Factor II Activity
Also known as: Prothrombin
Use
Evaluate an isolated prolonged PT or when there is prolongation of both the aPTT and PT and to document specific factor II deficiency6-8
Special Instructions
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. Refer to Coagulation Collection Procedures for directions. Ideally, the patient should not be on anticoagulant therapy. Avoid warfarin therapy for two weeks prior to the test and heparin, direct Xa, and thrombin inhibitor therapies for about three days prior to testing.
Limitations
Direct Xa or thrombin inhibitor therapy may cause factitiously low results. Potential interactions with oral anticoagulants or vitamin K deficiency should be considered. Severe deficiencies or inhibitors can impact the results, necessitating confirmatory testing or correlation with clinical findings. Factor II activity in excess of 115% could increase thrombosis risk, and the presence of lupus anticoagulants might require additional investigation to rule out false positives or negatives in coagulation assays.
Methodology
Other
Biomarkers
LOINC Codes
- 3289-6
- 3289-6
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tube
Collection Instructions
Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion. The sample should be mixed immediately by gentle inversion at least six times. A discard tube is required when using a winged blood collection set.
Patient Preparation
Ideally the patient should not be on anticoagulant therapy. Avoid warfarin therapy two weeks prior and heparin, direct Xa, and thrombin inhibitor therapies three days prior.
Storage Instructions
Freeze.
Causes for Rejection
Severe hemolysis; improper labeling; clotted specimen; specimen diluted with IV fluids; samples thawed in transit; improper sample type; sample out of stability
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 28 days |
Other tests from different labs that may be relevant