Test Directory
Protein C Activity
Justification
Reduced protein C may be seen in warfarin therapy, DIC, liver disease, acute infection, uremia, cancer, cancer therapy, vitamin K deficiency and when autoantibodies are present. Congenital or acquired deficiency of protein C are associated with venous thromboembolism and DVT.
Increased levels of protein C can be seen in nephrotic syndrome, hyperlipidemia and with normal aging.
Protein C is a Vitamin K-dependent plasma protein synthesized in the liver. In the activated state, protein C neutralizes the procoagulant activities of the factors Va and VIIIa in the presence of protein S, a vitamin K-dependent protein and cofactor of activated protein C. In inhibiting the factors Va and VIIIa, protein C helps to limit thrombus extension, and thus acts as a major regulator of the coagulation process.
STAT: < 24 hours (7 days a week)
Clot-based
Draw Tube: Blue Top
Sample Type: Citrated Plasma
Specimen Requirements
| Sample Type | Volume Required | Minimum Volume | Stability | |
|---|---|---|---|---|
| PREFERRED | Citrated Plasma | 1mL | 0.5mL | Frozen (-20C): 2 weeks Frozen (-80C): 6 months |
| ALTERNATIVE | - | - | - | - |
| REJECTION CRITERIA | Thawed in transit, refrozen or clotted sample |
| SPECIAL INSTRUCTIONS | - |
General Information
| METHODOLOGY | Clot-based |
| STAT TAT | < 24 hours (7 days a week) |
| STAT TAT Performance | > 90% of results released in 24 hours 7 days a week |
| ROUTINE TAT | < 3 days (M-F) |
| ALTERNATIVE NAMES | PC |
| DESCRIPTION | Protein C is activated in the presence of the specific activator extracted from Agkistrodon c. contortrix venom. The resulting activated protein C inhibits factors V and VIII, and thus prolongs the APTT of a system in which all factors are present, constant, and in excess, except protein C which is derived from the sample being tested. |
| LIMITATIONS | - |
| NORMAL RANGE | 63-143% |
| ASSOCIATED TESTING | - |
| REFERENCES | - |
| SAMPLE REPORT | Upon request |
| NEW YORK STATE APPROVED | - |
Test Codes
| ORDER CODE | P3098 |
| CPT CODE | 85303 |
| LOINC CODE | 27819-2 |