Occupational and Environmental Medicine, School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Department of Respiratory Medicine and Allergology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
PLoS One. 2021 Jun 25;16(6):e0253825. doi: 10.1371/journal.pone.0253825. eCollection 2021.
Small airways are difficult to access. Exhaled droplets, also referred to as particles, provide a sample of small airway lining fluid and may reflect inflammatory responses. We aimed to explore the effect of smoking on the composition and number of exhaled particles in a smoker-enriched study population. We collected and chemically analyzed exhaled particles from 102 subjects (29 never smokers, 36 former smokers and 37 current smokers) aged 39 to 83 years (median 63). A breathing maneuver maximized the number exhaled particles, which were quantified with a particle counter. The contents of surfactant protein A and albumin in exhaled particles was quantified with immunoassays and the contents of the phospholipids dipalmitoyl- and palmitoyl-oleoyl- phosphatidylcholine with mass spectrometry. Subjects also performed spirometry and nitrogen single breath washout. Associations between smoking status and the distribution of contents in exhaled particles and particle number concentration were tested with quantile regression, after adjusting for potential confounders. Current smokers, compared to never smokers, had higher number exhaled particles and more surfactant protein A in the particles. The magnitude of the effects of current smoking varied along the distribution of each PEx-variable. Among subjects with normal lung function, phospholipid levels were elevated in current smokers, in comparison to no effect of smoking on these lipids at abnormal lung function. Smoking increased exhaled number of particles and the contents of lipids and surfactant protein A in the particles. These findings might reflect early inflammatory responses to smoking in small airway lining fluid, also when lung function is within normal limits.
小气道难以进入。呼出气液滴，也称为颗粒，提供了小气道衬里液的样本，并可能反映炎症反应。我们旨在探索吸烟对富含吸烟者的研究人群中呼出气颗粒的组成和数量的影响。我们收集并化学分析了 102 名年龄在 39 至 83 岁（中位数 63 岁）的受试者（29 名从不吸烟者、36 名前吸烟者和 37 名现吸烟者）的呼出气颗粒。呼吸动作最大限度地增加了呼出气颗粒的数量，并用颗粒计数器对其进行了定量。用免疫测定法定量测定呼出气颗粒中表面活性剂蛋白 A 和白蛋白的含量，并用质谱法定量测定二棕榈酰-和棕榈酰-油酰-磷脂酰胆碱的磷脂含量。受试者还进行了肺量测定和氮单呼吸洗脱。在调整了潜在混杂因素后，使用分位数回归测试吸烟状况与呼出气颗粒内容物分布和颗粒数浓度之间的关系。与从不吸烟者相比，现吸烟者的呼出气颗粒数更多，颗粒中的表面活性剂蛋白 A 含量更高。当前吸烟对每种 PEx 变量分布的影响大小各不相同。在肺功能正常的受试者中，与肺功能异常时吸烟对这些脂质没有影响相比，当前吸烟者的磷脂水平升高。吸烟增加了呼出气颗粒的数量以及颗粒中脂质和表面活性剂蛋白 A 的含量。这些发现可能反映了小气道衬里液中对吸烟的早期炎症反应，即使肺功能在正常范围内也是如此。
