ANA Test in Children
What is an ANA test?
An antinuclear antibody (ANA) test looks for antinuclear antibodies in your child’s blood. If your child tests positive for ANAs, it may mean they have an autoimmune disease. An autoimmune disease causes your child’s immune system to attack their own cells, tissues and organs by mistake.
What are antinuclear antibodies?
Antibodies are proteins made by white blood cells in your child’s immune system. Antibodies help defend against invaders (such as viruses and bacteria) that cause disease or infection.
Sometimes antibodies mistakenly attack your child’s own cells. These antibodies are called autoantibodies. An antinuclear antibody is an autoantibody that targets the center (nucleus) of a cell. The nucleus contains DNA, which tells the cell what to do. If there are enough antinuclear antibodies present, your child’s immune system may start to attack its own body.
Large amounts of ANAs in your child’s blood may be a sign of an autoimmune disease. But not everyone with elevated ANA levels has an autoimmune disease. Up to 30% of healthy people have detectable levels of ANAs. They’re also present in people with viral infections and in people using certain medications.
What is an ANA test used for?
ANAs can be present in various situations. Your child’s healthcare provider doesn’t use an ANA test to diagnose an autoimmune disorder. But they can use the results of an ANA test to help determine what kind of disease your child may have. Autoimmune diseases that can cause a positive ANA result include:
- Systemic lupus erythematosus (SLE): SLE (lupus) is an inflammatory disease. It causes joint pain, fever, weakness, fatigue, skin rashes and organ damage.
- Scleroderma: Scleroderma is a rare disease that causes abnormal thickening and hardening of your child’s skin and tissues. It can also affect your child’s gastrointestinal tract, lungs, kidneys, heart, blood vessels, muscles and joints.
- Polymyositis: Polymyositis is a disease of your child’s muscles that causes inflammation and weakness. It usually affects the muscles closest to your child’s trunk.
- Dermatomyositis: Dermatomyositis occurs when people have disease features of polymyositis and also skin involvement such as a scaly rash, swelling and purple spots.
- Mixed connective tissue disease (MCTD): MCTD shares features with SLE, scleroderma and polymyositis. Usually, the symptoms of these diseases don’t occur at the same time. Rather, they occur one after the other over a long period of time.
- Juvenile onset idiopathic arthritis (JIA): JIA is a type of arthritis that may affect the joints in a variety of ways in your child’s body. Their hands, wrists, knees and other joints may be affected. It may also affect other parts of your child’s body, including their skin, eyes, lungs, heart and blood.
- Sjögren’s syndrome: Sjögren’s syndrome is a condition that reduces the amount of moisture produced by the glands in your child’s eyes and mouth. Your child’s immune system damages the tear system in their eyes and the salivary glands in their mouth.
If your child has lupus and is taking an immunosuppressant, their healthcare provider may order frequent laboratory tests to track the effectiveness of the medication. But they typically won’t repeat or use the ANA as a marker of disease activity.
Why would my child need an ANA test?
Your child’s healthcare provider may order an ANA test if your child has symptoms of an autoimmune disease. Symptoms of autoimmune disorders may include:
How does an ANA test work?
An ANA test measures the level of antinuclear antibodies in a blood serum sample. The most widely used method is called indirect immunofluorescence assay (IFA). Another name for this method is fluorescent antinuclear antibody (FANA) test.
With an ANA screen with IFA, a pathologist will add your child’s serum sample to a microscope slide. They’ll add an antibody containing a fluorescent dye to the sample. The fluorescent antibody attaches to the cells in the sample. When a pathologist views the slide under a special microscope, any present ANAs will appear as fluorescent cells.
How does my child prepare for an ANA test?
Your child doesn’t need to do anything special to prepare for an ANA test. They can eat and drink normally on the day of the test. Some medications can cause positive ANA test results, so you’ll want to discuss any medications your child is taking with their provider. Your child’s healthcare provider can also answer any questions you or your child have.
What should my child expect during an ANA test?
An ANA test is a blood test. Your child’s healthcare provider will collect a small amount of blood in their office or a laboratory. Your child’s healthcare provider will look for a good vein to use on your child’s arm. Once they find a usable vein, they may tie an elastic band around your child’s upper arm or ask your child to make a fist. They’ll clean the site and then insert a small needle into the vein.
