VON WILLEBRAND FACTOR ANTIGEN

Code
000.0000
Name
VON WILLEBRAND FACTOR ANTIGEN
Category
None
Department
Send-Out
Start Date
Expiration Date
Synonyms
CPT Codes
85246
Site
SBMF
Reference Test
25188
ATLAS Test Code

Specimen Information

Type

Blue, Citrate Platelet-poor plasma (PPP)

Volume

2.0 mL (Two aliquots, 1.0 mL each)

Transport Info

Separate plasma from cells immediately
• Promptly centrifuge 15 minutes
• Carefully transfer plasma portion of sample to separate plastic tube using plastic pipette
• Centrifuge transferred plasma sample again to produce platelet-poor plasma (PPP)
• Use second plastic pipette to carefully transfer PPP sample into plastic aliquot tubes
Frozen

Fasting Required?
False
Patient Instructions

Reference Range

50-160% of Factor VIII Related Antigen
Patients with vonWillebrand’s disease have been reported with normal levels of Factor VIII Related Antigen. The diagnosis of vonWillebrand’s syndrome should not be made based on this test alone.Patients with suspected vonWillebrand’s should be tested on several different occasions to the variability in the test results observed. Fluctuations have been noted in the levels of the immunologically detectable protein as well as in the functional activity in the Factor VIII molecule.

Methodology

Immunoturbidimetric Assay

Clinical Significance

Differentiate patients with von Willebrand's disease from those with Hemophilia A and in detecting carriers of Hemophilia A
vonWillebrand factor plays an important role both in primary hemostasis, during which it is involved in the adhesion of platelets to the vascular sub-endothelium in the formation of thrombi, and in the coagulation process by acting as a carrier protein for factor VIII (antihemophilic factor A). There is vWF function as described above and there is vonWillebrand disease. The vWF disease is the most common inherited bleeding disorder. Clinically, it is often characterized by mucocutaneous hemorrhages. Type 1 disease corresponds to a quantitative deficiency (most frequent).Type 2 disease refers to qualitative deficiency of vWF and Type 3 disease is characterized by a virtual total absence of vWF in both the plasma and cellular compartments. vWF deficiencies may be associated with several clinical states such as myeloma, lymphoma, systemic lupus erythematosus, hypothyroidism, etc. These cases may be referred to as acquired vonWillebrand diseases.

Back