Occupational and Environmental Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
Eur Respir J. 2012 Jan;39(1):59-66. doi: 10.1183/09031936.00195610. Epub 2011 Jun 30.
Particles in exhaled air (PEx) may reflect the composition of respiratory tract lining fluid (RTLF); thus, there is a need to assess their potential as sources of biomarkers for respiratory diseases. In the present study, we compared PEx from patients with asthma and controls using time-of-flight-secondary ion mass spectrometry (TOF-SIMS) and multivariate analysis. Particles were collected using an instrument developed in-house. 15 nonsmoking subjects with physician-diagnosed asthma and 11 nonsmoking healthy controls performed 10 consecutive forced exhalations into the instrument. Particle concentrations were recorded and samples of particles collected on silicon plates were analysed by TOF-SIMS. Subjects with asthma exhaled significantly lower numbers of particles than controls (p=0.03) and the ratio of unsaturated to saturated phospholipids was significantly lower in samples from subjects with asthma (0.25 versus 0.35; p=0.036). Orthogonal partial least squares-discriminant analysis models showed good separation between both positive and negative spectra. Molecular ions from phosphatidylcholine and phosphatidylglycerol, and protein fragments were found to discriminate the groups. We conclude that analysis of PEx is a promising method to examine the composition of RTLF. In the present explorative study, we could discriminate between subjects with asthma and healthy controls based on TOF-SIMS spectra from PEx.
呼出气颗粒（PEx）可能反映呼吸道衬里液（RTLF）的组成；因此，需要评估其作为呼吸疾病生物标志物来源的潜力。在本研究中，我们使用飞行时间二次离子质谱（TOF-SIMS）和多变量分析比较了哮喘患者和对照组的 PEx。使用内部开发的仪器收集颗粒。15 名非吸烟哮喘患者和 11 名非吸烟健康对照者连续进行了 10 次强制呼气进入仪器。记录颗粒浓度，并对硅片上收集的颗粒样本进行 TOF-SIMS 分析。哮喘患者呼出的颗粒数量明显低于对照组（p=0.03），且哮喘患者样本中不饱和与饱和磷脂的比值明显较低（0.25 比 0.35；p=0.036）。正交偏最小二乘判别分析模型显示正负谱之间有很好的分离。发现磷脂酰胆碱和磷脂酰甘油的分子离子以及蛋白质片段可区分两组。我们得出结论，PEx 的分析是一种很有前途的方法，可以检查 RTLF 的组成。在本探索性研究中，我们可以根据 PEx 的 TOF-SIMS 谱区分哮喘患者和健康对照组。