Your child’s healthcare provider will draw a small amount of blood into a test tube or vial. When the tube is full, they’ll remove the elastic band from around your child’s arm and withdraw the needle from their arm. Your child may feel a slight sting as the needle goes in or out. They may also feel a slight throbbing at the site where the blood was drawn.
What should my child expect after an ANA test?
After the ANA test, your child’s healthcare provider may use gauze or a cotton ball to apply slight pressure to the site where the blood was drawn. This helps reduce bleeding, swelling and bruising. They’ll apply a clean, dry bandage to the site. The entire process usually takes less than five minutes. Then, your child’s healthcare provider will send the sample to a laboratory for testing.
What are the risks and side effects of an ANA test?
There’s very little risk to having a blood test. Your child may experience minor discomfort or bruising at the site where the blood was drawn. But any pain or bruising should quickly subside.
Results and Follow-Up
When should I know the results of my child’s ANA test?
The length of time it takes to receive ANA test results can vary. They may be available within a few days. If your child’s healthcare provider orders other tests, they may share the results with you after reviewing all of them.
What do the results of an ANA test mean?
An ANA test report will show three factors: interpretation, titer reading and fluorescent pattern.
A negative interpretation means your child’s blood had no detectable levels of ANAs. An autoimmune disorder is less likely. A positive interpretation means your child’s blood had detectable levels of ANAs. An autoimmune disorder is possible, but more tests are necessary to confirm.
Titer reading measures the amount of antibodies in your child’s blood. A pathologist will add salt water (saline) to the protein-rich liquid part of your child’s blood (plasma). This method is like making lemonade from a can of frozen concentrate. You dilute one can of concentrate into four cans of water. For a titer reading, they’ll mix one part plasma into 40 parts saline to create a 1:40 dilution. The mixture is called a titer.
They’ll take the mixture through a series of additional steps of dilution. They’ll create a new sample at half the strength (1:80). They’ll continue this process until the test yields a negative result. The pathologist will report the last dilution that yields a positive result.
If ANAs are present, the pathologist will see fluorescent cells making a staining pattern. The fluorescent pattern seen can help identify the type of autoimmune disease present. Staining patterns include:
- Homogenous: A homogenous staining pattern means the entire nucleus is stained with ANA. It’s the most common type of staining pattern. A homogenous pattern can mean any autoimmune disease but more specifically, lupus or Sjögren’s syndrome.
- Speckled: A speckled staining pattern means fine, coarse speckles of ANA are present throughout the nucleus. A speckled pattern may indicate various diseases, including lupus and Sjögren’s syndrome.
- Centromere: A centromere staining pattern means the ANA staining is present along the chromosomes. A centromere pattern may indicate scleroderma.
- Nucleolar: A nucleolar staining pattern means ANA staining is present around the nucleoles. The nucleoles is inside the nucleus and produces the cell’s ribosomes. A nucleolar pattern may indicate scleroderma. But it can also indicate Sjögren’s syndrome or mixed connective tissue disease or be a false positive.
- Peripheral: A peripheral staining pattern means ANA staining is present around the edges of the nucleus. It has a shaggy appearance. A peripheral pattern may indicate lupus.
What does a positive ANA result mean?
A positive ANA screen result means antinuclear antibodies are in your child’s blood. This may mean your child has an autoimmune disease, such as lupus. But elevated ANA in your child’s blood doesn’t mean your child has an autoimmune disorder. Many healthy people have ANAs in their blood. Also, certain medications and viral infections can affect the results of an ANA test.
If your child’s ANA test is positive, their provider will usually order further tests before making a diagnosis. ANA test results can’t interpret an autoimmune disorder on its own. To diagnose or rule out an autoimmune disorder, your child’s healthcare provider will consider your child’s:
- ANA test results.
- Physical examination.
- Other lab tests.
What questions should I ask my child’s healthcare provider?
- How should my child prepare for an ANA test?
- Will my child have other tests at the same time as the ANA test?
- How does my child’s ANA test result help me understand the cause of their symptoms?
- Does my child need any follow-up tests based on their test result?
A note from Cleveland Clinic
If your child needs an ANA test, you may both be worried. The test itself is a simple blood draw that should take less than five minutes. The results of an ANA test are just one factor your child’s healthcare provider will look at when diagnosing an autoimmune disease. They’ll also look at your child’s symptoms, family history and other test results before making a diagnosis. However, the results of an ANA test can help provide valuable clues to help figure out if your child has an autoimmune disease.
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