Research of Subset and Function of Th Cells in Bone Marrow of Myelodysplastic Syndrome Patients.

Objective

To study the quantity and ratio of Th1, Th2 cells in the bone marrow of patients with MDS;The tumor burden that Th1 cells bear in the patients with MDS. Evaluation of the correlation between the ratio of the blast cells and the number of the Th1 cells in the bone marrow in the patients with MDS.

Methods

By FACS, the quantity and ratio of IFN-γ producing CD₄⁺ T cell (Th1) and IL-4 producing CD₄⁺ T cell (Th2) cells in the bone marrow were detected in 21 patients with MDS,18 normal controls and 13 patients with SAA respectively;The karyotypes of 18 patients with MDS and 15 normal controls were detected, The burden,(the number of the cells with anormal karyotypes /the number of all the detected cells) that Th1 cells bear in the patients with MDS and that in normal controls were analyzed;The correlation between the ratio of the blast cells in the bone marrow and the number of the Th1 cells in the patients with MDS was also analyzed.

Results

The percentages of Th1 cells and Th2 cells and ratio of Th1/Th2 in the bone marrow of normal controls were: (0.48±0.10)%,(0.24±0.19)%,2.31±0.76 respectively, while those of the patients with MDS were (0.36±0.11)%,(0.76±0.35)% and 0.51±0.13. The percentage of Th1 cells of patients with MDS was reduced and the ratio of Th1/Th2 of them was significantly lower than that of normal controls(p<0.01); Those of the patients with SAA were: (4.75±0.49)%,(0.40±0.28)%,26.5±8.79 respectively, their Th1 cells and ratio of Th1/Th2 were markedly higher than those of normal controls (P<0.01); In all of the 15 normal controls the karyotypes were normal, and tumor cell burden was zero, While in the group of MDS, tumor cell burden, (the number of the cells with anormal karyotype /the number of all detected cells) was (50.00±0.10)%. The MDS patients’ ratio of tumor cell burden / Th1 cells (1.72±1.23) was much higher than that of normal controls whose burden was zero;The lower ratio of the Th1 cells in the bone marrow of the patients with MDS and the AML which converts from MDS, the higher percentage of the blast cells, they were negatively correlated (r=−0.563, p<0.01).

Conclusion

1. The immune function of T lymphocytes in MDS is abnormal: the balance between Th1 and Th2 cells is broken. Th1 cell, the most important element for antitumorigenesis, is decreased.

2. Comparing with the burden of the malignant clone, the number of Th1 cells of the patients with MDS is overwhelmingly scarce.

3. With descending of the number of Th1 cells in the bone marrow of the patients with MDS, the number of the blast cells contrarily grows.

4. MDS is a heterogeneous group of neoplastic disease accompanied with hypofunction of the T lymphocytes mediating immune surveillance.

All these hint that during the treat of clearing the malignant clone of MDS, enhancement of the T cell fuction should been done.