Ordering Guidance

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

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.

Multiple coagulation profile tests are available. For testing that is performed with each profile, see Coagulation Profile Comparison.

Shipping Instructions

Send all vials in the same shipping container.

Specimen Required

Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vials

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

Collection Instructions:

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

2. If collecting sample through a port/line, be sure to waste the appropriate amount prior to collection.

3. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.

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

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

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

Additional Information:

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

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