Factor VIII Inhibitor Screening (Plasma)
This test checks for the presence of antibodies against Factor VIII, a protein involved in blood clotting. These antibodies can interfere with normal clotting and may be linked to hemophilia-related bleeding disorders.
["This test helps diagnose bleeding disorders caused by immune-mediated interference with Factor VIII."]
Key facts at a glance
- LOINC
- 3207-8
- Short code
- Fact VIII Inhib PPP Ql Chro
- Synonyms
- Fact VIII Inhib PPP Ql Chro
- Category
- chemistry
- Sample
- plasma
- Container
- Lavender-top (EDTA) or Green-top (Heparin)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- chromo
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may recommend this test if you experience unexplained bleeding, excessive bruising, or bleeding that doesn’t stop easily. It’s also used in patients with hemophilia or those who have received Factor VIII treatments to monitor for immune responses.
How the Test Works
A small blood sample is taken from your arm. The plasma is then tested for the presence of Factor VIII inhibitors using a specialized immunoassay method. This helps determine if your immune system is producing antibodies that block Factor VIII’s ability to help blood clot.
What to Expect Before the Test
No special preparation is needed, but inform your healthcare provider about any medications, supplements, or recent illnesses that could affect results. Avoid vigorous physical activity before the blood draw.
What to Expect During the Test
The blood draw is quick and typically done in a clinic or lab. You may feel a slight pinch, but most people tolerate it well. The test itself involves analyzing the plasma sample in a lab setting.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results for Factor VIII inhibitors are critical for managing hemophilia and other bleeding disorders. They indicate a condition called inhibitor hemophilia, where the immune system attacks Factor VIII, leading to prolonged bleeding. Treatment may include alternative clotting factors or immune-modulating therapies to control bleeding episodes.
Short name
Factor VIII Antibody Test
Frequently asked questions
How long does it take to get results?
What does a positive result mean?
Can lifestyle changes affect this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy