Factor V Inhibitor Profile, Comprehensive
Also known as: Bethesda Titer
Use
Confirmation and characterization of factor V inhibitor
Special Instructions
Sample should be collected in a blue-top (sodium citrate) tube by double centrifugation to ensure proper mixing of blood and anticoagulant. The plasma must be frozen immediately and maintained frozen until tested. Separate samples should be provided if multiple tests are requested on frozen specimens to avoid delays.
Limitations
The presence of direct Xa or thrombin inhibitor anticoagulant therapy can lead to false-positive results. Residual coagulation factor may falsely lower results. Lupus anticoagulant activity must be ruled out before testing for factor inhibitors. Autoimmune inhibitors cannot be accurately measured due to their kinetic properties in the Bethesda titer system. Repeated assays are needed for patients on inhibitor suppression therapy to manage dosage and determine the responder status, distinguishing between low and high responders.
Methodology
Automated Analyzer
Biomarkers
LOINC Codes
- 96458-5
- 5902-2
- 5959-2
- 33356-7
- 33884-8
- 14979-9
- 3193-0
- 3191-4
Result Turnaround Time
3-5 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
6 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tubes
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. Mix immediately by gentle inversion at least six times. Freeze immediately and maintain frozen until tested.
Patient Preparation
The patient should not be on anticoagulant therapy. Do not draw from an arm with a heparin lock or heparinized catheter.
Storage Instructions
Freeze. Stable at room temperature for four hours.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 hours |