The Change Of FOXP3, The Ratio Of FN-γ To IL-4 And CD4~+CD25~+ T Cells During Specific Immunotherapy For Children With Allergic Asthma

ObjectiveThe allergic asthma is a kind of chronic respiratory passage disease, whose mechanisms remain unclear. It has been accepted for a long time that this allergic disease is related to the imbalance of Thl/Th2 and the predominance of Th2 cells. But this theory can not explain all the mechanisms. The chief therapy of asthma is anti-inflammation and spasmolysis for a long time. The allergen specific immunotherapy (SIT) may be the only etiotropic treatment which can change the course of disease. But its mechanisms remain unclear. So, the current study was designed to investigate the mechanisms of SIT and find new therapy through detecting the change of FOXP3, ratio of IFN-γto IL-4 and CD4+CD25+ T cells during specific immunotherapy for children with allergic asthma.MethodsThe forty patients with allergic asthma (24 boys and 16 girls) were from department of pediatics of the first affiliated hospital of Zhengzhou Univercity. The mean age was 8.42 years old. All the patients had the typical symptoms and medical history of asthma, fullfilled the diagnostic criteria of asthma.Their skin test of dust mites was positive and they undertook the SIT (ALK, Danmark). In this study, the patients were divided into three groups:pre-SIT, post-SIT for 1 year and post-SIT for 2 years.The peripheral venous blood was obtained respectively at the pre-SIT, post-SIT for 1 year and post-SIT for 2 years time. FOXP3, IFN-γand IL-4 mRNA in PBMCs were detected by SYBR Green I real-time RT-PCR; The percentages of CD4+CD25+ T cells and CD4+CD25high T cells in peripheral blood CD4+ T cells were evaluated by flow cytometry. In the end, the results were dealt with the statistical software.ResultsWith the progression of SIT, we found that the ratio of IFN-γto IL-4 on mRNA expression level rised gradually, it was 5-fold in post-SIT for 1 year than that in pre-SIT,3-fold in post-SIT for 2 year than that in pre-SIT. The expression of FOXP3 mRNA in post-SIT for 1 year group was 4.4-fold than that in pre-SIT group, but it reduced in post-SIT for 2 years group significantly, was 1.9-fold than that in pre-SIT group. The percentage of CD4+CD25+ T cells in periphery blood CD4+ T cells did not change remarkably during the SIT(P>0.05); The percentage of CD4+CD25high T cells in peripheral blood CD4+ T cells in post-SIT for 1 year group was much higher than that in pre-SIT group(P<0.05), and it retained in high level in post-SIT for 2 years group.ConclusionsWith the progression of SIT, the ratio of IFN-γto IL-4 on mRNA expression level rising gradually indicates that the disequilibrium of Thl/Th2 is retrieved. The expression of FOXP3 mRNA and the percentage of CD4+CD25high T cells in peripheral blood CD4+ T cells increased suggestes that they could play a critical role in the SIT.