Patient education: Antinuclear antibodies (The Basics)

What are antinuclear antibodies? — 

Antinuclear antibodies, or "ANA," are proteins in the blood. They are made by the "immune system," which is the body's infection-fighting system.

Normally, a person's immune system makes antibodies when they get an infection. The antibodies attack the germs causing the infection.

If a person's immune system is not working normally, it sometimes makes antibodies that target their own body. These are called "autoantibodies." ANA are specific autoantibodies that attack substances inside of cells. Sometimes, this does not cause any problems. But for some people, the autoantibodies can damage different parts of the body. These include the blood, skin, joints, kidneys, lungs, and nervous system. When this happens, it is called an "autoimmune disease."

What is an ANA test? — 

This is a test that measures the amount of ANA in your blood:

●A "negative" result means you have no (or very little) ANA in your blood.

●A "positive" result means you have ANA in your blood.

Why might I get an ANA test? — 

A doctor or nurse will order an ANA test to help figure out if you have an autoimmune disease.

Many types of autoimmune diseases can cause a positive ANA test result. Some of these affect the whole body, such as:

●Lupus

●Scleroderma (sometimes called "systemic sclerosis")

●Mixed connective tissue disease

●Polymyositis

●Dermatomyositis

●Rheumatoid arthritis

Other autoimmune diseases affect only 1 part of the body, such as the thyroid (a gland in the neck), liver, or lungs.

For an ANA test, you have to get a blood draw.

What happens during a blood draw? — 

A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take "blood thinner" medicines or have a bleeding problem – They will make sure your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.

What do my results mean? — 

Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If you have a negative result, you probably do not have lupus, Sjögren's disease, mixed connective tissue disease, or scleroderma.

If you have a positive result, you might have 1 of these autoimmune diseases.

A positive result does not always mean you have an autoimmune disease. Healthy people can have a positive ANA test. Sometimes, a positive ANA test can happen for other reasons, like a recent infection. The higher the number (called the "titer") of your ANA test, the greater the chance you have an autoimmune disease.

If your ANA test shows any abnormal results, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out whether you have an autoimmune disease. These might include blood tests that look for more specific autoantibodies. These can help your doctor figure out which autoimmune disease you might have.

If you have a health problem, your doctor will work with you to come up with a treatment plan.

More on this topic

Patient education: Lupus (The Basics)
Patient education: Systemic sclerosis (scleroderma) (The Basics)
Patient education: Polymyositis (The Basics)
Patient education: Dermatomyositis (The Basics)
Patient education: Rheumatoid arthritis (The Basics)
Patient education: Polyarteritis nodosa (The Basics)
Patient education: Vasculitis (The Basics)
Patient education: Sjögren's disease (The Basics)

Patient education: Antinuclear antibodies (ANA) (Beyond the Basics)
Patient education: Systemic lupus erythematosus (Beyond the Basics)
Patient education: Polymyositis, dermatomyositis, and other forms of idiopathic inflammatory myopathy (Beyond the Basics)
Patient education: Rheumatoid arthritis symptoms and diagnosis (Beyond the Basics)
Patient education: Vasculitis (Beyond the Basics)
Patient education: Sjögren's disease (Beyond the Basics)