Clinical and Molecular Characteristics of Megakaryocytes in Myelodysplastic Syndrome.

 Myelodysplastic syndrome (MDS) is a malignant clonal disorder of hematopoietic stem cells which is characterized by morphologic dysplasia. However, the pathological characteristics of megakaryocytes (MKs) in MDS patients with gene mutation are not well established.  Bone marrow MK specimens from 104 patients with primary MDS were evaluated, and all patients were distributed into two groups according to gene mutation associated with functional MKs. The morphologic and cellular characteristics of MKs and platelets were recorded and compared.  The more frequently mutated genes in MDS patients were (11.54%), (8.65%), (5.77%), and the most common point mutation was p.(R307H) and p.(Q43P). Patients with MK mutation showed a decrease in adenosine diphosphate-induced platelet aggregation, high proportion of CD34 CD61 MKs (10.00 vs. 4.00%,  = 0.012), and short overall survival (33.15 vs. 40.50 months,  = 0.013). Further, patients with a higher percent of CD34 CD61 MKs (≧20.00%) had lower platelet counts (36.00 × 10 /L vs. 88.50 × 10 /L,  = 0.015) and more profound emperipolesis (  = 0.001). By analyzing RNA-sequencing of MKs, differentially expressed mRNA was involved in physiological processes including platelet function and platelet activation, especially for MDS patients with high percent of CD34 CD61 MKs. The high levels of expression of CD62P, CXCL10, and S100A9 mRNA, shown by RNA sequencing, were validated by PCR assay.  High proportion of CD34 CD61 MKs was a poor prognostic factor in MDS patients with MK mutation. CD62P, CXCL10, and S100A9 may be the potential targets to evaluate the molecular link between gene defects and platelet function.