Test Background Von Willebrand disease (vWD) is the commonest inherited bleeding disorder, affecting up to 1 % of individuals, irrespective of gender or ethnicity. It comprises a number of types, all of which are characterised by a bleeding defect that resembles a platelet function defect, as platelet adhesion is impaired. The von Willebrand factor (vWF) also serves as a carrier protein for factor VIII and levels of factor VIII are often decreased when vWF levels are decreased. vWD is usually inherited as an autosomal dominant condition.
Clinical Indications Bleeding diathesis/hypocoagulopathy with presentations of epistaxis, menorrhagia and GI haemorrhaging Differential diagnosis of haemophilia and other forms of bleeding diathesis
Reference Range See Factor Assays for the Factor VIII reference ranges and Collagen Binding assay for appropriate range also
Sample Required 3 x 2.7 mL sodium citrate (pale blue top) adults3 x 1.8 mL sodium citrate (pale blue top) paediatrics
Turnaround Time 14 days
Notes
Special handling: avoid prolonged stasis during venepuncture. Sample must be received by lab within 4 hours of collection. Please note: samples will be rejected if underfilled or overfilled.
Adult Reference Range:
Note: The reference ranges for use on patients over the age of 16 years, has been locally verified in accordance with CLSI Guideline EP28-A3c through evaluation on representative normal individuals across the sites to reflect our patient population.
Data sourced via Stago from:
Monagle P. et al. Thromb Haemost 2006; 95: 362-372.
Summerhayes R. et al. J Thromb Haemost, 2007; 5, Supp 2: P-M-105.
Summerhayes R. et al. J Thromb Haemost, 2007; 5, Supp 2: P-S-397.
Paediatric Reference Range
Note: Due to the complexity of collecting blood samples for analysis on normal neonates and paediatric patients, the reference ranges for use on patients up to 16 years of age have been taken from published data, from a research study using comparable methodology and equipment as that currently employed in our organisation. Please contact the laboratory for coagulation paediatric ranges.
Data sourced via Stago from:
Monagle P. et al. Thromb Haemost 2006; 95: 362-372.
Summerhayes R. et al. J Thromb Haemost, 2007; 5, Supp 2: P-M-105.
Summerhayes R. et al. J Thromb Haemost, 2007; 5, Supp 2: P-S-397.