Normal Values:

Results are usually reported in one of two ways:

• Less than 40-60 u/mL
• Less than 1:80 (1 to 80) titer

A low number (normal result) usually means you do not have rheumatoid arthritis or Sjogren syndrome. However, some people who do have these conditions still have a "normal" or low rheumatoid factor (RF).

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean:

An abnormal result means the test is positive, which means higher levels of rheumatoid factor have been detected in your blood.

• Most patients with rheumatoid arthritis, and almost all patients with Sjogren syndrome have positive RF tests.
• The higher the level, the more likely one of these conditions is present.There are also other confirmatory tests for these disorders.
• However, not everyone with higher levels of rheumatoid factor has rheumatoid arthritis or Sjogren syndrome.

People with the following diseases may also have higher levels of rheumatoid factor:

• Scleroderma
• Systemic lupus erythematosus
• Adult Still's disease
• Dermatomyositis
• Sarcoidosis

Higher-than-normal levels of RF may be seen in people with other medical problems. However, these higher RF levels cannot be used to diagnose these other conditions.:

• AIDS, hepatitis, influenza, infectious mononucleosis, and other viral infections
• Certain kidney diseases
• Endocarditis, tuberculosis, and other bacterial infections
• Parasite infections
• Leukemia, multiple myeloma, and other cancers
• Chronic lung disease
• Chronic liver disease

Sometimes, people who are healthy and have no other medical problem will have a higher-than-normal RF level.

What the risks are:

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)