Patients with monoclonal gammopathies of uncertain significance (MGUS) may develop an acquired bleeding disorder similar to congenital von Willebrand disease, called acquired von Willebrand syndrome (AvWS). In these patients, measures to improve hemostasis are required to prevent or treat bleeding episodes. We diagnosed 10 patients with MGUS and AvWS: 8 had IgGkappa (3) or lambda (5) MGUS and 2...

OBJECTIVE The metalloprotease ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) regulates the size of von Willebrand factor multimers. A deficiency in ADAMTS13 activity is associated with the life-threatening disease thrombotic thrombocytopenic purpura (TTP). The vast majority of patients have acquired TTP, where circulating anti-ADAMTS13 autoantibodie...

A murine monoclonal antibody directed at or near a platelet membrane receptor for the von Willebrand factor was produced by the hybridoma technique. Purified F(ab')2 fragments and/or intact antibody completely blocked the agglutination of platelets induced by both ristocetin and bovine von Willebrand factor and the binding of von Willebrand factor antigen to platelets. The antibody also decreas...

Abstract Recent studies have reported that patients with von Willebrand disease treated perioperatively a factor (VWF)/factor VIII (FVIII) concentrate ratio of 2.4:1 (Humate P/Haemate P) often present VWF and/or FVIII levels outside prespecified target necessary to prevent bleeding. Pharmacokinetic (PK)-guided dosing may resolve this problem. As clinical guidelines increasingly recommend aiming...

We have investigated whether von Willebrand factor, ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13), and D-Dimer were associated with different levels of renal function in patients with type 1 diabetes. Patients were classified according to level of renal function through estimated glomerular filtration rate: ≥90 and <130mL/min/1,73m2, n=52 (control gr...

The antibiotic ristocetin only aggregates platelets in the presence of plasma von Willebrand factor. Platelets from patients with Bernard-Soulier syndrome do not aggregate upon addition of ristocetin although, in contrast to von Willebrand's disease, plasma levels of factor VIII complex (factor VIII clotting activity, von Willebrand factor activity, and von Willebrand antigen) are normal. The m...

Precipitating antibodies to factor VII/von Willebrand factor can develop in patients with severe homozygous-like von Willebrand's disease following multiple transfusions with blood derivatives. This study of 4 patients treated with cryoprecipitate for 13 different bleeding episodes demonstrates that the occurrence of such antibodies interferes with the management of the disease. The control of ...