The complex multimeric composition of factor VIII/von
willebrand factor.
Hajage et al., "ADAMTS-13 and von
Willebrand factor predict venous thromboembolism in patients with cancer," Journal of Thrombosis and Haemostasis, vol.
Von
Willebrand 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 disease.
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).