A rheumatoid factor test measures the amount of rheumatoid factor in your blood. 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. But rheumatoid factor may be detected in some healthy people, and people with autoimmune diseases sometimes have normal levels of rheumatoid factor.
Jul. 09, 2013
- Firestein GS, et al. Kelley's Textbook of Rheumatology. 9th ed. Philadelphia, Pa.: Saunders Elsevier; 2013. http://www.mdconsult.com/das/book/body/208746819-6/0/1807/0.html. Accessed April 4, 2013.
- Rheumatoid factor. Lab Tests Online. http://labtestsonline.org/understanding/analytes/rheumatoid/tab/glance. Accessed April 4, 2013.
- Shmerling RH. Origin and utility of measurement of rheumatoid factors. http://www.uptodate.com/home. Accessed April 4, 2013.
- Ferri FF. Ferri's Clinical Advisor 2013: 5 Books in 1. Philadelphia, Pa.: Mosby Elsevier; 2012. http://www.mdconsult.com/books/about.do?eid=4-u1.0-B978-0-323-08373-7..00002-9&isbn=978-0-323-08373-7&about=true&uniqId=343863096-23. Accessed April 4, 2013.