von Willebrand disease (VWD) is reportedly the most common inherited bleeding disorder, and can also arise as an acquired disorder called acquired von Willebrand syndrome (AVWS). VWD and AVWS arise as a result of a deficiency and/or defect in the adhesive plasma protein von Willebrand factor (VWF). In turn, VWF possesses various functional activities, and primarily binding to platelets (via the glycoprotein Ib [GPIb] receptor), damaged endothelium (via collagen), and to factor VIII (FVIII), thereby protecting FVIII against degradation. VWF binding to platelets and collagen permits immobilisation of platelets to sites of vascular injury, and provides the scaffolding for the development of the ‘platelet plug’ (or thrombus) to seal the damage and prevent blood loss. VWD therefore represents a serious bleeding disorder that must be appropriately managed to prevent blood loss. To achieve this, patients suspected to have a bleeding disorder are assessed for VWD, so that VWD can be diagnosed or excluded. There are six types of VWD, and these may have different management approaches. Thus, in addition to diagnosis, a correct type classification is also required. The diagnosis and typing of VWD requires a clinical assessment plus thorough laboratory testing. In brief, patients are assessed for VWF plasma level and activity using a variety of assays. These assays comprise combinations of VWF:Ag (antigen; level of VWF protein), one or more GPIb binding assays (VWF:RCo [ristocetin cofactor], VWF:GPIbR [GPIb binding using recombinant VWF and ristocetin], or VWF:GPIbM [GPIb binding using recombinant mutant VWF without ristocetin]), and FVIII activity (FVIII:C), and if available VWF:CB (collagen binding). Based on initial testing, more specific and specialised testing can be undertaken (e.g., multimer analysis, ristocetin induced platelet aggregation [RIPA], VWF FVIII binding [VWF:FVIIIB], genetic studies). Various VWD guidelines have been published over the last decade, with the latest being the ‘ASH ISTH NHF WFH 2021 guidelines’. This talk will cover the diagnosis of VWD in the age of the new guidelines, and highlight strengths and challenges of laboratory assays as well as applying such guidelines to laboratory practice, in particular in developing countries.

Treatment of VWD requires management of mucocutaneous bleeding including epistaxis and heavy menstrual bleeding as well as therapy to prevent or treat provoked bleeding in the setting of surgery, invasive procedures and birth. Therapies include desmopressin to induce endothelial release of stored von Willebrand factor (VWF) and factor VIII (FVIII) and use of VWF concentrates, including both plasma-derived and recombinant products, as well as adjuvant therapies, such as antifibrinolytic tranexamic acid. Treatment is individualized based on the specific subtype of VWD, the bleeding phenotype and the clinical context. Potential complications of therapies should be considered and prevented whenever possible. Case examples will be presented to illustrate the principles of treatment with reference to the ASH ISTH NHF WFH 2021 guidelines on the management of VWD.  

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