Expression Of IgE And CD4~+CD25~+T Cells In Asthmatic Children With Respiratory Syncytial Virus Infection

Objectives:1.to compare serum IgE level of asthmatic children between RSV infection group and non RSV infection group.2.to compare the percentage of CD4~+CD25~+T cells in CD4~+T cells of asthmatic children between RSV infection group and non RSV infection group.3.to explore the relationship between RSV infection and childhood asthma.Methods:a total of 59 asthmatic children who were treated in outpatient department of Pediatrics and wards of Affiliated Hospital of Yan'an University from December 2016to March 2018 were selected.According to whether they were infected with RSV,they were divided into group of 24 cases infected with RSV(RSV infection group)and group of 35 cases not infected with RSV(non RSV infection group).In addition,40 healthy subjects(control group)were randomly selected for normal control.ELISA method was used to detect serum IgE levels in each group by BN II automatic protein analyzer.Besides,T cell surface antigen and cell monoclonal antibody were combined to react with fluorescence labeled two antibody,and the percentage of CD4~+CD25~+T cell in CD4~+T cells was directly read out by flow cytometry.The statistical analysis of the experimental data was carried out.Results:1.The characteristics of age distribution of RSV infection in asthmatic children:Of 59 asthmatic children aged from 2 to 12,18 cases infected with RSV were aged under 5 years old(including 5 years),which makes up the majority of the total number,accounting for 56.25%;5 cases infected with RSV were aged between 5 to 10,accounting for 26.32%of the total;1 case infected with RSV was aged beyond 10,accounting for 12.5%of the total.2.Serum total IgE level:IgE in the RSV infection group is 2838.88+962.32IU/ml,in the non RSV infection group is 312.56 56.82IU/ml,and in the control group is 58.95+7.93IU/ml.F=304.46,P<0.05.The difference is statistically significant.The level of serum IgE in the RSV infection group was significantly higher than that in the control group.The level of IgE in the non RSV infection group was higher than that in the control group.The level of IgE in the RSV infection group was higher than that in the non RSV infection group.3.The level of the percentage of CD4~+CD25~+T cells in peripheral blood:the percentage of CD4~+CD25~+T cells in the RSV infection group was 4.42+0.36;the percentage of CD4~+CD25~+T cells in the non RSV infection group was 5.53+0.48;the percentage of CD4~+CD25~+T cells in the control group was 6.37+0.52.F=129.622,P<0.05.The difference was statistically significant.The percentage of CD4~+CD25~+T cells in peripheral blood of the RSV infection group was significantly lower than that of the control group.The percentage of CD4~+CD25~+T cells in peripheral blood of the non RSV infection group was lower than that of the control group,and the percentage of CD4~+CD25~+T cells in peripheral blood of the RSV infection group was lower than that of the non RSV infection group.Conclusions:1.According to the findings of age distribution of RSV infection in children,the study demonstrates that RSV infection is mainly distributed in children under the age of 5 years old(including 5 years old).2.The study comes to the conclusion that the serum IgE level of the asthmatic children is higher than that of the control group.The serum IgE level of the RSV infection group is higher than that of the non RSV infection group.The serum IgE level of the RSV infection group is much higher than that of the control group.The conclusion suggests that probably RSV infection as a specific allergen stimulatesthe body and elevatesthe level of total IgE in serum in several days,causing asthma.3.The study shows that the percentage of CD4~+CD25~+T cell in CD4~+T cells of the asthmatic children decreases compared with that of the normal children;the percentage of CD4~+CD25~+T cell in CD4~+T cells of the RSV infection asthmatic children reduces compared with that of the non RSV infection asthmatic children;the percentage of CD4~+CD25~+T cells in CD4~+T of the RSV infection asthmatic children is significantly lower than that of the normal children.The decrease of CD4~+CD25~+T cell secretion level leads to a reduction in the number,which results in the disorder of body's immune system.The immune system cannot effectively exert the immune suppressive function,thus making asthma attack.4.All the children selected for this study are from the Yan'an area,and the number of samples is small,the results of the study,therefore,need to be further studied and verified.