Imbalance of Peripheral Th17 and Treg cells in Children with Allergic Rhinitis and Bronchial Asthma

To investigate the prevalence of Th17 and Treg cells in children with allergic rhinitis (AR) accompanying with bronchial asthma (BA).24 children with AR, 22 children with BA, 18 children with AR accompanying with BA, and 20 age-matched, healthy control subjects were recruited. The prevalence of peripheral blood Th17 and Treg cells were determined by flow cytometry. mRNA expression of ROR-γt and Foxp3 were determined by realtime polymerase chain reaction. Cytokines expression in plasma were determined by enzyme linked immunosorbent assay.The frequency of Th17 cells, ROR-γt mRNA expression, and the plasma levels of IL-17 were significantly higher, while the frequency of Treg cells and the plasma levels of TGF-β1 were significantly lower in children with AR accompanying with BA compared with those in children with AR or BA alone or control subjects. There were no significant difference in the prevalence of Th17 cells and Treg cells, ROR-γt and Foxp3 mRNA expression, and plasma levels of IL-6, IL-17, IL-23 and TGF-β1 between the AR and BA children. In children with allergic airway disease, total IgE levels were positively correlated to the frequency of Th17 cells (r=0.607, P<0.01), plasma IL-17 levels, and negatively correlated to the frequency of Treg cells (r=-0.429, P<0.01) and TGF-β1 levels (r=-0.224, P<0.01). While FEV1 (% predicted) was negatively correlated to the frequency of Th17 cells (r=-0.602, P<0.01), plasma IL-17 levels (r=-0.577, P<0.01), and positively correlated to the frequency of Treg cells (r=0.504, P<0.01) and TGF-β1 levels (r=0.231, P<0.05).The imbalance of peripheral Th17/Treg cells plays an important role in the pathogenesis of AR accompanying with BA.