Does recombinant factor VIIa, apart from overall hemostasis, regulate TAFI dependent fibrinolysis? In vitro analysis using overall hemostasis potential (OHP) assay

Summary

Using the recently developed overall hemostatic potential (OHP) assay, we investigated the effects of different concentrations of recombinant factor VIIa on overall hemostasis and on thrombin activatable fibrinolysis inhibitor (TAFI) dependent fibrinolysis in different factor deficient plasmas. rFVIIa increased OHP in FV, FVIII and FIX deficient plasmas but not up to the levels in normal pooled plasma (NPP). Maximal levels were found at 2.4 µg/mL of rFVIIa, while higher doses did not further increase OHP. In FXII deficient plasma, OHP is higher than in NPP and addition of rVIIa further increased it. Even very high concentrations of rFVIIa (9.6 µg/mL) did not induce a significant increase of OHP in NPP. Higher concentrations of rVIIa down-regulated fibrinolysis in FVIII, FIX and FXI deficient plasmas to values obtained in NPP. Using potato tuber carboxy-peptidase inhibitor (PTCI), a specific inhibitor of TAFI, it was found that TAFI’s influence on fibrinolysis down-regulation in FVIII and FIX deficient plasmas increased after addition of higher concentrations of rFVIIa.

From this in vitro study it seems that rFVIIa in a concentration of 2.4 µg/mL improves overall hemostasis in FV, FVIII and FIX deficient plasmas. rFVIIa, even at very high (supra-therapeutic) concentrations, does not induce hypercoagulability either in NPP or in deficient plasmas. Higher concentrations of rVIIa induce, at least partly, TAFI dependent down-regulation of fibrinolysis in FVIII and FIX deficient plasmas. These results, together with some previous ex vivo studies, point to OHP assay as a possible diagnostic tool for evaluating the hemostatic effects of rFVIIa.

Keywords

rVIIa - coagulation factor deficient plasma - overall hemostatic potential (OHP) - thrombin activatable fibrinolysis inhibitor (TAFI) - fibrinolysis

