A Study On CD4~+CD25~+Regulatory T Cells And Cytokines In RSV Bronchiolitis And Bronchial Asthma

Aim:To observe the percentage of CD4+CD25+regulatory T cells (Treg) and the number of eosinophils (EOS) in peripheral blood of infants with respiratory syncytial virus (RSV) bronchiolitis and infants with bronchial asthma, and to observe the levels of IFN-γ, IL-4, IL-10, TGF-β and IL-17in peripheral blood of infants with RSV bronchiolitis and infants with bronchial asthma. Discuss the role of Treg and EOS in RSV bronchiolitis and bronchial asthma, and the relationship between RSV bronchiolitis and bronchial asthma.Methods:We collected27hospitalized infants with RSV bronchiolitis and23hospitalized infants with bronchial asthma in our hospital from November,2010to April,2011, and collected21hospitalized infants with non-RSV viral pneumonia and healthy infants as the control groups at the same time. The percentage of Tregs was detected by flow cytometer (FCM). The number of EOS was measured by electrical impedance. The levels of IFN-γ, IL-4, IL-10, TGF-β and IL-17were determined by enzyme-linked immunosorbent assay (ELISA).Results:1. The percentage of Tregs in peripheral blood of the infants with RSV bronchiolitis and the infants with bronchial asthma was significantly lower than that of the infants with non-RSV viral pneumonia and healthy infants (P<0.05).2. The number of EOS in peripheral blood of the infants with RSV bronchiolitis and the infants with bronchial asthma was significantly higher than that of the infants with non-RSV viral pneumonia and healthy infants (P<0.05).3. There is a negative correlation between the percentage of Treg and the number of EOS in RSV bronchiolitis and bronchial asthma, and the correlation coefficient is r=-0.86and-0.93respectively (P<0.05).4. The levels of IFN-γ, IL-10and TGF-β in peripheral blood of the infants with RSV bronchiolitis and the infants with bronchial asthma were significantly lower than those of the infants with non-RSV viral pneumonia and healthy infants (P<0.05), and the levels of IL-4and IL-17in peripheral blood of the infants with RSV bronchiolitis and the infants with bronchial asthma were significantly higher than those of the infants with non-RSV viral pneumonia and healthy infants (P<0.05). The levels of IFN-γ, IL-4, IL-10, TGF-β and IL-17were not significantly different between the infants with RSV bronchiolitis and the infants with bronchial asthma (P>0.05).Conclusions:1. The decrease of the percentage and function of Tregs and the increase of the number of EOS in peripheral blood of infants with RSV bronchiolitis and infants with bronchial asthma may be a common pathogenesis of RSV bronchiolitis and infants with bronchial asthma, which causes bronchial mucosal inflammation and airway hyperreactivity.2. The changes of levels of IFN-γ, IL-4, IL-10, TGF-β and IL-17are the same between infants with RSV bronchiolitis and infants with bronchial asthma, which may be a common molecular pathogenesis of RSV bronchiolitis and bronchial asthma.