Laboratory Evaluation of Von Willebrand Disease: Phenotypic Analysis

von Willebrand disease (vWD) is recognized to be the most common inherited bleeding disorder, and arises due to defects in, or reduced levels of, von Willebrand factor (vWF), an adhesive plasma protein essential for primary hemostasis. Diagnosis of vWD requires clinical evaluation and laboratory analysis, with the latter reviewed in this chapter. Testing should comprise assessment of factor VIII, vWF antigen, and vWF activity using multiple assays, including ristocetin cofactor and collagen binding. Tests should be repeated for confirmation, and more extensive testing is selectively applied, before excluding or diagnosing vWD. This edition first published 2013