Factor VIII Inhibitor Panel

Test Code

CPT Codes
85240, 85335

Factor VIII Inhibitor, EIA Screen and Factor VIII Activity, Clotting

If Factor VIII Inhibitor, EIA Screen is positive, the Nijmegen Assay will be performed at an additional charge (CPT code(s): 85335).

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

Minimum Volume
1 mL (x2)

Submit a total of 4 mL (2 mL in each of 2 tubes).
Centrifuge light blue-top tube 15 minutes at approx. 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

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 14 days

See individual tests

Setup Schedule
Set up: Tues, Thurs, Sun; Report available: 4 days

Reference Range

See individual tests

Clinical Significance
The presence of alloantibodies against factor VIII activity is a complication of treatment in hemophilia A, while the presence of autoantibodies may develop spontaneously in patients with acquired Factor VIII-C deficiency. The presence of Factor VIII inhibitor may lead to the neutralization (inactivation) of transfused or endogenous Factor VIII activity. The detection and magnitude of Factor VIII inhibitor is of great importance in the care of these patients. Factor VIII inhibitor EIA assay provides a quick method for the detection of Factor VIII inhibitor with less sample volume.

Performing Laboratory
Quest Diagnostics Nichols Institute
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.