Protein C Activity

Protein C Chromogenic, Protein C Functional, Protein C Level, UOW883

Protein C Activity is a quantitative assay to determine the functional protein C levels in plasma using synthetic chromogenic substrate. Acquired or congenital protein C deficiency is associated with increased risk for venous thrombosis. This assay is not affected by heparin, direct thrombin inhibitors or direct Xa inhibitors. Warfarin or other vitamin K antagonists (VKA) reduce protein C levels and patients should wait at least 2 weeks after the last dose of VKA to measure protein C levels.

This is the preferred initial test to evaluate for congenital protein C deficiency.

3 mL or 5 mL Light Blue Citrate Tube

Plasma

MUST PROCESS WITH 4 HOURS OF COLLECTION
Platelet poor Coag Citrate Specimen processing:
1. Gently invert tube 2-3 times prior to placing in Centrifuge
2. Centrifuge Citrate whole blood at 4500 rpm for 10 minutes
3. Carefully pipette plasma, avoiding the platelet/buffy coat into a plastic vial
4. Centrifuge plasma at 4500 rpm for 10 minutes
5. Pipette the plasma to a plastic vial, leaving the bottom 0.25 mL undisturbed
6. Freeze plasma immediately and transport frozen. 

1 mL

This assay is insensitive to hemoglobin (up to 2 g/l), bilirubin (up to 200 mg/l) and triglycerides (up to 4 g/l). PIVKA protein C (PIVKA: protein induced by vitamin K antagonists) present in the plasma of patients receiving oral anticoagulant therapy may be measured by the colorimetric method.

Patients on warfarin therapy may see decrease in protein C activity because of the vitamin K antagonistic effect of the drug. Protein C is a vitamin K dependent factor.

The presence of aprotinin in the plasma may result in an underestimation of the protein C level.

Coagulation

Stago STA Stachrom Protein C

Monday, Thursday

85303

Units: % 

Male/Female

0-29d           20-150

1m-2m        21-150

3m-5m        28-150

6m-11m     37-150

1y-5y           40-150

6y-9y          45-150

10y -            65-150  

Effective date: 07/01/2004

Elevated Protein C is not associated with thrombosis or bleeding.

No

UW

27819-2