Search Tests
Search by Dept.
General Information
Alias: WF Assay, Ristocetin Cofactor Activity, Glycoprotein 1B Binding
Performed: Wednesday, 0700-1530
Turn Around Time: 1-7 days
CPT Codes: 85245
Performed By: Hematology
Notes:
Results not affected by Hgb up to 70 mg/dL, bilirubin up to 4.2 mg/dL, triglycerides up to 1020 mg/dL and Rheumatoid Factor (RF) up to 200 IU/mL. RF may produce overestimation of vWF activity.
Pediatric Reference Ranges are from the following publications:
1. Andrew M; Paes; Johnston M
Development of the hemostatic system in the neonate and young infant
American Journal of Pediatric Hematology/Oncology 1990; 12(1): 95-104
2. Andrew M, Vegh P, Johnston M, Bowker J, Ofosu F, Mitchell L.
Maturation of the hemostatic system during childhood.
Blood. 1992 Oct 15; 80(8):1998-2005.
Clinical Utility: Quantitative determination of von Willebrand Factor Activity aids in the diagnosis of von Willebrand Disease (VWD), which is probably the most common congenital bleeding disorder.
Unacceptable Conditions: QNS, clotted, hemolyzed, and/or turbid samples
Components
| Name |
Method |
Sex |
Age Range |
Ref. Range Low |
Ref. Range High |
Units |
| v Willebrand Factor |
Latex based immunoassay |
|
0 Minutes - Day 1 |
50.0 |
287.0 |
% |
| v Willebrand Factor |
Latex based immunoassay |
|
Day 1 - Day 4 |
50.0 |
287.0 |
& |
| v Willebrand Factor |
Latex based immunoassay |
|
Day 5 - Day 29 |
50.0 |
254.0 |
% |
| v Willebrand Factor |
Latex based immunoassay |
|
Day 30 - Day 89 |
50.0 |
246.0 |
% |
| v Willebrand Factor |
Latex based immunoassay |
|
Day 90 - Day 179 |
50.0 |
206.0 |
% |
| v Willebrand Factor |
Latex based immunoassay |
|
Day 180 - Day 364 |
50.0 |
197.0 |
% |
| v Willebrand Factor |
Latex based immunoassay |
|
1 Year - 5 Years |
60.0 |
120.0 |
% |
| v Willebrand Factor |
Latex based immunoassay |
|
6 Years - 10 Years |
44.0 |
144.0 |
% |
| v Willebrand Factor |
Latex based immunoassay |
|
11 Years - 16 Years |
46.0 |
153.0 |
% |
| v Willebrand Factor |
Latex based immunoassay |
|
17 Years - 150 Years |
40.3 |
163.4 |
% |
Specimen Requirements
| Type |
Container |
Volume |
Units |
Collection / Delivery |
Storage / Transport |
Off Campus |
| Blood |
Blue Na Citrate, 3mL |
Draw to fill line |
|
Send to Lab within 3 hrs of collection. |
Room Temperature |
Deliver to Logistics Hematology Lab via STAT courier |