Activated Protein C-Resistance

Test Code

CPT Codes
85307

Preferred Specimen

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

Minimum Volume

1 mL

Instructions

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 Temperature

Frozen

Specimen Stability

Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 60 days

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

Gross hemolysis • Received room temperature • Received refrigerated • Clotted specimen • Serum

Methodology
RVVT-based Assay (Clot-based)

Setup Schedule

A.M. Sets up 1 day a week

Limitations

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
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130

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.