Functional Protein C & S with Reflex

Message
For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

If unable to process and properly store specimens within 4 hours of collection then call CompuNet transportation for a STAT pick-up at (937) 297-8262 option 1.

This test needs a completed Anticoagulant Drug List submitted with the specimen. For a copy of the 2 page form click here
 


Test Code
FUNPCS


CPT Codes
85303; 85306

Includes
Functional Protein S (Activity),
Functional Protein C Activity
Possible Reflexes:
Protein S Activity reflexes to Protein STotal Antigen when abnormally low and Protein C Activity reflexes to Protein C Antigen when abnormally low.


Preferred Specimen
3 plastic (2.7mL) completely filled Sodium Citrate (light blue top) tube


Minimum Volume
4 Frozen Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)


Instructions
Use standard venipuncture and disposal techniques.
Collect the required quantity of Sodium Citrate (light blue top) tubes.
If unable to process specimens within 4 hours of collection then call CompuNet transportation for a STAT pick-up at (937) 297-8262 option 1. Sodium Citrate (light blue top) tube(s):
Process immediately (stable only 4 hours), following instructions below:
 Note: We recommend aliquot tubes to be made of polypropylene plastic as this material is safe to freeze at <-70 degrees C.
1. Centrifuge capped Sodium Citrate (light blue top) tubes at 3000 rpm for 10 minutes, or at speed and time required to consistently produce Platelet Poor Plasma (<5/kmm3).
2. Carefully remove the plasma from all Sodium Citrate (light blue top) tubes; avoid disturbing the WBC/buffy coat, and combine all plasma into a 15mL plastic conical centrifuge tube.
Note: If the plasma shows any hemolysis, it must be recollected.
3. Centrifuge the plasma in the 15mL plastic conical centrifuge tube for a second time as in step 1.
4. In one smooth motion, carefully and quickly pour the centrifuged plasma into a second 15mL plastic conical centrifuge tube. A small amount of plasma along with a red cell button should remain on the bottom of the original conical tube if the pour was executed correctly.
Note: This quick-pour method prevents platelet transfer and contamination.
5. Aliquot at least 1mL of plasma into each aliquot tubes labeled "plasma." Refer to the Minimum Volume section above for the number of aliquots required per test.
6. Finally, place all aliquots into a <-20 degrees C freezer within 4 hours.
Note: Aliquots must remain frozen until they are picked up by the CompuNet courier. Call CompuNet transportation department if frozen specimen boxes are needed.


Transport Container
Whole blood Sodium Citrate (light blue top) tube
OR
Frozen -Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)


Transport Temperature
Room Temperature: Whole blood Sodium Citrate (light blue top) tube
Refrigerated: Unacceptable for Sodium Citrate (light blue top) tube whole blood or capped plasma aliquots
Frozen: Capped aliquots of Sodium Citrate plasma (Polypropylene tubes


Specimen Stability
Room Temperature: Whole blood Sodium Citrate (light blue top) tube < 4 hours
Refrigerated: Unacceptable for Sodium Citrate (light blue top) tube whole blood or capped plasma aliquots
Frozen: Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended) <30 days at <-20 degrees C
                                                                                                                                               <1 month at <-70 degrees C


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Rejected for hemolysis, clotted, improper fill, incorrect specimen type, thawed frozen aliquots, refrigerated plasma or blood, expired test tubes, >4 hours old if not processed into separated frozen plasma vials.


Methodology
Clotting

Setup Schedule
Wednesday
SCOAG


Report Available
1 - 6 days


Limitations
Anti-coagulant
Heparin levels > 1.0 IU/mL
FVIII (8) activity levels > 250%
Antiphospholipid Antibodies


Clinical Significance
This assay detects a deficiency in Protein C that maybe otherwise normal when tested using Antigenic and Chromogenic methods.  

Protein C deficiencies exist as both acquired and inherited disorders. Acquired Protein C deficiencies are found in hepatic disorders, oral anticoagulant therapies and DIC. Congenital Protein C deficiencies are characterized by recurrent venous thrombosis and exist in different types:
     o Type I deficiency shows decrease of both functional and antigenic levels of Protein C.
     o Type II deficiency shows decrease in Functional Protein C level, but normal with chromogenic levels of Protein C.

Screen for increased risk of thrombi-embolism and to differentiate between the different Types of Protein deficiencies.


Performing Laboratory
CompuNet Clinical Laboratories, LLC
2308 Sandridge Drive
Moraine, Ohio 45439


Last Updated: August 17, 2023


The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.