About the Test
Purpose of the test
The purpose of an ANA test is to detect, measure, and evaluate ANA in your blood sample. ANA testing can assist health care providers in diagnosing autoimmune disorders and provide information that may help determine your specific type of autoimmune disorder.
Testing for ANAs may be suggested if you have symptoms of an autoimmune disorder. ANA may be detected in several of the following disorders, including:
- Systemic lupus erythematosus
- Sjögren’s syndrome
- Polymyositis and dermatomyositis
- Juvenile idiopathic arthritis
- Raynaud’s phenomenon
- Drug-induced lupus
- Mixed connective tissue disease
- Autoimmune hepatitis
- Scleroderma (systemic sclerosis)
- Thyroid disease
- Type I diabetes
- Psoriasis and psoriatic arthritis
ANA testing cannot diagnose an autoimmune disorder on its own. Doctors consider your ANA test results along with your symptoms, physical exam, and other laboratory tests to diagnose or rule out an autoimmune disorder.
What does the test measure?
Testing detects and measures the presence and amount of ANA in your blood. ANA attack the nucleus of healthy cells, which is why they are called “antinuclear.” The nucleus is a cell’s command center, sending signals that trigger important cell functions.
To help fight body infections, the immune system produces many antibodies. Sometimes these antibodies mistakenly identify normal proteins as foreign. A type of abnormal antibodies, ANAs are referred to as autoantibodies. ANAs that identify normal proteins in a cell’s nucleus as foreign are dangerous and can trigger a process of inflammation in which the body begins to attack itself.
About 3% to 15% of healthy people have a small number of autoantibodies in their blood. Levels of ANAs often increase with age, with up to one-third of healthy adults over 65 years of age testing positive for ANAs. When large amounts of autoantibodies are detected, it may indicate an autoimmune disorder.
When should I get an ANA?
Your doctor may test for ANA if you have symptoms of an autoimmune disorder. Common symptoms of autoimmune disorders include:
- Tiredness or fatigue
- Joint symptoms, including pain and swelling
- Muscle pain
- Abdominal pain
- Swollen glands
Once you are diagnosed with an autoimmune disorder, repeat ANA testing is not necessary. ANA testing does not diagnose a specific disease, nor is it useful in monitoring your disease or response to treatment.
Finding an Antinuclear Antibody Test
How can I get an antinuclear antibody test?
Testing for ANA is typically performed following a doctor’s recommendation. This test requires a blood sample drawn from a vein in your arm.
Can I take the test at home?
At-home testing for ANA is not currently available in the U.S. If you are interested in at-home autoimmune disorder testing, you may find it helpful to discuss this with a doctor.
How much does the test cost?
The cost for ANA testing can vary depending on several factors, including:
- Your health insurance coverage
- Where the test is conducted
- If ANA testing is combined with other blood tests
The testing costs may include additional fees for the blood draw, laboratory analysis, and office visits if you have health insurance. If the test is prescribed by a doctor, your health insurance often covers most or all of these costs. Discuss the copays, deductibles, and other fees that may be required with your health care provider.
Taking an Antinuclear Antibody Test
An ANA test is performed on a blood sample, which is taken in a doctor’s office, health clinic, or laboratory.
Before the test
ANA testing requires no pre-test preparation. As with other blood tests, it may be helpful to discuss any supplements or medications you are taking before the test. Some medications can cause a positive ANA test result. A doctor can also address any questions or concerns you have before taking this test.
During the test
To obtain the sample for an ANA test, blood is usually drawn from a vein in your arm using a needle. This process only takes a few minutes.
Once an appropriate vein is located, the health care provider may tie an elastic band around your upper arm and ask you to make a fist. They clean the site before inserting a needle and collecting blood into a tube. When the tube is full, the elastic band is removed from the arm and the needle is withdrawn. The health care provider may ask you to put pressure on the draw site area with a gauze pad; it is bandaged shortly after that.
