Department of Pulmonary Medicine, School of Medicine, Fukushima Medical University, Fukushima City, Japan.
Ann Allergy Asthma Immunol. 2011 Dec;107(6):480-6. doi: 10.1016/j.anai.2011.09.002. Epub 2011 Oct 1.
In the latest Global Initiative for Asthma guideline, neither sputum eosinophilia nor fractional exhaled nitric oxide (FeNO) have been evaluated prospectively as an aid in asthma diagnosis, but these measurements are being evaluated for potential use in determining optimal treatment.
To report criteria for screening asthma using subjective symptoms and FeNO levels and results of a prospective validation study using these criteria.
Sixty-one outpatients with recurrent cough, wheezing, or dyspnea underwent measurements of FeNO levels, pulmonary function, methacholine airway responsiveness, and inflammatory cells in induced sputum. The sensitivity, specificity, and concordance achieved using the FeNO-based criteria (at least 1 of the following subjective symptoms: recurrent cough, wheezing, or dyspnea and/or FeNO level ≥ 40 ppb) were analyzed and compared with the values obtained using conventional asthma diagnostic criteria, which includes subjective symptoms with any 2 of the following conditions: airway hyperresponsiveness, reversible airflow limitation, and eosinophilia in induced sputum.
Of the 61 patients, 41 were diagnosed as having asthma by the conventional criteria, and 33 were diagnosed as having asthma by the FeNO-based criteria, which showed a sensitivity of 78.6%, a specificity of 89.5%, and a concordance rate of 0.62. Nine of 42 patients were misdiagnosed as not having asthma by FeNO-based criteria (mean [SD] FeNO level, 23.9 [8.0] ppb). Seven of 9 patients were diagnosed as having nonatopic asthma according to IgE levels.
Asthma may be accurately diagnosed in daily practice on the basis of subjective symptoms and FeNO levels, particularly in atopic patients.
在最新的全球哮喘倡议指南中，痰嗜酸性粒细胞和呼出气一氧化氮（FeNO）都没有被前瞻性评估作为哮喘诊断的辅助手段，但这些测量方法正在被评估用于确定最佳治疗方案。
报告使用主观症状和 FeNO 水平筛查哮喘的标准，并报告使用这些标准进行前瞻性验证研究的结果。
61 例反复咳嗽、喘息或呼吸困难的门诊患者进行了 FeNO 水平、肺功能、乙酰甲胆碱气道反应性和诱导痰中炎症细胞的测量。分析并比较了基于 FeNO 的标准（至少存在以下 1 种主观症状：反复咳嗽、喘息或呼吸困难和/或 FeNO 水平≥40 ppb）的敏感性、特异性和一致性，与包括以下任意 2 种情况的传统哮喘诊断标准获得的值进行比较：气道高反应性、可逆性气流受限和诱导痰中嗜酸性粒细胞增多。
在 61 例患者中，41 例符合传统标准诊断为哮喘，33 例符合基于 FeNO 的标准诊断为哮喘，其敏感性为 78.6%，特异性为 89.5%，一致性为 0.62。9 例（42 例）患者按基于 FeNO 的标准被误诊为无哮喘（平均[标准差]FeNO 水平为 23.9[8.0]ppb）。根据 IgE 水平，7 例患者被诊断为非过敏性哮喘。
基于主观症状和 FeNO 水平，哮喘可以在日常实践中得到准确诊断，特别是在特应性患者中。