• References

• 1 Hedner U, Glazer S. Management of hemophilia patients with inhibitors. Hematol Oncol Clin North Am 1992; 6: 1035-46.
• 2 Negrier C, Hay CRM. The treatment of bleeding in hemophilic patients with inhibitors with recombinant factor FVIIa. Semin Thromb Hemost 2000; 26: 407-12.
• 3 Scharrer I. Recombinant factor VIIa for patients with inhibitors to factor VIII or IX or factor VII deficiency. Haemophilia 1999; 5: 253-9.
• 4 Poon MC, d’Oiron R. Recombinant activated factor VII (NovoSeven) treatment of platelet-related bleeding disorders. International registry in recombinant factor VIIa and platelet disorders group. Blood Coagul Fibrinolysis 2000; 11 (suppl 1) S55-68.
• 5 Kjalke M, Johannessen M, Hedner U. Effect of recombinant factor VIIa (NovoSeven) on thrombocytopenia-like conditions in vitro. Semin Hematol 2001; 38 (suppl 12) 15-20.
• 6 Kristensen J, Killander A, Hippe E. et al. Clinical experience with recombinant factor FVIIa in patients with thrombocytopenia. Haemostasis 1996; 26: 159-64.
• 7 Aldouri M. The use of recombinant factor FVIIa in controlling surgical bleeding in non-hemophilic patients. Pathophysiol Haemost Thromb 2002; 32 (suppl 1) 41-6.
• 8 Fishman RHB. Factor VIIa used in critically wounded. Lancet 1999; 354: 134
• 9 Kjalke M, Ezban M, Monroe DM. et al. High dose factor VIIa increases initial thrombin generation and mediates faster platelet activation in thrombocytopenia –like conditions in a cell based model system. Br J Haematol 2001; 114: 114-20.
• 10 Broze GJ, Higuchi DA. Coagulation-dependent inhibition of fibrinolysis: role of carboxy-peptidase-U and the premature lysis of clots from haemophilic plasma. Blood 1996; 88: 3815-23.
• 11 Bajzar L, Morser J, Nesheim ME. TAFI, or plasma procarboxypeptidase B, couples the coagulation and fibrinolytic cascades through the thrombin-thrombomodulin complex. J Biol Chem 1996; 271: 16603-8.
• 12 Lisman T, Mosnier LO, Lambert T. et al. Inhibition of fibrinolysis by recombinant factor FVIIa in plasma from patients with severe hemophilia A. Blood 2002; 99: 175-9.
• 13 Hedner U. Dosing and monitoring NovoSeven treatment. Haemostasis 1996; 26: 102-8.
• 14 Kenet G, Lubetsky A, Loboshitz D. et al. Comparison of different treatment regimens with rFVIIa – a single center experience. Thromb Haemost 2001; (suppl 1) P2548 (abstract)
• 15 Cid AR, Lorenzo JI, Haya S. et al. A comparison of FVII:C and FVIIa assays for the monitoring of recombinant factor VIIa treatment. Haemophilia 2001; 7: 39-41.
• 16 Johannessen M, Kjalke M, Hedner U. et al. The in vitro effect of recombinant factor FVIIa (NovoSeven) on the endogenous thrombin potential (ETP) Thromb Haemost. 2001; (suppl 1) P1400 (abstract)
• 17 Kawaguchi C, Takahashi Y, Hanesaka Y. et al. The in vitro analysis of the coagulation mechanism of activated factor VII using thromboelastogram. Thromb Haemost 2002; 88: 768-72.
• 18 He S, Antovic A, Blombäck M. A simple and rapid laboratory method for determination of haemostasis potential in plasma II. Modifications for use in routine laboratories and research work. Thromb Res 2001; 103: 355-61.
• 19 He S, Bremme K, Blombäck M.. A laboratory method for determination of overall haemostatic potential in plasma. I. Method design and preliminary results. Thromb Res 1999; 15 (96) 145-56.
• 20 Jones AJ, Meunier AM. A precise and rapid microtitre plate clot lysis assay: methodology, kinetic modeling and measurement of catalytic constants for plasminogen activation during fibrinolysis. Thromb Haemost 1990; 64: 455-63.
• 21 Williams S, Fatah K, Ivert T. et al. The effect of acetylsalicylic acid on fibrin gel lysis by tissue plasminogen activator. Blood Coagul Fibrinolysis 1995; 6: 718-25.
• 22 Hemker HC, Wielders S, Kessels H. et al. Continuous registration of thrombin generation in plasma, its use for the determination of the thrombin potential. Thromb Haemost 1993; 70: 617-24.
• 23 Wielders S, Mukherjee M, Michielis J. et al. The routine determination of the endogenous thrombin potential, first results in different forms of hyper-and hypocoagulability. Thromb Haemost 1997; 77: 629-36.
• 24 Al Dier R, Peyvandi F, Santagostino E. et al. The thrombogram in rare inherited coagulation disorders: its relation to clinical bleeding. Thromb Haemost 2002; 88: 576-82.
• 25 Antovic JP, Antovic A, He S. et al. Overall haemostatic potential can be used for estimation of thrombin activatable fibrinolysis inhibitor – dependent fibrinolysis in vivo and for possible follow-up of recombinant factor FVIIa treatment in patients with inhibitors to factor VIII. Haemophilia 2002; 8: 781-6.
• 26 Von dem Borne PAK, Meijers JCM, Bouma BN. Feedback activation of factor XI by thrombin in plasma results in additional formation of thrombin that protects fibrin clot from fibrinolysis. Blood 1995; 86: 3035-42.
• 27 Mannhalter C, Fischer M, Hopmeier P. et al. Factor XII activity and antigen concentration in patients suffering from recurrent thrombosis. Fibrinolysis 1987; 1: 259-63.
• 28 Rodeghiero F, Castaman G, Ruggeri M. et al. Fibrinolytic studies in 13 unrelated families with factor XII deficiency. Haematologica 1991; 76: 28-32.
• 29 Levi M, Hack CE, de Boer JP. et al. Reduction of contact activation related fibrinolytic activity in factor XII deficient patients. Further evidence for the role of contact system in fibrinolysis in vivo. J Clin Invest 1991; 88: 1155-60.
• 30 Gallistl S, Cvirn G, Muntean W. Recombinant factor VIIa does not induce hypercoagulability in vitro. Thromb Haemost 1999; 81: 245-9.
• 31 van't Veer C, Golden NJ, Mann KG. Inhibition of thrombin generation by the zymogen factor VII: implications for the treatment of hemophilia A by factor VIIa. Blood 2000; 95: 1330-5.
• 32 Von dem Borne PA, Bajzar L, Meijers JC. et al. Thrombin-mediated activation of factor XI results in a thrombin-activatable fibrinolysis inhibitor-dependent inhibition of fibrinolysis. J Clin Invest 1997; 99: 2323-7.