咳嗽变异性哮喘患儿诱导痰神经生长因子和白细胞介素-4水平检测

目的：检测咳嗽变异性哮喘（CVA）患儿诱导痰中神经生长因子（NGF）和白细胞介素-4（IL-4）的表达，探讨NGF和IL-4在小儿CVA中的作用。方法：34例CVA患儿纳入研究，20例健康儿童作为正常对照。对受试者进行痰诱导，苏木精-伊红染色计数诱导痰中嗜酸性粒细胞的百分比。酶联免疫吸附双抗体夹心法检测诱导痰液上清中NGF和IL-4的表达。荧光定量PCR检测诱导痰液沉淀细胞中NGF和IL-4 mRNA的表达。结果：CVA组患儿诱导痰中嗜酸性粒细胞百分数为（13.4±3.6）%，显著高于对照组的（2.6±1.7）%（P<0.01）。CVA组患儿诱导痰上清中NGF和IL-4的表达水平及诱导痰沉淀细胞中NGF和IL-4 mRNA的表达水平均显著高于对照组，差异有统计学意义（均P<0.05）。诱导痰上清中NGF和IL-4的表达水平及诱导痰中NGF和IL-4 mRNA的表达水平与嗜酸性粒细胞计数均呈正相关（均P<0.05）。CVA患儿治疗后诱导痰上清中NGF和IL-4的表达水平及诱导痰中NGF和IL-4 mRNA的表达水平均出现了显著的减低（均P<0.05）。结论：嗜酸性粒细胞的浸润和炎性介质NGF、IL-4的升高参与了小儿CVA的发生发展过程，在小儿CVA的诊断和治疗中具有一定的价值。

Levels of nerve growth factor and interleukin-4 in the induced sputum of children with cough variant asthma

Objective To examine the levels of nerve growth factor(NGF) and interleukin-4(IL-4) in the induced sputum of children with cough variant asthma(CVA),with the aim of studying the roles of NGF and IL-4 in childhood CVA.Methods Thirty-four children with CVA were enrolled in this study.Twenty healthy children were used as a normal control group.The induced sputum was separated into supernatant and cells.Hematoxylin and eosin staining was used to count differential cells.The expression of NGF and IL-4 in supernatant was measured using ELISA.The mRNA expression of NGF and IL-4 in cells was determined by Real-time PCR analysis.Results The percentage of eosinophils in the CVA group was significantly higher than in the control group (13.4±3.6)% vs(2.6±1.7)%;P<0.01].The expression of NGF and IL-4 protein and mRNA in induced sputum was significantly higher in the CVA group than in the control group(P<0.05).The expression of NGF and IL-4 protein and mRNA was positively correlated with the percentage of eosinophils(P<0.01).The expression of NGF and IL-4 protein and mRNA in induced sputum was significantly reduced in the CVA group after treatment(P<0.05).Conclusions Eosinophils infiltration and increased expression of NGF and IL-4 play key roles in the development of childhood CVA,suggesting that they may be useful in the diagnosis and treatment of childhood CVA.