What number is positive for lupus?
ANA (Antinuclear Antibody) Test
An ANA test is a blood test that looks for antinuclear antibodies in your blood. Antibodies are proteins that your immune system makes to fight foreign substances, such as viruses and bacteria. But an antinuclear antibody attacks your own healthy cells instead. It’s called «antinuclear» because it targets the nucleus (center) of the cells.
It’s normal to have a few antinuclear antibodies in your blood. But a large number may be a sign of an autoimmune disorder. If you have an autoimmune disorder, your immune system attacks the cells of your organs and tissues by mistake. These disorders can cause serious health problems.
Other names: antinuclear antibody panel, fluorescent antinuclear antibody, FANA, ANA, ANA reflexive panel
What is it used for?
An ANA test is used to help diagnose autoimmune disorders, such as:
- Systemic lupus erythematosus (SLE), the most common type of lupus. Lupus is a chronic (long-lasting) disease that affects many parts of the body, including the joints, skin, heart, lungs, blood vessels, kidneys, and brain.
- Rheumatoid arthritis, a condition that mostly affects joints, causing pain and swelling often in the wrists, hands, and feet.
- Scleroderma, a rare disease that may affect the skin, blood vessels, and organs.
- Sjögren’s syndrome, a rare disease that affects the glands that make tears and saliva (spit) and other parts of the body.
- Addison Disease, which affects your adrenal glands, causing fatigue and weakness.
- Autoimmune hepatitis, which causes swelling in your liver.
Why do I need an ANA test?
Your health care provider may order an ANA test if you have symptoms of an autoimmune disorder. The symptoms depend on the part of the body that’s affected. They may include:
- Rash, blisters, or skin color changes
- Joint pain, stiffness, and swelling
- Muscle pain
What happens during an ANA test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Will I need to do anything to prepare for the test?
You don’t need any special preparations for an ANA test.
Are there any risks to the test?
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results mean?
Results from an ANA test alone cannot diagnose a specific disease. Your provider will use your ANA test results along with other tests and information about your health to make a diagnosis.
A negative result on an ANA test means that antinuclear antibodies were not found in your blood, and you’re less likely to have an autoimmune disorder. But a negative ANA test doesn’t completely rule out the possibility that you could have an autoimmune disorder.
A positive result on an ANA test means that antinuclear antibodies were found in your blood. A positive result may be a sign of:
- Systemic lupus erythematosus (SLE)
- A different type of autoimmune disease
- A viral infection (antinuclear antibodies from a virus are usually temporary)
- Another health condition that can cause antinuclear antibodies, such as cancer.
If your ANA test results are positive, your provider will likely order more tests to make a diagnosis.
Having antinuclear antibodies in your blood doesn’t always mean you have a disease. Some healthy people have antinuclear antibodies in their blood, and levels tend to increase with age. As many as one-third of healthy adults over the age of 65 may have a positive ANA test result. Also, certain medicines can cause antinuclear antibodies.
If you have questions about your results, talk with your provider.
- American College of Rheumatology [Internet]. Atlanta: American College of Rheumatology; c2022. Antinuclear Antibodies (ANA); [updated 2021 Dec; cited 2022 Apr 27]; [about 3 screens]. Available from: https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Antinuclear-Antibodies-ANA
- Hinkle J, Cheever K. Brunner & Suddarth’s Handbook of Laboratory and Diagnostic Tests. 2nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Antinuclear Antibodies (ANAS); p. 53.
