Factor X Activity
Also known as: Stuart Prower Factor
Use
Evaluate an isolated, prolonged PT, evaluate prolongation of both the aPTT and PT, and to document factor X 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. Acquired specific factor X inhibitors are rare in patients without congenital deficiency. The test may also be impacted by improper sample handling or collection, including severe hemolysis, clotted specimens, or samples thawed in transit.
Methodology
Other
Biomarkers
LOINC Codes
- 3218-5
- 3218-5
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. Mixed immediately by gentle inversion. For winged blood collection sets, draw a discard tube first to prevent under-filling.
Patient Preparation
Ideally, the patient should not be on anticoagulant therapy. Avoid warfarin (Coumadin) therapy for two weeks prior to the test and heparin, direct Xa, and thrombin inhibitor therapies for about three days prior to testing.
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