Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
Clin Exp Allergy. 2013 Nov;43(11):1217-25. doi: 10.1111/cea.12147.
Exhaled breath contains disease-dependent volatile organic compounds (VOCs), which may serve as biomarkers distinguishing clinical phenotypes in asthma. Their measurement may be particularly beneficial in relation to treatment response.
Our aim was to compare the performance of electronic nose (eNose) breath analysis with previously investigated techniques (sputum eosinophils, exhaled nitric oxide (FeNO) and airway hyperresponsiveness) to discriminate asthma from controls and identify steroid responsiveness in steroid-free patients. Trial registration ACTRN12613000038796.
Twenty-five patients with mild/moderate asthma had their inhaled steroid treatment discontinued until loss of control or 28 days. They were subsequently treated with oral prednisone 30 mg/day for 14 days. Steroid responsiveness was defined as an increase of either > 12% FEV1 or > 2 doubling doses PC20 AMP. Steroid-free assessment of sputum eosinophils, FeNO and exhaled breath VOCs were used to construct algorithms predicting steroid responsiveness. Performance characteristics were compared by ROC analysis.
The eNose discriminated between asthma and controls (area under the curve = 0.766 ± 0.14; P = 0.002) with similar accuracy to FeNO (0.862 ± 0.12; P < 0.001) and sputum eosinophils (0.814 ± 0.15; P < 0.001). Steroid responsiveness was predicted with greater accuracy by VOC-analysis (AUC = 0.883 ± 0.16; P = 0.008) than FeNO (0.545 ± 0.28; P = 0.751) or sputum eosinophils (0.610 ± 0.29; P = 0.441).
Breath analysis by eNose can identify asthmatic patients and may be used to predict their response to steroids with greater accuracy than sputum eosinophils or FeNO. This implies a potential role for breath analysis in the tailoring of treatment for asthma patients.
呼气中含有与疾病相关的挥发性有机化合物（VOCs），这些化合物可能作为生物标志物，区分哮喘的临床表型。它们的测量可能特别有益于治疗反应。
我们的目的是比较电子鼻（eNose）呼吸分析与之前研究过的技术（痰嗜酸性粒细胞、呼气一氧化氮（FeNO）和气道高反应性）在区分哮喘和对照以及识别无类固醇治疗患者的类固醇反应性方面的性能。试验注册 ACTRN12613000038796。
25 例轻度/中度哮喘患者停用吸入性类固醇治疗，直至控制不佳或 28 天。随后，他们每天口服泼尼松 30mg 治疗 14 天。类固醇反应性定义为 FEV1 增加>12%或 PC20AMP 增加>2 倍剂量。使用无类固醇治疗的痰嗜酸性粒细胞、FeNO 和呼气 VOC 来构建预测类固醇反应性的算法。通过 ROC 分析比较性能特征。
eNose 能够区分哮喘和对照组（曲线下面积=0.766±0.14；P=0.002），与 FeNO（0.862±0.12；P<0.001）和痰嗜酸性粒细胞（0.814±0.15；P<0.001）的准确性相似。VOC 分析预测类固醇反应性的准确性更高（AUC=0.883±0.16；P=0.008），优于 FeNO（0.545±0.28；P=0.751）或痰嗜酸性粒细胞（0.610±0.29；P=0.441）。
eNose 呼气分析可以识别哮喘患者，并可能比痰嗜酸性粒细胞或 FeNO 更准确地预测其对类固醇的反应。这意味着呼气分析在哮喘患者治疗个体化方面可能具有潜在作用。
