Activated Protein C-Resistance

*Take to processing ASAP to be spun down and froze

Test Code

Alias/See Also

CPT Codes

Preferred Specimen
2 mL frozen platelet-poor citrated plasma collected in a 3.2% sodium citrate (light-blue-top) tube

Minimum Volume
1 mL

Platelet-poor plasma: Centrifuge light blue-top tube for 15 minutes at approximately 1500 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.

Transport Container
Transport tube

Transport Temperature

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 60 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Clotted specimen • Serum

RVVT-based Assay (Clot-based)

Setup Schedule

Report Available
1-8 days

Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: no effect; Heparin (UFH or LMWH): no effect; Dabigatran or Argatroban (Thrombin Inhibitors): unable to obtain assay endpoint; Rivaroxaban or Apixaban (Factor Xa Inhibitors): no effect.

Reference Range
≥2.1 Ratio

Clinical Significance
Activated protein C (APC) 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.

Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042

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.