Rheumatoid Factor
Rheumatoid factor (RF) is an antibody the immune system can make that targets other antibodies in the body. It is found in some people with rheumatoid arthritis and other inflammatory conditions, but also in a small fraction of healthy adults.
Why it matters: RF positivity, especially with elevated levels, is one finding considered alongside symptoms and other markers when reviewing for rheumatoid arthritis. RF alone is not enough to identify a specific condition — clinical context matters.
What is Rheumatoid Factor?
Rheumatoid factor (RF) is an antibody the immune system can make that targets other antibodies in the body. It is found in some people with rheumatoid arthritis and other inflammatory conditions, but also in a small fraction of healthy adults.
What might a high or low Rheumatoid Factor mean?
RF positivity, especially with elevated levels, is one finding considered alongside symptoms and other markers when reviewing for rheumatoid arthritis. RF alone is not enough to identify a specific condition — clinical context matters.
What is the typical reference range for Rheumatoid Factor?
The general-population reference range shown here is 0 – 14 IU/mL. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.
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