What is RF test in blood?
A rheumatoid factor (RF) test measures the amount of rheumatoid factor (RF) in your blood. Rheumatoid factors are proteins produced by the immune system. Normally, the immune system attacks disease-causing substances like viruses and bacteria.
What does a positive RF test mean?
Results. A positive rheumatoid factor test result indicates that a high level of rheumatoid factor was detected in your blood. A higher level of rheumatoid factor in your blood is closely associated with autoimmune disease, particularly rheumatoid arthritis.
What does the presence of RFs mean for a patient?
Rheumatoid factor (usually IgM) is present in approximately 70% of patients with RA. Higher levels and the presence of IgG and IgA RFs correlate with more severe disease.The assay that we use is supposed to detect all classes of RF but probably detects mainly IgM.
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.
Does everyone have RA factor in blood?
What it means: About 70% to 90% of people with a high reading have RA. But people without RA can still have rheumatoid factor. In general, if you have RA but don’t have high RF, your disease will be less severe. RF levels may stay high even if you go into remission.
What if RA factor is negative?
If the result is above the normal level, it is positive. 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.
What is an RF blood test?
An RF test is most often used to help diagnose rheumatoid arthritis. Rheumatoid arthritis is a type of autoimmune disorder that causes pain, swelling, and stiffness of the joints. Rheumatoid factors may also be a sign of other autoimmune disorders, such as juvenile arthritis, certain infections, and some types of cancer. Other names: RF Blood Test.
What is a rheumatoid factor (RF)?
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 a rheumatoid factor test called?
Rheumatoid Factor (RF) Test. What is a rheumatoid factor (RF) test? A rheumatoid factor (RF) test measures the amount of rheumatoid factor (RF) in your blood. Rheumatoid factors are proteins produced by the immune system.
Can an RF test be used to diagnose osteoarthritis?
An RF test is not used to diagnose osteoarthritis. Although rheumatoid arthritis and osteoarthritis both affect the joints, they are very different diseases. Rheumatoid arthritis is an autoimmune disease that affects people at any age, but usually occurs between the ages of 40 and 60. It affects more women than men.