Advantage of recombinant von Willebrand factor for peri-operative management in paediatric acquired von Willebrand syndrome

Distinct Mechanisms of IgM-Antibody-Mediated Acquired von Willebrand Syndrome and Successful Treatment with Recombinant von Willebrand Factor in One Patient

Acquired von Willebrand Syndrome (AVWS) is a rare coagulation disorder which can be associated with IgM paraproteinaemia. Recently, recombinant von Willebrand factor (rVWF) has become available for the treatment of bleedings in patients with inherited von Willebrand disease, but experience in patients with AVWS is limited. We report on 2 patients with AVWS with underlying IgM paraproteinaemia with distinct underlying pathomechanisms. In 1 patient, the paraprotein built unspecific complexes with von Willebrand factor (VWF). In the other patient, we were able to detect an IgM antibody against VWF. Bleeding in this patient was successfully treated with rVWF. To our knowledge, this is the first report about the successful use of rVWF in a patient with AVWS with the detection of a VWF-specific antibody.

Von Willebrand Disease: Current Status of Diagnosis and Management

Von Willebrand disease (VWD) is a common bleeding disorder, affecting male and female individuals equally, that often manifests in mucosal bleeding. VWD can be secondary to a quantitative (Type 1 and Type 3) or qualitative (Type 2) defects in Von Willebrand factor (VWF). Initial testing includes VWF antigen, as well as a platelet binding assay to differentiate between qualitative and quantitative defects. Further subtyping requires additional testing and is needed to ensure appropriate treatment. Desmopressin, antifibrinolytics, hormonal treatments for heavy menstrual bleeding, and VWF concentrates are commonly used in the treatment of VWD.

Successful Perioperative Management of Orthotopic Cardiac Transplantation in a Pediatric Patient With Concurrent Congenital von Willebrand Disease and Acquired von Willebrand Syndrome Using Recombinant von Willebrand Factor

Von Willebrand disease (VWD) is the most common bleeding disorder and reportedly affects 1:1,000 of the world's population. There are three subtypes of VWD characterized by a quantitative defect (types 1 and 3 VWD) or a qualitative defect (type 2 VWD). Type 1 VWD results in a partial deficiency of von Willebrand factor (VWF) and affects approximately 75% of individuals with VWD, whereas type 3 VWD results in a severe or complete deficiency of VWF. Individuals with type 2 VWD subtypes (types 2A, 2B, 2M, and 2N VWD) express a dysfunctional VWF protein that has impaired interactions with platelets or factor VIII. The majority of individuals with VWD have mild type 1 VWD and occasionally require bolus infusions of VWF for severe bleeding or major surgery. A subset of patients, especially those with type 2A or 3 VWD, may require more frequent VWF replacement or prophylaxis for refractory bleeding or bleeding prevention, respectively. Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that primarily occurs as a result of an underlying disease or other pathologic mechanism. Cases of AVWS associated with heart valve defects, left ventricular assist devices, or congenital cardiac disease result from high shear stress in the circulation that induces VWF unfolding and subsequent proteolysis of high-molecular-weight multimers by ADAMTS-13. In rare instances, plasma-derived factor VIII-containing VWF concentrates have been administered to individuals with AVWS for persistent or challenging bleeding events. In this case report, the hemostatic challenges and the perioperative management of cardiac transplantation surgery using a novel recombinant VWF product in a pediatric patient diagnosed with AVWS concomitant with congenital type 1 VWD are described. Written informed consent was obtained from the patient's mother for this case report. The diagnosis of congenital VWD remains a challenge because of multiple potential modifiers that can alter VWF laboratory results. Concurrent conditions, such as congenital heart disease and the rare secondary condition of AVWS, in addition to congenital VWD, can further affect interpretation of coagulation studies. This can result in delays in diagnosis, increase severity of the bleeding phenotype, and complicate hemostatic management in individuals at risk for bleeding and thrombosis. A multidisciplinary approach, including anesthesiologists, cardiologists, cardiovascular surgeons, hematologists, and pharmacists, is critical to achieving optimal patient outcomes, as highlighted in this case report. As diagnostic capabilities and understanding of VWD broaden, future studies evaluating alternative treatment approaches for individuals with various types of VWD would be of great benefit to the medical community.