Rheumatoid arthritis Factor (RA Factor / RF / RFAC / RhF) Lab Test

Rheumatoid arthritis Factor (RA Factor / RF / RFAC / RhF)

Clinical Definition of Rheumatoid Arthritis Factor (RA Factor / RF / RFAC / RhF)

Rheumatoid factors are proteins produced by your immune system that can attack healthy tissue in your body. Rheumatoid factor is an autoantibody most often associated with autoimmune diseases; mostly Rheumatoid arthritis which attacks synovial joints and Sjögren's syndrome that affects the glands that produce tears & saliva.


How do You Understand the Result?

Understanding the results of the test is relatively simple. However, the doctor might conduct certain other tests along with the RF test to be able to provide an accurate diagnosis. One needs to remember that even in the blood of healthy people sometimes the rheumatoid factor test is positive.

The RA factor normal range is below 14 IU/ml for the Rheumatoid factor. Any values about 14IU/ml or above are considered high.


Why do I need this test?

Rheumatoid arthritis doesn’t have specific symptoms but creeps into the system very slowly with symptoms from other diseases and viruses, and gradually the frequency of these symptoms increases and the immune system becomes more vulnerable and weak. Symptoms to watch out for are:

• Weakness

• Dry eyes

• Dry mouth

• Loss of appetite

• Low fever

• Swollen glands Fatigue

Joint pain

• Chest pain when taking a breath

• Eye burning

• Itching

• Discharge

• Nodules under the skin Warm, tender, and stiff joints when not used

• Joint pain is on both sides of the body

• Swollen and spongy joints Numbness, tingling or burning in the hands and feet

• Joint pain in the mornings especially

• Warm, tender, and stiff joints when not used

• Joints may become deformed over the time

• Joint destruction may occur within 1 - 2 years after the disease appears

Along with this test, there might be tests suggested by the doctor for Sjögren syndrome. In this disease, the mucous membranes and the moisture-secreting glands of the mouth and eyes are attacked by white blood cells. These conditions result in dry mouth and eyes and excessive fatigue and joint and muscle pain.


What other tests might I have along with this test?

There are other blood tests also which are:

• Anti-nuclear antibody (ANA)

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

• C-reactive protein (CRP)

• Erythrocyte sedimentation rate (ESR, or sed rate)


When do you expect results?

The RA blood test results can be expected right away. There is no wait time required for the test results. It a test quickly done in a few minutes.


RA Factor Test Price

The RA Factor test is priced in the range of Rs 400 to Rs. 650.


What is a Rheumatoid Arthritis Factor (RA Factor / RF / RFAC / RhF) Lab Test?

The RA factor test or the Rheumatoid Arthritis Factor measures the amount of rheumatoid factor in your blood.

When the rheumatoid factor in the blood is high, it is often due to autoimmune diseases, like rheumatoid arthritis and Sjogren's syndrome. However, rheumatoid factor has also been detected in some healthy people, and there are people with normal levels of rheumatoid factor and still suffering from autoimmune diseases. The reasons for this are still unclear.


How is this test done?

The RF test is like any other simple blood test. The healthcare provider would draw blood from mostly the vein in your arm or, in rare cases, from the back of your hand. The entire procedure barely takes a few minutes. The steps that the healthcare provider would follow are mentioned below –

• First, the skin over the vein is cleaned.

• To have the blood fill the vein faster, an elastic band is tied around the arm

• Then a needle is inserted in the blood-filled vein

• The blood is collected in a sterile vial

• The puncture site is covered with either a gauze or an adhesive bandage

• The collected blood sample is sent for testing. 


Does this test pose any risk?

Since the blood test is fairly simple, the chances of any risk or complication are very rare. Either one of the following might occur at the puncture site –

• pain

• bleeding

• bruising

• infection

In rare cases, you might develop an infection at the puncture site or you might feel lightheadedness, dizziness, or fainting, while the blood is being drawn. If any of these occur, please inform the healthcare practitioner about the same.


How do I prepare for the test?

Since this is a very simple test, there is no preparation required for the same. The only thing to remember not everyone is comfortable with blood being taken. In case of any questions, please ask the doctor before the test. And if you feel nauseous or faint, please inform the practitioner.

In short,

No Fasting Required.

No other special preparations required.


Sample Required?

Specimen type: Serum (Blood Sample)

Specimen collection procedure: Venipuncture (Collection of blood from a vein, usually from the arm)


What do my test results mean?

In case of the RF test, the results are reported as a titer. Basically, it is a measurement of how much dilution is needed in the blood, so that the RF antibodies are no longer detectable. For 80% of the people suffering from rheumatoid arthritis, the test is positive. However, the titer level determines the severity of the disease.

Post the patient has been treated with any disease-modifying agents, there has been a visible decrease in the RF titer values. In case the disease needs to be monitored further, C-reactive protein (CRP) and the Erythrocyte sedimentation rate (ESR, or sed rate) tests can be used.

Further, it’s important to understand that a positive test doesn’t necessarily mean that one has rheumatoid arthritis.


Understanding results of Rheumatoid arthritis Factor (RA Factor / RF / RFAC / RhF)

Reference RangeInterpretation
Below 15 IU/mlNon-reactive


‘*A Reference range is a set of values which helps the healthcare professional to interpret a medical test. It may vary with age, gender, and other factors. Reference ranges may also vary between labs, in value & units depending on instruments used and method of establishment of reference ranges’