Antibodies are proteins made by your immune system. They help your body recognize and fight infections. Normally antibodies target foreign materials, like bacteria and viruses, to help the immune system get rid of them.
Sometimes, antibodies are mistakenly made against normal proteins in the body. These antibodies can trigger an autoimmune response against your own cells and tissues. Antibodies that target healthy proteins in the nucleus of your cells are called antinuclear antibodies, or ANAs.
When the body receives signals to attack itself, autoimmune diseases like lupus, scleroderma, and mixed connective tissue disease can occur. While it is normal to have ANAs, an excess of these proteins can signal that you have, or are at increased risk for, an autoimmune disease.
Your doctor will order an ANA panel if you have signs of an autoimmune disorder, such as lupus, scleroderma, or rheumatoid arthritis. Symptoms vary for the different diseases, but they may include rashes, arthritis, or fatigue.
An ANA panel can help your doctor diagnose the underlying cause for your symptoms. A negative test means that an active autoimmune disease is unlikely.
If you have a positive test, your doctor will need to do additional tests. Further antibody testing can help determine which autoimmune disease might be causing your symptoms.
There is no preparation needed for the ANA panel. However, it is important to tell your doctor about any medications or supplements you are taking, even over-the-counter ones. Some drugs can affect the accuracy of the test.
The ANA panel is similar to any other blood test. An elastic band will be tied around your upper arm to make your veins swell with blood, making it easier to find a vein. After cleaning the site with an antiseptic, a needle will be inserted into a vein. Blood is then collected in a tube attached to the needle. You might feel some pain when the needle goes in, but the test itself is not painful. Once the blood is collected, the needle is removed from your vein and the insertion site is covered.
In infants or children, a lancet 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.
Collected blood is sent to a lab for examination.
A positive ANA test means that you have significant levels of ANA detected in your blood. However, this does not mean you have an autoimmune disease. According to the American College of Rheumatology, up to 15 percent of completely healthy people have a positive ANA test (ACR).
On its own, a positive ANA test does not diagnose a specific disease. However, some conditions are associated with a positive ANA test. These include:
- systemic lupus erythematosus
- chronic liver disease
- rheumatoid arthritis
- collagen vascular disease
- Sjögren syndrome
- thyroid disease
If your test comes back positive, your doctor will likely do a complete physical exam and blood tests for other antibodies. 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. This panel is not meant to be a diagnostic tool; it simply helps your doctor in ruling conditions in or out.
The ANA test is especially helpful when diagnosing lupus. According to the American College of Rheumatology, more than 95 percent of individuals with lupus will test positive (ACR). However, not everyone with a positive ANA has lupus, and not everyone with lupus tests positive for ANA. Therefore, the test cannot be used as the only method of diagnosis.
Some individuals may experience more discomfort than others during the blood test, as their veins may be harder to access. The risks of having the ANA panel done are minimal, but can include:
- excessive bleeding
- hematoma (blood building up under the skin)