Diagnostics
Antinuclear Antibody test (ANA)
What is the ANA test?
An ANA test is a blood test that checks for antinuclear antibodies in the blood.
Antibodies are proteins the immune system makes to fight off foreign substances like viruses and bacteria. However, antinuclear antibodies mistakenly attack healthy cells, specifically the nucleus (center) of the cells.
Having a few antinuclear antibodies in the blood is normal. However, having a large number may indicate an autoimmune disorder. In autoimmune disorders, the immune system mistakenly attacks the body’s own organs and tissues, which can lead to potentially serious health issues.
The ANA test may also be called an antinuclear antibody panel, fluorescent antinuclear antibody, FANA, ANA, or ANA reflexive panel.
What should I do to prepare for the test?
For an ANA test, a blood sample is required. If the sample is solely for the ANA test, the patient can eat and drink normally before the test. However, if the blood sample is used for other tests, it is important to follow any fasting instructions provided by the doctor. It is really important to talk to the doctor about the medicines you are currently taking.
A laboratory technician will locate a vein in the arm, clean the site, and insert a small needle to draw blood into a vial. The process typically takes a few minutes. The blood sample will be sent to a lab for analysis, and the results may be available within a day.
What is it used for?
An ANA test is used to help diagnose various autoimmune disorders, including:
- Systemic lupus erythematosus (SLE): This is the most common type of lupus, a chronic disease that can affect multiple parts of the body, such as joints, skin, heart, lungs, kidneys, blood vessels, and brain.
- Rheumatoid arthritis (RA): RA primarily affects the joints, leading to pain and swelling, often in the wrists, hands, and feet.
- Scleroderma: This is a rare disease that can impact the skin, blood vessels, and organs, causing hardening and thickening of tissues.
- Sjögren’s syndrome: Sjögren’s syndrome is a rare disorder that primarily affects the glands responsible for producing tears and saliva, leading to dryness of the eyes and mouth. It can also affect other parts of the body.
- Addison’s disease: Addison’s disease affects the adrenal glands, leading to symptoms like fatigue, weakness, and low blood pressure.
- Autoimmune hepatitis: This condition involves inflammation and swelling in the liver, resulting in liver damage.
What do the results mean?
A negative result on an ANA test indicates that antinuclear antibodies were not detected in blood. This suggests a lower likelihood of having an autoimmune disorder.
A positive result on an ANA test means that antinuclear antibodies were found in the blood. A positive result doesn’t always mean someone has a disease. Healthy individuals, especially women over 65, can also have positive ANA tests.
Antinuclear antibodies can sometimes be associated with certain infectious diseases, cancers, or certain medications.
References
- Antinuclear Antibodies (ANA). Available from: https://rheumatology.org/patients/antinuclear-antibodies-ana
- ANA test. Available from: https://www.mayoclinic.org/tests-procedures/ana-test/about/pac-20385204
- ANA (Antinuclear Antibody) Test. Available from: https://medlineplus.gov/lab-tests/ana-antinuclear-antibody-test/
