Department of Pulmonary and Critical Care Medicine, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China.
Department of Pulmonary and Critical Care Medicine, Tongji Hospital, School of Medicine, Tongji University, 389 Xincun Road, Shanghai 200065, China.
Ther Adv Respir Dis. 2023 Jan-Dec;17:17534666231181259. doi: 10.1177/17534666231181259.
The diagnosis of cough-variant asthma (CVA) is based on bronchial provocation test, which is challenging to be conducted. Most CVA patients have type 2 airway inflammation and small airway dysfunction. FeNO, reflecting small airway inflammation, may be used to diagnose CVA.
This study aimed to explore and compare the value of lower airway exhaled nitric oxide (FeNO, FeNO, and CaNO) combined with small airway parameters for diagnosing CVA.
Chronic cough patients who attended the clinic from September 2021 to August 2022 were enrolled and divided into CVA group ( = 71) and non-CVA (NCVA) group ( = 212). The diagnostic values of FeNO, FeNO, concentration of alveolar nitric oxide (CaNO), maximal mid-expiratory flow (MMEF), forced expiratory flow at 75% of forced vital capacity (FEF) and forced expiratory flow at 50% of forced vital capacity (FEF) for CVA were evaluated.
FeNO [39(39) ppb 17(12) parts per billion (ppb), < 0.01], FeNO [17(14) ppb 8(5) ppb, < 0.01] and CaNO [5.0(6.1) ppb 3.5(3.6) ppb, < 0.01] in CVA group were significantly higher than those in NCVA group. The optimal cut-off values of FeNO, FeNO, and CaNO for diagnosis of CVA were 27.00 ppb [area under the curve (AUC) 0.88, sensitivity 78.87%, specificity 79.25%], 11.00 ppb (AUC 0.92, sensitivity 88.73%, specificity 81.60%) and 3.60 ppb (AUC 0.66, sensitivity 73.24%, specificity 52.36%), respectively. For diagnosing CVA, the value of FeNO was better than FeNO ( = 0.04). The optimal cut-off values of MMEF, FEF, and FEF for the diagnosis of CVA were 63.80% (AUC 0.75, sensitivity 53.52%, specificity 86.32%), 77.9% (AUC 0.74, sensitivity 57.75%, specificity 83.49%) and 73.50% (AUC 0.75, sensitivity 60.56%, specificity 80.19%), respectively. The AUCs of FeNO combined with MMEF, FEF, and FEF for the diagnosis of CVA were all 0.89. The AUCs of FeNO combined with MMEF, FEF, and FEF for the diagnosis of CVA were all 0.93.
FeNO > 11 ppb contributed strongly for differentiating CVA from chronic cough, especially in patients with small airway dysfunction.
咳嗽变异性哮喘（CVA）的诊断基于支气管激发试验，但该试验具有一定挑战性。大多数 CVA 患者存在 2 型气道炎症和小气道功能障碍。呼出气一氧化氮（FeNO，反映小气道炎症）可用于诊断 CVA。
本研究旨在探讨和比较下气道呼出气一氧化氮（FeNO、FeNO 和 CaNO）联合小气道参数对 CVA 的诊断价值。
纳入 2021 年 9 月至 2022 年 8 月就诊的慢性咳嗽患者，分为 CVA 组（n=71）和非 CVA（NCVA）组（n=212）。评估 FeNO、FeNO 浓度、肺泡一氧化氮（CaNO）、最大呼气中期流量（MMEF）、用力肺活量 75%（FEF）和用力肺活量 50%（FEF）对 CVA 的诊断价值。
CVA 组的 FeNO[39（39）ppb 17（12）ppb，<0.01]、FeNO[17（14）ppb 8（5）ppb，<0.01]和 CaNO[5.0（6.1）ppb 3.5（3.6）ppb，<0.01]明显高于 NCVA 组。FeNO、FeNO 和 CaNO 诊断 CVA 的最佳截断值分别为 27.00 ppb（AUC 0.88，敏感度 78.87%，特异性 79.25%）、11.00 ppb（AUC 0.92，敏感度 88.73%，特异性 81.60%）和 3.60 ppb（AUC 0.66，敏感度 73.24%，特异性 52.36%）。对于 CVA 的诊断，FeNO 的价值优于 FeNO（=0.04）。MMEF、FEF 和 FEF 诊断 CVA 的最佳截断值分别为 63.80%（AUC 0.75，敏感度 53.52%，特异性 86.32%）、77.9%（AUC 0.74，敏感度 57.75%，特异性 83.49%）和 73.50%（AUC 0.75，敏感度 60.56%，特异性 80.19%）。FeNO 联合 MMEF、FEF 和 FEF 诊断 CVA 的 AUC 均为 0.89。FeNO 联合 MMEF、FEF 和 FEF 诊断 CVA 的 AUC 均为 0.93。
FeNO＞11 ppb 对区分 CVA 与慢性咳嗽具有重要作用，尤其对小气道功能障碍患者。
