Factor VIII Inhibitor Profile, Comprehensive
Also known as: Bethesda Titer
Use
Confirmation and characterization of factor VIII inhibitor
Special Instructions
The test involves mixing patient plasma with normal plasma and assessing the presence and level of factor VIII inhibitors which may vary based on residual coagulation factor activity, lupus anticoagulant activity, and the presence of antithrombotic agents. Accurate sample collection using citrated plasma, ensuring proper blood to anticoagulant ratios, and specific storage conditions are critical for precise results.
Limitations
Residual coagulation factors or lupus anticoagulant activity may cause false negative results in the Bethesda titer assay. The presence of antithrombotic agents should be ruled out to avoid falsely positive results. Some factor inhibitors may neutralize factors rapidly, and autoimmune inhibitors displaying second order kinetics might not be accurately measured using this system.
Methodology
Other
Biomarkers
LOINC Codes
- 96456-9
- 14979-9
- 5946-9
- 43734-3
- 30323-0
- 3209-4
- 3204-5
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
3 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tube
Collection Instructions
Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Ensure the tubes are filled to completion and mixed immediately by gentle inversion. Use a discard tube when using a butterfly needle. Double centrifugation is required, and plasma should be transferred into a Labcorp PP transpak frozen purple tube and stored frozen.
Patient Preparation
The patient should not be anticoagulated. Do not draw from an arm with a heparin lock or heparinized catheter.
Storage Instructions
Freeze
Causes for Rejection
Not specified.