What is von Willebrand disease?
According to the Centers for Disease Control and Prevention (CDC), von Willebrand disease (VWD) is the most common bleeding disorder, affecting up to 1% of the US population, or more than 14 million Americans.
Because most cases of VWD are mild, many people are asymptomatic and do not know they have a defect in their von Willebrand factor (VWF) gene.
VWD is equally likely to affect men and women, though because of reproductive factors, women are more likely to be diagnosed. Nevertheless, according to a CDC survey (N=75), it takes an average of 16 years from the onset of symptoms for women to receive an accurate diagnosis.
Diagnostic considerations for von Willebrand disease
Each patient needs individualized assessment based on his or her specific history, signs, and symptoms.
- One diagnostic approach is based on a personal bleeding history that is translated into a bleeding score, which can be used with laboratory tests to help diagnose von Willebrand disease
- A family history that is positive for an established bleeding disorder is frequently not present for persons who have milder forms of von Willebrand disease
Proper testing for early diagnosis of VWD can optimize treatment and help patients live a more normal, active life.
- Identification of VWD type and subtype requires multiple laboratory tests for adequate management of the condition
Adapted from The Diagnosis, Evaluation and Management of von Willebrand disease. Full Report. National Heart, Lung, and Blood Institute. NIH Publication No. 08-5832. 2007.
- If the initial clinical evaluation suggests a bleeding disorder, initial hemostasis tests should be ordered, followed by or along with initial VWD assays indicated in the algorithm above. Referral to a hemostasis specialist is appropriate for help with interpreting and ordering repeat or specialized tests.
- Correction in the PTT mixing study immediately and after 2-hour incubation removes an FVIII inhibitor from consideration. Investigation of other intrinsic factors and lupus anticoagulant may also be indicated.
CBC: complete blood count. PT: prothrombin time. PTT: partial thromboplastin time. RIPA: ristocetin-induced platelet aggregation. TT: Thrombin time. VWF:Ag: VWF antigen. VWF:RCo: VWF ristocetin cofactor activity.