[Von Willebrand disease: from diagnosis to treatment]

Von Willebrand disease is the most frequent bleeding disorder caused by inherited defects in the concentration, structure, or function of von Willebrand factor (VWF). The genetic defects are essentially located in the VWF gene, but can potentially be located within other genes, and induce an heterogeneous clinical pattern inherited as an autosomal trait, mostly dominant. Three main categories are distinguished; type 1 includes partial quantitative deficiency of VWF, type 3 (recessive form) includes virtually complete deficiency of VWF, and type 2 includes variants with either a defective VWF-dependent platelet function or a defective binding of VWF to factor VIII. These categories correlate with important clinical features and therapeutic requirements. In type 1, the mildest form, desmopressin, which induces secretion of VWF from endothelial cells, is most effective with a variable-lasting response. In type 2, responsiveness to desmopressin is variable (contraindicated in type 2B) with the persistence of the qualitative abnormality, and replacement therapy with blood products containing VWF is often necessary. Patients with type 3, the severe form, are unresponsive to desmopressin since they lack VWF in storage compartments, and the treatment or the prophylaxis of bleeding require replacement therapy.