Factor VIII Activity, Chromogenic
Use
The chromogenic Factor VIII (FVIII) assay using bovine-based reagents is used to accurately measure endogenous or infused factor VIII activity, especially in patients receiving emicizumab (Hemlibra®), which interferes with one‑stage aPTT‑based assays. It is also advantageous in cases of acquired inhibitors like lupus anticoagulant that may interfere with clot‑based methods. The assay aids in diagnosing bleeding disorders such as hemophilia A and acquired hemophilia, guiding appropriate therapy.
Special Instructions
This assay is insensitive to emicizumab and is recommended when patients are receiving that therapy. Providers should use both one‑stage clotting and chromogenic assays when evaluating suspected bleeding disorders, to avoid missed diagnoses.
Limitations
Not explicitly stated on the source pages; limitations such as interference from rivaroxaban or dabigatran are mentioned for similar assays at other institutions, but not specifically for the Quest chromogenic FVIII assay.
Methodology
Other
Biomarkers
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
Not provided
Minimum Volume
Not provided
Other tests from different labs that may be relevant