Study On The Percentage And Polarization Of Bone Marrow Macrophages And Their Correlations With Erythropoiesis In MDS Patients

Objectives:Ineffective erythropoiesis is one of the typical features of myelodysplastic syndromes?MDS?.Macrophages play a key role in supporting erythropoiesis.To explore the role of macrophages in the pathogenesis of MDS,and provide a novel viewpoint for the treatment of anemia,we investigate the percentage and polarization of the macrophages in MDS bone marrow,and their effect on the differentiation and apoptosis of erythroblasts.Methods:The percentage of macrophages,M1 and M2 cells in bone marrow from normal controls and MDS patients were measured by flow cytometry,immunohistochemistry and qRT-PCR.The IFN-?and IL-4 in bone marrow were detected by enzyme-linked immunosorbent assay.The activation of Th cell and the differentiation and apoptosis of erythroblasts were evaluated by flow cytometry.Results:?1?Lower-risk MDS patients showed increased percentage of macrophages in bone marrow,which were biased to M1 phenotype compare with controls and higher-risk MDS patients and positive correlated with the proportion of Th1 cells.?2?The differentiation arrest of erythroblasts,quantified by ratio of CD71⁺CD235a⁺/CD71^intCD235a⁺in CD45^-cells,was observed in lower risk MDS,which is positively correlated with the percentage of macrophages.?3?The apoptosis ratio of nucleated erythrocytes was significantly increased in lower risk MDS,when compared to normal controls, which was positively correlated with M1 macrophages.?4?Hemoglobin concentration in peripheral blood was inversely correlated with the percentage of macrophages in bone marrow.?5?The percentage of macrophages in bone marrow in MDS patients was inversely correlated with IPSS scores.?6?There was an inversely correlation between the percentage of macrophage and CD34+cells in bone marrow in MDS patients.Conclusions:Our data indicated that type I polarization of macrophage has negative influence on erythropoiesis in bone marrow,which may contribute to the anemia in lower risk MDS.The percentage of bone marrow macrophages in MDS patients was negatively correlated with the IPSS score and the proportion of CD34+cells,which may indicate the degree of disease progression and evaluate the prognosis of MDS patients.