Anti-factor IXa Aptamer reduces propagation of thrombin generation in plasma anticoagulated with warfarin.

Journal Article (Journal Article)

BACKGROUND: Warfarin is routinely used in the prevention and treatment of prothrombotic events. During initiation of warfarin therapy levels of factor (F) VII and protein C decrease rapidly but prothrombin, FIX and FX decline much slower. Therefore, propagation of thrombin generation (TG) remains unaffected much longer, increasing the risk of inadequate anticoagulation. Recently, a novel agent, anti-IXa aptamer, RB006, has been developed. Therefore, we have evaluated the in vitro effects of this agent in warfarin plasma. METHODS: The investigation consisted of two parts. First, a computer simulated time course of TG with warfarin alone and in combination with FIXa inhibition was evaluated and, second, normal volunteer, protein C deficient, FVII deficient and commercial warfarin plasmas (INR 2.1 and 3.1) were spiked with increasing concentrations of aptamer (0-24 microg/ml) and its anticoagulant effects were evaluated using prothrombin time (PT), activated partial thromboplastin time (aPTT) and TG with tissue factor and Actin as activators. Direct effects of aptamer on protein C were also evaluated. RESULTS: Simulation of coagulation during warfarin induction showed that TG can be significantly delayed and decreased by inhibiting FIXa (i.e., with anti-FIXa aptamer). The anti-FIXa aptamer inhibited TG in all tested plasmas, but was most efficacious in warfarin and FVII deficient plasma. The aptamer itself did not inhibit protein C and had no effect on PT, but concentration-dependently increased aPTT. CONCLUSION: The anti-FIXa aptamer potentiates the inhibitory effects of warfarin on TG, and may fill the need as an adjuvant agent during initiation of warfarin therapy.

Full Text

Duke Authors

Cited Authors

  • Szlam, F; Luan, D; Bolliger, D; Szlam, AD; Levy, JH; Varner, JD; Tanaka, KA

Published Date

  • May 2010

Published In

Volume / Issue

  • 125 / 5

Start / End Page

  • 432 - 437

PubMed ID

  • 20004955

Electronic International Standard Serial Number (EISSN)

  • 1879-2472

Digital Object Identifier (DOI)

  • 10.1016/j.thromres.2009.11.018


  • eng

Conference Location

  • United States