Lamb M A, Reisner H M, Cooper H A, Wagner R H
J Lab Clin Med. 1981 Nov;98(5):751-63.
An improved XIEP technique has been described that is capable of resolving under nondenaturing conditions at least five populations of FVIIIR:Ag directly from microliter amounts of normal human plasma. Resolution has been achieved by increasing the concentration of agarose in the electrophoretic medium to 2% or 3% and extending the period of electrophoresis to take advantage of molecular sieving effects. Normal human plasma demonstrates an electrophoretic pattern indicating that the majority of FVIIIR:Ag is assembled as higher-molecular-weight multimers. The distribution of FVIIIR:Ag appears to be independent of antigen concentration and sample storage temperature. Plasmas from two individuals with variant VWD demonstrate a lack of the higher-molecular-weight multimers coupled with an absolute increase in the lower-molecular-weight antigenic populations, suggesting a defect in antigen assembly. Commercial FVIII preparations, reported to be ineffective in correcting the bleeding abnormality in VWD, have also been found to lack the higher-molecular-weight multimers. On the other hand, cryoprecipitate, preferred in the treatment for VWD, had essentially the same antigen distribution as normal plasma. The similarities in the distribution of FVIIIR:Ag in variant plasmas and commercial FVIII concentrates provide further evidence that it is primarily the higher-molecular-weight multimers that function in maintaining hemostasis.
已描述了一种改进的XIEP技术，该技术能够在非变性条件下直接从微升量的正常人血浆中分辨出至少五种FVIIIR:Ag群体。通过将电泳介质中琼脂糖的浓度提高到2%或3%，并延长电泳时间以利用分子筛效应，实现了分辨。正常人血浆显示出一种电泳模式，表明大多数FVIIIR:Ag组装成高分子量多聚体。FVIIIR:Ag的分布似乎与抗原浓度和样品储存温度无关。两名变异型VWD患者的血浆显示缺乏高分子量多聚体，同时低分子量抗原群体绝对增加，提示抗原组装存在缺陷。据报道，商业FVIII制剂在纠正VWD出血异常方面无效，也发现其缺乏高分子量多聚体。另一方面，在VWD治疗中首选的冷沉淀，其抗原分布与正常血浆基本相同。变异血浆和商业FVIII浓缩物中FVIIIR:Ag分布的相似性提供了进一步证据，表明主要是高分子量多聚体在维持止血中起作用。
