Antinuclear Antibody Lab Values

A normal function of the immune system is the synthesis of antibodies to fight foreign invaders like bacteria and viruses, however, ANA are abnormally produced in the presence of autoimmune disease. They are called antinuclear because they attack the nucleus of healthy cells. Measurement is used to detect autoimmune disorders.

Antinuclear Antibody

Proteins synthesized by the immune system
Attacks healthy cells
Targets the nucleus
Present in autoimmune disease

Indications:

Indicated:

Aids diagnosis of autoimmune disorders
- NOT definitive, but assistive

Normal Therapeutic Values:

Normal –

Negative

Collection:

Serum Separator Tube

What would cause a positive test result?

ANA present in the blood

Could indicate:
- Systemic Lupus Erythematosus – joints, blood vessels, kidneys, brain
- Rheumatoid Arthritis – pain and swelling in the joints, mostly hands and feet
- Scleroderma – skin, joints, blood vessels
- Sjogren’s syndrome – rare disease affecting body’s moisture-producing glands
- Thyroid disease – Hashimoto’s, Grave’s
- IBD
- Pulmonary fibrosis
- Viral, bacterial, and parasitic infection
“False” Positive
3- 15% of healthy individuals test positive for ANA
Cancer diagnosis
Medications
Age-dependent
- 10-37% prevalence > 65 years of age

What would cause a negative test result?

A negative blood test identifies a lack of antinuclear antibodies

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Transcript

Hi there, Abby here with nursing.com. In this lesson, we’ll discuss antinuclear antibodies. We’ll talk about normal values and the conditions in which they might be increased or decreased. Let’s dive in!

An antinuclear antibody test measures and aids in the detection of autoimmune diseases. So, what are antibodies? Antibodies are made by the immune system, right? And the immune system makes these wonderful, helpful, little antibodies when there’s bacteria, or a viral infection, or some kind of parasitic infection, right? And it’s meant so that these antibodies will actually attack these foreign invaders. However, in the case of autoimmune diseases, these are proteins, specifically antinuclear antibodies, that are synthesized by the immune system, and they’re actually called autoantibodies. And what they do is that they attack healthy cells. They’re abnormally produced, so they’re attacking cells that we love, and these in particular are antinuclear, which means that they’re anti nucleus. Now, do you remember what lives in the nucleus? That’s right, DNA. That’s my version of the double helix, right? And so that’s really not great, because our DNA is what gets transcripted and then passed on to new daughter cells, right? So, these cells are present in autoimmune disease, where the body is essentially attacking itself. Just like in this picture, this gentleman has lupus.

So, a clinical indication is to aid in the diagnosis of autoimmune disease, but it’s not definitive. It’s assistive. So, lots of labs are taken in a panel or as part of a lab study, as they sometimes call it. This is another picture or another example of an autoimmune disease, rheumatoid arthritis, where there’s tons of inflammation in the joints.

A normal result for the antinuclear antibody test is negative. That would show a lack of those antibodies. Its collection happens through a serum separator tube like this gold top. So, let’s look at the lab results. If it’s positive, that means that those antinuclear antibodies are present in the blood, and we see those antinuclear antibodies in these autoimmune diseases, and they can even be present in thyroid disease, pulmonary fibrosis, and as I mentioned, viral, bacterial, and parasitic infections. But beware, there can be false positives. Look how crazy this is. In 3 to 15% of healthy individuals, they will test positive for antinuclear antibodies, nothing’s perfect. And we can see these antinuclear antibodies pop up in a cancer diagnosis as a side effect of certain medications. And even with advanced age, 10 to 13% prevalence in those that are 65 years of age or older, have a presence of antinuclear antibodies, and a negative test result.

A negative test result shows us that there is a lack of antinuclear antibodies. This is one of those tests or one of those times when we like to be negative.

The linchpins of this lesson are that antinuclear antibodies are proteins that are synthesized abnormally by the immune system, and they attack healthy cells, particularly the nucleus. When we have a normal test result, that means negative, we don’t have those ANAs in the blood. When it’s positive, this is going to aid in the diagnosis of autoimmune disease, but they can also be present in infection, advanced age, as a result of medications, and some cancer diagnoses. The negative test result that we want is a lack of antinuclear antibodies. They should be absent or a normal production.

That wraps up our lesson on antinuclear antibodies. You all did a great job. Now, remember, we know you can do it, and we love you. Now, go out and be your best self today, and as always. happy nursing.