Factor VIII assay
Factor VIII Assay
A Factor VIII assay is a blood test that helps diagnose and monitor the progression of hemophilia A, the most common form of hemophilia. It measures the amount of Factor VIII (FVIII) activity in the blood, which is an essential blood-clotting protein. A deficiency of Factor VIII can cause a range of bleeding disorders, from mild to severe. The result of this test can guide treatment and any necessary lifestyle changes.
Preparation for a Factor VIII Assay
Most of the time, no special preparation is required for this test. Depending on the person and their physician, fasting may be recommended. Following the doctor’s instructions is important.
Procedure of a Factor VIII Assay
The test is performed using a sample of blood taken from a vein in the arm. The sample is centrifuged to separate the plasma, which is then examined for the Factor VIII levels.
Types of Factor VIII Assay
There are two main types of Factor VIII (FVIII) assays:
- Clotting-based tests
- Chromogenic-based tests
The clotting-based test is the older of the two. It is still used in many countries, but is becoming less popular because it takes longer to complete the test results. The chromogenic-based test is becoming more popular because it is faster and more reliable.
Risks of a Factor VIII Assay
The risks associated with a Factor VIII assay are minimal. The risks include pain and bruising at the blood draw site, bleeding or infection, and rare side effects such as an allergic reaction to the needle or blood.
Why Is a Factor VIII Assay Prescribed?
A Factor VIII assay is typically performed when a person is experiencing excessive bleeding, has a family history of bleeding disorders, or when a diagnosis of a Factor VIII disorder is being considered. It is also used to monitor the levels of Factor VIII in people with a known Factor VIII disorder.
When Is a Factor VIII Assay Prescribed?
A Factor VIII assay is typically prescribed when a person is experiencing bleeding for no apparent reason, has a history of Factor VIII deficiency, or has been diagnosed with a bleeding disorder. It is also used to monitor Factor VIII levels during therapy.