Protein C Antigen [4948X]

Test Code
19673

CPT Codes
85302

Preferred Specimen
1 mL 3.2% plasma collected in a Sodium citrate (light blue-top) tube

Minimum Volume
0.5 mL

Instructions
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.
General Drawing Instructions:
Refer to Quest Diagnostics Nichols Institute Directory of Services under Specimen Collection section, Coagulation Testing, for further information on specimen processing.

Transport Container
Plastic screw-cap vial

Transport Temperature
Frozen

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen -20ºC: 14 days
Frozen -70ºC: 1 year



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

Gross hemolysis



Methodology
Immunoassay (IA)

Setup Schedule
Set up: Mon-Fri a.m.; Report available: Next day

Limitations
Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: no effect to decrease; Heparin (UFH or LMWH): no effect; Dabigatran or Argatroban (Thrombin Inhibitors): no effect; Rivaroxaban or Apixaban (Factor Xa Inhibitors): no effect.

Reference Range
70-140 % normal

Clinical Significance
Aids in diagnosis of congenital deficiencies 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.

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



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.