Advisory Information

This test is for detection of presence of specific inhibitors against factor VIII (FVIII). If the presence or type of inhibitor is unknown, APROL / Prolonged Clot Time Profile, Plasma or ALUPP / Lupus Anticoagulant Profile, Plasma should be ordered first.

This test is indicated for testing for FVIII inhibitors in patients being treated with the specific antibody emicizumab (Hemlibra).

Multiple coagulation profile tests are available. See Coagulation Profile Comparison in Special Instructions for testing that is performed with each profile.

Shipping Instructions

Send all vials in the same shipping container.

Specimen Required

See Coagulation Guidelines for Specimen Handling and Processing in Special Instructions.

Patient Preparation: If drawing sample through a port/line, be sure to waste the appropriate amount prior to collection

Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (citrate)

Submission Container/Tube: Plastic vials

Specimen Volume: 2 mL in 2 plastic vials, each containing 1 mL

Collection Instructions:

1. Specimen must be drawn prior to factor replacement therapy.

2. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.

3. Aliquot plasma into 2 separate plastic vials (1 mL in each) leaving 0.25 mL in the bottom of centrifuged vial.

4. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, ≤-40° C.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. If a priority specimen, mark request form, give reason, and request a call-back.

3. Each coagulation assay requested should have its own vial.