Laboratory Medicine Program
Protein C Activity
(PC)
Clinical Decription:
Protein C (PC) is a vitamin K dependent anticoagulant protein synthesized in the liver that, in association with its cofactor protein S, inactivates clotting factors Va and VIIIa. Congenital and acquired deficiencies of PC are associated with a hypercoagulable state. Hereditary heterozygote PC levels are 30-65%. Acquired PC is seen in liver disease, disseminated intravascular coagulation (DIC), estrogen therapy, pregnancy, vitamin K deficiency or antagonism.
<br/><em>Stenflo J: Structure and Function of Protein C, Sem. Thromb. Haem., 10, No. 2, 109-121, 1984.
Nicham F., Guichaoua J.F., Martinoli J.L.: "Functional Protein C Assay Using the Specific Activator from Agkistrodon c. contortrix Venom and the New Chromogenic Substrate </em>
Method: Chromogenic; Siemens Sysmex CS-5100
Component Tests Used: n/a
Reference Ranges Used:
> 0.70 IU/mL
Specimen Type: Citrated plasma
Collected In: 3.2% Sodium Citrate
Volume: 1.0 mL (minimum: 1.0 mL)
Shipping: Send frozen on dry ice.
Special Instructions: Patient should be fasting, if possible. Anticoagulants should be held for a requisite amount of time prior to testing to ensure no anticoagulant effect on the plasma. The specimen must be double-centrifuged to obtain a platelet-poor plasma specimen (Plt <10x10E9/L): 1. Immediately centrifuge specimen at 1500xG for 10 minutes. 2. Separate the plasma from the platelet/buffy coat and transfer into a clean plastic tube. 3. Centrifuge the separated plasma at 1500xG for 10 minutes. 4. Transfer 1.0 to 2.0 mL of the double-centrifuged plasma into a clean plastic tube, leaving approx. 200 uL for discard. 5. Freeze plasma aliquot immediately for storage. Maintain frozen for shipping and handling.
Testing Schedule(s): Weekly.
Turnaround Time: 10 Business days
For more information, call 416.340.5227 or 1.866.865.5227