Test Code LAB491 Protein S Activity, Plasma

Important Note

PROTEIN S

Additional Codes

Sunquest: PRSFUM

Mayo: SFX

Specimen Required

Specimen Type: Platelet-poor plasma

Patient Preparation: Patient must not be receiving Coumadin.

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing

2. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.

3. Aliquot plasma into a plastic vial leaving 0.25 mL in the bottom of centrifuged vial.

4. Freeze specimen immediately (no longer than 4 hours after collection) below -40° C.

Secondary ID

617792

Useful For

Second-order testing for diagnosis of congenital or acquired protein S deficiency, ie, as an adjunct to initial testing based on results of protein S antigen assay (free protein S antigen, with or without total protein S antigen assay)

Evaluating patients with a history of venous thromboembolism

Special Instructions

Coagulation Guidelines for Specimen Handling and Processing

Method Name

Optical Clot-Based

Reporting Name

Protein S Activity, P

Specimen Type

Plasma Na Cit

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type	Temperature	Time	Special Container
Plasma Na Cit	Frozen	14 days

Reject Due To

Gross hemolysis	Reject
Gross lipemia	Reject
Gross icterus	Reject

Reference Values

Males: 65-150%

Females

<50 years: 50-150%

≥50 years: 65-150%

Newborn infants have normal or near-normal free protein S antigen (≥50%), although total protein S antigen is usually below the adult reference range. There are insufficient data concerning protein S activity in normal neonates, infants, and children; but normal or near-normal activity (≥50%) probably is present by age 3 to 6 months.

Method Description

The functional activity of free protein S is performed on the instrumentation laboratory ACL TOP. It is determined by measuring the degree of prolongation of a prothrombin time in the presence of the recombinant human tissue factor, phospholipids, calcium ions, and activated protein C. The protein S activity is correlated with the prolongation of the clotting time of protein S deficient plasma to which diluted sample has been added. The clotting time is directly proportional to the amount of functional protein S in the patient's plasma and can be quantified using a standard curve.(Package insert: HemosIL Protein S Activity. Instrumentation Laboratory Company; Rev 08/2012)

Day(s) Performed

Monday through Friday

Report Available

1 to 4 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

85306

LOINC Code Information

Test ID	Test Order Name	Order LOINC Value
SFX	Protein S Activity, P	27822-6

Result ID	Test Result Name	Result LOINC Value
SFX	Protein S Activity, P	27822-6

Forms

If not ordering electronically, complete, print, and send an Coagulation Test Request (T753) with the specimen.

UnityPoint Health-Trinity Quad Cities Additional Information:

ALIAS: