Protein S Deficiency Profile

Casandra

Casandra Test Code LC31703Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 117754CPT Codes 85305, 85306

Protein S Deficiency Profile

Clinical Use

Order Test

Use

Confirmation and characterization of protein S (PS) congenital deficiency

Special Instructions

If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. 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.

Limitations

The presence of heparin or lupus anticoagulants leads to overestimation of PS. aPC resistance due to factor V Leiden mutation or other causes can falsely lower measured PS activity levels. The test may be affected by various factors such as anticoagulant therapy, liver disease, and hormonal status.

Test Details

Methodology

Immunoassay (Other)

Biomarkers

Protein S, Free

Protein

Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

Protein S, Functional

Protein

Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

Protein S, Total

Protein

Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

LOINC Codes

Order Codes

87557-5

Result Codes

27823-4
27821-8
27822-6

Result Turnaround Time

2-3 days

Specimen

Plasma

Volume

1 mL

Minimum Volume

Not provided

Container

Blue-top (sodium citrate) tube

Collection Instructions

Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion. Mix immediately by gentle inversion at least six times. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap. Freeze immediately.