You may experience minor pain or stinging sensation when the needle is inserted and removed. Once the needle is removed, you may have some minor discomfort at the draw site, but this usually improves in a short while.
After the test
After the blood draw is complete and the needle is withdrawn, you may be given gauze or cotton and be asked to apply pressure to the site where the needle was inserted. Pressure helps reduce bleeding, swelling, and bruising.
There are no restrictions on activities you can engage in after a blood draw for ANA testing.
Antinuclear Antibody Test Results
Receiving test results
How long it takes to receive test results can vary. Results may be available within a few business days, and doctors may review the results of ANA testing with you after additional tests are completed. When test results are available, they may be shared over the phone, by mail, or electronically.
Interpreting test results
There are several methods to measure ANAs. The indirect immunofluorescent ANA (IIF-ANA) test is the most widely used method. This test report includes a negative or positive interpretation, ANA levels, and patterns seen in antibodies during the test.
A negative interpretation indicates that autoantibodies weren’t detected in your blood sample and the presence of an autoimmune disorder is less likely. And a positive interpretation indicates that autoantibodies were detected in your blood sample.
A positive result on an ANA test does not always indicate that you have an autoimmune disorder. Some healthy patients can test positive for ANAs. Positive results can also be related to a viral infection, medications, certain cancers, and other health conditions. If test results are positive, a doctor may order follow-up testing, especially if you have persistent symptoms of an autoimmune disorder.
Results of ANA testing may include a titer. Antibody titer testing measures the number of antibodies in the blood by setting up various dilutions of the blood with normal saline (such as 1:40, 1:80, and 1:160) and observing the presence of fluorescence.
While reference ranges can vary from laboratory to laboratory, in general, a positive ANA would be a ratio of 1:60 or greater. Reference ranges for ANA tests are controversial. Labs may vary in what ratio they interpret as positive for ANAs. You may find it helpful to discuss reference ranges with your doctor.
The IIF-ANA test report also describes various fluorescent staining patterns produced during testing. Your blood specimen is mixed with a unique fixed tissue matrix called a substrate (HEp-2 cells) which have a strong affinity for and will bind to ANAs if present. A fluorescent dye is attached to another type of antibody (fluorescent-labeled anti-human immunoglobulin) that will attach to ANA.
Under a fluorescent microscope, different fluorescent patterns can be observed. While a staining pattern can’t diagnose a health condition definitively, some patterns are loosely associated with certain diseases. They also give doctors clues about the type of ANA present in your blood and can signal the need for additional testing. Staining patterns include:
Another method of ANA testing is a solid phase assay, called an enzyme-linked assay (EIA). Two types of EIA tests are used: a basic EIA test and the enzyme-linked immunosorbent assay (ELISA). The basic EIA is a generic assay for ANA and is reported much like the IIF-ANA as positive or negative. Yet the ELISA test is more specific and will detect single autoantigens such as daDNA, SS-A/Ro, SS-B/La, Scl-70, Sm, and SM/RNP.
When you present with symptoms associated with an autoimmune disorder, the IIF-ANA may be initially done and if positive, followed up with additional testing that specifically identifies certain autoantibodies present.
The presence of certain autoantibodies (like daDNA, SS-A/Ro, SS-B/La, Scl-70, Sm, SM/RNP, and Jo-1) has been associated with specific disorders such as lupus, Sjogren’s, and other autoimmune problems. Note that a single positive ANA test does not necessarily mean that you have a disease.
Autoimmune disorders can be difficult to diagnose. You may want to work with a rheumatologist who focuses on autoimmune disorders and conditions of the muscles, joints, and bones, along with your primary care physician. They can answer questions about autoimmune disorders and interpret ANA test results.
When discussing ANA testing with your doctor, you may find it helpful to review the following questions:
- How do I need to prepare for this test?
- Will additional tests or panels be performed at the same time as the ANA test?
- How does my test result help me understand the cause of my symptoms?
- Do I need any follow-up tests based on my test result?