■咳嗽变异性哮喘(CVA)的诊断基于支气管激发试验,这是具有挑战性的进行。大多数CVA患者有2型气道炎症和小气道功能障碍。FeNO200,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(FeNO50,FeNO200和CaNO)与小气道参数联合诊断CVA的价值。
■纳入2021年9月至2022年8月就诊的慢性咳嗽患者,并分为CVA组(n=71)和非CVA(NCVA)组(n=212)。FeNO50,FeNO200,肺泡一氧化氮(CaNO)浓度的诊断价值,最大呼气中流量(MMEF),评估了CVA的75%用力肺活量(FEF75%)时的用力呼气流量和50%用力肺活量(FEF50%)时的用力呼气流量。
■FeNO50[39(39)ppb与17(12)十亿分之一(ppb),p<0.01],FeNO200[17(14)ppb与8(5)ppb,p<0.01]和CaNO[5.0(6.1)ppb对3.5(3.6)ppb,p<0.01]CVA组明显高于NCVA组。FeNO50、FeNO200和CaNO诊断CVA的最佳临界值为27.00ppb[曲线下面积(AUC)0.88,灵敏度78.87%,特异性79.25%],11.00ppb(AUC0.92,灵敏度88.73%,特异性81.60%)和3.60ppb(AUC0.66,灵敏度73.24%,特异性52.36%),分别。为了诊断CVA,FeNO200的值优于FeNO50(p=0.04)。MMEF的最佳截止值,FEF75%,诊断CVA的FEF50%为63.80%(AUC为0.75,敏感性为53.52%,特异性86.32%),77.9%(AUC0.74,灵敏度57.75%,特异性83.49%)和73.50%(AUC0.75,灵敏度60.56%,特异性80.19%),分别。FeNO50与MMEF结合的AUC,FEF75%,诊断CVA的FEF50%均为0.89。FeNO200与MMEF结合的AUC,FEF75%,诊断CVA的FEF50%均为0.93。
■FeNO200>11ppb对区分CVA和慢性咳嗽有很大贡献,尤其是小气道功能障碍患者。
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. FeNO200, 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 (FeNO50, FeNO200, 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 (n = 71) and non-CVA (NCVA) group (n = 212). The diagnostic values of FeNO50, FeNO200, concentration of alveolar nitric oxide (CaNO), maximal mid-expiratory flow (MMEF), forced expiratory flow at 75% of forced vital capacity (FEF75%) and forced expiratory flow at 50% of forced vital capacity (FEF50%) for CVA were evaluated.
FeNO50 [39(39) ppb versus 17(12) parts per billion (ppb), p < 0.01], FeNO200 [17(14) ppb versus 8(5) ppb, p < 0.01] and CaNO [5.0(6.1) ppb versus 3.5(3.6) ppb, p < 0.01] in CVA group were significantly higher than those in NCVA group. The optimal cut-off values of FeNO50, FeNO200, 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 FeNO200 was better than FeNO50 (p = 0.04). The optimal cut-off values of MMEF, FEF75%, and FEF50% 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 FeNO50 combined with MMEF, FEF75%, and FEF50% for the diagnosis of CVA were all 0.89. The AUCs of FeNO200 combined with MMEF, FEF75%, and FEF50% for the diagnosis of CVA were all 0.93.
FeNO200 > 11 ppb contributed strongly for differentiating CVA from chronic cough, especially in patients with small airway dysfunction.