Protein C, Activity

Last Modified: 8/31/2023 3:23:29 PM


Medical Necessity Documentation: Recommended as outpatient testing only
Client Notes:  
Patient Preparation:  
Specimen Requirements: 1.0 mL Platelet Poor Plasma from a Blue Top Tube - 3.2% Na Citrate in a Plastic Vial
Collection Instructions:
Draw blood in light blue-top tube containing 3.2% sodium citrate, and mix gently by inverting 3-4 times. 
Centrifuge 15 minutes at 1500 x g within 1 hour of collection. 
Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. 
Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial(s). 
Freeze immediately and transport on dry ice.

Avoid Hemolysis 

Avoid presence of microclots
Transport & Storage: Temperature/Stability:

Unacceptable Ambient
Unacceptable Refrigerated
14 days Frozen
Reference Range: 70% - 180% of normal

Detection Limit: 50% of normal
Critical Ranges:  
Test Comments: For all results less than 70%: Decreased levels of Protein C Activity may be found in hereditary deficiency, treatment with oral anticoagulants, liver disease, D.I.C., and post surgery. 

For results greater than 140%: An elevated Protein C activity is not clinically significant. Only deficiencies are associated with an increased thrombotic risk.
Methodology: Clotting Assay
Clinical Significance: Aids in diagnosis of decreased activity of Protein C characterized by recurrent venous thrombosis. Acquired deficiencies associated with Protein C include: oral anticoagulant therapy, liver disease, vitamin K deficiency, malignancy, consumptive DIC, surgery, trauma, antibodies to Protein C, and hepatic immaturity of the newborn.
Documentation:  
Custom Panel: No

PRODUCTION SCHEDULE

Turn Around Time: 3 to 5 days
Days Performed: Monday, Tuesday, Wednesday, Thursday, Friday
Sites Performed: Quest - Chantilly
PHL Test Code: PROTC
EPIC Test Code: LAB489
Send Out Test Code: 23513 / 1777X
Included Tests:  
CPT Coding: 85303

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