Department of Internal Medicine, Pulmonary Diseases and Allergy, Medical University of Warsaw, Warsaw, Poland.
J Asthma. 2022 Jul;59(7):1376-1386. doi: 10.1080/02770903.2021.1923741. Epub 2021 May 20.
In patients with suspected asthma and no airflow limitation in spirometry, methacholine challenge testing (MCT) for airway hyperresponsiveness (AHR) is an option of documenting variable airflow limitation. The goal of the study was to assess the ability of blood eosinophils, fractional concentration of exhaled nitric oxide (FeNO) and distal airways function to discriminate patients with AHR from those with normal airway responsiveness (AR).
We analyzed baseline data from 42 participants who underwent MCT because of asthma-like symptoms and no airflow limitation in spirometry.
Eosinophil count was higher among participants with borderline AHR comparing to those with normal AR (340 cells/µL, IQR 285-995 vs. 125 cells/µL, IQR 75-180, post-hoc = 0.041). FeNO and percent predicted of functional residual volume (FRC%pred) were higher in participants with moderate-marked AHR compared to those with normal AR (40 ppb, IQR 30.5-100.5 vs. 18 ppb, IQR 13-50, post-hoc = 0.008; 140.1%±17.0% vs. 107.3%±20.7%, post-hoc < 0.001, respectively). Percentage predicted of the maximal expiratory flow at 25% of the forced vital capacity (MEF%pred) was lower in participants with mild AHR and borderline AHR compared to those with normal AR (72.9%±16.9% vs. 113.0%±36.8%, post-hoc = 0.017; 73.3%±15.9% vs. 113.0%±36.8%, post-hoc = 0.045; respectively). Level of AHR correlated with eosinophil count, FeNO, MEF%pred, forced expiratory flow between 25% and 75% of vital capacity (FEF%pred), FRC%pred and specific airway resistance (sR.
Blood eosinophils, FeNO and small airways dysfunction markers are related to the level of AR to methacholine in patients with asthma-like symptoms and no airflow limitation in spirometry.
在肺通气功能检查中无气流受限但疑似哮喘的患者中，气道高反应性（AHR）的乙酰甲胆碱激发试验（MCT）是记录可变气流受限的一种选择。本研究的目的是评估血嗜酸性粒细胞、呼气一氧化氮分数（FeNO）和远端气道功能对 AHR 患者与正常气道反应性（AR）患者的鉴别能力。
我们分析了 42 名因哮喘样症状和肺通气功能检查无气流受限而接受 MCT 的参与者的基线数据。
与正常 AR 相比，具有边界 AHR 的参与者的嗜酸性粒细胞计数更高（340 个/μL，IQR 285-995 与 125 个/μL，IQR 75-180，post-hoc = 0.041）。与正常 AR 相比，具有中度至显著 AHR 的参与者的 FeNO 和功能残气量预计百分比（FRC%pred）更高（40 ppb，IQR 30.5-100.5 与 18 ppb，IQR 13-50，post-hoc = 0.008；140.1%±17.0% 与 107.3%±20.7%，post-hoc ＜0.001）。与正常 AR 相比，具有轻度 AHR 和边界 AHR 的参与者的最大呼气流量在用力肺活量的 25%（MEF%pred）预计百分比较低（72.9%±16.9% 与 113.0%±36.8%，post-hoc = 0.017；73.3%±15.9% 与 113.0%±36.8%，post-hoc = 0.045）。AHR 水平与嗜酸性粒细胞计数、FeNO、MEF%pred、用力肺活量 25%至 75%之间的呼气流速（FEF%pred）、FRC%pred 和气道阻力（sR）有关。
在肺通气功能检查无气流受限但有哮喘样症状的患者中，血嗜酸性粒细胞、FeNO 和小气道功能障碍标志物与乙酰甲胆碱激发试验的 AHR 水平相关。
