[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.