Department of Respiratory Medicine, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; Institut d'Investigació Biomédica Sant Pau (IIB Sant Pau), Barcelona, Spain.
Electronic Systems Group, Universitat de les Illes Balears, Palma de Mallorca, Spain.
Respir Med. 2018 Mar;136:111-117. doi: 10.1016/j.rmed.2018.02.008. Epub 2018 Feb 13.
Airway colonization by Potentially Pathogenic Microorganisms (PPM) in bronchiectasis is associated with worse clinical outcomes. The electronic nose is a non-invasive technology capable of distinguishing volatile organic compounds (VOC) in exhaled breath. We aim to explore if an electronic nose can reliably discriminate airway bacterial colonization in patients with bronchiectasis.
Seventy-three clinically stable bronchiectasis patients were included. PPM presence was determined using sputum culture. Exhaled breath was collected in Tedlar bags and VOC breath-prints were detected by the electronic nose Cyranose 320. Raw data was reduced to three factors with principal component analysis. Univariate ANOVA followed by post-hoc least significant difference test was performed with these factors. Patients were then classified using linear canonical discriminant analysis. Cross-validation accuracy values were defined by the percentage of correctly classified patients.
Forty-one (56%) patients were colonized with PPM. Pseudomonas aeruginosa (n = 27, 66%) and Haemophilus influenzae (n = 7, 17%) were the most common PPM. VOC breath-prints from colonized and non-colonized patients were significantly different (accuracy of 72%, AUROC 0.75, p < 0.001). VOC breath-prints from Pseudomonas aeruginosa colonized patients were significantly different from those of patients colonized with other PPM (accuracy of 89%, AUROC 0.97, p < 0.001) and non-colonized patients (accuracy 73%, AUROC 0.83, p = 0.007).
An electronic nose can accurately identify VOC breath-prints of clinically stable bronchiectasis patients with airway bacterial colonization, especially in those with Pseudomonas aeruginosa.
支气管扩张症患者气道中潜在致病微生物（PPM）的定植与更差的临床结局相关。电子鼻是一种能够区分呼气中挥发性有机化合物（VOC）的非侵入性技术。我们旨在探索电子鼻是否能可靠地区分支气管扩张症患者气道细菌定植。
纳入 73 例临床稳定的支气管扩张症患者。通过痰培养确定 PPM 的存在。采集呼气于 Tedlar 袋中，用电子鼻 Cyranose 320 检测 VOC 呼气特征。用主成分分析对原始数据进行降维，得到三个因素。用单因素方差分析（ANOVA），对这些因素进行事后最小显著差异检验。然后用线性判别分析对患者进行分类。交叉验证的准确性值通过正确分类的患者百分比来定义。
41 例（56%）患者定植有 PPM。定植的 PPM 中，铜绿假单胞菌（n=27，66%）和流感嗜血杆菌（n=7，17%）最为常见。定植与非定植患者的 VOC 呼气特征明显不同（准确率为 72%，AUROC 0.75，p<0.001）。定植铜绿假单胞菌患者的 VOC 呼气特征与定植其他 PPM（准确率 89%，AUROC 0.97，p<0.001）和非定植患者（准确率 73%，AUROC 0.83，p=0.007）明显不同。
电子鼻可以准确识别临床稳定的支气管扩张症患者气道细菌定植的 VOC 呼气特征，尤其是定植铜绿假单胞菌的患者。
