Thromboelastography measurements of whole blood from factor VIII-deficient mice supplemented with rFVIII.

The rotational thromboelastography (ROTEG) assay system allows the real-time analysis of clot formation (fibrin formation) in a whole-blood assay format. The ROTEG system provides significant advantages over the current plasma-based assay systems as it includes the important interactions between cellular and plasmatic coagulation factors. We have employed the ROTEG system to characterize clot formation dynamics in factor VIII- deficient mouse whole blood and examined the ability of recombinant FVIII (rFVIII) supplementation to restore the normal phenotype. The ability to generate a clear dose-response relationship by adding rFVIII to FVIII-deficient murine whole blood (FVIII-/-) demonstrates the feasibility of this approach. A dose-response from 1 U to 0.00001 U mL(-1) demonstrates the enhanced sensitivity of the ROTEG system. Further characterization of this experimental approach may provide a potential tool for comparing the activity of FVIII concentrates and/or evaluating FVIII mutants.