Bleeding occurred without correlation to elevated platelet counts and was associated with reduced large VWF multimers, indicating a diagnosis of acquired von Willebrand syndrome (AVWS), which resolved after initiation of CML treatment.
The acquired von Willebrand syndrome (AvWS), which is associated with left ventricular assist device support, is caused by the loss of the von Willebrand factor (vWF) high molecular weight multimers (HMWMs).
The diagnosis of acquired von Willebrand syndrome was made based on decreased ristocetin cofactor activity to von Willebrand factor antigen ratio and/or abnormal multimer analysis.
These cause excessive cleavage of VWF multimers resulting in a loss of HMW multimers, known as acquired von Willebrand syndrome (AVWS), a hemostatic disorder similar to VWD type 2A.
A receiver operating characteristic curve was used to identify the optimal cutoff of VWFpp/VWF:Ag for discrimination of patients with a modestly increased (most VWD cases) versus those with a markedly increased clearance (AVWS and VWD type 1 Vicenza), and this cutoff was identified at the value of 3.9 (sensitivity: 0.70, specificity: 0.97).
Acquired von Willebrand syndrome (AVWS) is a rare, potentially fatal bleeding disorder caused by low activity of von Willebrand factor (VWF) in patients without congenital deficiency.
Acquired von Willebrand Syndrome (AVWS) in patients undergoing continuous-flow left ventricular assist device support is due to the loss of von Willebrand factor (vWF) high molecular weight multimers (HMWMs) by shear-mediated mechanisms.
Seventy-six (84.4%) patients had HeartWare (Medtronic, Mounds View, MN) and 14 (15.5%) had Heartmate II (Thoratec, Pleasanton, CA) implanted. vWF level, ristocetin cofactor level, and platelet count were measured before and after implantation to determine the presence of acquired von Willebrand Syndrome; aortic valve movement and postoperative RHF were evaluated to compare the difference in bleeding and nonbleeding patient groups.
They are more commonly directed against factor VIII (FVIII) or von Willebrand factor leading to acquired hemophilia A or acquired von Willebrand syndrome, respectively.
Therefore, we recruited N = 31 consecutive patients with severe AS and performed a high-resolution Western blot with densitometrical band quantification to characterize the von Willebrand factor (VWF) multimeric structure and reevaluate the AVWS subtype classification.
Twelve patients, whose blood samples were analyzed for aVWS before CPB and immediately after discontinuation of CPB on a routine basis, were eligible for the analysis. von Willebrand factor antigen (VWF:Ag), ristocetin cofactor activity (VWF:RCo), collagen binding activity (VWF:CB), VWF:multimers and factor VIII activity (FVIII:C) were determined.
In this article, we review the evidence showing that VWF is involved in blood vessel formation, discuss the role of VWF high-molecular-weight multimers in regulating angiogenesis, and review the value of studies on BOEC in developing a precision medicine approach to validate novel treatments for angiodysplasia in congenital VWD and acquired von Willebrand syndrome.
Thrombocytopenia, hemolysis, factor XIII deficiency and acquired von Willebrand syndrome (loss of high-molecular-weight von Willebrand factor multimers) were typical findings, and the patients spontaneously recovered after discontinuation of the extracorporeal system.
This study was performed to determine the onset of AVWS after implantation and the recovery of von Willebrand factor (VWF) parameters after explantation of ECMO in a large cohort of patients.
Hypothyroidism leads to a higher incidence of acquired von Willebrand's syndrome and with increasing levels of free thyroxine, levels of fibrinogen, factor VIII and von Willebrand factor, amongst others, increase gradually, to the extent that they may lead to symptomatic venous thromboembolism in patients with hyperthyroidism.
Impaired binding of Von Willebrand factor (VWF) to platelets and to collagen due to acquired Von Willebrand syndrome (AVWS) is associated with support from a ventricular assist device (VAD) and can contribute to bleeding tendencies in patients with VADs.
Methods VWD evaluations for patients with LVAD or TAH (2013-14) were retrospectively analyzed and included: VWF activity (ristocetin cofactor, VWF:RCo), VWF antigen (VWF:Ag), ratio of VWF:RCo to VWF:Ag, and quantitative VWF multimeric analysis.
The ORs of VWF:CB/VWF:Ag < 0.7 (a marker of acquired von Willebrand syndrome) in the UC and CD groups were 11.9 (95%CI: 4.4-32.4) and 13.3 (95%CI: 4.6-38.1), respectively.
We report a case of severe autoimmune AVWS in a woman with SLE who presented with clinical and laboratory features of type 3 VWD (undetectable VWF antigen, ristocetin cofactor activity, and VWF multimers).
This review outlines the pathobiology of VWF disruption in the context of VADs as well as current diagnostic and management strategies of the associated acquired von Willebrand disease.
This ELISA was assessed successively in a LVAD-model, healthy subjects (n=39), acquired TTP-patients (n=4), VWD-patients (including VWD-2A(IIA), n=22; VWD-2B, n=26; VWD-2A(IIE), n=21; and VWD-1C, n=8) and in AVWS-patients (AS, n=9; LVAD, n=9; and MGUS, n=8).
Hypothyroidism leads to a higher incidence of acquired von Willebrand's syndrome and with increasing levels of free thyroxine, levels of fibrinogen, factor VIII and von Willebrand factor, amongst others, increase gradually, to the extent that they may lead to symptomatic venous thromboembolism in patients with hyperthyroidism.