Protein C and S Activity with Reflex to Protein C and/or S Antigen

7942

If Protein C Activity is <70%, then Protein C Antigen will be performed at an additional charge (CPT code(s): 85302).
If Protein S Activity is <70% for males or <60% for females, then Protein S Antigen will be performed at an additional charge (CPT code(s): 85305).

2 mL frozen citrated platelet-poor plasma (x2) collected in separate 3.2% sodium citrate (light blue-top) tubes

1 mL (x2)

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.

Plastic vials

Frozen

Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 14 days

Hemolysis

Set up and Report available: See individual tests

Aids in characterization of protein C (PC) and/or protein S (PS) deficiency. PC and PS deficiency is associated with increased thrombotic risk and may be congenital or acquired. Acquired PC and PS deficiency may occur with vitamin K antagonists/deficiency, liver disease, malignancy, consumptive DIC, surgery, trauma, and hepatic immaturity of the newborn. In addition, PS deficiency is physiologic in pregnancy.

Anticoagulant interference: Expected impact by therapeutic levels (potential interference depends upon drug concentration): 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.