免疫性血小板减少症患儿外周血CD4+CD25+调节T细胞和Th17细胞的变化

Changes of CD4+CD25+ Regulating T Cells and Th17 Cell Subsets and Its Clinical Significance in Children with Immune Thrombocytopenia

目的通过测定免疫性血小板减少症(ITP)患儿外周血Th17细胞、CD4+CD25+调节性T细胞(Treg)及血浆IL-17水平,探讨它们在ITP发生和发展、糖皮质激素治疗中的作用。方法选择2010年10月至2012年6月在宁夏医科大学总医院儿科住院治疗的ITP患儿50例,同期门诊体检的健康儿童50例作为正常对照组,于清晨空腹抽取外周血,应用流式细胞术检测其外周血中Th17细胞、CD4+CD25+Treg细胞数量,采用酶联免疫吸附试验(ELISA法)测定血浆IL-17水平。所有ITP患儿行骨髓细胞学检查巨核细胞数量。结果(1)与正常对照组相比,ITP患儿治疗前外周血CD4+CD25+Treg细胞比例明显降低(P<0.05),治疗后虽有所增高,但仍低于正常对照组(P<0.05);(2)ITP患儿组中,Th17细胞百分率明显高于正常对照组(P<0.05);ITP患儿组中,Treg/Th17比例明显低于正常对照组(P<0.05);(3)ITP患儿组中,27例患儿血浆IL-17水平与正常对照组相比差异无统计学意义(P>0.05)。(4)巨核细胞数目与Th17细胞无明显相关性。结论 (1)CD4+CD25+Treg细胞的减少及Treg/Th17比例失衡可能是ITP患儿血小板自身免疫损伤的机制之一。(2)激素可能通过诱导CD4+CD25+Treg细胞扩增从而达到治疗ITP的目的。(3)巨核细胞数目与Th17细胞亚群之间无明显相关性。

Objective To detect Th17 cells,CD4+CD25+ regulatory T cells( Treg) in peripheral blood and IL-17 level in plasma of children with immune thrombocytopenia( ITP) and to explore their role in the occurrence and development of ITP,as well as response to glucocorticoid treatment. Methods 50 children with ITP hospitalized in pediatrics department from October 2010 to June 2012 were enrolled,50 healthy children were selected as control group. Peripheral blood samples were collected in the morning in all children.Th17 cells and CD4+ CD25+ Treg cells were detected by flow cytometry and IL-17 level in the plasma was measured by enzyme-linked immunosorbent assay( ELISA). The number of megakaryocytes in bone marrow was measured by bone marrow cytomorphologic examination. Results( 1) Peripheral blood CD4+CD25+ Treg cell ratio in ITP children was significantly lower than that of normal healthy children( P &lt;0. 05) before treatment. The ratio increased after treatment while still lower than that in normal control group( P &lt;0. 05);( 2) The percentage of Th17 cells in ITP group was significantly higher than that in the control group( P &lt; 0. 05); Treg / Th17 ratio in ITP group was significantly lower than that in normal control group( P &lt;0. 05);( 3) The plasma IL-17 level in ITP group has no obvious difference with that in normal control group( P &gt; 0. 05);( 4) The number of megakaryocytes had no obvious correlation with Th17 cells. Conclusion( 1) The reduction of CD4+CD25+ Treg cells and imbalance of Treg /Th17 proportion imbalance might be one of the mechanisms of autoimmune damage of autoimmune destruction of platelets in ITP children.( 2) Glucocorticosteroid may treat ITP through the induction of CD4+CD25+ Treg cells amplified.( 3) The number of megakaryocytes had no obvious correlation with Th17 cells.