Imbalance of Peripheral Th17 and Regulatory T Cells in Children with Allergic Rhinitis and Bronchial Asthma.

The purpose of the present study is to investigate the prevalence of Th17 and regulatory T (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 healthy controls were recruited. The prevalence of peripheral blood Th17 and Treg cells were determined by flow cytometry. mRNA expression of retinoid-acid receptor-related orphan receptor (ROR)-γt and forkhead box P3 (Foxp3) were determined by realtime polymerase chain reaction. Cytokine expressions 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 Treg cells and Transforming growth factor (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. 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 Forced expiratory volume in one second (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). Our results demonstrate that the imbalance of peripheral Th17/Treg cells plays an important role in the pathogenesis of AR accompanying with BA.