Effective July 1, 2021, the Coagulation Department within the Spectrum Health Regional Laboratory will go live with an in-house, bovine based, Chromogenic Factor VIII assay.
This assay, a photometric determination of Factor VIII activity, is useful for monitoring coagulation factor replacement therapy of selected extended half-life coagulation factor replacements and Emicizumab therapy, a recombinant, monoclonal antibody that restores the function of the missing activated factor VIII by bridging FIXa and FX. The action of Emicizumab interferes with all APTT clot based and human chromogenic based assays, leading to an overestimation of Factor VIII activity. As such, the bovine based Chromogenic Factor VIII assay is recommended. The Chromogenic Factor VIII activity also assists in the diagnosis of hemophilia A using a 2-stage assay, particularly when the 1-stage clot based assay is normal.
For questions about this test, please refer to the laboratory catalog or use the Contact Us link above.
Chromogenic Factor VIII Activity – Epic Code: LAB1230831 | Interface Code: 1230831 | CPT: 85240