移植相关性血栓性微血管病(TA-TMA)是异基因造血干细胞移植（allo-HSCT）后严重的合并症，尤其是肠道TMA患者长期生存显著缩短，迫切需要探讨新的防治策略；因此，深入研究肠道TMA发病机制，有重要的临床实际和理论意义。在前期研究中，首次发现肠道TMA的肝细胞生长因子（HGF）/内皮祖细胞（EPCs）调控轴的独特作用，并与Th1/Th2失衡密切关联；这一发现目前国内外未见报道。强烈提示HGF特异调控EPCs的动员迁移和特异性归巢，以及特异性CTL介导EPCs过度凋亡，可能在肠道TMA发病中起关键作用；本课题拟进一步深入研究HGF/EPCs轴和特异性CTL的关联，初步阐明HGF/EPCs轴对肠道TMA血管内皮细胞受损和修复的影响，探讨其对继发血小板活化和凝血异常的作用，有望HGF/EPCs成为预测肠道TMA特异的生物标记物，为临床肠道TMA防治策略提供新的理论依据。

Thrombotic microangiopathy after hematopoietic stem cell transplantation (post-HSCT TMA)is a serious transplantrelated complication. Because of shorter long-term survival in patients with intestinal TMA, We need to explore a new therapeutic strategy. It is very important clinical practical and theoretical significance to study pathogenesis of intestinal TMA following HSCT.We the first time found that the abnormal synthesis and secretion of hepatocyte growth factor(HGF) in patients with intestinal TMA, and the effect of HGF on mobilizing and homing of endothelial progenitor cells (EPCs) after allo-HSCT, it has not been reported. It strongly suggested that the regulation of HGF/EPCs axis and specific CTL-mediated apoptosis of EPCs probably are the important pathogenesis in intestinal TMA patients after allo-HSCT. We will further research that the correlation HGF/EPCs axis with CD3+CD8+T cells in the subject in the future. We will study the effect HGF/EPCs on the damaged cells of vascular endothelial and repair obstacles, and secondary platelet activation and trigger coagulopathy. It is expected to become the biomarker of HGF/EPCs in patients with the intestinal TMA, and new opportunity for intestinal TMA.