Factor XII assay

Factor XII Assay

What is Factor XII Assay?
Factor XII Assay is a blood test used to measure the amount of a clotting protein in the blood. The protein, also known as coagulation factor XII, is essential for proper blood clotting. It is sometimes referred to as the Hageman Factor.

Why is the Factor XII Assay Used?
The Factor XII Assay is used to help diagnose and monitor certain hereditary blood clotting disorders, such as hemophilia A and B, as well as von Willebrand disease. It can also be used to evaluate a suspected acquired clotting disorder or the effectiveness of clotting factor replacement therapy.

Preparation for the Test:
No special preparation is typically required for the Factor XII Assay. However, it is important to inform the doctor of all medications being taken, including vitamins, supplements, and herbal remedies. Certain medications can interfere with the accuracy of laboratory tests.

Procedure:
The Factor XII Assay is a simple procedure. A blood sample is taken from a vein, usually in the arm, using a small needle. The sample is sent to a laboratory for analysis and the results are usually available within a few days.

Types:
There are two types of Factor XII Assays: qualitative and quantitative. The qualitative assay measures the activity of the protein, while the quantitative assay provides a numerical value indicating the amount present.

Risks:
The Factor XII Assay is a low-risk procedure. The most common risk associated with the test is slight pain or discomfort at the site where the blood was drawn. Bruising and a small amount of bleeding may also occur.

When is the Factor XII Test Ordered?
The Factor XII Assay may be ordered when there is a suspicion of a hereditary or acquired clotting disorder. It may also be ordered as part of a routine medical exam or if a person is having a clotting disorder evaluation or receiving clotting factor replacement therapy.

What do the Test Results Mean?
Normal results for the Factor XII Assay vary depending on the type of test and the laboratory performing the test. Generally, a value greater than 70% is considered normal, although some laboratories may use different standards. Lower-than-normal results (less than 70%) can indicate a clotting disorder such as hemophilia A or B, von Willebrand disease, or another clotting problem.