RESUMO
<p><b>OBJECTIVE</b>To study the levels of CD4+CD25+CD127- and CD3+CD4-CD8- regulatory T (Treg) cells in peripheral blood of children with idiopathic thrombocytopenic purpura (ITP).</p><p><b>METHODS</b>The flow cytometry was used to detect the expression of CD4+CD25+CD127- and CD3+CD4-CD8- Treg cells in peripheral blood of 33 children with ITP and 21 healthy children.</p><p><b>RESULTS</b>The expression levels of CD4+CD25+CD127-［(2.7±1.7)% vs (4.8±1.6)%; P<0.01］and CD3+CD4-CD8-［(5.2±3.1)% vs (8.1±3.5)%; P<0.01］Treg cells in children with ITP were significantly lower than in the controls.</p><p><b>CONCLUSIONS</b>The expression levels of CD4+CD25+CD127- and CD3+CD4-CD8- Treg cells decrease in children with ITP, suggesting that CD4+CD25+CD127- and CD3+CD4-CD8- Treg cells might play a role in the pathogenesis of ITP.</p>