骨髓增生异常综合征患者T细胞亚型和CD3zeta表达的分析

免疫介导的骨髓抑制和(或)造血异常被认为是导致MDS患者血细胞减少的重要机制之一。本研究旨在通过分析11例骨髓增生异常综合征患者外周血T淋巴细胞亚群及CD3zeta的表达，以进一步评价MDS患者的免疫状态，探讨MDS患者血细胞减少可能的原因。对11例诊断明确的MDS患者，用流式细胞术计数外周血表达IFNγ^ CD4^ 细胞(Th1)、IL4^ CD4^ 细胞(Th2)、IFNγ^ CD8^ 细胞(Tc1)及IL4^ CD8^ 细胞(Tc2)，同时分析CD3zeta在T细胞亚群中的表达。结果显示：CD8^ 细胞在MDS患者外周血中比例明显升高；T细胞亚群Th1／Th2、Tc1／Tc2比值与正常对照无显著差异；T细胞活化信号传导通路上的功能蛋白CD3zeta在CD8^ 细胞中的表达明显增高。结论：MDS患者外周血T细胞亚群比例异常，以CD8^ 细胞增高为主要表现；CD3zeta在CD8^ 细胞中表达明显增高，在CD4^ 细胞中变化不大，提示MDS患者细胞免疫的过度活化主要与CD8^ 细胞有关；T细胞介导的细胞免疫过度活化是MDS患者外周血细胞减少的重要机制之一。

Analysis of T Cell Subsets and CD3zeta Chain Expression in Myelodysplastic Syndrome Patients

Immune mediated suppression of hematopoiesis has been considered as one of the most important mechanisms leading to pancytopenia in myelodysplastic syndromes. This research was aimed at evaluating immune state of the MDS patients, analyzing the peripheral blood T cell subsets and CD3zeta chain expression and searching the possible reasons of hematopoietic disorders in 11 cases of MDS. Peripheral blood mononuclear cells were collected from 11 patients whose diagnosis was confirmed according to the new WHO diagnostic criteria. Flow cytometry was used for the counts of IFNgamma(+)CD4(+) cell (Th1), IL4(+)CD4(+) cell (Th2), IFNgamma(+)CD8(+) cell (Tc1), and IL4(+)CD8(+) cell (Tc2), and for the analysis of expression of CD3zeta chain in T cell subsets. The results showed that CD8(+) cells increased significantly in MDS patients; there was no significant difference between Th1/Th2, Tc1/Tc2 ratios of T cell subsets and normal control; CD3zeta chain, the functional protein in the signal transduction pathway of T cell, was over expressed in the CD8(+) cell. In conclusion, research indicates that abnormal changes of T cell subgroups exist in peripheral blood of MDS patients. Enhancement of CD8(+) cells and over-expression of CD3zeta chain are important features, which suggest that CD8(+) cells play the most critical role in the pathologic process as compared with other T cell subsets. The over active immunity mediated by T cell subset may be one of the major mechanisms resulting in cytopenia in MDS.