[Evaluation of a semi-automated test for quantification of von Willebrand multimers]

The assessment of von Willebrand factor (VWF) multimer distribution, particularly following the implantation of circulatory support devices, is a crucial parameter in hemostasis. Our study aimed to evaluate the semi-automated quantification of VWF multimers using the Sebia Hydrasys analyzer. Our analysis focused on quantifying high molecular weight, intermediate weight, and low molecular weight VWF multimers. Electrophoretic migration was performed using the Hydrasys 2 scan, and interpretation was carried out using densitometric analysis with the Phoresis software. The Hydrasys scan 2 successfully separated all the expected VWF multimer profiles based on the type of von Willebrand disease. The analysis revealed that in patients with circulatory support devices, elevated levels of plasma VWF rendered multimer migration unanalyzable using the methodology recommended by the manufacturer. Therefore, adjustment to a 100 % VWF antigenic level improved gel precision. We also suggest using as a standardized control the Cryocheck™ plasma, and have established reference values. Overall, this semi-automated, standardized, and optimized VWF multimer analysis system allows for an effective assessment of the VWF multimeric profile.