Protein C Deficiency Profile
Use
Confirmation and characterization of protein C deficiency
Special Instructions
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted as per Coagulation Collection Procedures. Warfarin therapy should be halted for two weeks, and heparin therapy for two days before the test. Do not draw from an arm with a heparin lock or heparinized catheter.
Limitations
Patients with heterozygous protein C deficiency may exhibit low normal PC levels. Warfarin treatment reduces vitamin K-dependent factors including PC. Elevated factor VIII levels during acute phase reaction can normalize aPTT, effectively reducing PC levels. PC levels may falsely appear lowered in individuals with factor VLeiden mutation. Testing is not recommended during immediate convalescent periods after thrombotic events due to potential PC depletion. Heparin therapy up to 1 unit/mL does not impact PC levels, but thrombin inhibitors like hirudin or argatroban do. Results interpretation should consider these variations.
Methodology
Immunoassay (Multiplex Protein Panel)
Biomarkers
LOINC Codes
- 27820-0
- 27820-0
- 27818-4
Result Turnaround Time
2-4 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL (each tube)
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tubes (2 tubes)
Collection Instructions
Citrated plasma samples should be collected by double centrifugation. Ensure a proper blood to anticoagulant ratio by filling tubes completely. Mix sample gently at least six times. Centrifuge for 10 minutes, then use a plastic pipette to transfer plasma. Deliver to a Labcorp PP transpak frozen purple tube, and freeze immediately.
Patient Preparation
Avoid warfarin (Coumadin) therapy for two weeks and heparin therapy for two days prior to the test. Do not draw from an arm with a heparin lock or heparinized catheter.
Storage Instructions
Freeze immediately and maintain frozen until tested.
Causes for Rejection
Gross hemolysis; clotted specimen; frozen specimen thawed in transit; improper labeling