Factor V Inhibitor Evaluation, Plasma
Use
Factor V inhibitors can occur in patients with congenital factor V deficiency after transfusion of fresh frozen plasma, however, they more commonly occur spontaneously in previously healthy older patients who have no underlying diseases. Detection and quantitation of inhibitors against coagulation factor V is useful. Topical bovine thrombin or fibrin glue, which contain bovine thrombin and factor V, are commonly used in surgery for topical hemostasis and can result in development of anti-bovine thrombin/factor V inhibitors that cross-react with human thrombin and factor V. Associations include antibiotics, transfusions, and malignancies.
Special Instructions
This test is for factor V inhibitors only. If the presence or type of inhibitor is unknown, first order APROL / Prolonged Clot Time Profile, Plasma, except for patients with known hemophilia A or B. When screening studies are needed for patients with known hemophilia A or B, order 8INHE / Factor VIII Inhibitor Evaluation, Plasma; or 9 INHE / Factor IX Inhibitor Evaluation, Plasma; respectively.
Limitations
This test is not useful for the detection of a lupus-like circulating anticoagulant inhibitor, a nonspecific circulating anticoagulant, or other inhibitors that are not specific for coagulation factors. Occasionally, a potent lupus-like anticoagulant may cause false-positive testing for a specific factor inhibitor.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 96458-5
- 3193-0
- 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 containing1 mL
Container
Polypropylene plastic vials
Collection Instructions
Specimen must be collected prior to factor replacement therapy. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again. Aliquot plasma (1-2 mL per aliquot) into 3 separate plastic vials leaving 0.25 mL in the bottom of centrifuged vial. Freeze plasma immediately (no longer than 4 hours after collection) at -20 degrees C or, ideally, -40 degrees C or below.
Patient Preparation
Fasting: 8 hours, preferred but not required. Patient must not be receiving Coumadin (warfarin) or heparin therapy.
Causes for Rejection
Gross hemolysis, Gross lipemia, Gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14 days |