Last Updated on July 28, 2022 by Dr. Neeraj Gujar
An antinuclear test is a blood check that checks for specific types of antibodies in your body. This test is also known as FANA (fluorescent-antinuclear antibody).
Antibodies are proteins that your immune system uses to fight bacteria, viruses, and other germs. Sometimes, however, your immune response may mistake your body cells for foreign invaders. You can be attacked by special antibodies called auto-antibodies that attack your cells. Autoantibodies can cause damage to your joints, skin, and muscles, as well as other parts of your body.
They can also be signs of autoimmune diseases such as:
- Rheumatoid arthritis
- Systemic lupus is the most common type.
- Sjogren’s syndrome
An ANA test can be positive for people who have cancer or are taking certain medications. ANA tests can be positive for people who have no medical conditions.
Also Read: The Complete Guide to PSA Test & How It Can Diagnose Prostate Cancer
Why Test Is Done?
Many rheumatic conditions have the same symptoms like joint pain, fatigue, and fever. Although the ANA test cannot confirm a particular diagnosis, it can rule certain diseases out. If the ANA test results are positive, you can have your blood tested for antinuclear antibodies. Some of these antibodies are specific to certain diseases.
When To Get Tested?
Your doctor might order an ANA test if you have symptoms of an autoimmune disease, such as:
- Joint and/or muscle pain, stiffness, or swelling
- Recurring or persistent fever
- Numbness and tingling in your hands or feet
- A red rash on the cheeks and bridge of the nose that looks like a butterfly
- Hair loss
- Light sensitivity
How To Get Tested?
Usually, you don’t have to prepare for an ANA exam. However, you should inform your doctor about any medications, vitamins, or supplements that you are taking. These can have an impact on the ANA test results.
During the Test
A lab tech will collect a sample from your blood, usually from a vein on your arm. To make the vein swell and fill up, they will tie a band around your upper arm. After that, they will clean the area with antiseptic and insert needles into your vein. The tube or vial will contain your blood.
The blood test will take only a few minutes. After the blood test is complete, the needle and band are removed and the area will be covered with gauze and a bandage.
A lab will test the blood sample. The lab will test your blood to determine if you have an antinuclear antibody.
After The Test
The blood test has very few risks. You might feel a slight sting as your blood is drawn. You may notice a small bruise later.
You may also have a slight chance of:
- Dizziness or fainting
If it finds an antinuclear antibody in your blood, the test is considered positive. If it finds none, it is negative. However, a positive test does not necessarily mean you have an autoimmune disorder. Antinuclear antibodies are found in between 3% and 15%, even in people who have no other conditions. They can also be caused by certain medicines and other diseases.
Some people with an autoimmune disorder will not test positive. The ANA blood testing is only one part of a doctor’s autoimmune disease diagnosis. They will also take into account your symptoms and perform a physical examination. Most likely, they will also do other tests.
ANA tests are usually positive for the following conditions:
- Systemic lupus, erythematosus
- Sjogren’s syndrome — A disease that causes dry eye and lips
- Scleroderma — A connective tissue disorder
- Rheumatoid arthritis — This causes joint damage, discomfort, swelling
- Polymyositis — A disease that causes muscle weakness
- Mixed connective tissue disorder — A condition with symptoms like lupus and scleroderma.
- Juvenile Chronic Arthritis — A type of autoimmune disease that affects children
- Dermatomyositis — A rare condition that causes a rash and weak muscles
- Polyarteritis Nodosa — A rare condition that causes blood vessels to swell and cause organ damage
- Autoimmune hepatitis
If you have any of these conditions, the ANA test can sometimes be positive.
- Raynaud’s Syndrome — A disease where your fingers and toes become blue and feel cold
- Thyroid Diseases — Hashimoto’s thyroiditis and Grave’s disease
- Liver Diseases – Autoimmune Hepatitis, Primary Biliary Cirrhosis
- Inflammatory Bowel Disease
- Lung diseases — idiopathic pulmonary fibrosis
- Viral infections
Around 20% of healthy individuals will test positive for antinuclear antibodies, even if they don’t have an autoimmune disease.
False positive results are more common in those who:
- Is a woman 65 years old or older eligible for Medicare?
- An infection such as mononucleosis, or tuberculosis
- Take blood pressure or anti-seizure drugs
Also Read: What’s the Purpose of Liver Function Test? What Diseases Does It Detect?
What To Do in Case of High Levels?
The ANA test can only detect if you have an autoimmune condition. It cannot diagnose the exact one.
Your doctor may test you for ANAs specific to certain diseases if your ANA test results are positive.
- Scleroderma is diagnosed by an anti-centromere test.
- A test for lupus that detects anti-double-stranded (anti-dsDNA), is available.
- A blood test for anti-histones diagnoses lupus caused by medication.
- Your doctor can use an ENA panel to determine if you have an autoimmune disease.
It is important to understand your ANA results. Ask about the other tests that you will need to confirm your diagnosis. Find out what your test results mean for your treatment.
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- Weselman K. (2021). Antinuclear antibodies (ANA).