Bourti Yasmine, Fazavana Judicael, Armand Marine, Saller François, Lasne Dominique, Borgel Delphine, Bianchini Elsa P
E. P. Bianchini, UMR-S1176, 80 rue du Général Leclerc, 94276 Le Kremlin-Bicêtre Cedex, France, Tel.: +33 1 49595646, Fax: +33 1 46719472, E-mail:
Thromb Haemost. 2016 Aug 30;116(3):452-60. doi: 10.1160/TH15-12-0927. Epub 2016 Jul 14.
In the absence of specific antidote to fondaparinux, two modified forms of antithrombin (AT), one recombinant inactive (ri-AT) and the other chemically inactivated (chi-AT), were designed to antagonise AT-mediated anticoagulants, e. g. heparins or fondaparinux. These inactive ATs were previously proven to effectively neutralise anticoagulant activity associated with heparin derivatives in vitro and in vivo, as assessed by direct measurement of anti-FXa activity. This study was undertaken to evaluate in vitro the effectivity of inactive ATs to reverse anticoagulation by heparin derivatives and to compare them with non-specific fondaparinux reversal agents, like recombinant-activated factor VII (rFVIIa) or activated prothrombin-complex concentrate (aPCC), in a thrombin-generation assay (TGA). Addition of fondaparinux (3 µg/ml) to normal plasma inhibited thrombin generation by prolonging lag time (LT) as much as 244 % and lowering endogenous thrombin potential (ETP) to 17 % of their control (normal plasma) values. Fondaparinux-anticoagulant activity was reversed by ri-AT and chi-AT, as reflected by the corrections of LT up to 117 % and 114 % of its control value, and ETP recovery to 78 % and 63 %, respectively. Unlike ri-AT that had no effect on thrombin generation in normal plasma, chi-AT retained anticoagulant activity that minimises its reversal capacity. However, both ATs were more effective than rFVIIa or aPCC at neutralising fondaparinux and, unlike non-specific antidotes, inactive ATs specifically reversed AT-mediated anticoagulant activities, as suggested by their absence of procoagulant activity in anticoagulant-free plasma.
由于磺达肝癸钠没有特异性解毒剂，因此设计了两种抗凝血酶（AT）的修饰形式，一种是重组无活性形式（ri-AT），另一种是化学灭活形式（chi-AT），以拮抗AT介导的抗凝剂，例如肝素或磺达肝癸钠。通过直接测量抗FXa活性评估，这些无活性的AT先前已被证明在体外和体内均能有效中和与肝素衍生物相关的抗凝活性。本研究旨在通过凝血酶生成试验（TGA）在体外评估无活性AT逆转肝素衍生物抗凝作用的有效性，并将它们与非特异性磺达肝癸钠逆转剂，如重组活化因子VII（rFVIIa）或活化凝血酶原复合物浓缩物（aPCC）进行比较。向正常血浆中添加磺达肝癸钠（3μg/ml）可通过延长滞后时间（LT）多达244％并将内源性凝血酶潜力（ETP）降低至其对照（正常血浆）值的17％来抑制凝血酶生成。ri-AT和chi-AT可逆转磺达肝癸钠的抗凝活性，LT校正分别高达其对照值的117％和114％，ETP恢复分别达到78％和63％。与对正常血浆中的凝血酶生成没有影响的ri-AT不同，chi-AT保留了抗凝活性，这使其逆转能力最小化。然而，在中和磺达肝癸钠方面，两种AT均比rFVIIa或aPCC更有效，并且与非特异性解毒剂不同，无活性的AT特异性地逆转了AT介导的抗凝活性，这在无抗凝剂血浆中它们缺乏促凝活性得到了证明。
