Procoagulant Activity of Sulfated Polysaccharides

Abstract 4419

BAX513, a Laminaria japonica-derived fucoidan and other non-anticoagulant sulfated polysaccharides (NASPs) have been shown to improve clotting in FVIII- and FIX-deficient plasma (Liu et al. Thromb Haemost 2006; 95:68). In this study we assessed the procoagulant activities of fucoidans derived from a variety of brown sea algae species, and correlated the activity with molecular weight (MW) and degree of sulfation. Highly purified fucoidan preparations were studied in FVIII-inhibited whole blood by tissue factor-triggered thromboelastography (TEG). The procoagulant activity was characterized by calibrated automated thrombography (CAT) in FVIII- and FIX-deficient plasma and in combination with established hemophilia therapeutics. A dilute prothrombin time assay based on tissue factor pathway inhibitor supplementation (TFPI-dPT) was used to demonstrate the dose-dependent TFPI-inhibiting effect of BAX513 (EC₅₀ = 0.18 ± 0.03 μ g/mL) in FVIII-deficient plasma. TEG in normal and FVIII-inhibited blood showed a dose-dependent procoagulant effect of most compounds where the optimal concentrations (1-100 nM) were dependent on the MW of the fucoidan. In FVIII-inhibited blood BAX513 at concentrations of ~10 nM (1.2 μ g/mL) completely normalized the TEG parameters. In contrast to sulfated fucoidans, undersulfated fucoidan hardly affected thrombin generation (TG). By CAT, the procoagulant window of NASPs in hemophilic plasma spanned more than two orders of magnitude with maximum effects being equivalent to (mU/mL) 730–940 FVIII, 32–80 FIX and 590–1230 FEIBA. NASPs combined with FVIII, FEIBA or FVIIa had an additive procoagulant effect. The optimal selection of molecular characteristics of NASPs will support the development of alternative hemophilia therapies.