Test Overview
Test Methodology

Latex Immunoturbidometric

Test Usage

Used to identify and quantitate a Protein S defect or deficiency in those patients subject to recurrent venous thrombosis or pulmonary emboli.

Reference Range *

Males: 73 - 130%; Females: 65 - 139%.

Test Details
Days Set Up
Tuedsay
Analytic Time

2 hours

Soft Order Code
PSAGF
MiChart Code
Protein S Antigen, Free
Synonyms
  • PSAGF
  • PROTEIN S ANTIGEN FREE
Laboratory
Hematopathology
Section
Coagulation
Specimen Requirements
Collection Instructions

Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.

Rejection Criteria
Specimens will be rejected if not properly filled, clotted, grossly hemolyzed, or contaminated with heparin.
Contraindications
This test is not indicated in patients receiving Coumadin (warfarin) therapy. This test is not indicated for inpatient evaluation of acute thrombosis.
Blue Top Tube
Normal Volume
Full 2.7mL tube or 1mL plasma aliquot
Minimum Volume
Full 1.8mL tube or 1mL plasma aliquot
Storage Temperature
Room temperature for whole blood or frozen aliquot of citrated plasma.
Additional Information

Protein S is a vitamin K dependent anticoagulant protein synthesized in the liver (and endothelium). Protein S circulates in plasma alone ("free") or reversibly bound to the complement regulatory protein C4b binding protein (C4bBP). C4bBP is an acute phase reactant and may be increased in inflammatory conditions, causing an acquired decrease of free protein S. Only free protein S has anticoagulant activity.

Billing
CPT Code
85306
Fee Code
31102
LOINC
27821-8
NY State Approved
No