[Expression of blood Th17 and CD4(+) CD25(+) Treg cells in patients with aplastic anemia].

This study was aimed to investigate the expression of blood Th17 and CD4+ CD25+ regulatory T cells(Treg) in the patients with aplastic anemia(AA).Forty-five patients with AA were enrolled into this study,and were divided into mild aplastic anemia(MAA) group(n=25) and severe aplastic anemia group(SAA)(n=20),blood cell count was recorded.15 healthy donors were enrolled as control.Proportions of blood Th17 and CD4+ CD25+ Treg cells were determined by flow cytometry.The serum levels of IL-17,IFN-γ and TNF-α,as well as their concentrations in culture supernatant of phytohemagglutinin(PHA)-stimulated peripheral blood mononuelear cells,were measured by ELISA.The results showed that the proportions of blood Th17 cells and concentration of blood serum IL-17 and IFN-γ increased in patients with SAA,compared with MAA and normal controls,but CD4+ CD25+ Foxp3+ Treg cells obviously decreased in patients with SAA.The concentrations of IL-17 and IFN-γ significantly increased in culture supernatant of SAA group.Hemoglobin level in the patients with AA negatively correlated with the population of Th17 cells and serum IL-17 level,whereas positively correlated with the expression of CD4+CD25+Treg cells.It is concluded that the increased response of Th17 cells and deficiency of CD4+CD25+ Treg cells present in severe aplastic anemia.The severity of anemia may be related with the imbalance between Th17 and CD4+CD25+Treg cell response.