The von Willebrand factor measurement is used in the differential diagnosis of the various forms of von Willebrand disease and haemophilia A from von Willebrand disease and in the monitoring of treatment of von Willebrand disease.
Von Willebrand disease is an autosomal recessive disorder inherited from the predominant type and due to a defect in coagulation factor VIII. This is a blood clotting disorder that results in varying degrees of bleeding abnormalities. Coagulation factor VIII has three properties, pre-coagulation activity (the von Willebrand circulating factor has recently been identified as a factor that may initiate platelet adhesion), antigenic activity and von Willebrand factor activity. In haemophilia A and haemophilia A vectors, von Willebrand factor activity is normal, but in von Willebrand disease, factor measurement is typically low (i.e., <40% of control sample activity).
The test helps distinguish between haemophilia A (classical haemophilia) and von Willebrand's disease when other coagulation tests are unclear.
Von Willebrand factor values may increase by 2-3 times during pregnancy. Increased values may also occur during stress, infection, inflammatory conditions, postoperatively, or after intense physical activity. Patients with blood group C may have up to 30% lower von Willebrand factor values than patients with other blood groups.
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. Correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.