Factor V Activity and Human Inhibitor

Test Code

CPT Codes
85220, 85335

Preferred Specimen
2 mL (x2) frozen platelet-poor plasma collected in two 3.2% sodium citrate (light blue-top) tubes

Minimum Volume
1 mL (x2)

Platelet poor plasma: Centrifuge light blue-top tube for 15 minutes at approximately 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. Do not thaw.

Transport Container
Plastic screw-cap vials (x2)

Transport Temperature

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen -20°C: 14 days
Frozen -70°C: 1 year

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

Clot Based

Setup Schedule
Set up: Tues; Report available: 3 days

Reference Range
Factor V Activity 65-150 % normal
Factor V Human Inhibitor ≤0.4 BU

Clinical Significance
Factor V Human Inhibitor provides a quantitative determination of inhibitors. This aids in developing treatment strategies for patients with hemophilia.

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.