Chromogenic Factor VIII
General Information
- Lab Name
- Chromogenic Factor VIII
- Lab Code
- CHRF8
- Epic Name
- Factor VIII Activity, Chromogenic
- Description
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.
- Forms & Requisitions
Outside clients should fill and submit Coagulation Patient Clinical History Form: Coagulation Patient Clinical History Form
- Synonyms
- Chromogenic Factor 8 Activity, Refacto Assay (Recombinant F8)
- Components
Interpretation
- Method
Optical Chromogenic (2-stage) bovine-based assay
- Reference Range
-
Units: %
Female Male Age Range Age Range 0- 50-200 0- 50-200 Effective date: 08/17/2020
- Interferences and Limitations
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.
Ordering & Collection
- Specimen Type
- Blood
- Collection
-
3 or 5 mL BLUE TOP (CITRATE) tube
- Forms & Requisitions
Outside clients should fill and submit Coagulation Patient Clinical History Form: Coagulation Patient Clinical History Form
- Approval Required
- **Laboratory Medicine resident's approval is required for hospital inpatients and patients in Emergency Department.**
- Handling Instructions
The Laboratory MUST process specimen, within 4 hrs of blood collection.
- Quantity
- Requested: entire specimen
Processing
- Receiving Instructions
UW-MT Instructions: Take specimen to UW-MT Coag lab for processing. Coag tech will freeze plasma sample for transport to HMC Coag.
HMC Instructions: Take specimen to HMC Coag lab for processing.
Outside Laboratory: Centrifuge for 10 minutes, remove plasma & re-spin plasma for another 10 minutes. Decant & Freeze plasma (minimum 1.0 mL) @ -20°C to -80°C. Send Frozen on dry ice.
- Misc Sendout
Performance
- Lab Department
- Coagulation(COAG)
- Frequency
- Run Monday and Thursday. Reported by end of day.
- Available STAT?
- Yes. Contact Lab Medicine Resident for approval.
- Performing Location(s)
-
HMC Coagulation
206-520-4600325 9th Ave, Rm # GWH-47, Seattle, WA 98104-2420
Billing & Coding
- CPT Codes
- 85130
- LOINC
- 49865-9
- Interfaced Order Code
- UOW891
- Interfaced Result Code
- UOW891