Thromboelastography (TEG) has been shown to be a valuable point-of-care device for the rapid diagnosis of various bleeding disorders. However, TEG has thus far not been used for the screening for von Willebrand disease (VWD). We evaluated the performance of a modified TEG assay for the laboratory screening of VWD. Three hundred twenty-eight patients (148 male, 180 female, median age 8.4 years, range 0.1 - 72.7 years) were included in the study. The diagnosis and classification of patients was based on personal and familial case history, von Willebrand factor antigen, ristocetin cofactor levels, collagen binding assay, factor VIII coagulant activity and multimer analysis. The ratio of clot strength after preincubation with ristocetin, and without ristocetin, represents the component of clot strength that is formed by cross-linked fibrin fibres and is dependent on the agglutinated platelet fraction. The decrease of the maximum amplitude is a function of the ristocetin concentration and provides a diagnostic parameter able to differentiate between healthy individuals and patients having VWD. Based on a preliminary cut-off value of 25% for the area under the curve (AUC) ratio, the sensitivity varied from 53% to 100% for the different VWD patient groups. The test is suitable for use as a screening test using whole blood and has the additional benefit of being suitable as a point of care test. It appears also useful for monitoring responses to desmopressin (DDAVP) and infusion therapy.

BackgroundHemorrhage and blood loss are still among the main causes of preventable death. Global hemostatic assays are useful point-of-care test (POCT) devices to rapidly detect cumulative effects of plasma factors and platelets on coagulation. Thromboelastography (TEG) and Thromboelastometry (ROTEM) are established methods in many anesthesiological departments for guided hemostatic treatment. However, von Willebrand disease remains undetected by standard ROTEM, especially during emergency care, despite being the most prevalent congenital hemostatic disorder.MethodsIn our monocentric cohort pilot study we focused on hemostatic challenges associated with von Willebrand disease. Twenty-seven patients with suspected von Willebrand disease were included. We modified the routine ROTEM assay by adding a preincubation with ristocetin and commercially available plasma-derived von Willebrand factor to identify clinically relevant von Willebrand disease (VWD).ResultsAddition of von Willebrand factor to the ristocetin assay of a VWD type 3 patient restored the reaction of the whole blood probe to match the response of a healthy person. Our modified ROTEM assay with ristocetin (Ricotem) showed that all high responders (n = 7) had VWD. In the low responder group (n = 16) – 10 of 16 had VWD and in the normal responder group (n = 5), 2 of 5 had mild type 1 VWD.ConclusionsThis new modification of the standard ROTEM assay enables the detection of otherwise unnoticed critical von Willebrand disease based on alterations in clot formation and might serve as a novel approach to reliably assess severe VWD patients by platelet-mediated blood clotting in an emergency setting. We recommend incorporating this new VWD-focused screening tool into the current ROTEM-based management algorithm of acute microvascular bleeding.Electronic supplementary materialThe online version of this article (10.1186/s12871-018-0672-8) contains supplementary material, which is available to authorized users.

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