What is the Rheumatoid Factor (RA) test? 

Rheumatoid factor (RF) is measured in the blood as a routine blood test. It actually binds with other antibodies. These antibodies are normal proteins in the blood that are the most important part of our immune system. It can be referred to as an autoantibody. The presence of a high value may indicate the presence of serious autoimmune disorders such as rheumatoid arthritis, lupus erythematosus, and chronic infections like tuberculosis and leukaemia. Doctors use the rheumatoid factor test to assist in the diagnosis of rheumatoid arthritis.

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What are the other names for the Rheumatoid Factor (RA) test? 

The other names are the RA Factor, Rheumatoid Factor Qualitative, and Rheumatoid Factor Quantitative Test.

What parameters are included in the Rheumatoid Factor (RA) Test?

There is only one parameter.

What does the Rheumatoid Factor (RA) test measure?

A rheumatoid factor (RF) blood test analyses the amount of the RF antibody that is present in the blood. Normally, antibodies are produced by the immune system to help destroy and eliminate invading bacteria and viruses that can cause disease. But the RF antibody can attach to the normal body tissues, resulting in damage.

High levels of rheumatoid factor can be caused by various autoimmune diseases that include rheumatoid arthritis and some infections. Occasionally, increased levels of RF are present in healthy people.

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The amount of rheumatoid factor in the blood can be measured in two ways:

• Agglutination tests: One of the test methods involves mixing the blood with tiny rubber (latex) beads that are covered with human antibodies. If RF is present, the latex beads clump together to form an agglutination. This method is best used as a first-time screening test for rheumatoid arthritis. Another agglutination test mixes the blood being tested with sheep's red blood cells that have been covered with rabbit antibodies. If the RF is present, the red blood cells clump together. This methodology is often used to confirm the presence of the rheumatoid factor (RF).

• Nephelometry test: This RF test mixes the blood being tested with the antibodies that cause the blood to clump if RF is present. A laser light is shined on the tube containing the mixture, and the amount of light is blocked by the blood sample that is being measured. As the levels of RF increase, more clumping occurs, causing a cloudier sample and less light passing through the cuvette tube.

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What’s the normal range? 

Less than 15.8 lU/L.

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Who should get a Rheumatoid Factor (RA) test? 

A doctor may recommend a rheumatoid factor test if a patient is experiencing any signs and symptoms of rheumatoid arthritis. Symptoms of rheumatoid arthritis include:

• Joint symptoms, including pain and swelling

• Morning stiffness for 30 minutes or longer

• Tiredness or fatigue.

• Intermittent fever

• Appetite loss

• Weight loss

• Weakness

• Dry eyes and mouth.

• Firm lumps beneath the skin

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This is because rheumatoid factor testing is not used as a screening test for rheumatoid arthritis in patients without symptoms. Most patients who test positive for RF but don’t have any symptoms never go on to develop rheumatoid arthritis. Then the doctors can also recommend an RF test while testing for other health conditions. The other conditions in which RF testing might be used include:

• Sjögren’s syndrome

• Lupus

• Juvenile arthritis

• Scleroderma

• Certain infections, including mononucleosis or tuberculosis

• Certain types of cancer, including leukemia

• Hepatitis C

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Are there any preparations needed for the Rheumatoid Factor (RA) test?

No special preparation is required and fasting is not required.

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What is the cost of a Rheumatoid Factor (RA) test?

What is the type of sample required? 

This test requires a blood sample.

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Who will perform the Rheumatoid Factor (RA) test?

A healthcare provider, who is also called a phlebotomist, usually performs blood draws, including those for a Rheumatoid test, but any healthcare provider trained in drawing blood can perform this task. The samples are sent to a lab where a medical laboratory scientist prepares the samples and performs the tests on analysers or manually.

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What should I expect during my Rheumatoid Factor (RA) test?

You can expect the following during the blood test or a blood draw:

• You have to sit comfortably on the chair, and a healthcare provider will check your arms for an easily accessible vein. It is the inner part of your arm on the other side of your elbow.

• Once the phlebotomist has located a vein, they will clean and disinfect the area with an alcohol swab.

• Then they will insert a small needle into your vein to draw a blood sample. This might feel like a small pinch.

• After they insert the needle, the required amount of blood will be collected in a test tube.

• When they have collected enough blood for the test, they’ll remove the needle and hold a cotton ball or gauze on the site to stop any bleeding.

• They will apply a band-aid over the pricked site, and the blood collection is finished.

This process takes less than five minutes. 

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What should I expect after my Rheumatoid Factor (RA) test?

Once the healthcare provider has collected the blood sample, it will be sent to the laboratory for processing or testing. When the test reports are ready, your healthcare provider will share the results with you.

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What is the risk of the Rheumatoid Factor (RA) test?

These blood tests are common and don’t carry any significant risks. You may have a slight pain like an ant bite when the needle gets inserted, and a small bruise may develop there.

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When can I expect my Rheumatoid Factor (RA) test results?

This report is available via email or WhatsApp within 6 hours of the collection of the blood sample.

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What do the results of a Rheumatoid Factor (RA) test mean?

Interpreting test results

After the RF test is processed, test results are reported as either positive or negative. A numerical or titre value might be provided to indicate the levels of RF detected in the blood.  Negative results can be called normal, while positive results may be called abnormal.

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The reference ranges for this test can vary by laboratory and by the type of RF test performed. In interpreting test results, it is important to use the reference ranges provided by the individual laboratories.

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This is because rheumatoid factor testing is rarely used alone. The results of a rheumatoid factor (RF) test should be interpreted with caution. A negative test result indicates that little or no RF is found in the blood, but this does not rule out an underlying health issue. There are around 20% of people with rheumatoid arthritis who may have a negative RF test result, and their results may change over time.

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Testing positive for rheumatoid factors (RF) may indicate an underlying health condition, but this is insufficient to diagnose a condition on its own. In around 5 to 10% of healthy people, RF is detected in their blood. Positive results might also be related to an underlying autoimmune disorder, certain infections, or some types of cancer.

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While high values alone cannot diagnose any condition, research suggests that the higher the amount of RF in the blood, the greater the likelihood that a patient has an autoimmune disorder. In order to evaluate the cause of a patient’s symptoms, doctors often combine RF testing with physical examination, imaging tests, and other laboratory tests such as anti-CCP antibody testing, antinuclear antibody (ANA), and synovial fluid analysis.

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Working without a doctor when interpreting test results may be complex, so it’s important to work with a doctor when interpreting test results. Patients might also benefit from consulting a rheumatologist. Rheumatologists are doctors who specialise in diagnosing and treating autoimmune disorders and other conditions of the joints, muscles, and bones. A rheumatologist can help patients understand their test results as well as answer questions about the process of diagnosing autoimmune disorders.

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What are normal Rheumatoid Factor (RA) test results?

Less than 15.8 lU/L

The reference ranges may vary slightly among different laboratories. Some of the labs use different measurements or might test different samples. Talk to the doctor about the meaning of your specific test results.

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What other tests might I have along with this test?

• Anti-cyclic citrullinated peptide (anti-CCP).

• C-reactive protein test

• antinuclear antibody test

• Erythrocyte sedimentation rate test

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How do I book a Rheumatoid Factor (RA) test at home?

Log on to www.orangehealth.in and submit your details. Our highly trained, professional, and vaccinated eMedics will be at your doorstep within 60 minutes or at the time booked by you.