The fourth type, which is
Acquired Von Willebrand disease, occurs after an individual is diagnosed with some autoimmune disease, say lupus, or any cardio vascular disease, or any type of cancer.
Monitoring for new thrombosis,
acquired von Willebrand disease (VWD), and/or disease-related major bleeding (in patients with ET) and management of cardiovascular risk factors are recommended for all patients.
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. Immunofluorescence to find an underlying etiology was suggestive of MGUS.