再生障碍性贫血患者外周血CD4^+CD25^+调节性T细胞及Foxp3的变化及临床意义

Alteration of CD4^+CD25^+ regulatory T cells and Foxp3 in peripheral blood of aplastic anemia patients and its clinical significance

目的:探讨再生障碍性贫血(AA)患者外周血中CD4+CD25+调节性T细胞(Tregs)及Foxp3的表达及临床意义。方法:25例AA病人,其中含非重型再障(nSAA)18例、重型再障(SAA)7例,采用四色流式细胞检测技术分析AA患者外周血单个核细胞(PBMC)中CD4+T细胞、CD4+CD25+/CD4+、CD4+CD25high/CD4+T细胞百分比及绝对计数,并进一步分析AA患者PBMC的CD4+CD25+、CD4+CD25low及CD4+CD25highT细胞中Foxp3+T细胞的百分比,同时利用RT-PCR方法检测PBMC中Foxp3mRNA表达水平,并与29例正常对照组的上述指标进行比较。结果:与正常对照组相比,SAA患者及nSAA患者PBMC中CD4+T细胞、CD4+CD25+/CD4+、CD4+CD25high/CD4+百分比及绝对计数减低(P<0.05),并且SAA组明显低于nSAA组(P<0.001);AA患者CD4+CD25+、CD4+CD25low及CD4+CD25highT细胞中Foxp3的表达较正常对照组减低(P<0.05);AA患者PBMC中Foxp3 mRNA表达水平与正常对照组没有明显差别(P>0.05)。结论:CD4+CD25+调节性T细胞减低可能与AA的发病有关,SAA的Treg表达低于nSAA,为其作为AA病情变化的判断指标提供进一步的依据。

Objective：To investigate the levels of CD4＋CD25＋ regulatory T cells（Treg） and Foxp3 in peripheral blood of patients with aplastic anemia（AA）,and to explore the clinical significance of Tregs in AA.Methods：The percentage and absolute numbers of CD4＋ T cells、CD4＋CD25＋/ CD4＋ and CD4＋CD25high / CD4＋T cells in peripheral blood monouclear cell（PBMC） were examined with flow cytometry in 25 patients with AA,including 18 patients with non-severe aplastic anemia（nSAA） and 7 patients with severe aplastic anemia（SAA）.The expression of Foxp3 in CD4＋CD25＋,CD4＋CD25low and CD4＋CD25high T cells was analyzed by flow cytometry.The levels of Foxp3 mRNA in PBMC were determined by RT-PCR.Results：Compared with those of normal controls,the percentage and absolute numbers of CD4＋ T cells,CD4＋CD25＋/ CD4＋ and CD4＋CD25high / CD4＋T cells were decreased in patients with AA（P〈0.05）,especially in patients with SAA（P〈0.001）.The percentage of Foxp3＋ in CD4＋CD25＋,CD4＋CD25low and CD4＋CD25high T cells in patients with AA was lower than that in normal controls（P〈0.05）.However,the levels of Foxp3 mRNA was not significantly changed in AA patients（P〉0.05）.Conclusion：These findings suggest that the decrease of Tregs in patients with AA might be related to the incidence of AA.The absilute numbers of Tregs in SAA patients are lower than that in nSAA,which can provide hints for evaluation of disease progression.