Protein S Antigen, Total, Plasma
Use
Protein S is a vitamin K-dependent glycoprotein that plays a critical role in the natural anticoagulant system by acting as a cofactor to activated protein C (APC). It aids in the investigation of patients with a history of thrombosis. Congenital protein S deficiency can increase the risk of venous thrombosis and may be associated with recurrent miscarriage and other pregnancy complications. Acquired deficiency of protein S can occur due to factors like vitamin K deficiency, liver disease, or oral anticoagulant therapy.
Special Instructions
The test is only orderable as part of a profile. It's important to note if the patient is receiving heparin or Coumadin as these can affect protein S levels. Double-centrifuged specimens are critical for accurate results due to possible platelet contamination.
Limitations
Results can be affected by heparin (>4 U/mL), hemoglobin (>2 g/L), bilirubin (>100 mg/L), rheumatoid factor (>300 IU/mL), lipemia, and anti-rabbit antibodies. Acquired protein S deficiency is common but of uncertain hemostatic significance when conditions like pregnancy or inflammation are present.
New York Approved
Methodology
Immunoassay (Latex Immunoassay)
Biomarkers
LOINC Codes
- 27823-4
- 27823-4
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.5 mL
Container
Light-blue top (3.2% sodium citrate)
Collection Instructions
Centrifuge and transfer all plasma into a plastic vial and centrifuge again. Aliquot plasma into separate vials leaving 0.25 mL in the bottom of the centrifuged vial. Freeze plasma immediately and send in the same shipping container.
Patient Preparation
Patient must not be receiving heparin or Coumadin.
Storage Instructions
Freeze at -20 degrees C or ideally, at -40 degrees C or below.
Causes for Rejection
Gross hemolysis, gross lipemia, gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14 days |