Test Directory
Protein S Antigen (Total)
Justification
Reduced protein S may be seen in warfarin therapy, pregnancy, use of oral contraceptives, DIC, acute thrombosis, HIV, nephrotic syndrome, liver disease and L-asparaginase chemotherapy. Congenital or acquired deficiency of protein S is also a risk factor for venous thromboembolism (VTE).
Protein S is a vitamin K-dependent glycoprotein, and therefore it is reduced in patients stabilized on warfarin. Protein S is a cofactor for activated protein C, which inactivates procoagulant factors Va and VIIIa, thereby reducing thrombin generation. Protein S is also a cofactor for activated protein C in enhancing fibrinolysis. Free protein S measurement may be superior to functional protein S measurement in patients that have not been screened for the absence of the factor V Leiden (FVL) mutation.
STAT: < 1 week
ELISA
Draw Tube: Blue Top
Sample Type: Citrated Plasma
Specimen Requirements
Sample Type | Volume Required | Minimum Volume | Stability | |
---|---|---|---|---|
PREFERRED | Citrated Plasma | 1mL | 0.5mL | Room Temp.: 2 hours
Refrigerated: 2 hours Frozen (-20C): 2 weeks Frozen (-80C): 6 months |
ALTERNATIVE | - | - | - | - |
REJECTION CRITERIA | Thawed in transit, refrozen or clotted sample |
SPECIAL INSTRUCTIONS | - |
General Information
METHODOLOGY | ELISA |
STAT TAT | < 1 week |
STAT TAT Performance | > 90% of results released in 1 week |
ROUTINE TAT | < 1 week |
ALTERNATIVE NAMES | PS Total |
DESCRIPTION | - |
LIMITATIONS | - |
NORMAL RANGE | - |
ASSOCIATED TESTING | - |
REFERENCES | - |
SAMPLE REPORT | Upon request |
NEW YORK STATE APPROVED | - |
Test Codes
ORDER CODE | P3102 |
CPT CODE | 85305 |
LOINC CODE | 27823-4 |