Chromogenic Factor VIII

Chromogenic Factor 8 Activity is a photometric assay used to identify factor VIII deficiency as well as for monitoring coagulation factor replacement therapy of certain extended half-life coagulation factor replacements. This assay uses bovine-based factor reagents and can be used to measure native factor VIII levels in the presence of emicizumab (Hemlibra). Chromogenic Factor 8 activity in combination with C-reactive protein can also be used to evaluate risk for venous thormbosis.

Optical Chromogenic (2-stage) bovine-based assay

Effective date: 08/17/2020

Chromogenic FVIII level may be falsely decreased in the presence of direct factor Xa inhibitors such as rivaroxaban (Xarelto), apixaban (Eliquis) and edoxaban (Savaysa). There is no effect from up to 2.0 IU/mL of unfractionated heparin or low molecular weight heparin in the plasma. Certain extended half-life formulations of recombinant factor VIII may give unreliable results with various Factor VIII assays.

3 or 5 mL BLUE TOP (CITRATE) tube

Outside clients should fill and submit Coagulation Patient Clinical History Form: Coagulation Patient Clinical History Form

The Laboratory MUST process specimen, within 4 hrs of blood collection.