Mild forms of von Willebrand disease: diagnosis and management.

Diagnosis of mild forms of type 1 and 2 von Willebrand disease (VWD) may be difficult, especially when the levels of von Willebrand factor (VWF) activities measured as ristocetin cofactor are close to normal (30-60 U/dL) because the laboratory phenotype is highly heterogeneous and confounded by factors outside the VWF gene (eg, blood group) that may influence VWF levels. An array of tests is often required to characterize the VWD types of the disorder and establish the best treatment modality, but laboratory data should always be interpreted in the presence of personal and family bleeding history. The aim of treatment is to correct the dual defect of hemostasis (ie, abnormal coagulation expressed by low levels of factor VIII:C and abnormal platelet adhesion expressed by the prolonged bleeding time). Desmopressin (1-deamino-8-D-arginine vasopressin; DDAVP) is the treatment of choice for the mild forms of type 1 and 2 VWD because it often corrects the factor VIII/VWF levels and the prolonged bleeding time in most patients, but no prospective studies on clinical effects of DDAVP are available. In type 1 and type 2 VWD unresponsive to DDAVP, plasma virally inactivated concentrates containing VWF and factor VIII are the mainstay of treatment.