呼出气一氧化氮联合肺功能及外周血嗜酸性粒细胞比例检测在咳嗽变异性哮喘诊断中的价值

Diagnostic value of fractional exhaled nitric oxide combined with pulmonary function and the proportion of eosinophils in peripheral blood in cough variant asthma

目的探讨呼出气一氧化氮(FeNO)联合肺功能及外周血嗜酸性粒细胞比例检测在咳嗽变异性哮喘(CVA)诊断中的价值。方法选取2016年3月-2017年11月于川北医学院附属医院呼吸内科门诊诊断为慢性咳嗽的患者267例[分为CVA组(n=60)与非咳嗽变异性哮喘组(非CVA组,n=207)],另选择同期该院健康体检者30名作为对照组。对所有受试者行FeNO、常规肺功能、脉冲振荡肺功能、支气管舒张试验、外周血嗜酸性粒细胞比例检测,并分析CVA患者FeNO值与肺功能及外周血嗜酸性粒细胞比例的相关性。结果CVA组FeNO值、外周血嗜酸性粒细胞比例明显高于非CVA组及对照组[45(34.3,74.8)μg/L vs.14(10.0,19.0)μg/L vs.10(7.0,18.0)μg/L,P<0.001;5.9%±2.3%vs.2.3%±1.6%vs.2.6%±1.3%,P<0.001]。CVA组MEF75pre、MEF50pre、MEF25pre、FEV1pre、PEFpre和MMEFpre均明显低于正常范围,且均低于非CVA组及对照组(P<0.01),而R20pre较非CVA组和对照组明显增高(137.6%±40.7%vs.127.5%±40.1%vs.128.5%±45.4%,P<0.05)。使用支气管扩张剂后CVA组FEV1、MEF75、MEF50、MEF25及MMEF的改善率较非CVA组和对照组明显增高(P<0.001)。直线相关分析显示,CVA组FeNO值与FEV1pre、FEV1/FVC、PEFpre、MEF75pre、Z5、X5、R5pre、R20pre、Fres无相关性(P>0.05),而与MEF50pre、MEF25pre、MMEFpre呈负相关(P<0.05),与外周血嗜酸性粒细胞比例呈正相关(r=0.863,P<0.001)。结论FeNO、肺功能及外周血嗜酸性粒细胞比例检测均可作为慢性咳嗽患者筛选CVA的指标,三者联合效果更好。

Objective To explore the diagnostic value of screening cough variant asthma(CVA)by fractional exhaled nitric oxide(FeNO)combined with lung function and the proportion of peripheral blood eosinophils in patients with chronic cough.Methods Two hundred and sixty-seven patients with chronic cough diagnosed in the Respiratory Medicine Clinic of the Affiliated Hospital of North Sichuan Medical College from March 2016 to November 2017 were selected and divided into CVA group(n=60)and non-CVA group(n=207),and 30 healthy physical examiners in the same period served as the control group.All patients and health examiners were tested of FeNO,routine lung function,pulse oscillatory lung function,bronchodiastolic test,peripheral blood eosinophil proportion.Linear correlation was used to analyze the correlation of FeNO value to pulmonary function and the proportion of peripheral blood eosinophils in patients with CVA.Results The FeNO value and the proportion of peripheral blood eosinophils were obviously higher in CVA group than in non-CVA group and control group[45(34.3,74.8)μg/L vs.14(10.0,19.0)μg/L and 10(7.0,18.0)μg/L,P<0.001;5.9%±2.3%vs.2.3%±1.6%and 2.6%±1.3%,P<0.001].The MEF75pre,MEF50pre,MEF25pre,FEV1pre,PEFpre and MMEFpre were significantly lower in CVA group than the normal range and those in non-CVA group and control group(P<0.01),and the R20pre was significantly higher in CVA group(137.6%±40.7%)than in non-CVA group(127.5%±40.1%)and control group(128.5%±45.4%)(P<0.05).The improvement rates of FEV1,MEF75,MEF50,MEF25,MMEF were significantly higher after using bronchodilator in CVA group than in non-CVA group and control group(P<0.001).Linear correlation results showed that the FeNO value in CVA group showed no correlation with FEV1pre,FEV1/FVC,PEFpre,MEF75pre,Z5,X5,R5pre,R20pre,and Fres(P>0.05),while showed negative correlation with MEF50pre,MEF25pre and MMEFpre(P<0.05),and positive correlation with peripheral blood eosinophil proportion(r=0.863,P<0.001).Conclusion FeNO,pulmonary function and the proportion of peripheral blood eosinophils can be used as the index of screening CVA in patients with chronic cough.The combined effect of the three index may be better.