Von Willebrand factor is a multifaceted player in hemostasis requiring a diverse array of analytical and diagnostic approaches.

Introduction: Von Willebrand factor (VWF) plays a crucial role in hemostasis: its interactions with endothelial matrices, platelets, and factor VIII make it a key player in both primary hemostasis and coagulation. Pathology associated with VWF spans mild to severe bleeding manifestations in the case of inherited von Willebrand disease (VWD), the most common congenital bleeding disorder, or acquired von Willebrand syndrome (AVWS). Conversely, VWF can be associated with thrombotic manifestations in situations related to inflammation, infection, or inherited or acquired ADAMTS13 defects.

Areas Covered: This review article aims to provide guidance on the use and interpretation of clinical laboratory assays available to measure VWF and other factors related to VWD. Different VWF tests can be used in different clinical settings for efficient diagnosis and patient management. Assay limitations are also addressed.

Expert Opinion: A myriad of laboratory assays, from first line to esoteric assays, exist to enable adequate diagnosis of VWD and other diseases influenced by VWF. Clinical investigations of VWF are complicated because VWF has multiple functions which variably depend on the patient's pathophysiological status. The right choice of assays is therefore critical to provide adequate diagnosis in due time and with reasonable analytical efforts.