- Lupus Research Alliance [Internet]. New York: Lupus Research Alliance; c2022. About Lupus; [cited 2022 Apr 27]; [about 9 screens]. Available from: https://www.lupusresearch.org/understanding-lupus/what-is-lupus/about-lupus
- Lupus Research Alliance [Internet]. New York: Lupus Research Alliance; c2022. Symptoms; [cited 2022 Apr 27]; [about 11 screens]. Available from: https://www.lupusresearch.org/understanding-lupus/what-is-lupus/symptoms
- Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2022. Sjögren’s Syndrome; [modified 2020 Apr; cited 2022 Apr 27]; [about 5 screens]. Available from: https://www.merckmanuals.com/professional/musculoskeletal-and-connective-tissue-disorders/autoimmune-rheumatic-disorders/sjögren-syndrome
- Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2017. Systemic Lupus Erythematosus (SLE); [modified 2020 Apr; cited 2022 Apr 27]; [about 9 screens]. Available from: http://www.merckmanuals.com/home/bone,-joint,-and-muscle-disorders/autoimmune-disorders-of-connective-tissue/systemic-lupus-erythematosus-sle
- Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2022. ANA test; [cited 2022 Apr 27]; [about 4 screens]. Available from: https://www.mayoclinic.org/tests-procedures/ana-test/about/pac-20385204
- National Institute of Arthritis and Musculoskeletal and Skin Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Autoimmune Diseases; [reviewed 2016 Mar; cited 2022 Apr 27]; [about 6 screens]. Available from: https://www.niams.nih.gov/health-topics/autoimmune-diseases
- National Institute of Arthritis and Musculoskeletal and Skin Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Rheumatoid Arthritis; [reviewed 2019 Sep; cited 2022 Apr 27]; [about 5 screens]. Available from: https://www.niams.nih.gov/health-topics/rheumatoid-arthritis/basics/symptoms-causes
- NIH U.S. National Library of Medicine: Genetics Home Reference [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; rheumatoid arthritis; [updated 2020 Aug 18; cited 2022 Apr 27]; [about 8 screens]. Available from: https://ghr.nlm.nih.gov/condition/rheumatoid-arthritis
- Testing.com [Internet]. Seattle (WA).: OneCare Media; c2022. Antinuclear Antibody (ANA); [modified 2021 Nov 9; cited 2022 Apr 27]; [about 13 screens]. Available from: https://www.testing.com/tests/antinuclear-antibody-ana/
- UF Health: University of Florida Health [Internet]. University of Florida; c2017. Antinuclear antibody panel: Overview [updated 2019 Jan 10; cited 2022 Apr 27]; [about 4 screens]. Available from: https://ufhealth.org/antinuclear-antibody-panel
- University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2022. Health Encyclopedia: Antinuclear Antibody; [cited 2022 Apr 27]; [about 4 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=antinuclear_antibodies
- UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2022. Antinuclear Antibodies (ANA) Test; [updated 2021 Dec 20; cited 2022 Apr 27]; [about 8 screens].Available from: https://patient.uwhealth.org/healthwise/article/en-us/hw2297
Related Health Topics
- Autoimmune Diseases
- Immune System and Disorders
- Rheumatoid Arthritis
- Sjogren’s Syndrome
Antinuclear antibody panel
The antinuclear antibody panel is a blood test that looks at antinuclear antibodies (ANA).
- ANA are antibodies produced by the immune system that bind to the body’s own tissues.
- The antinuclear antibody test looks for antibodies that bind to a part of the cell called the nucleus.
If the test is positive, a panel of tests may be done to identify specific antibodies. This is the ANA antibody panel.
Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.
How the Test is Performed
Blood is drawn from a vein. Most often, a vein on the inside of the elbow or the back of the hand is used. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.
Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
Depending on the laboratory, the test may be processed in different ways. One method requires a technician to examine a blood sample under a microscope using ultraviolet light. The other uses an automated instrument to record the results.
How to Prepare for the Test
No special preparation is needed. However, certain drugs, including birth control pills, procainamide, and thiazide diuretics, affect the accuracy of this test. Make sure your provider knows about all the medicines you take.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others may feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the Test is Performed
You may need this test if you have signs of an autoimmune disorder, such as unexplained symptoms including arthritis, rashes, fevers or chest pain. Suspected systemic lupus erythematosus may be the most common reason why the test is done.
ANA test results are most often reported in 2 parts: the level or titer and the pattern.
- Titres are reported in ratios, most often 1:40, 1:80, 1:160, 1:320, and 1:640. Some, but not all labs will report a titre above 1:160 as positive.
- Patterns that are reported include, homogeneous, speckled, centromere, and others.
Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
Further tests can be run on blood with a positive ANA test to get more information.
