Management of inherited von Willebrand disease

von Willebrand disease is a bleeding disorder caused by quantitative or qua litative defects of von Willebrand factor. The diagnosis is based on measur ements of plasma and platelet von Willebrand factor, the ability of von Wil lebrand factor to interact with its platelet receptor and the analysis of t he multimeric composition of von Willebrand factor. Owing to the heterogene ity of von Willebrand factor defects, a correct diagnosis of types and subt ypes may be sometimes difficult but is very important for an appropriate th erapy. The aim of treatment is to correct the dual defects of haemostasis, i. e. abnormal coagulation, expressed by a low level of factor VIII, and ab normal platelet adhesion, expressed by a prolonged bleeding time. Desmopres sin is the treatment of choice in patients with type I von Willebrand disea se, who account for approximately 70% of cases, because it corrects the fac tor VIII/von Willebrand factor level and the prolonged bleeding time in mos t of these patients. In type 3 and in the majority of type 2 von Willebrand disease patients, desmopressin is not effective and it is necessary to res ort to plasma concentrates containing factor VIII and von Willebrand factor . Treated with virucidal methods, these concentrates are effective and curr ently safe, but they do not always correct the bleeding time defect. Platel et concentrates or desmopressin can be used as adjunctive treatments when a poor correction of the bleeding time after concentrates is associated with continued bleeding. Studies are in progress, first to better characterize patients with type I von Willebrand disease and to determine their response to desmopressin, and second, to evaluate the pharmacokinetios of factor VI II following factor VIII/von Willebrand factor concentrates and to establis h the indication for concentrates.