Rheumatoid Factor Test

The rheumatoid factor test is used to diagnose rheumatoid factor (RF) in your blood. This protein(RF) is part of a normal immunogenic response to the presence of a foreign body, such as bacteria or a virus, forming an intricate that the immune system can remove.

While normal antibodies attack pathogens like bacteria and viruses, autoantibodies such as RF mistakenly attack the body’s healthy cells and tissues.

Usually, not everyone has rheumatoid factors in their blood. And some people who have them are often healthy. But if you have specific symptoms and higher levels of rheumatoid factors, you may have an autoimmune disorder.

RF testing is mainly used with other tests to help diagnose rheumatoid arthritis. Rheumatoid arthritis (RA) is an autoimmune disorder that damages joints and causes pain, swelling, and stiffness. It is a chronic (long-lasting) condition that can also affect your organs and cause other symptoms.

What does the test measure?

RF testing estimates the amount of RF in the blood. There are many ways to measure RF, like an antibody titer test. These tests help detect how much of a specific type of antibody is present in the blood. Usually, an average titer is about 1:80, whereas a higher (>1:80) is a positive result.

When is RF testing advised?

The test is recommended if you are going through symptoms like-

• 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

Some factors that may increase the risk include smoking, women who have not given birth, children of mothers who smoked, and obesity. A decreased risk has been associated with women who breastfeed their babies.

It can be advised while testing for other health conditions. Other conditions in which RF testing may be used include:

• Sjögren’s syndrome
• Lupus
• Juvenile arthritis
• Scleroderma
• Certain infections, including mononucleosis or tuberculosis
• Certain types of cancer, including leukemia
• Hepatitis C
• Endocarditis
• Sarcoidosis

How is the test performed?

• Blood is drawn from a vein inside the elbow or the back of the hand.

• In infants or young children, a sharp tool called a lancet might be used to puncture the skin.

• The blood collects in a small glass tube called a pipette or on a slide or test strip.
• A bandage is put over the spot to stop any bleeding.

No special steps are to be taken before this test.

You may feel slight pain or a sting when the needle is inserted. And you may also feel some vibration at the site after the blood is drawn.