RA factor is an antibody that is measured in the blood. It is mainly used as a supportive tool in making a diagnosis of rheumatoid arthritis. What Do RA factor Test Results Mean? Approximately 70% of rheumatoid arthritis patients test positive for RA factor. RA factor is negative – could the diagnosis still be Rheumatoid arthritis? Yes!
Patients who test negative for RA factor but have signs and symptoms may still be diagnosed with rheumatoid arthritis. This is seen in around 30% patients with rheumatoid arthritis (seronegative rheumatoid arthritis). This number is as high as 50% particularly in the early stages of rheumatoid arthritis. So, a negative RA factor test does not rule out diagnosis of rheumatoid arthritis. In fact, there is no single test to diagnose rheumatoid arthritis. The diagnosis is made from a combination physical symptoms and medical history supported by various…
