中文摘要：

目的检测急性淋巴细胞白血病（ALL）患儿的CD4^＋CD25调节性T细胞（Treg），探讨其在儿童ALL发生、治疗过程中的意义。方法以40例ALL儿童不同治疗阶段的55份外周血为标本，细胞膜表面抗原采用双色或三色单克隆抗体直接标记法，检测细胞核抗原FoxP3时先标记膜表面抗原，固定破膜后再标记胞核抗原，应用多参数流式细胞仪进行检测。结果ALL患儿的CD4^＋CD25Treg同时表达CD62L和胞核抗原FoxP3。ALL标危组治疗不同阶段儿童的CD4^＋CD25高表达T细胞数值分别为：首次诱导缓解组（1．04±0．33）％，维持治疗组（1．60±0．44）％，持续完全缓解组（1．29±0．30）％；ALL中／高危维持治疗组则为（2．24±0．75）％。结论ALL患儿的CD4^＋CD25Treg数值高于健康儿童，并且与疾病的危险度和治疗的效应有一定的关系；CD4^＋CD25Treg水平升高可能是白血病复发的原因之一。

英文摘要：

Objective To evaluate the proportion and clinical significance of CD4^＋CD25^＋ regulatory T cells in childhood acute lymphocyte leukemia （ALL） during different therapeutic stages. Methods 55 peripheral blood samples from 40 children patients with ALL were detected by muhiparameter flow cytometry with fluoresce-labeled monoclonal antibody. Results Treg cells phenotypically express not only CD62L but also FoxP3 protein. In patients with ALL standard-risk the proportion of CD4^＋CD25^Hi was （1.04±0.33）% in the first course of induction treatment, （1.60±0.44）% in maintenance treatment groups, and （1.29±0.30）% in complete remission groups respectively, while in patients with ALL the intermediate and high risk during maintenance therapy was （2.24±0.75）%. Conclusion Compared with healthy children, the proportion of Treg cells in ALL is significantly higher, and may be related to the effect of chemical treatment and severity of ALL. The elevated proportion of Treg may contribute to disease relapse.