Plasma Exchange Donation in Treatment of Von Willebrand

血管性血友病（vWD）是最常见的遗传性出血性疾病。我们研究了单独使用由单一、专门的父亲供者反复使用ddavp刺激的血浆交换捐赠制备的低温沉淀治疗III型严重vWD儿童的疗效和可行性。儿童出血性疾病的特征显示FVIII:C水平为4%，FVIII:Ag水平为20%，vWF:RCo为21%，vWF:Ag为3%，表明严重的vWD。他的父亲携带一个vWF mRNA表达水平缺陷的等位基因，但他有阴性出血史，凝血值正常。低温沉淀由患者父亲连续捐赠的ddavp刺激血浆交换制备，采用外周静脉通路、ACD-A抗凝剂和自体低温上清血浆作为替代液。在患者生命的前15年，父亲接受了55次血浆交换捐赠，总共产生了150,633单位的FVIII。血浆交换捐献是标准化的，涉及处理4500毫升血浆，平均产生14袋低温沉淀，每袋FVIII含量约为330单位。反复血浆交换捐献耐受性良好，不良反应包括轻度头痛和由于DDAVP和柠檬酸盐毒性引起的潮红。低温沉淀在-70℃下可保存102个月。92%的低温沉淀在储存1年后输注，平均收集至输注间隔为2年。冷冻沉淀储存13 ~ 77个月后，FVIII活性恢复到原来的48% ~ 124%；随着储存时间的增加，活性降低。与类似剂量的商业浓缩因子相比，血浆交换捐献来源的FVIII的生产成本估计降低了50%。自出生以来发生的所有出血事件均采用该方法获得的低温沉淀进行处理。在15岁时，孩子一生中只接受过一次供体接触，即他的冷冻沉淀的父亲供体。通过反复血浆交换捐献vWD载体制备的低温沉淀具有优异的止血功能，即使在延长储存间隔超过1年之后也是如此。对于vWD的长期管理而言，承诺供体的血浆交换捐赠可能是最安全的选择，并且提供了一种具有成本效益的替代商业因子浓缩物的选择。

Von Willebrand Disease (vWD) is the most common inherited bleeding disorder. We have studied the efficacy and feasibility of treating a child with type III severe vWD solely with cryoprecipitate prepared by repeated DDAVP-stimulated plasma exchange donation from a single, dedicated, paternal donor. Characterization of the child's bleeding disorder revealed a FVIII:C level of 4 percent, FVIII:Ag level of 20 percent, vWF:RCo of 21 percent, vWF:Ag 3 percent, indicative of severe vWD. His father carried an allele with a defect at the level of vWF mRNA expression but he had a negative bleeding history with normal coagulation values. Cryoprecipitate was prepared from serial DDAVP-stimulated plasma exchange donation by the patient's father, using peripheral venous access, ACD-A anticoagulant, and autologous cryosupernatant plasma as replacement fluid. During the first 15 years of the patient's life, the father underwent 55 plasma exchange donations, yielding a total of 150,633 units of FVIII. Plasma exchange donation was standardized to involve processing of exactly 4,500 mL of plasma, which yielded a mean of 14 bags of cryoprecipitate, each having a FVIII content of approximately 330 units. Repeated plasma exchange donation was well tolerated, with adverse effects including mild headache and flushing due to the DDAVP and citrate toxicity. Cryoprecipitate was stored for up to 102 months at -70C. 92 percent of the cryoprecipitate was transfused after 1 year of storage, with a mean collection to transfusion interval of 2 years. Cryoprecipitate tested after 13 to 77 months of storage showed 48 to 124 percent of the original FVIII activity; decreased activity was noted with increasing length of storage. Manufacture of plasma exchange donation-derived FVIII resulted in an estimated 50 percent cost reduction compared with similar doses of commercial factor concentrates. All bleeding episodes that occurred in the patient since birth were managed with cryoprecipitate derived by this method. At age 15, the child has received only one donor exposure throughout his life, that of the paternal donor of his cryoprecipitate. Cryoprecipitate prepared by repeated plasma exchange donation of a vWD carrier provided excellent hemostatic function, even after prolonged storage intervals of greater than 1 year. Plasma exchange donation of a committed donor may be the safest option for long-term management of vWD, and provides a cost-effective alternative to commercial factor concentrates.