Rheumatoid factor (RF)
What is Rheumatoid Factor(RF)?
Rheumatoid factor (RF) is an antibody found in the blood of individuals with certain autoimmune diseases, such as rheumatoid arthritis. The RF antibody comes from Immunoglobulin M (IgM) proteins. IgM is a type of protein produced by the immune system as part of the body’s response to fighting infection or to some other types of antigen exposure. RF can be measured through a blood test and is used to help diagnose and monitor certain autoimmune diseases.
Preparation for Rheumatoid Factor Test
No special preparation is necessary before a rheumatoid factor test. You might need to fast for 8-12 hours prior to having your blood drawn, depending on the type of blood test your doctor orders.
Procedure for Rheumatoid Factor Test
A rheumatoid factor test is usually done by a health professional at a hospital or clinic. During the test, a small sample of blood is taken from a vein in your arm and sent to a lab for testing.
Types of Rheumatoid Factor Tests
There are several types of RF tests used in diagnosis. They are:
- Quantitative RF Test: This tests measure the amount of RF in the blood.
- IgM RF Test: This tests measure the amount of IgM RF in the blood.
- Antibody Specificity: This tests measure the type of antibody present in the blood.
Risks of Rheumatoid Factor Test
There are no known risks associated with a rheumatoid factor test. It is a safe and simple procedure.
Why Rheumatoid Factor Test Is Done?
A rheumatoid factor test is usually done to help diagnose or monitor the treatment of certain autoimmune diseases, such as rheumatoid arthritis. The presence of RF in the blood can help to confirm a diagnosis of rheumatoid arthritis.
When to Do Rheumatoid Factor Test?
Your doctor may order a rheumatoid factor test if they suspect that you have an autoimmune disease, such as rheumatoid arthritis. This test may also be done to help monitor how well treatment of an autoimmune disease is working. It can also be done to rule out other autoimmune diseases such as lupus, scleroderma, and Sjögren's syndrome.