Geisinger Medical Laboratories/Geisinger Proven Diagnostics Test Catalog

Order Display Name: Geisinger Epic Procedure Code Or ID CPT Code:  


Geisinger Epic Procedure Code: LAB2934         Geisinger Epic ID: 39226

Specimen type:
Platelet-free plasma
Preferred collection container:
Alternate Collection Container:
Other size blue-top (3.2% sodium citrate) tubes (e.g., 1.8 mL, 4.5 mL)
Specimen required:
2 mL platelet-free plasma.
Special notes:
Do not draw blood from a heparinized line. Avoid contaminating the sample with tissue thromboplastin or heparin. Venipuncture must be performed with no trauma. Hemolyzed samples are not acceptable. If blood is drawn from an indwelling catheter, flush with 5 mL of saline and discard the first 5 mL of blood collected.
Patient preparation:
Patient must be off heparin for 48 hours prior to testing. Patient must be off Coumadin 2 weeks prior to testing.

Specimen processing instructions:
Centrifuge the citrated blue-top tubes as soon as possible (within 60 minutes) at designated time and speed to obtain platelet-poor plasma (<10,000/µL). Using a plastic pipette, remove 1 mL of plasma and transfer to a plastic polypropylene aliquot tube and label with patient's name and a second patient identifier (e.g., date of birth, medical record number). Freeze upright and transport on dry ice. 
Transport temperature:
Specimen stability:
Room temperature: 4 hours. Frozen: -20°C for 30 days, -70°C for 6 months.
Rejection criteria:
Protein S activity rejected if clotted specimen or stability limits exceeded. Indications of thaw in transit are sample on slant in aliquot tube or in lid of tube. These samples will be run but will receive a comment of interpret results with caution as thawing suspected.
Protein S free and total rejected if stability exceeded or lipemic, hemolyzed, icteric or cloudy plasma.

Reference interval:
Protein S activity: 65-140%
Free Protein S: 60-140%
Total Protein S: 60-140%
Additional information:
Anticoagulation Impact on Coagulation Tests
CPT code(s):
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.  The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.
Test includes:
Protein S activity, Free Protein S, Total Protein S
Mechanical Clot-Based
Functional Protein S, Free Protein S, Total Protein S
Clinical significance:
Protein S is a vitamin K dependent protein that inhibits blood clot formation. Low protein S levels can be associated with an increase risk for a blood clot. Protein S deficiency is congenital or acquired. Acquired causes include liver disease, pregnancy, vitamin K deficiency, coumadin therapy, proinflammatory state, and DIC. Protein S activity is falsely low in patients with factor V Leiden and proinflammatory conditions. False normal protein S activity can occur in patients on direct thrombin inhibitors, anti-Xa inhibitors, heparin and lupus anticoagulant. Free and total protein S can be falsely normal in patient's with elevated rheumatoid factor.
Doctoral Director(s:)
Michelle Grant DO    
Review Date: 04/29/2019

Performing Locations

Geisinger Medical Center

Performing laboratory: Coagulation
Technical Lead: Margaret Knowles-Tuchman
Frequency: Twice per week
Performed stat? No
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