The relationship between the multimeric size of factor VIII-von Willebrand factor (FVlll-vWF) and the support of platelet adhesion to subendothelium was studied in an annular perfusion chamber, employing human renal and umbilical arteries. Commercial factor VIII concentrates containing multimers of low molecular weight that had been shown not to correct the bleeding time upon infusion into pati...

Studies of the functional properties and intravascular survival of normal and desialylated human Factor VIIIlvon Willebrand factor protein have been performed. The purified normal protein, possessing both procoagulant activity and ristecetin-induced platelet-aggregating activity, contains 154 = 15 nmol of sialic acid/mg of protein and 28 f 3 mol of Sk&k acid/m01 of 200,000 molecular weight subu...

Type 2A Von Willebrand disease (VWD) is clinically identified by a loss of high and intermediate Von Willebrand factor (VWF) multimers resulting in a loss of platelet-dependent function. The majority of mutations that cause type 2A disease occur in the A2 domain and are grouped by their effects on cellular retention of VWF or the susceptibility of VWF to proteolysis by ADAMTS13. However, a few ...

The present studies demonstrate that platelets from patients with platelet-type von Willebrand disease show specific and saturable binding of asialo von Willebrand factor (AS-vWF) under conditions where such binding is not observed with normal platelets. Although specific binding of 125I-AS-vWF to formalin-fixed normal platelets could not be demonstrated, specific binding to fixed patient plate...

We studied 17 patients with moderate to mild type I von Willebrand's disease (vWd) and correlated the bleeding time with the plasma von Willebrand factor antigen (vWf Ag), the plasma vWf activity (ristocetin cofactor), the platelet vWf Ag, and the platelet vWf activity. We found an excellent correlation between the bleeding time and the platelet vWf activity and, to a lesser extent, between the...

AIMS To investigate the abnormality in platelet function in two patients with type I Gaucher's disease causing a chronic bleeding tendency despite normalisation of the platelet count after spleen removal. METHODS Routine laboratory methods were used to assess baseline coagulation. Platelet aggregometry was used to assess platelet responses to a range of agonists, and abnormalities were furthe...