Factor VIII Inhibitor Panel
Test Code
Clinical Significance
Factor VIII Inhibitor Panel - The presence of alloantibodies against factor VIII activity is a complication of treatment in hemophilia A, while the presence of autoantibodies may develop spontaneously in patients with acquired Factor VIII-C deficiency. The presence of Factor VIII inhibitor may lead to the neutralization (inactivation) of transfused or endogenous Factor VIII activity. The detection and magnitude of Factor VIII inhibitor is of great importance in the care of these patients. Factor VIII inhibitor Chromogenic assay provides a quick method for the detection of Factor VIII inhibitor with less sample volume.
Test Resources
Test Details
Factor VIII Activity, Clotting
If Factor VIII Inhibitor, Chromogenic Screen is Positive, then Nijmegen Assay will be performed at an additional charge (CPT code(s): 85335).
Methodology
Reference Range(s)
| Factor VIII Inhibitor, Chromogenic Screen | Negative |
| Factor VIII Activity, Clotting | 50-180 % normal |
Alternative Name(s)
Preferred Specimen(s)
2 mL plasma collected in 3.2% sodium citrate (light blue-top) in each of two separate tubes
Minimum Volume
1 mL (x2)
Collection Instructions
Submit a total of 4 mL (2 mL in each of 2 tubes).
Centrifuge light blue-top tube 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcl). Freeze immediately and ship on dry ice.
Note: Storage of whole blood at refrigerated temperatures prior to processing may lead to cryoprecipitate formation and falsely low Factor VIII and von Willebrand Factor studies.
Transport Container
Transport tube(s)
Transport Temperature
Frozen
Specimen Stability
- Room temperature: Unacceptable
- Refrigerated: Unacceptable
- Frozen: 14 days
Reject Criteria
Hemolysis • Received room temperature • Received refrigerated • Received thawed
Setup Schedule
Centrifuge light blue-top tube 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcl). Freeze immediately and ship on dry ice.
Note: Storage of whole blood at refrigerated temperatures prior to processing may lead to cryoprecipitate formation and falsely low Factor VIII and von Willebrand Factor studies.
Refrigerated: Unacceptable
Frozen: 14 days