Protein C, Activity

Overview

  • EPIC Code:
  • LAB489
  • Soft Test Code:
  • PROTC
  • Send Out Test Code:
  • 23513 / 1777X
Alternate Names
  • Clotting
  • Protein C
  • Protein C Functional
Clinical Significance

Protein C Activity - Protein C (PC) deficiency may be congenital or acquired and is associated with venous thrombosis. Acquired PC deficiency may occur with vitamin K antagonists/deficiency, liver disease, malignancy, consumptive DIC, surgery, trauma, and hepatic immaturity of the newborn.

Anticoagulant interference: Expected impact by therapeutic levels (potential interference depends upon drug concentration): Vitamin K antagonists (eg warfarin): decrease; Heparin (UFH or LMWH): no effect to falsely increased activity levels at higher levels; Dabigatran or Argatroban (Thrombin Inhibitors): may falsely increase activity; Rivaroxaban, Apixaban, Edoxaban (Factor Xa
Inhibitors): may falsely increase activity.


Specimen Collection & Preparation

Specimen Requirements:

-OR-

1.0 mL Platelet Poor Plasma from a Blue Top Tube - 3.2% Na Citrate in a Plastic Vial
Minimum Volume:
0.5 mL Platelet Poor Plasma*

* This volume does not allow for repeat testing

Collection Instructions:

Draw blood in light blue-top tube containing 3.2% sodium citrate.

Mix gently by inverting 3-4 times.


Processing Instructions:

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


Rejection Criteria:

Hemolysis


Transport and Storage:
  • Ambient: Unacceptable
  • Refrigerated: Unacceptable
  • Frozen (-20 C or colder): 14 Days

    Preferred

    Transport on dry ice

Clinical Interpretation

Reference Range:

0 - 15 years: No reference range available 

> or = 16 years: 70-180% of normal 


Methodology:
  • Clotting Assay
Clinical Significance

Protein C Activity - Protein C (PC) deficiency may be congenital or acquired and is associated with venous thrombosis. Acquired PC deficiency may occur with vitamin K antagonists/deficiency, liver disease, malignancy, consumptive DIC, surgery, trauma, and hepatic immaturity of the newborn.

Anticoagulant interference: Expected impact by therapeutic levels (potential interference depends upon drug concentration): Vitamin K antagonists (eg warfarin): decrease; Heparin (UFH or LMWH): no effect to falsely increased activity levels at higher levels; Dabigatran or Argatroban (Thrombin Inhibitors): may falsely increase activity; Rivaroxaban, Apixaban, Edoxaban (Factor Xa
Inhibitors): may falsely increase activity.


Production Schedule

Sites Performed
  • Quest - Chantilly
Days Performed
Tuesday
Saturday
Departments
  • Sendouts - Clinical
Turn Around Time

1 to 4 days


Coding & Compliance

CDM

01420694


CPT Coding

85303


Medical Necessity Documentation

Recommended as outpatient testing only