Evaluating errors in the laboratory identification of von Willebrand disease in the real world

Diagnostic approach to von Willebrand disease

“…on May 10, 2018. by guest www.bloodjournal.org From cutoff normal values for VWF:Ag, VWF:RCo, and other specialized tests among laboratories can lead to a wide variation in the diagnosis of VWD type 1. 57,58 The VWF:RCo, used primarily to determine abnormalities in function of VWF, has a high coefficient of variation between laboratories, and this variation increases significantly when the level of VWF:RCo is below 15 IU/dL. 59,60 Novel automated systems that test VWF activity can minimize operator imprecision [61][62][63] and provide timely results useful in therapeutic trials 64 but may still show relatively wide coefficients of variation.…”

Preclinical evaluation of a semi‐automated and rapid commercial electrophoresis assay for von Willebrand factor multimers

“…However, multimer analysis is currently performed only by a limited number of expert laboratories because it is technically difficult, laborious, nonstandardized, and time‐consuming . Indeed, a high proportion of laboratories generate unreliable VWF multimer results using in‐house assays. To overcome technical difficulties and help in the standardization of the method, Sebia (Lisses, France) developed a simplified, same‐day results semi‐automated assay (Hydragel 5 von Willebrand multimers) to visualize VWF multimers.…”

The Platelet Function Analyser (PFA)‐100 and von Willebrand disease: a story well over 16 years in the making

“…VWD arises from deficiency and/or defects of von Willebrand factor (VWF), an adhesive plasma protein essential for effective primary haemostasis. Although a comprehensive panel of tests is required to diagnose VWD, and to assign a VWD type [1,2], laboratory evaluation for the presence or absence of VWD (and other bleeding disorders) using simple screening tools has value in many situations, including urgent pre-operative testing. Although a comprehensive panel of tests is required to diagnose VWD, and to assign a VWD type [1,2], laboratory evaluation for the presence or absence of VWD (and other bleeding disorders) using simple screening tools has value in many situations, including urgent pre-operative testing.…”