【作者】 刘芳；

【导师】 阮长耿；

【作者基本信息】 苏州大学 ， 内科血液学， 2006， 博士

【摘要】 血栓性血小板减少性紫癜(thrombotic thrombocytopenic purpura，TTP)是一种可以致死的微血管血栓性疾病，其发病原因主要是血管性血友病因子裂解蛋白酶(ADAMTS13，也叫VWF-CP)缺乏。TTP患者ADAMTS13缺乏主要有两种原因：一，ADAMTS13基因突变造成的ADAMTS13合成或分泌减少；二，体内存在抗ADAMTS13抗体，造成ADAMTS13功能抑制或抗原被廓清。TTP患者的发病机理主要因为ADAMTS13活性缺乏，造成在病理条件下内皮细胞释放的超大分子量血管性血友病因子(ul-VWF)不被降解，在微血管内血流高剪切力作用下，ul-VWF黏附血小板形成微血管血栓。目前研究证实，ADAMTS13活性严重降低是发生TTP的充分不必要条件，TTP发病还可能受到其它因素的影响，究竟哪些因素影响ADAMTS13的活性或参与VWF的降解是我们研究的主要内容；不同位点的ADAMTS13基因的突变对ADAMTS13合成、分泌、功能的影响也不同，ADAMTS13基因结构与功能关系的研究一直是相关领域的研究热点，我们诊断了国内首例遗传性TTP并对ADAMTS13基因新的突变对其的影响进行了研究；ADAMTS13基因在全身各组织细胞中广泛表达，但表达量极低，我们通过对肿瘤细胞株中ADAMTS13的检测，研究ADAMTS13在肿瘤中的表达及药物干预下的变化。上述研究对于深入认识TTP的发病和ADAMTS13基因有重要的意义。 一、血栓性血小板减少性紫癜发病机理的研究 1，利用国际上首批建立的ADAMTS13抗原检测方法检测TTP和其它相关疾病患者的ADAMTS13抗原含量，发现： 1) 正常汉族人ADAMTS13含量为601±145mU／ml(n=26)，与白种人ADAMTS13含量950±210mU／ml(n=20)相比有显著差异(p＜0.01)。正常人血清中ADAMTS13含量明显低于血浆，为413±232mU／ml(p＜0.01)。 2) 原发性TTP患者PE治疗前ADAMTS13抗原含量99±82mU／ml(n=11)与正常对照相比有显著差异(p＜0.01)，PE治疗后ADAMTS13含量有所升高449±232mU／ml(p＜0.01，n=10，与对照组比较)。继发性TTP患者2例，ADAMTS13抗原含量分别为1659mU／ml和698mU／ml。遗传性TTP患者PE治疗前ADAMTS13含量严重减低，低于原发性TTP，PE治疗后可相应的恢复，10名正常携带者的更多还原

【Abstract】 Thrombotic thrombocytopenic purpura (TTP) is a lethally microvascular occlusive "thrombotic microangiopathy", and associated with von Willebrand factor-cleaving protease(ADAMTS13) severely deficientcy. The reasons which ADAMTS13 is absent in TTP are because: firstly, the mutation in ADAMTS13 leads to impairment in gene’s synthesis and secretion; secondly, anti-ADAMTS 13 antibodies inhibit ADAMTS13’s function and/or contribute to its cleareance. Unusually large von willebrand factor (ul-VWF) multimers are secreted by endothelial cells injuried by inciting factor, and these ul-VWF multimers bind more efficiently than normal VWF in plasma to platelet glycoprotein receptors under highly shear stress in microvascular. Ul-VWF multimers will be cleaved into small pieces by ADAMTS13, which prevents thrombi forming. Thus, the person with ADAMTS13 deficiency may present TTP. But it is proved that ADAMTS13 deficiency is not sufficient for TTP, there may be other triggers for this disease and we put some efforts on investigating them; since the structure of ADAMTS13 is associated with its function, we studied on how the mutants of ADAMTS13 worked; ADAMTS13 mRNA is detected in almost every organ tissue, recently, we detected it in some cell lines of cancer and investigate the difference in expression of ADAMTS13 when NB4 was treated by ATRA.Studies on the pathogenesis of TTP1, We evaluated AD AMTS13 antigen levels in TTP and other diseases.1) The average ADAMTS13 antigen level in Chinese normal(CN) plasma was 601 ± 145mU/ml (mean ± SD, n=26), compared to the level set at 1 U/ml in pooled (n=20) normal human plasma from Caucasian origin, which mean was 950±210 mU/ml,the mean levels in serum of normal control were 413±232 mU/ml (p<0.01) .2) In idiopathic TTP plasma, before plasma exchange (pre-PE), 99±82mU/ml (n=11) was detected (p<0.01 versus CN), which upon PE increased to 449.4±232.33mU/ml(p<0.01, n=10, versus pre-PE).The antigens of ADAMTS13 in secondary TTP更多还原