What is the rheumatoid factor test?
Rheumatoid factors can harm healthy tissues, and elevated levels of rheumatoid factors in a blood sample can be indicative of autoimmune diseases, such as rheumatoid arthritis, Sjogren’s syndrome and lupus. For example, approximately 80 percent of adult patients with rheumatoid arthritis have high levels of these antibodies in their blood, notes MedicineNet. However, patients with hepatitis, mononucleosis and cancer can also have elevated levels of rheumatoid factors. Similarly, some healthy individuals may also have elevations in RF levels.
Sources: nih.gov, webmd.com, medicinenet.com