von Willebrand Factor Activity (Ristocetin Cofactor)
0030250
 
Ordering Recommendation
Order in conjunction with von Willebrand Factor Antigen (0030285) and Factor VIII Activity (0030095) as part of initial workup of suspected von Willebrand disease.
Mnemonic
RCF
Methodology
Platelet Agglutination
Performed
Mon-Sat
Reported
1-3 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.  
Specimen Preparation
Transfer 1.5 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)  
Storage/Transport Temperature
CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.  
Unacceptable Conditions
Serum. Hemolyzed or non-frozen specimens.  
Remarks
 
Stability
Ambient: 4 hours; Refrigerated: Unacceptable; Frozen: at -20°C: 3 months; Frozen at -70°C: 6 months  
Reference Interval
0-6 years: 51-215%
7-9 years: 52-176%
10-11 years: 60-195%
12-13 years: 50-184%
14-15 years: 50-203 %
16-17 years: 49-204%
18 years and older: 51-215%
Interpretive Data
Note
CPT Code(s)
85245
Components
Component Test Code*Component Chart Name
0030250von Willebrand Factor, Activity (RCF)
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, contact interface support at interface.support@aruplab.com.
Cross References
  • RCF
  • Ristocetin Cofactor, Plasma
  • von Willebrand Factor (vWF) Activity
  • von Willebrand Factor Antigen, Plasma
  • VWF:Ag
  • VWF:Rco