[Changes and the clinical significance of CD4⁺ CD25⁺ regulatory T cells and Th17 cells in peripheral blood of infants with respiratory syncytial virus bronchiolitis].

Aim: To observe the percentages of CD4(+);CD25(+); regulatory T cells (Tregs) and Th17 cells and the levels of IL-10, TGF-β and IL-17 in peripheral blood of infants with respiratory syncytial virus (RSV) bronchiolitis. The relationship between above cells, cytokines and RSV bronchiolitis was determined.

Methods: Thirty-three infants with RSV bronchiolitis, twenty-eight infants with non-RSV pneumonia and twenty-six healthy infants were enrolled. The percentages of Tregs and Th17 cells in peripheral blood were detected by flow cytometer (FCM), and the levels of IL-10, TGF-β and IL-17 in plasma were determined by ELISA.

Results: The percentage of Tregs and the levels of IL-10 and TGF-β in infants with RSV bronchiolitis were significantly lower than those in infants with non-RSV pneumonia and healthy infants (P<0.05), while the percentage of Th17 cells and the level of IL-17 in infants with RSV bronchiolitis were significantly higher than those in infants with non-RSV pneumonia and healthy infants (P<0.05).

Conclusion: The imbalance between Tregs and Th17 cells in peripheral blood of infants with RSV bronchiolitis may be one of the pathogenesis of RSV bronchiolitis.