儿童急性淋巴细胞白血病患者T淋巴细胞免疫功能的研究

Immunologic function of T lymphocytes in children with acute lymphocytic leukemia

目的 :研究儿童急性淋巴细胞白血病 (ALL)患者初治时和完全缓解 (CR)后外周血T淋巴细胞亚群及其分泌细胞因子的能力。方法 :采集B淋巴细胞系ALL儿童初治时、CR后的外周血 ,分离出其中的单个核细胞 (MNC)。用单克隆抗体在流式细胞仪上测定CD3、CD4、CD8以及IL 2受体CD2 5的含量 ;通过T淋巴细胞内细胞因子IFN γ和TNF α的测定 ,在单个细胞水平上分析T淋巴细胞功能的变化。结果 :①初治时 ,患者的CD4 /CD8为 (1.10± 0 .79) ,较健康儿童 (2 .74± 1.2 1)明显降低 (P <0 .0 1) ,CD4、CD8产生细胞因子IFN γ和TNF α的能力均低于正常对照 (P <0 .0 5 )。②CR后 ,CD4 /CD8为 2 .5 4± 1.39,比初治时明显提高 (P <0 .0 5 ) ,CD4、CD8产生细胞因子的能力增强 ,但与正常对照组相比 ,各项数值仍低。③初治患者的CD4 + CD2 5 + T淋巴细胞为 (0 .76± 0 .5 6 ) ,明显低于CR组 (2 0 .4± 5 .1) (P <0 .0 1)和对照组 (16 .3± 6 .3) (P <0 .0 1)。这表明 ,免疫损害在白血病的发病过程中起重要作用的细胞因子的产生和CD2 5都趋于正常。结论 :T淋巴细胞的免疫功能与儿童白血病的预后关系密切 。

Objective:To explore immunologic function of T lymphocytes in children with acute lymphocytic leukemia(ALL) and provide information for the treatment of leukemia.Methods:A series of peripheral blood(PB) samples from children with B cell precursor ALL were collected at diagnosis and after complete remission(CR). Using 3 color fluorescence flow cytometry, the T lymphocyte subset distribution, the intracellular cytokines (Interferon-γ and Tumor necrosis factor-α) secreted by T lymphocytes, and activated CD4 + lymphocytes(CD25)were detected. T lymphocytes from healthy children PB were used as control.Results:①At diagnosis, there is a lower CD4/CD8 ratio of T subset than that in normal control(P< 0.01). After CR, CD4/CD8 increased significantly compared with that of patient at diagnosis (P< 0.05). ② IFN-γ and TNF-α produced by CD4 +, CD8 + lymphocytes was significantly enhanced in CR patients compared with that of patients at diagnosis. ③Patients in CR showed a increased proportion of CD25 although we can find some CD25 + in patients at diagnosis.Conclusion:The role of T cell in the control of child ALL was suggested by the present study. Therapeutic strategies aimed at stimulating the immune compartment should be designed.