A low number (normal result) usually means you do not have rheumatoid arthritis or Sjogren syndrome. However, some people who do have these conditions still have a "normal" or low rheumatoid factor (RF).
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results mean
An abnormal result means the test is positive, which means higher levels of rheumatoid factor have been detected in your blood.
Most patients with rheumatoid arthritis or Sjogren syndrome have positive RF tests.
The higher the level, the more likely one of these conditions is present. There are also other tests for these disorders that help make the diagnosis.
Not everyone with higher levels of rheumatoid factor has rheumatoid arthritis or Sjogren syndrome.
Your provider may do another blood test (anti-CCP antibody) to help diagnose rheumatoid arthritis.
People with the following diseases may also have higher levels of rheumatoid factor:
In some cases, people who are healthy and have no other medical problem will have a higher-than-normal RF level.
Andrade F, Darrah E, Rosen A. Autoantibiodies in rheumatoid arthritis. In: Firestein GS, Budd RC, Gabriel SE, et al, eds. Kelley's Textbook of Rheumatology. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2012:chap 56.
Gordon A. Starkebaum, MD, Professor of Medicine, Division of Rheumatology, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.