Protein C and Protein S, Functional
Test Code
Clinical Significance
Protein C and Protein S, Functional - Protein C (PC) and Protein S (PS) deficiency may be congenital or acquired and is associated with venous thrombosis. Acquired PC or 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 ...
Test Resources
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Test Details
Protein S Activity
Methodology
Reference Range(s)
| Protein C Activity | ||
| 0-15 years | No reference range available | |
| ≥16 years | 70-180 % normal | |
| Protein S Activity | ||
| Males | 70-150 % normal | |
| Females | 60-140 % normal | |
Alternative Name(s)
Preferred Specimen(s)
1 mL frozen, platelet-poor plasma collected in each of two 3.2% sodium citrate (light blue-top) tube
Minimum Volume
0.5 mL each specimen
Collection 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 Container
Transport tube(s)
Transport Temperature
Frozen
Specimen Stability
- Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 14 days
Reject Criteria
Gross hemolysis
Setup Schedule
Refrigerated: Unacceptable
Frozen: 14 days