A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Protein C Antigen
Test CodePROTCAG
Quest Code
4948
Alias/See Also
4948
CPT Codes
85302
Preferred Specimen
1 mL frozen plasma collected in a 3.2% sodium citrate (light-blue top) tube
Minimum Volume
0.5 mL
Instructions
Please submit a separate, frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one 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.
Transport Temperature
Frozen
Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen -20° C: 14 days
Frozen -70° C: 30 days
Refrigerated: Unacceptable
Frozen -20° C: 14 days
Frozen -70° C: 30 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Received room temperature • Received refrigerated • Gross hemolysis
Methodology
Enzyme Immunoassay (EIA)
Setup Schedule
Set up: Sun-Mon, Wed, Fri; Report available: 1-4 days
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
0-15 years | No reference range available |
≥16 years | 70-140 % normal |
Clinical Significance
Aids in characterization of congenital protein C deficiency. Type I deficiency is characterized by reduction in activity (functional) and antigen levels. With type II deficiency (dysfunctional protein), antigen levels may be normal and activity levels are decreased. Acquired deficiencies may occur with vitamin K antagonists/deficiency, liver disease, malignancy, consumptive DIC, surgery, trauma, and hepatic immaturity of the newborn. Drug therapy with L-asparaginase or fluorouracil can also reduce Protein C antigen levels.
Anticoagulant interference: vitamin K antagonists (eg. warfarin) will decrease PC antigen levels. PC antigen testing is not impacted by other anticoagulants (heparins, and target specific anticoagulants such as Dabigatran, Argatroban, Rivaroxaban, Apixaban, Edoxaban).
Anticoagulant interference: vitamin K antagonists (eg. warfarin) will decrease PC antigen levels. PC antigen testing is not impacted by other anticoagulants (heparins, and target specific anticoagulants such as Dabigatran, Argatroban, Rivaroxaban, Apixaban, Edoxaban).
Performing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130