What does rheumatoid factor mean?

Rheumatoid factor is: An antibody that is not normally found in the blood, so your body's production of it may indicate RA or another connective tissue disease. However, it can also be present in healthy individuals with no known disease. By contrast, according to the national institutes of health, individuals with these types of diseases can have a low rheumatoid factor or none at all.

RF specifically.: It is usually an immunoglobin m antibody directed against the tail portion of immunoglobin g. What tricks the body into doing this is not known.