Chromogenic Factor VIII Inhibitor Bethesda Profile, Plasma
Use
The Chromogenic Factor VIII Inhibitor Bethesda Profile is useful for detecting the presence and quantifying the titer of specific inhibitors directed against coagulation factor VIII in patients being treated with the antibody emicizumab (Hemlibra). It helps in identifying inhibitors that target factor VIII, which can lead to severe bleeding complications. This test is specifically beneficial for patients who may have developed alloimmune inhibitors against infused factor VIII or autoimmune inhibitors during conditions such as pregnancy or autoimmune diseases.
Special Instructions
It is critical that specimens are collected prior to factor replacement therapy. When collecting samples through a port or line, appropriate wastage should be conducted before collection. Ensure that plasma is frozen immediately after double centrifugation to prevent platelet contamination and ensure accuracy. Separate vials are required for each coagulation assay requested.
Limitations
This test will not detect inhibitors directed against other clotting factors besides factor VIII, nor is it capable of detecting the presence of lupus anticoagulants. Specimen contamination with excess heparin or hemodilution can lead to erroneous results. It requires careful handling and processing to avoid these issues.
New York Approved
Methodology
Other (Chromogenic)
Biomarkers
LOINC Codes
- 95121-0
- 93450-5
- 95122-8
- 18771-6
- 49865-9
Result Turnaround Time
3-4 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
Not provided
Container
Plastic vials
Collection Instructions
1. Collect specimens prior to factor replacement therapy. 2. If collecting through a port/line, ensure appropriate wastage. 3. Follow guidelines for double centrifugation before freezing. 4. Freeze immediately, ideally at -40°C.
Storage Instructions
Freeze at -20°C or below, ideally at -40°C for longer stability.
Causes for Rejection
Gross hemolysis, lipemia, icterus, or IV heparin contamination will result in rejection.
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14 days |