ABSTRACT
Pathophysiology and Classification Normally, after initiation of coagulation, the tissue factor-Vila complex acti
vates factor IX. Factor IX, along with its co-factor VIII, then activates factor X. Patients with hemophilia bleed due to a lack of factor VIII or DC. Tissue factor-Vila can direcdy activate factor X, but this reaction is soon quenched by formation of Tissue Factor Pathway Inhibitor (Fig. 4.1).
