ANA Screen

The Antinuclear Antibody (ANA) Screen by Access Medical Labs is a single-biomarker lab test that detects the presence and quantity of clinically relevant circulating autoantibodies in serum.

Antinuclear Antibodies (ANA) are autoantibodies produced by the immune system that target components within the nucleus of cells. In other words, the body is producing antibodies that are programmed to attack one’s own cells, rather than a foreign invader. ANA testing is commonly used in the field of rheumatology to help screen for and diagnose autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis, Sjögren's syndrome, and others.

How is ANA Tested? 

The ANA test is performed using a blood sample. It detects the presence and quantity of ANA in the blood serum. The test is usually performed through an indirect immunofluorescence assay (IFA), where the patient's serum is exposed to cells that are fixed to a slide. If ANA is present, it will bind to the cells, and a fluorescent dye is used to visualize the binding pattern under a microscope.

ANA testing is not a specific diagnostic test for any particular autoimmune disease. Instead, it serves as a first-line screening tool to detect the presence of autoantibodies. A positive ANA result indicates that the patient has antibodies targeting nuclear components (which indicates autoimmunity), but further testing is required to determine the specific autoimmune condition.

The ANA test results are primarily reported as a titer, which represents the highest dilution of the patient's serum that still produces a positive result. For example, a titer of 1:320 means that the serum can be diluted 320 times and still show a positive result. Higher titers generally indicate a higher concentration of ANA in the blood.

ANA binding patterns can also provide additional information. These patterns include homogeneous, speckled, nucleolar, centromere, and others. Different patterns may be associated with specific autoimmune diseases, helping to guide further diagnostic investigations and follow-up tests.

It is important to note that a positive ANA test does not necessarily mean a person has an autoimmune disease, and a negative test cannot completely rule out autoimmunity. ANA can be present in healthy individuals or as a result of certain infections, medications, or other non-autoimmune conditions. Therefore, clinical correlation and additional testing are necessary to make a definitive diagnosis.

Who Should Get an ANA Test?

ANA (Antinuclear Antibody) testing is typically ordered for patients who present with symptoms that may be indicative of an autoimmune disorder. These symptoms can include:

Joint pain and swelling: Patients experiencing persistent joint pain, stiffness, and swelling may be tested for ANA to rule out conditions such as rheumatoid arthritis or systemic lupus erythematosus (SLE).

Fatigue and malaise: Unexplained fatigue, weakness, and a general feeling of being unwell can be signs of an autoimmune disorder, prompting ANA testing.

Skin rashes: Certain autoimmune conditions, like SLE, can cause characteristic rashes, such as a butterfly-shaped rash across the cheeks and nose. ANA testing may be ordered to investigate the underlying cause.

Raynaud's phenomenon: Patients with Raynaud's phenomenon, where fingers and toes become numb and cold in response to cold temperatures or stress, may be tested for ANA to assess for possible autoimmune connective tissue disorders.

Hair loss: Unexplained hair loss, especially in patches or in a diffuse pattern, can be associated with autoimmune conditions like alopecia areata. ANA testing may be considered in such cases.

Digestive issues: Chronic gastrointestinal symptoms, such as abdominal pain, diarrhea, or malabsorption, may prompt ANA testing to explore potential autoimmune causes like celiac disease or inflammatory bowel disease.

Thyroid dysfunction: Patients with unexplained thyroid dysfunction, such as hypothyroidism or hyperthyroidism, may undergo ANA testing to evaluate for autoimmune thyroid disorders like Hashimoto's thyroiditis or Graves' disease.

It is important to note that ANA testing alone cannot diagnose a specific autoimmune condition but can indicate the presence of autoantibodies that trigger further investigation and correlation with clinical symptoms. The decision to order ANA testing should be made by a healthcare provider based on a thorough evaluation of the patient's medical history, physical examination, and symptomatology.

What is a Normal ANA Range?

The results of ANA testing are reported as a titer, which indicates the concentration of antibodies in the blood, and a pattern, which describes the appearance of the antibodies under a microscope. The normal range for ANA titers is typically reported as less than 1:40 or less than 1:80, depending on the laboratory.

However, it is important to note that a positive ANA test does not necessarily mean a person has an autoimmune disease (many healthy individuals can have low levels of ANA in their blood), and in the presence of other symptoms or abnormal blood markers, a negative ANA cannot assure the absence of autoimmunity. Therefore, the interpretation of ANA results should be done in conjunction with a person's symptoms, medical history, and other diagnostic tests by a trained medical professional.

If a person has a positive ANA test, further testing may be done to determine the specific pattern of the antibodies and to evaluate for specific autoimmune diseases.

What Does High ANA Indicate?

A high ANA (antinuclear antibody) level is a result of a blood test that measures the presence and concentration of antibodies that target the nucleus of cells. ANA is commonly used as a screening test for autoimmune diseases, as these conditions often lead to the production of these antibodies.

A high ANA level indicates that there is an increased amount of these antibodies in the bloodstream. However, it is important to note that a high ANA level alone does not provide a definitive diagnosis of any specific autoimmune disease. It is just an indication that further investigation is necessary.

There are several reasons why someone may have a high ANA level:

Autoimmune diseases: Many autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis, Sjögren's syndrome, and systemic sclerosis, can cause a high ANA level. However, it is important to remember that not all individuals with high ANA levels will develop these diseases.

Infections: Certain infections, such as viral or bacterial infections, can cause a temporary increase in ANA levels. This is known as a false-positive result and usually resolves once the infection is treated.

Medications: Some medications, such as certain antibiotics, antihypertensives, and anticonvulsants, can lead to a high ANA level. This is also considered a false-positive result and typically resolves once the medication is discontinued.

Age and gender: ANA levels tend to be higher in older individuals and women, even in the absence of autoimmune diseases.

If a person has a high ANA level, further testing and evaluation are necessary to determine the underlying cause. This may involve additional blood tests, a thorough medical history, physical examination, and possibly a referral to a specialist, such as a rheumatologist or immunologist.

It is important to remember that the interpretation of ANA results should always be done in the context of the individual's symptoms, medical history, and other clinical findings. A high ANA level should not be used as a standalone diagnostic tool but rather as a starting point for further investigation.

What Does Low ANA Indicate?

A low ANA (Antinuclear Antibody) result typically indicates that there are no detectable levels of these antibodies in the blood. ANA antibodies are produced by the immune system and are directed against the body's own cells and tissues, so a low ANA result is generally considered normal, suggesting that there is no evidence of autoimmune activity or systemic autoimmune diseases such as lupus, rheumatoid arthritis, or Sjögren's syndrome. 

However, it is important to note that a low ANA does not completely rule out the possibility of these conditions, as some individuals with autoimmune diseases may still have low or negative ANA results.

It is also worth mentioning that ANA testing is just one tool used in screening for and diagnosing autoimmune diseases; a comprehensive evaluation of symptoms, medical history, and other laboratory tests is necessary for a definitive diagnosis.

If a person is experiencing symptoms that are suggestive of an autoimmune condition, but their ANA result is low, further investigation may be needed to determine the underlying cause of their symptoms. This may involve additional lab tests, imaging studies, or consultation with a specialist in autoimmune diseases.