title: Evaluation of a von Willebrand factor three test panel and chemiluminescent-based assay system for identification of, and therapy monitoring in, von Willebrand disease.
abstract: von Willebrand disease (VWD) is reportedly the most common bleeding disorder and arises from deficiency and/or defects of von Willebrand factor (VWF). Laboratory diagnosis and typing of VWD has important management implications and requires a wide range of tests, including VWF antigen (VWF:Ag) and various activities, involving differential identification of qualitative vs quantitative VWF defects. We have assessed a new hemostasis instrument, the chemiluminescent assay based ACL AcuStar™, and an associated HemosIL AcuStar three test panel comprising VWF:Ag, VWF ristocetin cofactor (VWF:RCo) and VWF collagen binding (VWF:CB) (Instrumentation Laboratory, Bedford, Ma. USA) for ability to identify VWD, to help provisionally type VWD, and for potential use in therapy monitoring. This test system was compared to previously evaluated and validated test systems including VWF:RCo on CS-5100 and BCS analyzers, the new Siemens INNOVANCE assay (VWF Ac) on CS-5100, and VWF:Ag and VWF:CB assays performed by automated ELISA. We employed a large total sample test set (n=535) comprising plasma and platelet-lysate samples from individuals with and without VWD, some on treatment, normal plasmas, and normal and pathological controls. We also evaluated desmopressin (DDAVP) responsiveness, plus differential sensitivity to reduction in high molecular weight (HMW) VWF. The chemiluminescent test panel (VWF:Ag, VWF:RCo, VWF:CB) showed good comparability to similar assays performed by alternate methods, and broadly similar data for identification of VWD, provisional VWD type identification, DDAVP and VWD therapy, and HMW VWF sensitivity, although some notable differences were evident. The chemiluminescent system showed best low level VWF sensitivity, and lowest inter-assay variability, compared to all other systems. In conclusion, we have validated theACL AcuStar and the chemiluminescent HemosIL AcuStar VWF test panel for use in VWD diagnostics, and have identified some favorable characteristics that may improve the future diagnosis of VWD.
authors.affiliation: Department of Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), Sydney Centres for Thrombosis and Haemostasis, Pathology West, NSW Health Pathology, Westmead Hospital, Westmead, NSW, Australia. Electronic address: emmanuel.favaloro@health.nsw.gov.au.
authors.forename: Emmanuel J
authors.initials: EJ
authors.lastname: Favaloro
authors.affiliation: Department of Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), Sydney Centres for Thrombosis and Haemostasis, Pathology West, NSW Health Pathology, Westmead Hospital, Westmead, NSW, Australia.
authors.forename: Soma
authors.initials: S
authors.lastname: Mohammed
mesh_terms: D006487:Hemostasis; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods*; D012680:Sensitivity and Specificity; D014842:von Willebrand Diseases / Q000097:blood / Q000175:diagnosis*; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D014841:von Willebrand Factor
keywords: AcuStar; Chemiluminescence; Collagen binding; Diagnosis; Laboratory testing; Ristocetin cofactor; VWD; VWF; von Willebrand disease; von Willebrand factor