[Study on bone marrow megakaryocytes in children patients with myelodysplastic syndrome].

The study was aimed to observe morphological characteristics and hematopoiesis function of bone marrow megakaryocyte in children patients with myelodysplastic syndrome (MDS), and analyse the cause and mechanism of thrombocytopenia. CD41 McAb immunohistochemical technique was used to detect micromegakaryocytes of bone marrow smear. Plasma clot culture and CD41 McAb immunohistochemical technique were used for the MK-colony forming assay. The colony formations of CFU-MK and BFU-MK were measured. The results showed that there was no significant difference of CFU-MK colony formation rate between groups of MDS and control. But, in 62.5% of children patients the colony formation rate of CFU-MK decreased, in 25% increased, and in 12.5% was normal while BFU-MK formation rate decreased in MDS group significantly. The number of micromegakaryocyte and the positive rate of type I lymphoid micromegakaryocyte were significantly higher than those of the control group. In conclusion, there may be two kinds of megakaryocyte clones in bone marrow of children patients with MDS. One is supposed to be pathologic and potentially malignant micromegakaryocytes, the another may be the normal megakaryocytic precursors. The thrombocytopenia in MDS patients induced by increase of pathologic MK leads to abnormal development and maturation of MK in bone marrow.