Malerba Mario, Ragnoli Beatrice, Azzolina Danila, Montuschi Paolo, Radaeli Alessandro
Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy.
Respiratory Unit, S. Andrea Hospital, Vercelli, Italy.
Front Pharmacol. 2021 Apr 19;12:630334. doi: 10.3389/fphar.2021.630334. eCollection 2021.
Cough variant asthma (CVA), a common asthma phenotype characterized by nonproductive cough and bronchial hyperreactivity (BHR), is usually detected by bronchial provocation tests (BPTs) which are timeconsuming, expensive, and unsafe. The primary study objective was to provide proof of concept for the use of fractional exhaled nitric oxide (FNO), eosinophil count percentage in induced sputum (sEOS%), forced expiratory flow between 25 and 75% of forced vital capacity (FEF) % predicted value, and FEF z-scores as surrogate markers predicting BHR in young adults with suspected CVA; the secondary objective was to compare the diagnostic performance of the various techniques. Three hundred and ten subjects (median age 24 years) were included in a cross-sectional study. Subjects were characterized as BHR positive (POS) ( = 147) or BHR negative (NEG) (n = 163) according to methacholine BPT. Classification accuracies were expressed as areas under the receiver operator characteristic curves (AUC). Compared with BHR NEG, FEF % predicted value and FEF z-scores were lower in the BHR POS group ( < 0.001), whereas FNO ( < 0.001) and sEOS% were higher ( < 0.001). AUC values for detecting BHR were as follows: FNO, 0.98 (SD = 0.02); sEOS%, 0.98 (SD = 0.02); FEF % pred, 0.93 (SD = 0.05); FEF z scores, 0.92 (SD = 0.05). Optimal cutoff values (OCV) for BHR prediction were as follows: FNO, 32.7 ppb (sensitivity = 0.93, specificity = 0.96), sEOS%, 3.80% (sensitivity = 0.94, specificity = 0.94), FEF % predicted value, 80.0% (sensitivity = 0.90, specificity = 0.87), and FEF z-score, -0.87 (sensitivity = 0.89, specificity = 0.87). Non-invasive/semi-invasive airway inflammatory or small airway functional measures might be used as surrogate markers predicting BHR in young adults with suspected CVA.
咳嗽变异性哮喘（CVA）是一种常见的哮喘表型，其特征为干咳和支气管高反应性（BHR），通常通过支气管激发试验（BPT）来检测，而该试验耗时、昂贵且不安全。主要研究目的是为使用呼出一氧化氮分数（FNO）、诱导痰中嗜酸性粒细胞计数百分比（sEOS%）、用力肺活量25%至75%之间的用力呼气流量（FEF）预测值百分比以及FEF z评分作为预测疑似CVA的年轻成年人BHR的替代标志物提供概念验证；次要目的是比较各种技术的诊断性能。一项横断面研究纳入了310名受试者（中位年龄24岁）。根据乙酰甲胆碱BPT，受试者被分为BHR阳性（POS）组（n = 147）或BHR阴性（NEG）组（n = 163）。分类准确率用受试者操作特征曲线下面积（AUC）表示。与BHR NEG组相比，BHR POS组的FEF预测值百分比和FEF z评分较低（P < 0.001），而FNO（P < 0.001）和sEOS%较高（P < 0.001）。检测BHR的AUC值如下：FNO为0.98（标准差 = 0.02）；sEOS%为0.98（标准差 = 0.02）；FEF预测值百分比为0.93（标准差 = 0.05）；FEF z评分为0.92（标准差 = 0.05）。预测BHR的最佳截断值（OCV）如下：FNO为32.7 ppb（灵敏度 = 0.93，特异度 = 0.96），sEOS%为3.80%（灵敏度 = 0.94，特异度 = 0.94），FEF预测值百分比为80.0%（灵敏度 = 0.90，特异度 = 0.87），FEF z评分为 -0.87（灵敏度 = 0.89，特异度 = 0.87）。非侵入性/半侵入性气道炎症或小气道功能指标可作为预测疑似CVA的年轻成年人BHR的替代标志物。
