Levels of nerve growth factor and interleukin-4 in the induced sputum of children with cough variant asthma / 中国当代儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSIONS</b>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.</p>