Factor XI Inhibitor Evaluation, Plasma
Use
Detection and quantitation of inhibitor to coagulation factor XI. It helps in diagnosing conditions in patients with congenital factor XI deficiency (hemophilia C) or after infusion of plasma or factor XI concentrates. It is not useful for detecting lupus-like anticoagulant inhibitors or non-specific circulating anticoagulants.
Special Instructions
Fasting for 8 hours is preferred. Patients should not be on anticoagulants such as Coumadin, heparin, direct thrombin inhibitors, or direct factor Xa inhibitors. Specimens must be double-centrifuged to avoid platelet contamination, and all vials should be shipped together. Each coagulation assay requires its own vial. The test is not orderable for patients in NY state since it's already NY state approved.
Limitations
The test is limited by its inability to detect lupus-like anticoagulant inhibitors or non-specific circulating anticoagulants. Potent lupus-like anticoagulant may cause false-positive results for specific factor inhibitors such as factor VIII or IX.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 96453-6
- 3226-8
- 69049-5
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
3 mL in 3 plastic vials, each containing 1 mL
Minimum Volume
2 Plastic vials, each containing 1 mL
Container
Light-blue top (3.2% sodium citrate) for collection, Polypropylene plastic vials for submission
Collection Instructions
Specimen must be collected prior to factor replacement therapy. Centrifuge, transfer all plasma into a plastic vial, centrifuge again. Aliquot plasma (1-2 mL per aliquot) into 3 separate plastic vials. Freeze plasma immediately at -20°C, ideally at -40°C or below.
Patient Preparation
Fasting for 8 hours preferred; do not take Coumadin, heparin, direct thrombin inhibitors, or direct factor Xa inhibitors.
Storage Instructions
Freeze plasma immediately at -20°C or ideally at -40°C or below.
Causes for Rejection
Gross hemolysis, gross lipemia, gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14 days |