What exactly is rheumatoid factor?
Rheumatoid factors are proteins produced by your immune system that can attack healthy tissue in your body. High levels of rheumatoid factor in the blood are most often associated with autoimmune diseases, such as rheumatoid arthritis and Sjogren’s syndrome.
What is a good rheumatoid factor?
What are the normal ranges for rheumatoid factor? The “normal” range (or negative test result) for rheumatoid factor is less than 14 IU/ml. Any result with values 14 IU/ml or above is considered abnormally high, elevated, or positive.
What do rheumatoid factors do?
Rheumatoid factors are proteins produced by the immune system. Normally, the immune system attacks disease-causing substances like viruses and bacteria. Rheumatoid factors attack healthy joints, glands, or other normal cells by mistake. An RF test is most often used to help diagnose rheumatoid arthritis.
What is the normal range for rheumatoid factor?
The normal range of RF is from 0-20 IU/ml. RF above 20 IU/ml is not considered enough to diagnose RA, as there other reasons the RF level may be elevated.
What happens if RA factor is positive?
If you have seropositive RA, you have a positive rheumatoid factor or anti-CCP blood test result. This means you have the antibodies that cause your immune system to attack joints.
What is a low rheumatoid factor?
A low number (negative result) most often means you do not have rheumatoid arthritis or Sjögren syndrome. However, some people who do have these conditions still have a negative or low RF. Normal value ranges may vary slightly among different laboratories.
Is RA factor 10 normal?
Most medical centers consider the normal range of rheumatoid factor to be up to 10 IU/mL or 20 IU/mL, says rheumatologist Steffan Schulz, MD, assistant professor of clinical medicine with Penn Medicine in Philadelphia.