Rheumatoid factor (RF) is a protein (antibody) made by the immune system that can attack the body's own tissues. An elevated rheumatoid factor may mean the presence of an inflammatory disease.
Rheumatoid factor can be measured with a blood test. This is most helpful for diagnosing rheumatoid arthritis, lupus, and Sjögren's syndrome. Certain heart and liver diseases, infectious diseases (such as tuberculosis), and normal aging may also increase RF levels.
To learn more about Healthwise, visit Healthwise.org.
© 1995-2020 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Donations to UW Health are managed by the University of Wisconsin Foundation, a publicly supported charitable organization under 501(c)(3) of the Internal Revenue Code.