At a Glance
Why Get Tested?
To help diagnose and distinguish between autoimmune disorders
When to Get Tested?
When your ANA (Antinuclear Antibody) test is positive; when you have symptoms that suggest an autoimmune disorder
A blood sample drawn from a vein in your arm
Test Preparation Needed?
The Test Sample
What is being tested?
An ENA (Extractable Nuclear Antigen Antibodies) panel detects the presence of one or more specific autoantibodies in the blood. Autoantibodies are produced when a person's immune system mistakenly targets and attacks the body's own tissues. This attack can cause inflammation, tissue damage, and other signs and symptoms that are associated with an autoimmune disorder.
ENA are a subset of antinuclear antibodies (ANA), antibodies directed against proteins found in the nucleus of cells. Certain autoimmune disorders are characteristically associated with the presence of one or more extractable nuclear antigen antibodies. This association can be used to help diagnose an autoimmune disorder and to distinguish between disorders.
The ENA panel is typically a group of 4 or 6 autoantibody tests. The number of tests offered will depend on the laboratory and the needs of the doctors and patients it serves. ENA panel tests, and other less common ENA tests, can also be ordered separately.
A 4-test ENA panel will include:
|Autoantibody||Also Known As|
|Anti-SS-A (Ro)||Anti-Sjögren Syndrome A|
|Anti-SS-B (La)||Anti-Sjögren Syndrome B|
A 6-test ENA panel will add:
|Autoantibody||Also Known As|
|Scl-70||Scleroderma Antibodies; anti-topoisomerase|
|Anti-Jo-1||Antihistidyl Transfer RNA Synthase Antibodies|
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
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