Coagulation Factor II Activity Assay, Plasma
Use
The test is useful for diagnosing a congenital deficiency of coagulation factor II, which is rare, as well as evaluating acquired deficiencies due to liver disease, vitamin K deficiency, oral anticoagulant therapy, or antibody-induced deficiencies like those associated with lupus anticoagulant. It is also utilized to determine the stabilization of warfarin treatment in patients with nonspecific inhibitors, such as lupus anticoagulant, and to assess the degree of anticoagulation with warfarin, correlating with the level of protein S. Additionally, it helps investigate prolonged prothrombin time or activated partial thromboplastin time.
Special Instructions
Coagulation testing is highly complex, often requiring multiple assays and correlation with clinical information. A coagulation consultation is suggested. It is important that the patient is not receiving coumadin (warfarin) or heparin therapy at the time of specimen collection, or if not possible, this should be noted in the request form.
Limitations
Factor II is one of the last vitamin K-dependent coagulation factors to decrease after starting warfarin therapy and one of the last to return to normal when anticoagulation is discontinued. It may take 10 to 14 days for a return to baseline levels. Inaccurate results can occur if the specimen is contaminated with platelets, hence double-centrifuged plasma is critical to avoid spurious results.
New York Approved
Methodology
Automated Analyzer (Coagulation)
Biomarkers
LOINC Codes
- 3289-6
- 3289-6
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.5 mL
Container
Plastic vial
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 into a plastic vial, 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. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results. Each coagulation assay requested should have its own vial.
Patient Preparation
Patient must not be receiving coumadin (warfarin) or heparin therapy. If not possible for medical reasons, note on request.
Storage Instructions
Freeze plasma immediately at -20 degrees C or, ideally, -40 degrees C or below.
Causes for Rejection
Gross hemolysis, Gross lipemia, Gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14 days |