Von Willebrand disease laboratory workup

The accurate subtyping of von Willebrand disease (VWD) relies heavily on the appropriate laboratory workups. An algorithmic approach to laboratory workup for VWD not only improves efficiency but also avoids unnecessary testing. This chapter will discuss the various assays that are used for laboratory evaluation of VWD including the routinely performed tests like von Willebrand factor (VWF) antigen, VWF activity assays, factor VIII assay, and VWF multimer analysis along with second-tier tests such as factor VIII binding assay, 2B binding assay, ristocetin-induced platelet aggregation, and collagen-binding assay. Finally, the role of the more esoteric VWF assays, VWF propetide assay, and VWF gene analysis will also be considered.