Decrease in the VWF:RoC and/or the VWF:Agn results will automatically reflex to von Willebrand multimers (CIEP), referred to LabCorp, at an additional charge.
Frozen - strict
Multimer samples are stabile for 14 days at -70°.
Refrigerated - NO
vWF:RoC - Activity by Ristocetin Cofactor
VWF:Ag - Turbidity of micro particle
FVIII:C - One stage clotting
|vWF:RCo||50 - 200%|
|vWF:AG||50 - 200%|
|FVIII:C||50 - 150%|
Von Willebrand factor activity levels are blood group specific with individuals of 'O' blood type showing lower von Willebrand activity levels than other blood groups.
Von Willebrand disease (VWD) is the most common inherited bleeding disorder. Clinically, it is often characterized by mucocutaneous hemorrhages. The three principle types of VWD are:
Acquired VWF deficiencies may be associated with several clinical states such as in myeloma, lymphoma, systemic lupus erythematosus, hypothyroidism, etc. These cases may be referred to as acquired von Willebrand diseases.
VWF is a protein involved in inflammation. Its level increases when there are damages of the vascular endothelium (post-operative period, infection, cancers, renal or hepatic disorders). Some authors have noted that high vWF levels are encountered during cardiovascular disorders, notably during some types of myocardial infarction.
Acquired von Willebrand Syndrome has been reported rarely with the use of griseofulvin, ciprofloxacin, tetracycline, thrombolytic agents and hydroxyethyl starch.