zero negative rheumatoid arthritis

Rheumatoid factor is a commonly ordered blood test to help diagnose rheumatoid arthritis. About 70-90% of people with adult rheumatoid arthritis are positive for rheumatoid factor and about 20% of people remain negative for rheumatoid factor even though they have been diagnosed with rheumatoid arthritis. Therefore, a positive test for rheumatoid factor is by no means necessary to indicate disease.

The result does not correlate with the activity of disease, but patients with a high amount rheumatoid factor are more likely to have erosive joint disease, extra-articular manifestations, and greater functional disability. In contrast, generally, rheumatoid factor negative patients exhibit a milder disease course.