Study on the Burden of Abnormal Hematopoietic Clone of the Patients with Myelodysplastic Syndromes.

Background Myelodysplastic syndromes (MDS) is a group of clone haematopoietic stem cell diseases. The burden of abnormal hematopoietic clone plays key roles in the development of this disease and needs to be further studied quantitively. Methods The ratio of the counted bone marrow cells with abnormal chromosomes to the total counted bone marrow cells was regarded as the index of MDS clone burden. The disease severity related parameters including white cell count, hemoglobin, platelet count, lactate dehydrogenase level, bone marrow blast, myeloid differentiation index, the ratio of cFU-GM to CFU-GM, micromegakaryocyte, transfusion, IL-2, TNF, CD4+ and CD8+ T cells of MDS patients were assayed and the correlations between those parameters and MDS clone burden were also analysed. Results The clone burden of MDS patients was (67.4±36.2)%. MDS clone burden correlated positively with bone marrow blasts(r =0.483, P=0.012), negatively with hemoglobin level(r = −0.445, P= 0.023); The number of blasts, hemoglobin and erythocytes in high clone burden(>50%) and low clone burden(≤50%) groups were (7.78±5.51)% and (3.45±3.34)%(P=0.035), (56.06±14.28)g/L and (76.40±24.44)g/L(P=0.013), (1.82±0.12)×10¹²/L and (2.32±0.21)×10¹²/L(P=0.034)respectively. CD4+ T lymphcytes of MDS patients and normal controls were (274.18±71.85)×10⁶/L and (454.82±205.88)×10⁶/L(P=0.012)respectively. CD8+ T lymphcytes of MDS patients and normal controls were (240.45±150.01)×10⁶/L an (305.27±145.14)×10⁶/L(P=0.317)respectively. The serum level of interleukin 2 of MDS patients and normal control group were (6.29±3.58)ng/ml and (3.11±1.40)ng/ml (P=0.002) respectively. The serum level of tumor necrosis factor of MDS patients and normal control group were (2.42±1.79)ng/ml and (1.68±0.69)ng/ml(P=0.124)respectively. The ratio of CD4 to CD8 in high clone burden MDS patients was (1.90±0.52), and that in low clone burden patients was (0.97±0.44)(P=0.022). Conclusion The quantitive clonal karyotype abnormalities and deficient T cell immunity are important parameters for evaluating MDS severeity and prediciting it’s progression.