Your health care professional may refer you to a doctor trained in autoimmune and arthritis conditions, called a rheumatologist. If the rheumatologist thinks you may have an autoimmune disease, they may order some additional tests.

ANA test

An antinuclear antibodies test, known as an ANA test, finds antinuclear antibodies in the blood. The immune system usually makes antibodies to help the body fight infection. In contrast, antinuclear antibodies often attack the body’s own tissues. If your rheumatologist suspects you have an autoimmune disease, you may need an ANA test to get more information. A positive ANA test result means you have antinuclear antibodies, while a negative test means that you don’t have them.

ENA test

The ENA test is often used as a follow-up test after a positive ANA test. The ENA test can be the next step in finding out if you have an autoimmune disease and which one you have.

If you have a positive ANA test, an ENA test can check the blood for the presence of antinuclear antibodies that are known to be markers of certain diseases.

The ENA test can help your health care team and your rheumatologist diagnose autoimmune diseases such as:

If you’re diagnosed with an autoimmune disease, your health care team may use the ENA test in the future to check how the disease changes over time.

An ENA test uses a blood sample. If your health care team is only using the blood sample for an ENA test, you can eat and drink as usual before the test. If the blood sample may be used for more tests, you might need to not eat, called fast, for a time before the test. Your health care team will give you directions before the test.

Some medicines can affect the test and can cause the test results to show you have autoantibodies when you don’t. So bring your health care team a list of the medicines and supplements you take.

For an ENA test, a member of your health care team takes a blood sample by inserting a needle into a blood vessel, called a vein, in your arm. The blood sample goes to a lab for testing. You can return to your usual activities right away.

Your ENA test is positive if test results show the blood sample has autoantibodies. Your rheumatologist can use a positive ENA test result, along with a physical exam and other tests, to see if you have certain autoimmune diseases.

ENA test results can be hard to understand. Generally, an expert should review the results. It’s important to talk about the results with your rheumatologist and ask any questions you may have.

© 1998-2024 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved.

We Make Health Possible

As East Central Indiana’s population grows, we’re putting health care where people need it most. Besides Hancock Regional Hospital, ranked as one of the nation’s safest by the Lown Hospital Index, our network includes more than 30 other locations near your home or work.

Learn More about Hancock