White blood cells of the immune system produce antibodies, which are defensive proteins. They protect the body against pathogens that cause disease or infection, such as viruses and bacteria. Some antibodies can occasionally mistakenly attack the body’s cells, called autoantibodies. Immunoglobulins that targets a cell’s nucleus explicitly is called antinuclear antibody. Most people have autoantibodies in tiny quantities, which is usually considered normal and won’t cause any health implications.

Overview
Antinuclear antibodies (ANA) are also known as antinuclear factors (ANF). These attach to the contents of the cell’s nucleus and destroy them. The presence of ANF is a classic indication of the presence of an autoimmune connective tissue disease. These can be detected in the serum with the help of the ANA test.

ANA Test
A blood test called an ANA test screens the serum for antinuclear antibodies (ANAs). You may have an autoimmune condition if you test positive for ANAs.

ANA tests scientific working
This test examines a patient’s serum for antinuclear antibodies using fluorescently labeled anti-immunoglobulins that can bind to ANA. The nuclear components needed for the examination can be obtained from Hep-2 cells. They are then incubated with a patient’s sample in dilutions to measure the ANA titer. Antibodies directed against nuclear components will bind to the Hep-2 cells’ nuclei if they exist. A secondary fluorescent-labeled antibody directed against the species-specific immunoglobulin can be used in fluorescence microscopy to identify the bound ones.

Applications of ANA Test
An ANA test is used to diagnose autoimmune illnesses like:

• SLE, or systemic lupus erythematosus – It is the most prevalent form of lupus and is a chronic disease that can harm the brain, blood vessels, kidneys, joints, skin, heart, lungs, and many other organs.
• Rheumatoid arthritis – The wrists, hands, and feet are the most frequently affected body parts by rheumatoid arthritis, which primarily affects the joints and causes discomfort and swelling.
• Scleroderma – Scleroderma is a rare disorder that can damage the skin, blood vessels, and internal organs.
• Sjögren’s syndrome – Sjögren’s syndrome is a rare condition that affects several body organs and glands that produce saliva and tears.
• Addison disease – Fatigue and weakness are the symptoms of Addison disease, which affects your adrenal glands.
• Autoimmune hepatitis – It is another autoimmune disorder that makes your liver inflate.
• Polymyositis – It is a condition that affects a child’s muscles and causes weakness and inflammation.
• Dermatomyositis – People with polymyositis-like symptoms and skin involvement, such as a scaly rash, swelling, and purple spots, are said to have dermatomyositis.
• Mixed connective tissue disease (MCTD) – MCTD has characteristics in common with polymyositis, scleroderma, and SLE. The symptoms typically don’t manifest simultaneously. Instead, they happen sequentially over a long period.
• JIA – Also known as juvenile-onset idiopathic arthritis, it is a form of arthritis that can affect your child’s joints. For example, their knees, hands, wrists, and other joints might be harmed.

Preparation and what to expect
A sample of blood is needed for an ANA test. You can usually eat and drink before the test. A healthcare professional uses a needle to draw blood from a vein in your arm for the test. An analysis of the sample is done in a lab. You can get back to your regular activities post the test.

Result interpretation

• Negative result– If your test gives a negative ANA result, it means that antinuclear antibodies were not found in your blood. This shows that you are less likely to have an autoimmune condition. However, it is to be noted that a negative ANA test does not entirely rule out the possibility of an autoimmune disorder.
• Positive result– A positive ANA test result indicates the presence of antinuclear antibodies in your blood. This outcome could indicate the following:
• Lupus erythematosus systemic (SLE)
• A separate autoimmune condition
• Viral contamination, though antinuclear antibodies from a virus, are usually temporary
• Antinuclear antibodies can also develop in patients with cancer.

After the ANA test
The following stages depend on the person’s general state of health after a successful outcome, including determining the cause of the ANA levels using their symptoms. The likelihood that the result is a “true positive,” i.e., you have significant ANAs and an autoimmune illness, increases with the titer. For example, the likelihood of such a disease is regarded as minimal for ratios of 1:10 or 1:18. A high probability is indicated by a titer ratio of 1:160 to 1: 640 or higher.
The doctor will advise patients on effective treatment of the disease if the test results are accompanied by a set of symptoms and a medical history supporting the diagnosis of an autoimmune disorder.