Recombinant factor VIIa for the treatment of congenital factor VII deficiency

Factor VII deficiency is a rare autosomal bleeding disorder with a highly v ariable hemorrhagic predisposition, Severe bleeding, including hemarthroses , may be encountered when plasma factor VII levels are below 1%, Patients h ave prolonged prothrombin times, and the final diagnosis is established by quantitative factor VII assays. Some patients have true deficiencies, that is, very low factor VII activity and low factor VII antigen (crossreacting material) levels (CRM-); others have normal antigen levels but low activity (CRM+). Still others have reduced antigen levels (CRMR). There is a rather poor correlation between clinical symptoms and factor VII activity levels in plasma. Treatment of these patients consists of fresh frozen plasma, pro thrombin complex concentrates, or factor VII concentrates. Recombinant acti vated factor VII (rFVIIa) is a very useful alternative, and several patient s have been treated successfully. Because of the short half-life of factor VIIa, repeated doses have to be administered, and continuous infusion may b e even better, Antibodies to factor VII have been reported but seem to be r ather rare. From the available data it appears that rFVIIa is a safe and ef fective treatment modality for patients with congenital factor VII deficien cy.