Methacholine challenge test: Diagnostic characteristics in asthmatic patients receiving controller medications
Methacholine challenge test: Diagnostic characteristics in asthmatic patients receiving controller medications
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DOI：
10.1016/j.jaci.2012.02.025
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发表时间：
2012-07-01
影响因子：
14.2
通讯作者：
Castro, Mario
中科院分区：
文献类型：
--
作者：
Sumino, Kaharu;Sugar, Elizabeth A.;Castro, Mario
背景：乙酰甲胆碱激发试验（MCT）通常用于评估气道高反应性，但在使用高效吸入皮质类固醇变得普遍后，接受控制药物的哮喘患者的诊断特征尚未得到充分研究。目的：我们调查了 MCT 区分医生诊断为哮喘的参与者与非哮喘参与者的能力。方法：我们对接受常规控制药物的哮喘参与者 (n = 126) 和非哮喘对照参与者 (n = 93) 进行了一项队列对照研究，以评估 MCT 的敏感性和特异性。结果：总体敏感性为 77%，特异性为 96%，阈值 PC20（激发浓度）乙酰胆碱导致 FEV1) 下降 20%，即 8 mg/mL。白人参与者的敏感性显着低于非裔美国人参与者（69% vs 95%，P = .015），特应性参与者的敏感性高于非特应性参与者（82% vs 52%，P = .005）。将 PC20 阈值从 8 mg/mL 增加到 16 mg/mL 并没有显着改善测试的性能特征。非裔美国人种族、是否存在特应性以及较低的预测 FEV1 百分比与阳性检测结果相关。结论：MCT 排除哮喘诊断的效用取决于种族和特应性特征。在使用该测试诊断哮喘时，临床医生应考虑到白人和非特应性哮喘患者的 MCT 敏感性降低。 （《过敏临床免疫杂志》2012 年；130：69-75。）
Background: The methacholine challenge test (MCT) is commonly used to assess airway hyperresponsiveness, but the diagnostic characteristics have not been well studied in asthmatic patients receiving controller medications after the use of high-potency inhaled corticosteroids became common. Objectives: We investigated the ability of the MCT to differentiate participants with a physician's diagnosis of asthma from nonasthmatic participants.Methods: We conducted a cohort-control study in asthmatic participants (n = 126) who were receiving regular controller medications and nonasthmatic control participants (n = 93) to evaluate the sensitivity and specificity of the MCT.Results: The overall sensitivity was 77% and the specificity was 96% with a threshold PC20 (the provocative concentration of methacholine that results in a 20% drop in FEV1) of 8 mg/mL. The sensitivity was significantly lower in white than in African American participants (69% vs 95%, P = .015) and higher in atopic compared with nonatopic (82% vs 52%, P = .005). Increasing the PC20 threshold from 8 to 16 mg/mL did not noticeably improve the performance characteristics of the test. African American race, presence of atopy, and lower percent predicted FEV1 were associated with a positive test result.Conclusions: The utility of the MCT to rule out a diagnosis of asthma depends on racial and atopic characteristics. Clinicians should take into account the reduced sensitivity of the MCT in white and nonatopic asthmatic patients when using this test for the diagnosis of asthma. (J Allergy Clin Immunol 2012;130:69-75.)