Rheumatoid Factor (RA) Test- Quantitative

A healthy immune system is vital to the functioning of the human body. The immune system protects the body against disease-causing microorganisms. However, immune deficiency diseases decrease the body’s ability to fight invaders, causing vulnerability to infections. In response to an unknown trigger, the immune system may begin producing antibodies that, instead of fighting infections, attack the body's tissues.

One such autoimmune disease is Rheumatoid Arthritis. It is caused by the presence of the rheumatoid factor, which is an autoantibody produced by the immune system. Rheumatoid Arthritis is a systemic autoimmune disease that is chronic (for a long time). It causes inflammation, stiffness, pain and gradually causes permanent joint damage. Usually, it occurs after the age of 40 years. Women are more prone to be affected by it as compared to men.

A doctor may recommend the Rheumatoid Factor (RA) quantitative test if a patient is showing symptoms of Rheumatoid Arthritis. RA quantitative test detects the level of rheumatoid factor in the blood, which aids in diagnosing autoimmune diseases such as Rheumatoid Arthritis. If the X-ray of the patient shows swelling in the joint capsules along with the loss of cartilage and bone, an RF test is advised.

The results of a rheumatoid factor quantitative test are based on a blood sample.

Test preparation

Before the test

This is a very simple test; hence there is no preparation required for the same.

During the test

The procedure for sampling blood for a rheumatoid factor quantitative test is similar to other general blood tests. A Phlebotomist collects the blood from the vein of the arm into a vial through a sterilised needle. This process barely takes 5 minutes.

After the test

Like any other blood test, after the sample is taken, the point of contact is cleaned and pressure is applied on the spot to stop any bleeding. There is no risk from this test and post-test restrictions.

Test inclusion: What parameters are included?

The rheumatoid factor quantitative test only indicates the levels of RF present in the body. This test, coupled with other tests, helps in the diagnosis of autoimmune diseases. The result of the rheumatoid factor quantitative test is reported as titer, which is a measurement of how much your blood can be diluted before RF antibodies are undetectable.

Although, the results of the rheumatoid factor quantitative test alone is not an absolute indicator of a disease present in the body as an individual can have high RF levels but still be healthy and vice versa.

Rheumatoid Arthritis, Lupus Erythematosus, Sjogren's Syndrome, Chronic Infections

• The normal range depends on the age of the individual.
• Elevated RF levels might not necessarily prove the presence of an autoimmune disorder.

The normal values, parameters, and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.

The rheumatoid factor quantitative test is generally classified as positive or negative depending upon the levels. If the level is within the normal range, the result comes out as negative, whereas, in an elevated range case, the result comes out positive. The range of RF factors also varies from laboratory to laboratory and is also dependent on the method through which the test is performed.

If the result of the rheumatoid factor test is in the elevated range, it could be the indicator of an autoimmune disease such as rheumatoid arthritis and Sjorgen’s syndrome. Higher the level of rheumatoid factors present in the body, the higher the chance of having an autoimmune disease. It is best to get the report studied by a rheumatologist for accurate diagnosis.

A positive RF test can indicate the presence of the following disorders:

• Sjogren’s syndrome
• Systemic Lupus
• Inflammatory lung disorders
• Cancer
• Connective tissue diseases

The results of rheumatoid factor testing help the physician diagnose and pinpoint the reason for the elevated RF levels. While having a higher RF points towards a higher chance and severity of an autoimmune disease, having a low RF doesn’t rule out the possibility of an underlying health issue. Rheumatoid arthritis is the most common disease for which rheumatoid factor quantitative test is prescribed along with other tests such as:

• CCP antibody test
• ANA testing
• Synovial fluid analysis
• Erythrocyte sedimentation rate
• CRP test

People of older age tend to have higher RF levels as their body loses mobility with time. People between the age of 60 to 80 are found to have high RF levels. They tend to be at a higher risk of autoimmune diseases like rheumatoid arthritis.

Along with the above-mentioned tests, a physical exam and a diagnosis of the symptoms are made to get a better idea of the issue at hand. An even better option is to consult a rheumatologist as they are the experts in diagnosing autoimmune diseases and RF-related health issues. They can better analyse the patient’s condition and assist through treatment and recovery.