Thrombin generation and platelet activation induced by rFVIIa (NovoSeven®) and NN1731 in a reconstituted cell-based model mimicking haemophilia conditions
| Autor: | U. Hedner, Marianne Kjalke, Majd Aljamali, Mikael Tranholm, Mirella Ezban |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
congenital
hereditary and neonatal diseases and abnormalities medicine.medical_specialty Haemophilia A Factor VIIa Pharmacology Hemophilia A Haemophilia Hemophilia B Tissue factor hemic and lymphatic diseases Humans Medicine Platelet Haemophilia B Platelet activation Cells Cultured Genetics (clinical) Factor IX Dose-Response Relationship Drug business.industry Thrombin Hematology General Medicine Factor VII Platelet Activation medicine.disease Blood Coagulation Factors Recombinant Proteins Surgery Coagulation business medicine.drug |
| Zdroj: | Haemophilia. 15:1318-1326 |
| ISSN: | 1365-2516 1351-8216 |
| Popis: | Summary. Replacement therapy with factor VIII (FVIII) and factor IX (FIX) is routinely used in haemophilia patients with haemophilia A and B, respectively, while recombinant activated FVII (rFVIIa) has proven to induce haemostasis in haemophilia patients with inhibitors. To evaluate the effect of therapeutic intervention in patients with residual factor activities, the effects of increasing concentrations of rFVIIa or NN1731 on thrombin generation and platelet activation were measured in a cell-based model system mimicking severe, moderate and mild haemophilia A or B. Purified monocytes stimulated to express tissue factor and non-activated platelets from peripheral blood of healthy donors were incubated with a mixture of purified human coagulation factors in the absence or presence of increasing concentrations of FVIII or FIX. Sub-samples were analysed for thrombin activity and platelet activation measured as exposure of P-selectin by flow cytometry. Dose-dependent increases in thrombin generation and platelet activation were observed following increasing concentrations of rFVIIa or NN1731 in both haemophilia A- and B-like conditions. At 25 nm rFVIIa, which nears the peak levels in patient plasma after 90 μg kg−1 intravenous dosing, the effects on maximum thrombin generation rate (maxTG) at 1–10% FVIII were comparable to those at 100% and 200% FVIII in the absence of rFVIIa. Normalization of maxTG required 500 nm rFVIIa and 25 nm NN1731 or 25–100 nm rFVIIa and 5 nm NN1731 in severe or moderate/mild haemophilia A and haemophilia B, respectively. This suggests that NN1731 holds its promise as a future bypassing agent for haemophilia patients with and without inhibitors. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|