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HelpTest Code LAB489 Protein C Activity, Plasma
Additional Codes
Sunquest: PRCAM
Mayo: CFX
Reporting Name
Protein C Activity, PUseful For
As an initial test for evaluating patients suspected of having congenital protein C deficiency, including those with personal or family histories of thrombotic events
Detecting and confirming congenital type I and type II protein C deficiencies
Detecting and confirming congenital homozygous protein C deficiency
Identifying decreased functional protein C of acquired origin (eg, due to oral anticoagulant effect, vitamin K deficiency, liver disease, intravascular coagulation and fibrinolysis/disseminated intravascular coagulation)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Plasma Na CitOrdering Guidance
Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason, consider ordering AATHR / Thrombophilia Profile, Plasma and Whole Blood.
Necessary Information
1. If the patient is being treated with Coumadin, this should be noted. Coumadin will lower protein C.
2. Heparin (unfractionated or low molecular weight) 2 U/mL or more may interfere with this assay.
Specimen Required
Specimen Type: Platelet-poor plasma
Patient Preparation: Fasting
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.
2. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.
3. Aliquot plasma into a plastic vial leaving 0.25 mL in the bottom of centrifuged vial.
4. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, at -40° C or below.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
2. Each coagulation assay requested should have its own vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma Na Cit | Frozen | 14 days |
Special Instructions
Day(s) Performed
Monday through Friday
Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
85303
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CFX | Protein C Activity, P | 27818-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CFX | Protein C Activity, P | 27818-4 |
Method Description
This Protein C activity assay is performed using the HemosIL Protein C kit on the Instrumentation Laboratory ACL TOP. Protein C in plasma is activated by a specific enzyme (protein C activator) from copperhead snake venom (Agkistrodon contortrix contortrix). The amount of activated protein C is determined by the rate of hydrolysis of the chromogenic substrate, S-2366 (pyroGlu Pro-Arg-pNA-HCL). The pNA release is measured kinetically at 405 nm and is directly proportional to the protein C level in the plasma.(Package insert: HemosIL Protein C. Instrumentation Laboratory; 03/2016)
Report Available
1 to 3 daysReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Method Name
Chromogenic
Forms
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.
Secondary ID
9339Reference Values
70-150%