FeNO和MMEF对儿童咳嗽变异性哮喘的诊断价值

目的:评价呼出气一氧化氮（FeNO）和肺功能相关指标在儿童伴或不伴变应性鼻炎（鼻炎）的咳嗽变异性哮喘（CVA）与其他慢性咳嗽中的诊断价值。方法: 收集2015年10月—2021年8月在天津医科大学第二医院儿科门诊行肺功能和FeNO检测的199例慢性咳嗽（慢咳）患儿信息，进行回顾性分析。将慢咳患儿分为CVA 组（n=86）和非CVA（NCVA组，n=113）。通过建立受试者工作特征（ROC）曲线，比较FeNO和肺通气功能指标，包括第一秒用力呼气容积（FEV1）、呼气峰流速值（PEF）、最大呼气中期流速（MMEF）、50%肺活量时的最大呼气流速（MEF50）及25%肺活量时的最大呼气流速（MEF25）在预测CVA的临床价值。结果:经过筛选FeNO预测价值最高（P<0.001）。FeNO、MMEF和MEF25可能是区分CVA和NCVA的有效指标（均P<0.05）。FeNO和MMEF对CVA和NCVA的鉴别预测最佳临界值分别为21.5 ppb 曲线下面积（AUC）为0.916;敏感性为80.16%;特异性为75.92%；PPV 64.12%；NPV:87.50%]和84.5%预计值（AUC为0.726；敏感性为61.90%；特异性为77.66%；PPV 75.58%；NPV 64.60%）。FeNO联合MMEF诊断CVA的最佳临界值为>21.5 ppb，MMEF <84.5%预计值（AUC为0.988）。FeNO对于鉴别儿童慢咳中鼻炎受试者和非鼻炎受试者的不同临界值分别:21.5 ppb（敏感性为95.9%，特异性为81.1%）和27 ppb（敏感性为84.6%，特异性为78.3%）。鼻炎受试者的AUC （0.925）明显高于非鼻炎受试者（0.871）。FeNO联合MMEF对于鉴别鼻炎患儿的AUC为0.989，敏感性为95.9%，特异性为84.4%。对于非鼻炎受试者，FeNO联合MMEF的AUC为0.500，敏感性为47.6%，特异性为80.0%。结论: FeNO和MMEF在儿童慢咳中对CVA鉴别可能有较大的价值。FeNO和MMEF联合使用的预测效果明显优于单独使用。FeNO联合MMEF对与儿童慢咳中CVA伴有鼻炎者预测的准确性高于非鼻炎患儿。

Diagnostic value of FeNO and MMEF for cough variant asthma in children

Objective: To evaluate the diagnostic value of exhaled nitric oxide（FeNO） and lung function-related indicators in cough variant asthma（CVA） and other chronic cough in children with and without allergic rhinitis. Methods: The information of 199 children with chronic cough who underwent pulmonary function and FeNO examinations in the Department of Pediatrics，The Second Hospital of Tianjin Medical University from October 2015 to August 2021 were collected for a retrospective analysis. Children with chronic cough were divided into CVA group（n=86） and non-CVA （NCVA） group （n=113） according to the published diagnostic criteria. The diagnostic efficacy of FeNO and pulmonary function-related indicators，including the first second forced expiratory volume （FEV1），peak expiratory flow rate （PEF），maximum mid-expiratory flow rate （MMEF），maximum expiratory flow rate at 50% of lung capacity （MEF50），and maximum expiratory flow rate at 25% of lung capacity（MEF25） in predicting CVA in children with chronic cough were evaluated by receiver operating characteristic（ROC） analyses. Results: After screening，FeNO had the highest predictive value（P<0.001）. FeNO，MMEF and MEF25 might be effective indicators in distinguishing CVA from NCVA（P<0.05）. The optimal threshold of distinguishing CVA from NCVA for FeNO and MMEF was 21.5 ppb （0.916 for AUC; sensitivity，80.16%; specificity，75.92%; PPV，64.12%; NPV，87.50%） and 84.5% expected values（AUC，0.726; sensitivity，61.90%；specificity，77.66%；PPV，75.58%；NPV，64.60%），respectively. The optimal critical value of FeNO combined with MMEF for CVA diagnosis was > 21.5 ppb，and MMEF <84.5%. The cutoff for the combination of FeNO with MMEF for identifying CVA from chronic cough was > 21.5 ppb，and MMEF <84.5%（AUC=0.988）. Furthermore，FeNO demonstrated different thresholds for differentiating CVA in children with and without rhinitis: 21.5 ppb（sensitivity 95.9%，specificity 81.1%） for rhinitis and 27 ppb（sensitivity 84.6%，specificity 78.3%） for non-rhinitis. The AUC of rhinitis subjects （0.925） was significantly higher than that of non-rhinitis subjects（0.871）. The AUC of FeNO combined with MMEF for identifying children with rhinitis was 0.989 （sensitivity，95.9%；specificity，84.4%）. For non-rhinitis participants，FeNO combined with MMEF had an AUC of 0.500 （sensitivity，47.6%; specificity，80.0%）. Conclusion: FeNO and MMEF show significant value in the identification of CVA in children with chronic cough. The combination of FeNO and MMEF has significantly better predictive value than MMEF alone. FeNO combined with MMEF is more accurate in predicting rhinitis in children with CVA than those without rhinitis.