and specificity calculated using the Youden index were 0.79 and 0.84, respectively. Exhaled biomarker patterns were easy to obtain with the device and were able to differentiate children with uncontrolled symptomatic asthma from asymptomatic controls.