Expression of CD4～+CD25～+regulatory T cells in patients with idiopathic thrombocytopenic purpura / 中国组织工程研究

ABSTRACT

AIM:It has been recently proved that either decreased number or impaired function of CD4+CD25+regulatory T cells(Treg)can lead to immune dysfunction.Deeper knowledge of CD4+CD25+Treg cells is crucial for a better understanding of the pathogenesis of many diseases,such as autoimmune diseases,graft-versus-host disease,and allergic disease.This study is aimed to investigate the correlation of CD4+CD25+Treg cells in patients with idiopathic thrombocytopenic purpura(ITP)and to analyze the possible immunopathogenesis. METHODS:The experiment was conducted in the laboratory of Institute of Hematology,Chinese Academy of Medical Sciences and Peking Union Medical College from June to September in 2007.After the patients and their relative signed informed consents, peripheral blood was obtained from ITP patients(n=27)and health people(n=15)admitted in the Hematology Hospital,Peking Union Medical College.All patients accorded with the standards of ITP diagnosis and curative effect.The amount of CD4+CD25+ Treg cells in peripheral blood of normal controls and ITP patients before and after therapy was detected by flow cytometry.For those 23 patients who received effective therapy,blood before and after therapy were both obtained,the mononuclear cells(MNCs)were isolated from peripheral blood by density gradient centrifugation,then reverse transcriptase polymerase chain reaction(RT-PCR) was used to analyze the expression of Foxp3 mRNA. RESULTS:The amount of CD4+CD25+Treg cells and the ratio of CD4+CD25+Treg to total CD4+T cells in peripheral blood of ITP patients were obviously decreased than those of the controls(P0.05),but the expression of Foxp3 mRNA in CD4+CD25+ Treg cells was significantly increased(P