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. But a number of other diseases and conditions can raise rheumatoid factor levels, including:
- Chronic infections
- Inflammatory lung diseases, such as sarcoidosis
- Mixed connective tissue disease
- Sjogren's syndrome
- Systemic lupus erythematosus
Some healthy people — particularly older individuals — have positive rheumatoid factor tests, though it's not clear why. And some people who have rheumatoid arthritis will have low levels of rheumatoid factor in their blood.
May 21, 2016
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- Shmerling RH. Origin and utility of measurement of rheumatoid factor. http://www.uptodate.com/home. Accessed May 5, 2016.
- Ferri FF. Rheumatoid arthritis. In: Ferri's Clinical Advisor 2016. Philadelphia, Pa.: Mosby Elsevier; 2016. https://www.clinicalkey.com. Accessed May 5, 2016.