Activated Protein C Resistance with Reflex to Factor V (Leiden) Mutation

Test Code

19704

Physician Attestation of Informed Consent

This germline genetic test requires physician attestation that patient consent has been received if ordering medical facility is located in AK, DE, FL, GA, IA, MA, MN, NV, NJ, NY, OR, SD or VT or test is performed in MA.

Includes

If Activated Protein C-Resistance is <2.1 ratio, then Factor V (Leiden) Mutation Analysis will be performed at an additional charge (CPT code(s): 81241).

Preferred Specimen

2 mL frozen platelet-poor citrated plasma collected in a 3.2% sodium citrate (light-blue-top) tube and
4 mL frozen whole blood collected in an EDTA (lavender-top) tube

Minimum Volume

1 mL platelet-poor plasma • 2 mL whole blood

Other Acceptable Specimens

Whole blood collected in: EDTA (royal blue-top) tube or ACD solution B (yellow-top) tube

Instructions

Platelet-poor plasma: Centrifuge light blue-top tube 15 minutes at approx. 1500 x g within 60 minutes 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. Plasma must be free of platelets (<10,000/mcL). Freeze immediately and ship on dry ice.

Whole Blood: Preferred shipping temperature is frozen, but room temperature shipping is acceptable.

Transport Temperature

Frozen

Specimen Stability

Plasma
Room temperature: 1 hour
Refrigerated: 4 hours
Frozen: 6 months

Whole blood
Room temperature: 8 days
Refrigerated: 8 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis

Methodology
Polymerase Chain Reaction & Detection • RVTT-Based Assay (Clot-Based)

Setup Schedule

See individual assays.

Clinical Significance

Activated Protein C Resistance is the most frequent hereditary defect associated with deep vein thrombosis. Over 95% of the APC resistance phenotype is due to the Factor V Leiden Mutation. The APC-resistance assay is a plasma based functional test for the determination of APC resistance caused by the Factor V Leiden Mutation.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.