Turecek P L, Gritsch H, Richter G, Auer W, Pichler L, Schwarz H P
IMMUNO AG, Vienna, Austria.
Thromb Haemost. 1997 Mar;77(3):591-9.
Three small animal models of bleeding are described and used to evaluate the effects of preparations intended for therapy of human bleeding disorders. We modified techniques for the assessment of bleeding to be able to reproducibly quantify blood loss and rate of blood flow in addition to the measurement of bleeding time. Temporary hemophilia was induced in a rabbit model by injection of high titer human inhibitor plasma [> or = 1000 Bethesda units (BU)/ml]. A decrease in rabbit FVIII from normal values to below the limit of detection was observed within 30 min, cuticle bleeding time changed from normal (approx. 10 min) to steady state bleeding (> 30 min), and the rate of blood flow increased from 4 to > 30 microliters blood/min. Infusion of an activated prothrombin complex concentrate, (FEIBA STIM4, Immuno) at doses between 75 and 150 U/kg normalized the rate of blood flow, while infusion of FVIII/vWF concentrate resulted in partial correction. Administration of FVIIa, both recombinant and plasma-derived, failed to correct bleeding, however. In an analogous murine model, FVIII/ vWF inhibitor plasma was obtained by immunizing goats with a purified human FVIII/vWF complex. This plasma cross-reacted with mouse vWF in vitro. Injection of the anti-FVIII/vWF inhibitor plasma into mice caused a decrease in vWF antigen, in some animals with a complete loss of vWF multimers comparable to severe von Willebrand disease. A specific anti-vWF inhibitor plasma obtained by immunization of goats with recombinant vWF was used in a further murine model, resulting in a gradual but substantial decrease in FVIII as well as in intensive bleeding. The infusion of a FVIII/vWF concentrate (IMMUNATE, IMMUNO) normalized the rate of blood flow in both murine models. The same assessment methods were used to characterize bleeding in a natural mouse model of von Willebrand disease (strain RIIIS/J). The use of quantitative techniques of assessment of blood loss and rate of blood flow appears to be a helpful tool for characterizing hemorrhagic situations and evaluating the capacity of therapeutic preparations to correct hemostatic defects.
本文描述了三种小动物出血模型，并用于评估旨在治疗人类出血性疾病的制剂的效果。我们改进了出血评估技术，除了测量出血时间外，还能够可重复地量化失血量和血流速度。通过注射高滴度人抑制物血浆[≥1000贝塞斯达单位（BU）/ml]在兔模型中诱导暂时性血友病。30分钟内观察到兔FVIII从正常值降至检测限以下，表皮出血时间从正常（约10分钟）变为稳态出血（>30分钟），血流速度从4微升血液/分钟增加至>30微升血液/分钟。输注剂量为75至150 U/kg的活化凝血酶原复合物浓缩物（FEIBA STIM4，Immuno）可使血流速度恢复正常，而输注FVIII/vWF浓缩物则导致部分纠正。然而，给予重组和血浆来源的FVIIa均未能纠正出血。在类似的小鼠模型中，通过用纯化的人FVIII/vWF复合物免疫山羊获得FVIII/vWF抑制物血浆。该血浆在体外与小鼠vWF发生交叉反应。将抗FVIII/vWF抑制物血浆注射到小鼠体内导致vWF抗原减少，在一些动物中vWF多聚体完全丧失，类似于严重的血管性血友病。通过用重组vWF免疫山羊获得的特异性抗vWF抑制物血浆用于另一个小鼠模型，导致FVIII逐渐但显著减少以及严重出血。输注FVIII/vWF浓缩物（IMMUNATE，IMMUNO）可使两个小鼠模型中的血流速度恢复正常。使用相同的评估方法对血管性血友病天然小鼠模型（RIIIS/J品系）的出血情况进行了表征。使用失血量和血流速度的定量评估技术似乎是表征出血情况和评估治疗制剂纠正止血缺陷能力的有用工具。
