Study Of CD4~+ CD25~+ Regulatory T Cells And Cytotoxic T Lymphocyte-associated Antigen-4s' Effects In The Respiratory Syncytial Virus-infection Induced Acute Episode Of Asthma In Children

Abstract:Objective:By investigating the changes of CD4+CD25+ regulatory T cells and the level of cytotoxic T lymphocyte-associated antigen-4 in the Respiratory Syncytial Virus-infection induction of asthma exacerbation in child, CD4+CD25+ regulatory T cells and cytotoxic T lymphocyte-associated antigen-4 were studied whether they participated in the onset of asthma and their impact on asthma. Methods: 108 chirldren with acute asthma aging from 2-12 and 20 normal control group were investigated. RSV-IgM was analized by ELISA on peripheral venous bood. The percentage of CD4+CD25+ regulatory T cells in CD4 +and CTLA-4 were measured by flow cytometry.Results:â‘ 46 cases(42.59%)of acute asthma children with RSV-IgM positive, and among them,34 cases(31.48%) were children under 5years.53 cases (49.07%) with Respiratory Syncytial virus and influenza virus and parainfluenza virus'IgM negative.â‘¡The percentage of CD4+CD25+ regulatory T cells in peripheral blood of asthma group was lower than that of the normal control group (P<0.05), especially for respiratory syncytial virus antibody-positive asthma group.â‘¢The level of CTLA-4 in serum in asthma group decreased, and that of children with respiratory syncytial virus antibody-positive asthma group was significantly less (P<0.01).â‘£The percentage of CD4+CD25+ regulatory T-cell s and CTLA-4 in peripheral blood of each group was positive correlation (P<0.01). Conclusion:â‘ Respiratory syncytial virus infection is a major cause that induces acute asthma attack in children, especially children under 5 years old. The distribution of affecting had some level age dependency.â‘¡The CD4+CD25+ regulatory T cells and CTLA-4 involved in the asthmatic immune balance adjustment, their number and reduction of the level of secretion can lead to the occurrence and aggravation of asthma.â‘¢The numbers of CD4+CD25+ regulatory T cells and the expression of CTLA-4 further reduced in respiratory syncytial virus infection-induced asthmatic children, increasing the immune dysfunction, which may be the one of reasons that caused the occurance and aggravation of asthma.â‘£Asthma can lead complex immune changes to body. CD4+CD25+ regulatory T cells and CTLA-4 expression is affected by many factors, and CTLA-4 is not express on T cell alone.