Last Modified:
10/5/2022 11:11:22 AM
Medical Necessity Documentation:
Client Notes:
Patient Preparation:
Specimen Requirements:
(2) 2.0 mL Plasma from a Blue Top Tubes - 3.2% Na Citrate in a Plastic Vials
Collection Instructions:
Please submit a separate, frozen vial for each special coagulation assay ordered.
Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times.
Centrifuge 15 minutes at 1500 g within one hour of collection.
Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial.
Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial(s). Freeze immediately and transport on dry ice.
Minimum Volume:
0.5 mL Plasma (x2)
Transport & Storage: Temperature/Stability:
Unacceptable Amient
Unacceptable Refrigerated
30 days Frozen
Rejection Criteria:
Hemolysis
Reference Range:
See interperetive results
Critical Ranges:
Test Comments:
Methodology:
Clotting Assay • Immunoturbidimetric Assay
Clinical Significance:
Protein S deficiency may either be hereditary or acquired and is associated with an increased risk for
venous thromboembolic disease. Congenital Protein S (PS) deficiency may be classified based on the PS Antigen (Free and Total) and activity results. Type I deficiency is characterized by a decrease in antigen and activity levels whereas a Type II deficiency will have normal antigen levels but reduced activity. A third classification, Type III deficiency, is characterized by reduced free PS antigen and activity, but normal total PS antigen levels associated with increased C4b binding protein level.
Anticoagulant interference: Expected impact by therapeutic levels (potential interference depends upon drug concentration): Vitamin K Antagonists (eg. warfarin): decrease; Heparin (UFH or LMWH): no effect to falsely increased activity levels at higher levels; Dabigatran or Argatroban (Thrombin Inhibitors): may falsely increase activity; Rivaroxaban, Apixaban, Edoxaban (Factor Xa Inhibitors): may falsely increase activity.
Documentation:
Custom Panel:
No
PRODUCTION SCHEDULE
Sites Performed:
Quest - Chantilly
PHL Test Code:
MSOT
EPIC Test Code:
MISC
Send Out Test Code:
93355
Alternate Test Names:
Protein S Functional; PS Antigen; PS Free
Included Tests:
Protein S Antigen, Free; Proten S Antigen, Total; Protein S Activity
CPT Coding:
85305, 85306 (x2)
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