EFFECT OF VON WILLEBRAND FACTOR ON THE ACTIVITY OF FACTOR VIII

第VIII因子(FVIII)与von Willebrand相互作用的研究 因子(VWF)已经沿着几条路线进行了。第一，能力 VWF阻断因子VIII与因子抗体的相互作用 利用贝塞斯达实验对进行了研究。抑制因子 制剂中以抗体的活性最大 几乎不包含或不包含vWF(约12,000 BU)，减少到 在血浆中看到的FVIII：VWF的比率约为5,000 BU，而对于 VWF比FVIII多3倍的制剂。正在进行的工作旨在 确定这种vWF效应是由于检测上的vWF效应还是 表示vWF阻断抗体。第二，vWF对 第八因子分析正在研究中。到目前为止产生的数据表明 VWF：Ag水平必须至少为50%或正常，才能完全表达 Fviii：C.第三，Fviii：Ag与个人vWF的联系 多聚体正在用十二烷基硫酸钠-琼脂糖电泳法进行研究 放射性标记的抗FVIII抗体。初步数据显示，Fviii 发现与中小型多聚体有关。

Investigation of interaction between factor VIII (fVIII) and von Willebrand factor (vWF) has been undertaken along several lines. First, the ability of vWF to block the interaction of factor VIII with antibodies to factor VIII has been studied by using the Bethesda assay. Inhibition of factor VIII activity by the antibodies is greatest when factor VIII preparations containing little or no vWF are tested (approx. 12,000 BU), decreases to about 5,000 BU for ratios of fVIII:vWF seen in plasma, and to 3500 for preparations with 3 times more vWF than fVIII. Ongoing work is intended to determine if this vWF effect is due to a vWF effect on the assay or represents blocking of the antibody by vWF. Second, the effect of vWF on factor VIII assays is being studied. Data generated thus far indicate that the vWF:Ag level must be at least 50% or normal for full expression of FVIII:C. And, third, the association of FVIII:Ag with individual vWF multimers is being investigated by SDS-agarose electrophoresis using radiolabelled anti-FVIII antibodies. Preliminary data indicate that FVIII is found in association with the small and intermediate size multimers.