What Abnormal Results Mean
A positive ANA is not enough to make a diagnosis. To diagnose any disease related to a positive ANA, it is important to have:
- A full assessment by a doctor who specializes in any of the illnesses listed below
- Further antibody testing, for certain illnesses
To make the diagnosis of SLE, the following must be present
- Certain clinical features
- Positive ANA results (a lack of ANA makes the diagnosis much less likely)
- Certain specific ANA antibodies, which help to confirm the diagnosis
Other disorders besides SLE where positive ANA results strongly suggest a diagnosis include:
- Systemic sclerosis (scleroderma)
- Sjögren syndrome (primary)
- Myositis (inflammatory muscle disease)
- Drug-induced lupus erythematosus
Other common diseases that ANA testing can help diagnose include:
- Mixed connective tissue disease
- Autoimmune hepatitis
- EB virus
- Hepatitis C
- Rheumatoid arthritis
- Thyroid disease
Veins and arteries vary in size from one person to another, and from one side of the body to the other. Obtaining blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
The ANA can be positive in relatives of people with SLE who do not have SLE themselves.
There is a very low chance of developing SLE at some time later in life if the only finding is a low titer of ANA.
American College of Rheumatology website. Antinuclear antibodies (ANA).
. Updated March 2019. Accessed May 12, 2021.
Peng SL, Craft JE. Anti-nuclear antibodies. In: Firestein GS, Budd RC, Gabriel SE, Koretzky GA, McInnes IB, O’Dell JR, eds. Firestein & Kelley’s Textbook of Rheumatology. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 58.
von Mühlen AC, Chan EKL, Ceribelli A, Fritzler MJ. Clinical and laboratory evaluation of systemic autoimmune rheumatic diseases. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 53.
Last reviewed on: 1/31/2021
Reviewed by: Diane M. Horowitz, MD, Rheumatology and Internal Medicine, Northwell Health, Great Neck, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
While no single test can determine whether a person has lupus, several laboratory tests may help the doctor confirm a diagnosis, or at least rule out other ailments. The most useful tests identify certain autoantibodies that are often present in the blood of lupus patients. A biopsy of the skin or kidneys may also be ordered if those organs are affected. The doctor will look at the entire picture – medical history, symptoms, and test results – to determine if you have lupus. Other laboratory tests are used to monitor the progress of the disease once it has been diagnosed.
ELEVEN CRITERIA OF LUPUS
At least four of the eleven criteria of lupus from the American College of Rheumatology are usually present for lupus to be diagnosed.
- Malar rash – a butterfly shaped rash across cheeks and nose
- Skin rash – raised red patches
- Photosensitivity – unusually strong reaction to sun light, causing a rash or flare
- Mouth or nose ulcers – usually painless
- Nonerosive arthritis – inflammation in two or more joints.
- Cardio-pulmonary involvement – inflammation of the heart lining and/or lungs
- Neurologic disorder – seizures and/or psychosis
- Kidney disorder – increased protein or clumps of red cells in urine
- Blood disorder – anemia caused by damaged red cells, low white cells or low platelet count
- Immunological disorder – when your immune system attacks healthy cells
- Antinuclear antibodies (ANA) – positive blood test not induced by drugs
The antinuclear antibody (ANA) test is commonly used to look for autoantibodies that attack components of your cells’ nucleus, or “command” center, triggering autoimmune disorders like lupus. 95% of people with lupus test positive for ANA, but a number of other, non-lupus causes can trigger a positive ANA, including infections and other autoimmune diseases. The ANA test simply provides another clue for making an accurate diagnosis.
For patients with a positive ANA, more tests are usually performed to check for other antibodies that can help confirm the diagnosis. This series of tests, commonly called an ANA panel, checks for the following antibodies: anti-double-stranded DNA, anti-Smith, anti-U1RNP, anti-Ro/SSA, and anti-La/SSB. Some laboratories also include other antibodies in their panel, including antinucleoprotein, anticentromere, or antihistone.
Doctors use these supplemental tests in conjunction with a person’s clinical history to help diagnose or rule out other autoimmune disorders. Specifically, they look for signs of inflammation, active lupus, active autoimmune disease, and kidney problems.
Laboratory tests for lupus include:
- Complete blood count (CBC)
- Erythrocyte sedimentation rate (ESR)
- Blood chemistries
- Complement levels
- Antinuclear antibody test (ANA)
- Anticardiolipin antibody test (blood clotting)
Content provided courtesy of Lupus Research Alliance .