Abstract 568: Biomarkers of Hemostasis and Thrombosis in Hemophilia A and B Patients

The defective hemostatic process in hemophiliacs overlaps with the underlying physiology contributing to bleeding risk in anticoagulated patients. Hemophiliacs may also develop compensatory changes in fibrinolysis, platelet reactivity, vascular inflammation, and remodeling secondarily. We therefore explored markers for these processes in hemophilia A and B as part of our larger effort to develop translational biomarkers to guide antithrombotic therapy and minimize bleeding risk. Plasmas from hemophilia A patients (11 severe; 1 moderate) and hemophilia B patients (3 severe; 3 mild or moderate), sampled after a treatment washout period, and 7 normal subjects were procured. Markers/assays pursued include: coagulation (F1+2, FPA, TAT, D-dimer), fibrinolysis (PAP, PAI-1, tPA), platelet activation (soluble P-selectin (sP-sel)), vascular inflammation (MCP-1), angiogenesis (VEGF), PT, aPTT, and thrombin generation assay (TGA). Consistent with aPTT prolongation and changes in TGA, both hemophilia groups displayed ...