The complex multimeric composition of factor VIII/von willebrand
Hajage et al., "ADAMTS-13 and von Willebrand
factor predict venous thromboembolism in patients with cancer," Journal of Thrombosis and Haemostasis, vol.
syndrome is a deficiency or dysfunction of von Willebrand
factor (vWF), a protein with binding sites for platelets, collagen, and factor VIII that "serves as a bridge between platelets and injury sites in vessel walls" and "protects factor VIII from rapid proteolytic degradation," Dr.
Studies have reported that half of the epistaxis patients had blood group O and blood group O was associated with a lower expression of vWF (Von Willebrand
factor) [10, 11] as compared with non-O groups.
There are 1,500 registered cases of hemophilia in the Philippines and 30 of the Von Willebrand
disease, said Villanueva, citing data from the Philippine Hemophilia Foundation.
Human von Willebrand
Factor Labeling with IgG:FITC and VWF-Platelet Solution.
Interestingly, on cultured ECs, the antiinflammatory effect of rADAMTS13 was reversed by recombinant von Willebrand
factor (rVWF), suggesting that VWF mediates the effect of ADAMTS13 on vascular inflammation.
Laboratory evaluation confirmed type 1 VWD with ristocetin cofactor activity of 38%, von Willebrand
antigen level of 41%, factor VIII level of 60%, and a normal von Willebrand
factor multimer distribution.
Types of bleeding disorders that may present with epistaxis include coagulation factor deficiencies, Von Willebrand
disease, and several rare inherited platelet function disorders associated with defects in specific aspects of platelet function (Table 1).
Further workup with coagulation studies showed decreased factor VIII, vWF antigen, and vWF: ristocetin cofactor assay, and negative Bethesda assay, indicating acquired von Willebrand
Recognition of acquired von Willebrand
syndrome (AVWS) and its many causes, including malignancy, is important and a high level of suspicion for AVWS must be maintained in the workup of bleeding disorders.
Objective: To determine the frequency of Von Willebrand
disease (vWD) in patients of heavy menstrual bleeding (HMB).