Protein C Activity

Test Code

PRTCC

Alias/See Also

LAB489

CPT Codes
<p>85303</p>

Preferred Specimen

Specimen Type: Platelet-poor plasma

Collection Container/Type: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

Draw blood into a light blue (sodium citrate) tube. Be sure to fill tubes completely.
Mix gently 5 to 6 times (do not over mix).
Centrifuge the sample for 10 minutes.
Using a pipette, aliquot plasma into a plastic vial being careful not disturb the buffy coat.
Centrifuge the plasma sample a second time for 10 minutes
Using a pipette, aliquot the top portion of plasma into a plastic vial. Be careful not to disturb the sediment at the bottom (leave approx. 0.25 mL of plasma at the bottom).
Label each tube as ""Plasma.""
Immediately freeze samples

For complete instructions, see Platelet Poor Plasma Instructions.

Minimum Volume

0.5 mL (if single test)

Instructions

Platelet-poor plasma: Centrifuge light blue-top tube for 15 minutes at approximately 1500 g within 60 minutes 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. Plasma must be free of platelets (<10,000/mcL). Freeze immediately and ship on dry ice.

Transport Container

Plastic vial

Transport Temperature

Frozen

Specimen Stability

Room temperature: Unacceptable

Refrigerated: Unacceptable

Frozen: 14 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Hemolysis

Methodology

Clotting Assay

Setup Schedule

Set up: Tues-Sat; Report available: 1-4 days

Report Available

1-4 days

Limitations

Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: decrease; Heparin (UFH or LMWH): UFH-no effect, LMWH-may falsely increase at higher levels; Dabigatran or Argatroban (Thrombin Inhibitors): may falsely increase; Rivaroxaban or Apixaban (Factor Xa Inhibitors): may falsely increase.

Reference Range

70-180 % normal

Clinical Significance

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.

Performing Laboratory
Quest Diagnostics Nichols Institute 14225 Newbrook Drive Chantilly, VA 20153

Last Updated: October 15, 2019

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.