Answer
Due to autoimmune clearance or inhibition, as follows:
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Lymphoproliferative diseases (lymphoma, leukemia)
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Monoclonal gammopathies (multiple myeloma, Waldenstrom macroglobulinemia)
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Systemic lupus erythematosus and other autoimmune disorders
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Some cancers (Wilms tumor, Ewing sarcoma, carcinoma)
Due to increased shear-induced proteolysis (vWF:Ag is often normal or even elevated), as follows:
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Ventricular septal defect
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Aortic stenosis
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Primary pulmonary hypertension
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Extracorporeal life support
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Due to other or unknown mechanisms, as follows:
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Hypothyrosis
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Drug-induced (hydroxyethyl starch, valproic acid)
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Myeloproliferative diseases (polycythemia, thrombocythemia)
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Angiodysplasia, glycogen storage disease
Increased vWF:Ag level and vWF:RCo activity are observed in acute phase reactions, as follows:
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Stress and extensive exercise
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Inflammation
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Cancer
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Obesity
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Postoperative period
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Diabetes
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Atherosclerosis and atherothrombosis
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Pregnancy
