Diagnosis and management of von Willebrand disease

Abstract

von Willebrand disease (vWD) is a bleeding disorder caused by quantitative or qualitative defects of von Willebrand factor (vWF). The diagnosis is based on measurements of plasma and platelet vWF, the ability of vWF to interact with its platelet receptor and the analysis of the mutlimeric composition of vWF. Due to the heterogeneity of vWF defects, a correct diagnosis of types and subtypes may be sometimes difficult but is very important for an appropriate therapy. The aim of treatment is to correct the dual defects of haemostasis, i.e. abnormal coagulation expressed by low levels of factor VIII (FVIII) and abnormal platelet adhesion expressed by a prolonged bleeding time (BT). Desmopressin is the treatment of choice in patients with type 1 vWD, who account for approximately 80% of cases, because it corrects the FVIII/vWF levels and the prolonged BT in most of these patients. In type 3 and in the majority of type 2 vWD patients, desmopressin is not effective and it is necessary to resort to plasma concentrates containing FVIII and vWF. Treated with virucidal methods, these concentrates are effective and currently safe, but the BT defect is not always corrected by them. Platelet concentrates or desmopressin can be used as adjunctive treatments when poor correction of the BT after concentrates is associated with continued bleeding.