Factor IX Inhibitor Profile, Comprehensive
Also known as: Bethesda Titer
Use
Confirmation and characterization of factor IX inhibitor
Special Instructions
Citrated plasma samples must be collected by the double centrifugation method to maintain proper blood to anticoagulant ratios and ensure accurate results. It is important to submit separate frozen specimens if multiple tests are requested to avoid delays in turnaround time.
Limitations
Residual coagulation factor activity can falsely lower the Bethesda titer result. Lupus anticoagulant activity and the presence of antithrombotic agents that function as inhibitors should be ruled out prior to testing to avoid false positives. Furthermore, some inhibitors may fully neutralize factors in less than two hours and autoimmune inhibitors with second order kinetics cannot be accurately measured by the Bethesda titer system.
Methodology
Immunoassay (Other)
Biomarkers
LOINC Codes
- 96459-3
- 14979-9
- 5946-9
- 43734-3
- 30323-0
- 44950-4
- 3187-2
- 3185-6
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
6 mL (2 mL in each of three tubes)
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. Evacuated collection tubes must be filled to completion. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette. Deliver to a plastic transport tube, cap, and recentrifuge for 10 minutes. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested.
Patient Preparation
The patient should not be anticoagulated. 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 | Stable for four hours |