Rheumatoid Arthritis Factor Test
The Rheumatoid Arthritis Factor is often evaluated in patients suspected of having any form of arthritis or destructive articular disease even though positive results can be due to other causes, and negative results do not rule out disease. But, in combination with signs and symptoms, it can play a role in both diagnosis and disease prognosis. It is part of the usual disease criteria of rheumatoid arthritis.
The Rheumatoid Arthritis Factor test is often evaluated in patients suspected of having any form of arthritis or destructive articular disease even though positive results can be due to other causes, and negative results do not rule out disease. But, in combination with signs and symptoms, it can play a role in both diagnosis and disease prognosis. It is part of the usual disease criteria of rheumatoid arthritis.
The presence of rheumatoid factor in serum can also indicate the occurrence of suspected autoimmune activity unrelated to rheumatoid arthritis, such as that associated with tissue or organ rejection. In such instances, RF may serve as one of several serological markers for autoimmunity. The sensitivity of RF for established rheumatoid arthritis is only 60-70% with a specificity of 78%.
Many rheumatic conditions and other chronic inflammatory processes may produce rheumatoid factors. The presence of rheumatoid factor, especially in low titer, is far from diagnostic for rheumatoid arthritis. Furthermore, with increasing age, people with no clinical illness may have rheumatoid factor. The presence of IgM RFs has been reported in as much as 10% of the normal population. Statistically, patients with rheumatoid arthritis who have high titer rheumatoid factor are more likely to have severe disease and systemic involvement than other patients. Rheumatoid factor can be detected in synovial fluid, pleural fluid, and pericardial fluid, but contributes little more than a positive serum test. Some rheumatoid factors may behave as cryoglobulins.
High levels of rheumatoid factor test (in general, above 20 IU/mL, 1:40, or over the 95th percentile; there is some variation among labs) occur in rheumatoid arthritis (present in 80%) and Sjögren's syndrome (present in 70%). The higher the level of RF the greater the probability of destructive articular disease. It is also found in Epstein–Barr virus or Parvovirus infection and in 5 to 10% of healthy persons, especially the elderly.
There is an association between rheumatoid factor and more persistently active synovitis, more joint damage, greater eventual disability, and arthritis.
Other than in rheumatoid arthritis, rheumatoid factor test may also be elevated in:
- Systemic lupus erythematosus (SLE)
- Juvenile Idiopathic Arthritis
- Sjögren syndrome
- Interstitial pulmonary fibrosis
- Hepatitis B, chronic liver disease, and chronic hepatitis
- Essential mixed cryoglobulinemia
- Primary biliary cirrhosis
- Infectious mononucleosis and any chronic viral infection
- Bacterial endocarditis
- Visceral leishmaniasis
- Systemic sclerosis
- After vaccination/transfusion in normal individuals
HOW DOES DISCOUNTEDLABS.COM WORK?
Go to the "Find a Location" page to find the closest lab location. No need to make an appointment since walk-ins are welcomed. Once you have identified your closest location, go to step 2.NOTE: We serve all states in the U.S. except New York, New Jersey, and Rhode Island. Residents of those states need a written lab order from an in-state provider. Individuals cannot obtain a blood draw in neighboring states.
If you have a discount coupon code, add it to your cart.
A $8 lab processing fee will be added to your total.
Pay using a credit card.
You will receive an order confirmation and instructions email on how to download your lab request.
Print lab request form that you downloaded.
Take that form to the closest Quest Diagnostics location with a picture ID. Get your blood drawn.
You will receive an email when the results are ready for you to download.Note: You cannot place an order under someone else's profile. The profile person's name will appear on the lab order form.
If you have questions, please review our FAQ Page.
If you have further questions, please email [email protected].