呼出气一氧化氮检测在慢性咳嗽病因诊断中的价值

目的 评估呼出气一氧化氮(FeNO)检测在慢性咳嗽病因诊断中的临床应用价值.方法 对2009年10月至2010年9月就诊的慢性咳嗽病例,根据<咳嗽的诊断与治疗指南(2009版)>,通过诱导痰细胞分类计数、肺功能、支气管激发试验、24 h食管pH值监测、变应原皮试及血清IgE检测等方法做出诊断,同时进行FeNO检测.绘制受试者工作特征(ROC)曲线,评价FeNO对咳嗽变异性哮喘(CVA)的鉴别诊断价值,分析FeNO诊断CVA的最佳界值.以同样的方法分析FeNO在非CVA患者中诊断嗜酸粒细胞性支气管炎(EB)的最佳界值.结果 106例慢性咳嗽患者中,诊断CVA 39例,EB 30例,诊断其他病因慢性咳嗽37例.CVA组的FeNO值为(54±21)ppb(1 ppb=1×10-9mol/L)显著高于EB组的(34±17)ppb及其他病因慢性咳嗽组的(21±10)ppb(均P<0.01),EB组高于其他慢性咳嗽组(P<0.01).应用FeNO从慢性咳嗽中诊断CVA的ROC曲线下面积为0.85,最佳界值为40 ppb,以该界值诊断CVA的敏感度为75%,特异度为86%,准确度为81%.应用FeNO从非哮喘慢性咳嗽中诊断EB的ROC曲线下面积为0.78,最佳界值为31 ppb,以该界值诊断EB的敏感度为63%,特异度为92%,准确度为72%.结论 不同病因的慢性咳嗽患者的FeNO水平存在显著差异,FeNO检测有助于慢性咳嗽的病因诊断和鉴别.

Abstract：

Objective To evaluate the diagnostic value of fractional exhaled nitric oxide(FeNO)in the diagnosis of chronic cough.Methods A total of 106 subjects with chronic cough and normal chest radiographs were recruited from October 2009 to September 2010.Based on the management guidelines of the Chinese Respiratory Society for cough,the golden standard methods were used to make the definite diagnosis of chronic cough,including sputum cell counts,pulmonary function tests,bronchial hyperresponsiveness,24-h esophageal pH monitoring,skin pricking test and serum immunoglobulin E.All subjects received a FeNO test by a NIOXMINO analyzer.The values of FleNO to diagnose cough variant asthma(CVA)from chronic cough and EB from non-asthma cough were respectively assessed by the receiver operating characteristic(ROC)curves.Results Among them,the definite diagnoses were cough variant asthma(CVA,n=39),eosinophilic bronchitis(EB,n=30)and other causes(n=37).The FeNO levels in CVA[(54±21)ppb]](1 ppb=1×109mol/L)were significantly higher than those in EB[(34±17)ppb,P<0.01]and other causes[(21±10)ppb,P<0.01].And the FeNO levels in EB were higher than those in other causes(P<0.01).To diagnose CVA from chronic cough,the optimal FeNO cutoff value was 40 ppb with a sensitivity of 75%,a specificity of 86%,a positive predictive value of 77%,a negative predictive value of 86%and an accuracy of 81%.To diagnose EB from non.asthma chronic cough,the optimal FeNO cutoff value was 31 ppb with a sensitivity of 63%,a specificity of 92%.a positive predictive value of 88%,a negative predictive value of 92%and an accuracy of 72%respectively.Condusion Thereare significant differences between the FeNO levels of different causes of chronic cough.A marked elevation of FeNO level helps to make a final diagnosis of CVA or EB.FeNO test is useful for making the diagnosis and differential diagnosis of chronic cough in clinic practices.

Values of fractional exhaled nitric oxide in the diagnosis of chronic cough

Objective To evaluate the diagnostic value of fractional exhaled nitric oxide(FeNO)in the diagnosis of chronic cough.Methods A total of 106 subjects with chronic cough and normal chest radiographs were recruited from October 2009 to September 2010.Based on the management guidelines of the Chinese Respiratory Society for cough,the golden standard methods were used to make the definite diagnosis of chronic cough,including sputum cell counts,pulmonary function tests,bronchial hyperresponsiveness,24-h esophageal pH monitoring,skin pricking test and serum immunoglobulin E.All subjects received a FeNO test by a NIOXMINO analyzer.The values of FleNO to diagnose cough variant asthma(CVA)from chronic cough and EB from non-asthma cough were respectively assessed by the receiver operating characteristic(ROC)curves.Results Among them,the definite diagnoses were cough variant asthma(CVA,n=39),eosinophilic bronchitis(EB,n=30)and other causes(n=37).The FeNO levels in CVA[(54±21)ppb]](1 ppb=1×109mol/L)were significantly higher than those in EB[(34±17)ppb,P<0.01]and other causes[(21±10)ppb,P<0.01].And the FeNO levels in EB were higher than those in other causes(P<0.01).To diagnose CVA from chronic cough,the optimal FeNO cutoff value was 40 ppb with a sensitivity of 75%,a specificity of 86%,a positive predictive value of 77%,a negative predictive value of 86%and an accuracy of 81%.To diagnose EB from non.asthma chronic cough,the optimal FeNO cutoff value was 31 ppb with a sensitivity of 63%,a specificity of 92%.a positive predictive value of 88%,a negative predictive value of 92%and an accuracy of 72%respectively.Condusion Thereare significant differences between the FeNO levels of different causes of chronic cough.A marked elevation of FeNO level helps to make a final diagnosis of CVA or EB.FeNO test is useful for making the diagnosis and differential diagnosis of chronic cough in clinic practices.