Protein C, Functional
Also known as: PROT C F
Use
The Protein C Functional test is used to detect protein C deficiency, which is associated with hereditary thrombophilia and increased risk of clotting disorders. It's particularly used in patients who may have a decreased ability to naturally prevent blood clot formation. This test is important for diagnosing protein C deficiency, especially in patients with unexplained thrombotic events, and may guide management and therapeutic interventions.
Special Instructions
The test should not be ordered if the individual has been on warfarin in the previous 2 to 4 weeks, as warfarin influences protein C levels. Platelet-poor plasma should be collected, and the specimen must be transported frozen at critical temperatures to ensure test accuracy. Sodium citrate (light blue top) tube is required for collection following hemostasis/thrombosis guidelines.
Limitations
The test may show decreased protein C values in patients on warfarin, as it affects protein C measurements. Additionally, artificial increases in protein C levels may arise from heparin therapy or the presence of direct thrombin or factor Xa inhibitors. These factors should be considered when interpreting test results as they can affect the functional activity measurement of protein C.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 27819-2
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1.5 mL
Minimum Volume
1 mL
Container
ARUP standard transport tube
Collection Instructions
Collect in a light blue top (sodium citrate) tube. Handle following hemostasis/thrombosis guidelines. Transfer plasma to transport tube.
Patient Preparation
Do not order if the patient has been on warfarin in the previous 2-4 weeks.
Storage Instructions
Transport at critical frozen temperatures.
Causes for Rejection
Serum, EDTA plasma, clotted or hemolyzed specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 hours |
| Frozen | 3 months |