吲哚胺2,3双加氧酶与FeNO在儿童过敏性哮喘中的诊断效能

目的 评估儿童过敏性哮喘患儿中吲哚胺2,3双加氧酶(indoleamine 2,3-dioxygenase,IDO)水平,以及IDO水平与呼出气一氧化氮浓度(fractional exhaled nitric oxide,FeNO)之间的关系.方法 选取2015-2016年我院儿科门诊5周岁以上的初次诊断为过敏性哮喘的患儿共33例,并纳入33例同期健康体检的年龄、性别匹配的健康儿童作为对照组;对受试对象进行完整的病史采集、肺功能检查、皮肤点刺试验、嗜酸性粒细胞计数、病情严重程度评分、FeNO测定;留取静脉血和诱导痰液用高效液相色谱法检测IDO代谢产物色氨酸及犬尿氨酸浓度.结果 与对照组儿童比较,儿童过敏性哮喘患者外周血及诱导痰液中IDO含量明显降低(P=0.001),与FeNO呈负相关关系(R=-0.564,R=-0.525),与患儿年龄、性别、血嗜酸性计数、严重程度分级等均没有显著相关关系(P ＞0.05);IDO联合FeNO对预测儿童过敏性哮喘的敏感性(96.7％)和特异性(93.3％)均较两者单用更高.结论 IDO在儿童过敏性哮喘患者中的表达明显降低,特别是在高FeNO水平的患儿中.IDO水平与哮喘严重程度没有显著关系,IDO与FeNO联合检测可作为临床辅助诊断儿童过敏性哮喘的生物学标志.

Value of indoleamine 2, 3-dioxygenase combined with exhaled nitric oxide in diagnosis of childhood allergic asthma

Objective To investigate the level of indoleamine 2,3-dioxygenase (IDO) in children with allergic asthma and its correlation with exhaled nitric oxide (FeNO).Methods Thirty-three children over 5 years of age diagnosed for the first time with allergic asthma in our department from 2015 to 2016 were selected from the pediatric outpatient department of our hospital,with another 33 healthy children as the controls.All the children were evaluated for their complete medical history,pulmonary function test results,skin prick test results,FeNO concentrations,eosinophil counts (EC),and disease severity scores.Samples of peripheral venous blood and induced sputum were collected from the children for measurement of the concentrations of IDO metabolites (tryptophan and kynurenine).Results IDO levels in the peripheral blood and induced sputum were significantly lower in children with allergic asthma than in normal children (both P＜0.001).IDO level was negatively correlated with FeNO (R =-0.564,R =-0.525) and was not significantly correlated with age,gender,EC,or disease severity score (P ＞ 0.05).IDO combined with FeNO showed a significantly higher sensitivity (96.7％) and a higher specificity (93.3％) than either IDO or FeNO alone in predicting allergic asthma in children.Conclusion IDO level is significantly lower in children with allergic asthma,particularly in those with high FeNO levels,but it is not significantly correlated with asthma severity.When combined with FeNO level,IDO level can serve as an indicator of the severity of airway allergic inflammation in asthmatic children.