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:

• Lupus. This also is known as systemic lupus erythematosus. The most common symptoms are fatigue, fever and weight loss. Lupus can affect the joints, skin, kidneys, blood cells, brain, heart and lungs. Lupus often causes a facial rash that resembles the wings of a butterfly.
• Mixed connective tissue disease. Early symptoms of this disease often involve the hands. But symptoms can be the same as those for other autoimmune disorders, making it difficult to diagnose this disease. Many people with this disease also have Sjogren's syndrome.
• Sjogren's syndrome. This condition often happens in people who have other immune system disorders. Its two most common symptoms are dry eyes and a dry mouth.
• Scleroderma. This also is known as systemic sclerosis. It is a group of rare diseases that cause hardening and tightening of the skin. It also may cause problems in the blood vessels, organs and digestive system.
• Polymyositis and dermatomyositis. People who have other autoimmune diseases are at higher risk of developing these diseases. Symptoms of polymyositis and dermatomyositis include muscle weakness and skin rash.

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.