Laboratory Testing for von Willebrand Disease Using a Composite Rapid 3-Test Chemiluminescence-Based von Willebrand Factor Assay Panel

Abstract

von Willebrand disease (VWD) is the most commonly reported inherited bleeding disorder and may alternatively occur as an acquired von Willebrand syndrome (AVWS). VWD/AVWS develops from defects and/or deficiency in the adhesive plasma protein von Willebrand factor (VWF). VWD/AVWS diagnosis/exclusion remains challenging because of the heterogeneity of VWF defects and the technical limitations of many VWF tests, as well as the VWF test panels (number and type of tests) chosen by many laboratories. Laboratory testing for these disorders utilizes evaluation of VWF level and activity, with activity assessment needing several tests due to the many functions performed by VWF in order to help counteract bleeding. This report explains procedures for evaluating VWF level (antigen; VWF:Ag) and activity by means of a chemiluminescence-based panel. Activity assays comprise collagen binding (VWF:CB) and a ristocetin-based recombinant glycoprotein Ib-binding (VWF:GPIbR) assay that reflects a contemporary alternative to classical ristocetin cofactor (VWF:RCo). This 3-test VWF panel (Ag, CB, GPIbR [RCo]) reflects the only such composite panel available on a single platform and is performed on an AcuStar instrument (Werfen/Instrumentation Laboratory). Certain regional approvals may also allow this 3-test VWF panel to be performed on the BioFlash instrument (Werfen/Instrumentation Laboratory).

Keywords: Glycoprotein Ib binding; Ristocetin cofactor; VWD; VWF:GPIbR; VWF:RCo; von Willebrand disease; von Willebrand factor (VWF); von Willebrand factor collagen binding (VWF:CB).