Positive rheumatoid factor blood test: What does it mean?

What conditions — other than rheumatoid arthritis — can cause a positive rheumatoid factor test?

- Joyce / Arizona

Answer

Rheumatoid factors (RFs) are antibodies that attach to other antibodies and may trigger inflammation in the body. A positive rheumatoid factor test means that rheumatoid factor has been detected in your blood. This test is used mainly to diagnose rheumatoid arthritis (RA) — about 80 percent of people with RA test positive for rheumatoid factor. But other conditions also can cause a positive rheumatoid factor test, including:

• Sjogren's syndrome
• Chronic mononucleosis
• Chronic hepatitis
• Lupus
• Tuberculosis
• Sarcoidosis
• Dermatomyositis
• Scleroderma
• Bacterial endocarditis
• Primary biliary cirrhosis
• Leukemia

In addition, rheumatoid factor can also be detected in healthy people. It's important to discuss with your doctor the significance of a positive rheumatoid factor test in your specific situation.

RELATED

• Arthritis: How is it diagnosed?
• Rheumatoid arthritis