Veripath Test Directory

Synonyms Factor VIII Antibody Screen
Description Factor VIII Inhibitor screen is used to screen patients with Hemophilia A for the presence of factor VIII inhibitor. This test is also used for detecting factor VIII inhibitor in patients with acquired Hemophilia A. It is a screening test and if positive, will reflex to Factor VIII Inhibitor Assay. (Factor VIII Inhibitor Quantitative Assay)
Specimen Requirements 
Container 3 mL Light-blue (3.2% sodium citrate) collection tube
Specimen Type Blood
Preferred Collection Volume 3 mL
Minimum Collection Volume Adult: 2 mL, Neonates : 2 mL
Collection Instructions When drawing specimens for coagulation testing, always draw a "pilot" tube (7-10ml plain red top tube), completely filled. This removes tissue fluid contamination. Samples should be obtained from peripheral vein whenever possible. If drawn from indwelling catheter, the line should be flushed with 15mL of saline. After irrigation, a "pilot" tube should be drawn and discarded.
Specimen Handling In-house patients, transport at room temperature.
In-house patients, transport at room temperature.
Out-side client, follow collection instructions and the steps below:
1. Spin light blue top tube. Remove plasma avoiding platelet/buffy coat layer. Spin plasma again to remove top portion of plasma ans place 1mL of PLATELET-POOR PLASMA in plastic tube. (Glass tube unacceptable). Double-centrifugation is critical for accurate results as platelet contamination may cause erroneous results.
2. Plasma must be frozen within 4 hours of collection. CRITICAL WARNING: Specimens must remain frozen until ready to test. Submit separate aliquots when multiple tests are ordered on the same patient specimen.
Rejection Criteria Hemolysis, clotted, short sample, >4 hrs old (if not frozen), thawed plasma, heparin contamination.
Methodology Clotting based assay
Reference Range See interpretive report.
CPT Code(s) 85370, 85732 X 2, 85390
Department Hemostasis/Coagulation
Contact Information Hemostasis Lab; 214-633-4959 Customer Service: 214-633-0400, Toll Free 1-877-887-8136.
Turn Around Time1-3 days
Performed Monday - Friday
Performed by Hemostasis Lab
Notes Fill tube as far as vacuum will fill and mix gently. Ratio of anticoagulant and blood must be maintained. Avoid slow flowing draws and traumatic venipunctures. Always draw another tube before the blue top tube, this removes tissue fluid contamination.
Updated/Reviewed 07/25/2016