Study On Peripheral Blood Treg/Th17Cells Of Newly Diagnosed And Diffierent Stages By Immunosuppressive Therapy In Children With Aplastic Anemia

Objective To investigate the levels of Treg cells(CD4+CD25+CD127LOWT cells)/T helper cells17cells(CD3+CD8TL-17T cells) and their related cytokines IL-6, IL-17and IFN-r secreted by T helper cell type1(T helper cells1, Thl) in the peripheral blood of the serve aplastic anemia(SAA) children, and explore the significance of Treg/Th17imbalance on morbidity and different therapeutic stages in SAA children.Methods30children were collected who are newly diagnosed as having SAA, and traced the17children who have been treated with immunosuppressive therapy. The time monitoring points of newly diagnosed、 transfusion independence and remission are made according to clinical actual conditions. Besides,25healthy subjects were selected as normal control group. The flow cytometry is used to evaluate the proportion of Treg cells and Th17cells in CD4+T cells in peripheral blood mononuclear Cells(PBMC). Enzyme-linked immunosorbent assay is used to assay the levels of IL-6、IL-17and IFN-y in plasma。 T-test and One-way ANOVA is used for statistical analysis while Pearson’s linear analysis is used for correlation analysis.Results1. In the newly diagnosed SAA children group, the proportion of CD4+T cells were lower than healthy control group[(3.93α1.38)%vs (6.96α0.79),(P<0.05);the proportion of Th17cells in CD4+T cells was significantly higher than healthy control group[(2.16±1.89)%vs (0.43±0.10)%](P<0.05);but the Treg/Thl7ratio was less than healthy controls[(2.94±3.20) vs (16.88±4.39)](P<0.05)2. The concentration of IL-6%IL-17and IFN-y in the peripheral blood of childhood aplastic anemia were significantly higher than the control group[(25.56±11.98)pg/ml vs (10.44±2.51)pg/ml、(200.58±89.06)pg/ml vs (123.71±22.84)pg/ml、(465.49±243.13)pg/ml vs (48.93±12.01)pg/ml](P<0.05).3. The percentage of Treg had negative correlation with the plasma concentration of IL-6(r=-0.418,P<0.05).The proportion of Th17cells in the peripheral blood of childhood aplastic anemia were positively correlated to the plasma levels of IL-6、 IL-17and IFN-y(r=0.566; r=0.408; r=0.921).4. In the plasma of the9transfusion independence children who were receiving IST treatment, the percentage of Treg and Th17cells in CD4+cells decreased while the ratio of Treg/Th17increased. Besides, in the7of9children who were remission, the percentage of Treg and Th17cells in CD4+cells increased, and the ratio of Treg/Th17increased by the time of transfusion independence, and then decreased by the time of remission.5. In the plasma of the9transfusion independence children who were receiving1ST treatment, the level of IL-17and IL-6decreased while IFN-γ level increased. Besides, in the7of9children who were remission, the level of IFN-y decreased during the treatment periodConclusion The ratio of Treg/Th17increased in the first time and than decreased during1ST treatment in the remission children prompt that the imbalances of the Treg/Th17ratio may plays a significence role in predicting prognosis of children with SAA.The increase expression of IL-6、IL-17and IFN-r may be one of the factors causing the imbalance of Treg/Th17cells. Furthermore, the level of IFN-y decreased throughout the process of treatment in the transfusion independence and remission children point out that ATG may reaction with the Thl/Th17reduced. the imbalance between Treg cells and Th17cells could be valuable for predicting the disease severity and therapeutic effect of AA.