von Willebrand Disease - VWD

von Willebrand disease (VWD) is the most common congenital bleeding disorder. VWD may result from either a quantitative (types 1 and 3) or qualitative (type 2) abnormality of von Willebrand factor (VWF).

  • Diagnosis
  • Algorithms
  • Screening
  • Monitoring
  • Background
  • Lab Tests
  • References
  • Related Topics
  • Videos

Indications for Testing

  • Initial evaluation (personal/family history and physical examination) suggestive of a bleeding disorder

Laboratory Testing

  • Initial testing
    • Important to evaluate other potential causes of mucocutaneous bleeding
      • Disorders of the liver, kidneys, blood, or bone marrow
      • Undiagnosed thrombocytopenia (type 2B and platelet-type von Willebrand disease [PT-VWD] may have thrombocytopenia)
      • Anti-platelet medications (aspirin, NSAIDs, clopidogrel, others)
    • Initial evaluation for a bleeding disorder (to exclude other coagulation defects)
      • CBC with platelet count
        • VWD type 2B and platelet type may have thrombocytopenia
      • Prothrombin time/partial thromboplastin time (PT/PTT)
      • Fibrinogen, or thrombin time (TT)
        • Fibrinogen or TT are optional (ASH, 2012)
    • In the presence of a strong history of mucocutaneous bleeding, tests for VWD could be considered as part of the initial evaluation
    • VWD may prolong the PTT – it is a carrier for factor VIII
    • PTT often normal in VWD
    • If PTT abnormal, PTT mixing studies may be useful in the initial evaluation to differentiate factor deficiency from inhibitor as cause of prolonged PTT
      • In VWD, decreased factor VIII may result in a prolonged PTT that corrects with mixing study
    • Refer to Anticoagulants and Possible Coagulation Test Interferences table for possible interferences with coagulation parameters based on the specific drug administered
  • VWD testing
    • Initial testing
      • VWF antigen (VWF:Ag) – measures the amount of protein
      • VWF ristocetin cofactor activity (VWF:Rco) – measures the function of the protein
      • Factor VIII activity – measures amount of protein
    • Selected special testing  – usually used for subtyping
      • Multimeric analysis
        • Shows the distribution of different-sized multimers
        • Not recommended for initial screening except in suspected cases of acquired VWD
          • Multimeric abnormalities may be the only abnormality identified in some cases of acquired VWD
        • Types 2A, 2B, and platelet type and acquired cases have abnormal multimeric distributions
        • Abnormal result defined as absence of high- and/or intermediate-molecular-weight multimers
      • VWF:Rco to VWF:Ag ratio
        • VWD types 2A, 2B, platelet type, and 2M characteristically have lower levels of VWF:Rco compared to VWF:Ag, resulting in a decreased VWF:Rco-to-VWF:Ag ratio
          • Ratios <0.7 or <0.6 suggest one of these qualitative subtypes
      • Ristocetin-induced platelet aggregation (RIPA)
        • Not sensitive to mild forms of VWD (most type 1 cases)
        • Typically used to confirm and distinguish between type 2 subtypes (2A, 2B/platelet type)
          • Low-dose RIPA detects abnormally increased aggregation seen in type 2B and platelet-type VWD
      • vWF:platelet binding
        • Detects abnormally increased platelet binding seen in type 2B
        • Differentiates type 2B from platelet-type VWD
          • Test is normal in platelet type
      • VWF:FVIII binding
        • Differentiates between type 2N and hemophilia A
          • Test is normal in hemophilia A
      • Genetic/molecular testing
        • Confirm phenotypic diagnosis of VWD where it affects therapeutic decisions
        • Distinguish VWD type 2B from platelet-type VWD
        • Distinguish VWD type 2N from hemophilia A
        • Evaluate family members of individuals with known mutations
  • Factors that may affect laboratory testing in VWD
    • VWF values fluctuate over time
      • If clinical suspicion is high and values are normal, repeat testing may be required for diagnosis
    • With mild disease – may have normal test results
    • Mildly decreased VWF values are not diagnostic
    • VWF and FVIII are acute phase reactants and may be elevated by stress, illness, or medications (false-negative)
      • Conditions include pregnancy, estrogen-containing medications, inflammation, infection, liver disease, malignancy, exercise, stress/anxiety, and trauma (including traumatic venipuncture)
    • VWF values and FVIII activity are affected by ABO blood type
      • Type O individuals have ~25% lower values than non-ABO individuals
    • VWF and FVIII results can be affected by preanalytical variables such as collection technique, specimen preparation, storage, and transport
      • Cold storage of citrated whole blood prior to centrifugation
        • Can markedly reduce VWF and FVIII values
        • Can also induce multimeric abnormalities
        • Can lead to incorrect diagnosis or subtyping

