Why it's done

A rheumatoid factor test is one of a group of blood tests primarily used to help pinpoint a diagnosis of rheumatoid arthritis. These other tests may include:

  • Anti-nuclear antibody (ANA)
  • Anti-cyclic citrullinated peptide (anti-CCP) antibodies
  • C-reactive protein (CRP)
  • Erythrocyte sedimentation rate (ESR, or sed rate)

The amount of rheumatoid factor in your blood may also help your doctor choose the treatment approach that will work best for your situation.

May 21, 2016
  1. Firestein GS, et al. Autoantibodies in rheumatoid arthritis. In: Kelley's Textbook of Rheumatology. 9th ed. Philadelphia, Pa.: Saunders Elsevier; 2013. http://www.clinicalkey.com. Accessed May 5, 2016.
  2. Rheumatoid factor. Lab Tests Online. American Association for Clinical Chemistry. https://labtestsonline.org/understanding/analytes/rheumatoid/tab/test. Accessed May 5, 2016.
  3. Shmerling RH. Origin and utility of measurement of rheumatoid factor. http://www.uptodate.com/home. Accessed May 5, 2016.
  4. Ferri FF. Rheumatoid arthritis. In: Ferri's Clinical Advisor 2016. Philadelphia, Pa.: Mosby Elsevier; 2016. https://www.clinicalkey.com. Accessed May 5, 2016.