Harris M G, Exner T, Rickard K A, Kronenberg H
Am J Hematol. 1985 Aug;19(4):387-93. doi: 10.1002/ajh.2830190409.
Despite markedly prolonged activated partial thromboplastin times (APTT) patients with Fletcher factor (prekallikrein) deficiency do not clinically bleed. However, there is one reported case of myocardial infarction associated with prekallikrein deficiency. These clinical observations suggest that the contact mechanism has a minor role in normal in vivo hemostatic function. We report a further two cases of prekallikrein deficiency in Caucasian siblings. The propositus presented with multiple cerebral thrombosis. Cautious anticoagulation resulted in massive cerebral hemorrhage and death of this patient. The sibling was investigated in an attempt to establish a possible defective fibrinolytic pathway in vivo. New sensitive tests for fibrinolysis were used. These included radioimmunoassay of fibrin degradation product "D," B beta 15-42, and in vitro 125I-labelled fibrin lysis assays. The plasma half-life of prekallikrein in this patient was calculated to be 58 hr. Family studies of heterozygotes were also performed. Prekallikrein deficiency is found not to be important in normal in vivo fibrinolysis, which possibly operates via tissue or vessel wall fibrinolytic activator release.
尽管患有弗莱彻因子（前激肽释放酶）缺乏症的患者活化部分凝血活酶时间（APTT）明显延长，但临床上并无出血症状。然而，有一例报告称心肌梗死与前激肽释放酶缺乏有关。这些临床观察表明，接触机制在正常体内止血功能中作用较小。我们报告了另外两例高加索族同胞患有前激肽释放酶缺乏症的病例。先证者出现多发性脑血栓形成。谨慎抗凝导致该患者发生大量脑出血并死亡。对其同胞进行了调查，试图确定体内可能存在的纤溶途径缺陷。使用了新的纤溶敏感试验。这些试验包括纤维蛋白降解产物“D”、Bβ15 - 42的放射免疫测定以及体外125I标记纤维蛋白溶解试验。该患者前激肽释放酶的血浆半衰期经计算为58小时。还对杂合子进行了家系研究。发现前激肽释放酶缺乏在正常体内纤溶过程中并不重要，正常体内纤溶可能是通过组织或血管壁释放纤溶激活剂来进行的。
