目前最主要的抗凝血酶是抗凝血酶Ⅲ(ATⅢ)。ATⅢ是一种分子量约65,000的α-球蛋白。它能灭活抗凝血酶、因子Xa和在凝血过程中产生的其它丝氨酸蛋白酶。在肝素存在时灭活凝血酶和Xa的作用大大加速且更有效。 ATⅢ缺乏症是一种常染色体显性遗传性疾病,男女罹患相同。患者ATⅢ血浆浓度系正常的25-60%。不是所有ATⅢ缺乏者均患血栓形成,所报告的ATⅢ缺乏者中约45%并无血栓发生,但50岁前仅10%无症状,青春期前血栓形成虽少见但也有所发生。典型的首次血栓栓塞性疾病常与已知易患血栓形成的情况同时发生,如创伤、手术、妊娠、分娩或口服 The most important antithrombin is antithrombin Ⅲ (AT Ⅲ). AT Ⅲ is a α-globulin with a molecular weight of about 65,000. It inactivates antithrombin, factor Xa and other serine proteases that are produced during the clotting process. The effect of inactivating thrombin and Xa in the presence of heparin is much faster and more effective. AT III deficiency is an autosomal dominant genetic disease, suffering from the same men and women. AT Ⅲ plasma concentration in patients with normal 25-60%. Not all patients with AT III have thrombosis, and about 45% of those reported with ATIII deficiency do not have thrombosis, but only 10% are asymptomatic prior to age 50 and prethrombotic thrombosis is rare but occurs. A typical first thromboembolic disease often coincides with a known predisposition to thrombosis such as trauma, surgery, pregnancy, childbirth or oral administration