Prophylaxis in von Willebrand disease.

This paper reviews current issues regarding short-term (i.e. for surgery and invasive procedures) and long-term (i.e. regular infusions to prevent bleeding on a permanent or temporary basis) prophylaxis treatment using replacement concentrates for patients with von Willebrand disease (VWD) who do not respond satisfactorily to desmopressin. The standard treatment of these patients is with factor concentrates containing von Willebrand factor (VWF) and factor VIII (FVIII). When dosing these concentrates, the broad variations in content and quality of VWF as well as the FVIII content in the products should be considered. Peri-operative management strategies will depend on the VWD subtype, baseline VWF and FVIII levels, and size of procedure. FVIII level and VWF ristocetin cofactor activity may both be used to determine concentrate potency and to monitor treatment. Long-term prophylaxis, which has become a state-of-the-art approach in haemophilia, is not very common in VWD. However, more recent data suggest that a substantial number of VWD patients could benefit from prophylactic treatment with VWF-containing concentrates. For example, 35 Swedish VWD patients who required prophylaxis (mainly because of nose/mouth bleeds and joint bleeds) showed a substantial overall reduction in bleeding episodes and there were no signs of arthropathy in children who began prophylaxis before the age of 5 years since initiation of treatment with Haemate P/Humate-P. Studies of prophylaxis in VWD are urgently needed to develop evidence-based guidelines for this approach; the VWD International Prophylaxis study, for example, has commenced by the VWD Prophylaxis Network.