OBJECTIVE To analyze the preoperative plasma antigenic concentration and activity of von Willebrand factor and its main cleaving protease ADAMTS-13 in pediatric patients with cyanotic congenital heart disease undergoing surgical treatment and investigate possible correlations with postoperative bleeding. METHODS Plasma antigenic concentrations (von Willebrand factor:Ag and ADAMTS-13:Ag) were ...

Von Willebrand disease (VWD), the most common genetic bleeding disorder, is characterised by a quantitative or qualitative defect of von Willebrand factor (VWF). Patients with VWD suffer from mucocutaneous bleeding, of severity usually proportional to the degree of VWF defect. In particular, gastrointestinal bleeding associated with angiodysplasia is often a severe symptom of difficult manageme...

Background Von Willebrand ́s disease (VWD) is the most common congenital disorder of hemostasis, characterized by deficient or defective von Willebrand factor. Patients are treated by intravenous replacement of factor VIII/VW (FVIII/ VW) when needed, for prophylaxis before surgical procedures. Anaphylactic reactions to FVIII/VW are rare and desmopressin (DDAVP) can be used as an alternative.

A modification of Salzman's method has been used in an attempt to provide an assay in vitro for the von Willebrand factor. Platelet adhesiveness was increased in von Willebrand's disease by previously coating the beads with normal or haemophilic plasma or cryoprecipitate, whereas von Willebrand plasma had no corrective effect. Antihaemophilic factor (AHF) concentrates were studied in the same w...

The assembly of von Willebrand factor multimers in the Golgi apparatus requires D1D2 domains of the von Willebrand factor propeptide, which may act as an oxidoreductase to promote disulfide bond formation or rearrangement between two D3 domains in the mature subunit. This mechanism predicts that the propeptide should form a transient intrachain disulfide bond with the D3 domain before multimeri...

Type IIA von Willebrand's Disease (vWD) is the most common type II variant, and all reported cases (56 individuals in 26 families) have had autosomal dominant inheritance. An eight-year-old female with an increased bleeding tendency since infancy was found to have laboratory values typical of type IIA vWD, but her parents and siblings were asymptomatic. With the exception of uniformly decreased...

Genetic analysis of von Willebrand disease by von Willebrand factor gene sequencing has not yet become routine practice. Nevertheless, the prospects for molecular diagnosis have changed dramatically in recent years with the unveiling of next-generation sequencing platforms. With the goal of applying this technology to von Willebrand disease, we designed a strategy for von Willebrand factor gene...

von Willebrand factor-cleaving protease (ADAMTS13) cleaves von Willebrand factor (VWF) and regulates its physiologic function. To investigate the relation between ADAMTS13 activity and VWF, we compared ADAMTS13 activity with the VWF-related parameters VWF antigen (VWF:Ag), VWF collagen-binding activity (VWF:CBA), VWF-propeptide, proVWF, and VWF multimeric composition in 10 healthy volunteers an...

Instead of pulsatile ventricular assist devices an increasing number of nonpulsatile ventricular assist devices are introduced to clinical practice. The different flow characteristics of this new technique lead to alteration in shear stress on blood components, which may affect the coagulation system. Repeated von Willebrand factor analyses were performed in a patient who first was implanted wi...

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