Antibodies are proteins made by your immune system. They help your body recognize and fight infections. Antibodies normally target harmful substances, such as bacteria and viruses, by activating the immune system to get rid of them.
Sometimes, however, antibodies mistakenly target your healthy cells and tissues. This is known as an autoimmune response. Antibodies that attack healthy proteins in the nucleus (brain) of your cells are called antinuclear antibodies (ANA).
When the body receives signals to attack itself, autoimmune diseases such as lupus (SLE), scleroderma, mixed connective tissue disease, and others can occur. Symptoms vary by disease, but they may include rashes, swelling, arthritis, or fatigue.
While it’s normal to have some ANA, having too many of these proteins will put you at an increased risk for developing an autoimmune disease, such as lupus. An ANA panel helps determine the level of ANA in your blood. You may have an autoimmune disorder if the level is too high.
Your doctor will order an ANA panel if you show signs of an autoimmune disorder. An ANA test can indicate that you have some type of autoimmune condition, but it can’t diagnose you with a specific disorder. If your test comes back positive, your doctor will need to do more specific and detailed testing to determine which autoimmune disease is causing your symptoms.
There is no preparation needed for the ANA panel. However, it’s important to tell your doctor about any medications or supplements that you’re taking, even over-the-counter ones. Some drugs can affect the accuracy of the test.
The ANA panel is similar to other blood tests. A phlebotomist will tie an elastic band around your upper arm so your veins swell with blood. This makes it easier for them to find a vein. After cleaning the site with an antiseptic, they’ll insert a needle into a vein. You might feel some moderate pain when the needle goes in, but the test itself isn’t painful. Blood is then collected in a tube attached to the needle. Once the blood is collected, the phlebotomist will remove the needle from your vein and cover the puncture site.
In infants or children, a lancet (small scalpel) may be used to puncture the skin, and blood may be collected in a small tube called a pipette. It may also be collected on a test strip.
The blood is then sent to a lab for examination.
The risks of doing an ANA panel are minimal. People with veins that are harder to access may experience more discomfort than others during the blood test. Other risks can include:
- excessive bleeding
- infection at the puncture site
- hematoma (blood building up under the skin)
A negative test means that an active autoimmune disease is unlikely.
A positive ANA test means that you have high levels of ANA in your blood. However, this doesn’t mean that you have an autoimmune disease. Up to 15 percent of completely healthy people have a positive ANA test. This is called a “false-positive” test result.
A positive ANA test alone can’t diagnose a specific disease. However, some conditions that are associated with a positive ANA test include:
- systemic lupus erythematosus (lupus): an autoimmune disorder that can affect different parts of your body, including the heart, digestive tract, and skin
- chronic liver disease (cirrhosis): scarring of the liver, which is most commonly caused by alcohol abuse and viral infections
- rheumatoid arthritis: an autoimmune disorder that causes pain, swelling, and stiffness in the joints
- Sjögren syndrome: an autoimmune disorder that affects the salivary and lacrimal glands, which produce saliva and tears
- scleroderma: an autoimmune disorder that primarily affects the skin and other connective tissues
- thyroid disease: a range of conditions can affect your thyroid, including hypothyroidism and hyperthyroidism
- temporal arteritis: a disorder, likely caused by an autoimmune response, in which the arteries supplying blood to the head and brain become damaged
Labs can differ in their standards for a positive test. Talk with your doctor about what your levels mean and how your symptoms may be explained by the presence of ANA. If your ANA test comes back positive, your doctor will need to run more tests in order to give you a diagnosis.
The ANA test is especially helpful in diagnosing lupus. More than 95 percent of people with lupus will test positive. However, not everyone that tests positive for ANA has lupus — and not everyone with lupus tests positive for ANA. Therefore, the test can’t be used as the only method of diagnosis.
Speak with your doctor about additional tests that can be done to determine the underlying cause of increased ANA in your blood.