OBJECTIVEThis study determined the changes of CD4+CD25+ regulatory T cells, IL-10 and TGF-beta1 levels in peripheral blood in children with asthma in order to explore immunologic mechanism of asthma attacks.

METHODSSeventy-four children with asthma attacks, twenty-eight children with stable asthma and twenty healthy children were enrolled. The percentage of CD4+CD25+ regulatory T cells in CD4+ T cells in peripheral blood was detected by flow cytometry. Serum levels of IL-10 and TGF-beta1 were measured using enzyme linked immunosorbent assay (ELISA).

RESULTSThe percentage of CD4+CD25+ regulatory T cells and IL-10 levels in peripheral blood in the asthma attacks group were significantly lower than those in the stable asthma and the control groups (p<0.01) .The stable asthma group showed a similar percentage of CD4+CD25+ regulatory T cells and IL-10 levels to the control group. Compared with the stable asthma and the control groups, serum TGF-beta1 level in the asthma attacks group increased significantly (p<0.05). In the asthma attacks, the stable asthma, and the control groups, the percentage of CD4+CD25+ regulatory T cells in peripheral blood was not correlated to serum levels of IL-10 and TGF-beta1.

CONCLUSIONSThe percentage of CD4+CD25+ regulatory T cells in peripheral blood and serum IL-10 levels decrease and serum TGF-beta1 levels increases in children with asthma attacks, which results in a decreased immunosuppressive effect. This might contribute to one of the immunologic mechanisms of asthma attacks.