Causes, etiology and diagnosis of acquired von Willebrand disease: a prospective diagnostic workup to establish the most effective therapeutic strategies.

Acquired von Willebrand disease (aVWD) occurs in association with a variety of underlying disorders, most frequently in lymphoproliferative and myeloproliferative disorders, other malignancies, and cardiovascular disease. aVWD is a complex and heterogeneous defect with a multifactorial etiology and the pathophysiologic mechanisms remain unclear in many cases. Assays for anti-factor VIII (FVIII)/von Willebrand factor (VWF) activities often yield negative results although antibodies may be present in autoimmune disease and some lymphoproliferative disorders. Functional assays of VWF in patients' plasma and particularly in heart valve disease, VWF multimer analysis are important for aVWD diagnosis. In patients with normal partial thromboplastin times and normal VWF activity, the diagnosis of aVWD is based on clinical suspicion and a careful bleeding history, which should prompt the clinician to initiate further laboratory investigations. Management of bleeding in aVWD relies mainly on desmopressin, FVIII/VWF concentrates and high-dose intravenous immunoglobulin. The half-life of VWF may be very short, and in bleeding episodes high doses of FVIII/VWF concentrates at short intervals may be necessary even when high-dose intravenous immunoglobulin was applied before. Since the optimal treatment strategy has not yet been defined for aVWD of different etiology, controlled multicenter trials aiming at the development of standardized treatment protocols are urgently needed.