Differential Diagnosis

  • Population screening not recommended
  • Screening when other family members have VWD – no specific recommendations but may be considered depending on clinical scenario
  • In patients initially receiving desmopressin
    • Based on therapeutic trial in nonbleeding state after clinical use
    • Measure von Willebrand panel at baseline and 1-2 hours after administering desmopressin (depending on preparation used and desired protocol)
    • Additional 2-4 measurements in patients with previous history of poor response to evaluate for decreased half-life due to rapid clearance
  • After major surgery in patients receiving desmopressin
    • Monitoring with VWF:RCo and FVIII until bleeding risk is reduced
    • Additional postoperative desmopressin, based on bleeding and lab values
    • Monitoring of electrolytes if numerous doses of desmopressin given
    • In patients with cardiovascular disease, desmopressin has rarely precipitated myocardial infarction or stroke; consider replacement with VWF concentrates rather than desmopressin in patients with thrombotic risk factors


  • Incidence
    • May be as high as 1/100
  • Sex – M:F, equal
  • Ethnicity – more common in Caucasians


  • VWF is a large multimeric plasma protein that mediates adherence of platelets to the vessel wall at sites of injury and is a carrier for factor VIII
  • VWD results from VWF deficiency or dysfunction
  • Acquired VWD is associated with other conditions

Clinical Presentation


Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

Prothrombin Time 0030215
Method: Electromagnetic Mechanical Clot Detection

Partial Thromboplastin Time 0030235
Method: Electromagnetic Mechanical Clot Detection

von Willebrand Panel 0030125
Method: Electromagnetic Mechanical Clot Detection/Platelet Agglutination/Microlatex Particle-Mediated Immunoassay

von Willebrand Panel with Reflex to von Willebrand Multimeric Analysis 2003387
Method: Electrophoresis/Clotting/Microlatex Particle-Mediated Immunoassay/Platelet Agglutination


VWF and FVIII are acute phase reactants that may be elevated by stress or illness

Normal values do not exclude VWD

VWF and FVIII values are affected by ABO blood type (lower in blood type O)


2012 Clinical Practice Guideline on the Evaluation and Management of von Willebrand Disease (VWD). American Society of Hematology. Washington DC [Revised : 2012; Accessed: Dec 2016]

Keeney S, Bowen D, Cumming A, Enayat S, Goodeve A, Hill M, UK Haemophilia Centre Doctors' Organisation (UKHCDO). The molecular analysis of von Willebrand disease: a guideline from the UK Haemophilia Centre Doctors' Organisation Haemophilia Genetics Laboratory Network. Haemophilia. 2008; 14(5): 1099-111. PubMed

Nichols WL, Hultin MB, James AH, Manco-Johnson MJ, Montgomery RR, Ortel TL, Rick ME, Sadler JE, Weinstein M, Yawn BP. von Willebrand disease (VWD): evidence-based diagnosis and management guidelines, the National Heart, Lung, and Blood Institute (NHLBI) Expert Panel report (USA). Haemophilia. 2008; 14(2): 171-232. PubMed

The Diagnosis, Evaluation, and Management of von Willebrand Disease. National Heart, Lung, and Blood Institute. Bethesda, MD [Accessed: Feb 2017]

General References

Castaman G, Hillarp A, Goodeve A. Laboratory aspects of von Willebrand disease: test repertoire and options for activity assays and genetic analysis. Haemophilia. 2014; 20 Suppl 4: 65-70. PubMed

Favaloro EJ, Bodó I, Israels SJ, Brown SA. von Willebrand disease and platelet disorders. Haemophilia. 2014; 20 Suppl 4: 59-64. PubMed

Federici AB. Clinical and laboratory diagnosis of VWD. Hematology Am Soc Hematol Educ Program. 2014; 2014(1): 524-30. PubMed

Franchini M, Montagnana M, Lippi G. Clinical, laboratory and therapeutic aspects of platelet-type von Willebrand disease. Int J Lab Hematol. 2008; 30(2): 91-4. PubMed

James PD, Lillicrap D. von Willebrand disease: clinical and laboratory lessons learned from the large von Willebrand disease studies. Am J Hematol. 2012; 87 Suppl 1: S4-11. PubMed

Lillicrap D. Von Willebrand disease - phenotype versus genotype: deficiency versus disease. Thromb Res. 2007; 120 Suppl 1: S11-6. PubMed

Mohri H. Acquired von Willebrand syndrome: features and management. Am J Hematol. 2006; 81(8): 616-23. PubMed

Ng C, Motto DG, Di Paola J. Diagnostic approach to von Willebrand disease. Blood. 2015; 125(13): 2029-37. PubMed

Robertson J, Lillicrap D, James PD. Von Willebrand disease. Pediatr Clin North Am. 2008; 55(2): 377-92, viii-ix. PubMed

Yawn B, Nichols WL, Rick ME. Diagnosis and management of von Willebrand disease: guidelines for primary care. Am Fam Physician. 2009; 80(11): 1261-8. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Desai DS, Lyon E, Rodgers GM, Jama MA, Wallentine SL, Smock KJ. Elderly female with a personal and family history of a bleeding disorder Clin Chem. 2015; 61(7): 909-12. PubMed

Flanders MM, Crist RA, Roberts WL, Rodgers GM. Pediatric reference intervals for seven common coagulation assays. Clin Chem. 2005; 51(9): 1738-42. PubMed

Medical Reviewers

Last Update: October 2017