Analysis of CD4+CD25+ regulatory T cells and Foxp3 mRNA in the peripheral blood of patients with asthma

The changes of CD4+CD25+ regulatory T cells (CD4+CD25+ Treg) and Foxp3 mRNA in peripheral blood mononuclear cells (PBMCs) from patients with asthma were investigated in order to elucidate the possible roles of CD4+CD25+ Treg in the development of asthma. The peripheral blood samples were collected from 29 healthy controls (normal control group) and 78 patients with asthma which included 30 patients in exacerbation group, 25 patients in persistent group, and 23 patients in remission group. By using flow cytometry and RT-PCR, the CD4+CD25+ Treg ratio and Foxp3 mRNA in PBMCs were detected. The CD4+CD25+ Treg ratio and Foxp3 mRNA in PBMCs of exacerbation and persistent groups were lower than that of remission and normal control group (P<0.05). Although the CD4+CD25+ Treg ratio and Foxp3 mRNA of remission group also lower than that of normal control group, there was no significant difference between them (P>0.05). As compared with persistent group, exacerbation group had lower CD4+CD25+ Treg ratio and Foxp3 mRNA (P<0.05). It was indicated that the decrease of CD4+CD25+ Treg ratio and its function in PBMCs may be responsible for pathogenesis of asthma.