Von Willebrand disease diagnostic study of choice

There is no single diagnostic study of choice for the diagnosis of von Willebrand disease, but von Willebrand disease can be diagnosed based on screening tests followed by confirmatory tests. The screening tests for VWD that are selected by the National Heart, Lung, and Blood Institute include testing for vWF antigen, VWF ristocetin cofactor activity and factor VIII clotting activity. When one of the VWD screening test is abnormal, further confirmatory tests are performed to establish the correct diagnosis and determine the type of VWD. Genotyping is most beneficial for type 1 patients with vWF ≤30 IU/dL and those with type 2 or 3. Genotyping also detects a benign type of vWD (caused by the D1472H mutation which affects ristocetin binding but not vWF function).

There is no single diagnostic study of choice for the diagnosis of von Willebrand disease, but von Willebrand disease can be diagnosed based on screening tests followed by confirmatory tests.

The following screening tests for VWD are selected by the National Heart, Lung, and Blood Institute^[1]

• VWD screening tests
  • (VWF:Ag) VWF antigen
  • (VWF:RCo) VWF ristocetin cofactor activity
  • (FVIII:C) factor VIII clotting activity

When one of the VWD screening test is abnormal, the following tests should be performed to establish the correct diagnosis and determine the type of VWD.^[1]

• VWD Confirmatory Tests
  • VWF multimer distribution
  • (VWF:CB) VWF collagen binding
  • (VWF:PB) VWF platelet binding
  • (LD-RIPA) low-dose ristocetin-induced platelet aggregation
  • (VWF) FVIIIB
  • VWF gene sequencing

The following findings on performing VWD tests are confirmatory for von willebrand disease

VWF:Ag VWF antigen; VWF:RCo VWF ristocetin cofactor activity; FVIII:C factor 8 activity; VWF:CB VWF collagen binding LD-RIPA low-dose ristocetin-induced platelet aggregation; VWFpp VWF propeptide;

The prothrombin time (PT), activated partial thromboplastin time (aPTT), platelet count, Factor VIII activity, ristocetin cofactor (RCoF) activity concentration of vWF antigen (vWF:Ag) must be performed when:

• The patient presented with easy bruising, skin bleeding, prolonged oropharyngeal, gastrointestinal, uterine bleeding, prolonged bleeding after trauma or surgical procedure.
• If the initial tests are positive then the above mentioned confirmatory tests should be performed.
• Genotyping is most beneficial for type 1 patients with vWF ≤30 IU/dL and those with type 2 or 3.
• Genotyping also detects a benign type of vWD (caused by the D1472H mutation which affects ristocetin binding but not vWF function).

Von Willebrand disease may be diagnosed at any time if one or more of the following criteria are met:^[2]

• Positive family history
• Prominent mucocutaneous bleeding history
• Abnormal laboratory tests

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