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Blood Test Tracker

Antinuclear Antibodies (ANA) Screen

A first-step blood test that looks for antibodies to the cell nucleus. A positive result is common and does not by itself mean you have an autoimmune disease.

AI-verified against cited sources. Awaiting expert reviewAlso called ANA, FANALOINC 42254-3

What it is

Antinuclear antibodies (ANA) are immune proteins that attach to parts of the body's own cells, mainly the nucleus, which holds the cell's DNA. The usual test, called an IFA, mixes your serum with human cells on a slide, and a lab scientist looks for a glow under a microscope. The screen is reported as negative or positive. A positive result usually comes with a titer (how far the sample can be diluted and still glow) and a pattern, which are separate results. Some labs use ELISA or multiplex tests instead, and those give a number or an index.

Why it matters

ANA is often an early test when symptoms could come from an autoimmune disease such as lupus, Sjögren's disease or systemic sclerosis. In studies, about 98 in 100 people with lupus tested positive at 1:80 or higher. So a negative ANA makes lupus less likely. But a positive ANA is common in healthy people too, so it does not settle anything on its own. In a US government survey, about 11% to 16% of people tested positive at a 1:80 dilution, depending on the years surveyed. Your clinician reads the result with your symptoms, the titer, the pattern and other tests.

If it’s high

A positive result means antibodies to parts of the cell nucleus were found. Low-level positives are common in healthy people, especially women and older adults. A positive result can also be linked to autoimmune diseases such as lupus, to some infections, to some medicines and to some cancers. Higher titers and certain patterns tell your clinician more. They may order follow-up antibody tests based on your symptoms.

Common causes

  • Low-level ANA in healthy people, more often in women and older adults
  • Autoimmune rheumatic diseases such as lupus, Sjögren's disease, systemic sclerosis, mixed connective tissue disease and some forms of myositis (muscle inflammation)
  • Autoimmune liver disease and autoimmune thyroid disease
  • Some infections, including viral and long-lasting ones
  • Some medicines
  • Some cancers

What can help

  • Ask your clinician whether the titer and pattern, or follow-up antibody tests, would help for your symptoms
  • Bring a list of your medicines and supplements, since some can cause a positive result
  • Note symptoms such as joint pain or swelling, rashes, mouth sores, dry eyes or mouth, and fingers that change color in the cold, and share them at your visit

What can affect your result

  • Age: low-titer ANA becomes more common in older adults
  • Sex: women are more likely than men to have a positive ANA
  • Method: IFA on HEp-2 cells, ELISA and multiplex tests can disagree on the same sample
  • The screening dilution each lab uses, for example 1:40 or 1:80
  • Medicines, infections and some other conditions
  • A positive ANA can show up before any symptoms start
  • Some medicines, some infections and some cancers can cause a positive result. Talk with your clinician before changing any medicine because of this result.
  • Different methods can disagree. IFA on HEp-2 cells, ELISA and multiplex tests use different antigens and cutoffs, so the same blood can look positive on one and negative on another.
  • Labs screen at different dilutions (for example 1:40 or 1:80), which changes how many people are called positive.
  • Very cloudy (lipemic), hemolyzed or contaminated samples can interfere. Quest lists gross hemolysis, gross lipemia and microbial contamination as reasons to reject a sample.

Results often stay the same over time. The titer is not usually used to track how active a condition is.

When to talk to a clinician

A positive ANA on its own is not an emergency. Talk with your clinician if you also have joint pain or swelling that lasts, a rash that gets worse in sunlight, mouth sores, dry eyes or mouth, fingers that turn white or blue in the cold, or fever and fatigue with no clear cause. Get urgent care for chest pain, trouble breathing or sudden weakness.

Questions you could ask

  • Do I need to repeat this test, or is one result enough?
  • Does my titer and pattern change what we should do next?
  • Would follow-up antibody tests help, given my symptoms?
  • Could any medicine I take explain this result?

Questions people ask

I tested positive for ANA. Does that mean I have lupus?

No. ANA is positive in many healthy people. In one study of healthy adults, about 13 in 100 were positive at 1:80 and about 5 in 100 at 1:160. Whether someone has lupus is decided from symptoms, an exam and other tests. Your clinician can tell you what your result means for you.

What do titers like 1:80 or 1:320 mean?

The titer shows how many times your sample was diluted before the glow faded. A bigger second number means more antibody. Low titers are common in healthy people, and higher titers are more likely to matter. The titer and the pattern are reported as their own results.

Does a negative ANA rule out an autoimmune disease?

It makes some diseases, such as lupus, less likely, but it does not rule out every autoimmune disease. Talk with your clinician if you still have symptoms.

Show the science and sources

For clinicians and researchers

ANA by indirect immunofluorescence (IFA) on HEp-2 cells is the reference method: Quest and Labcorp cite the ACR position, and the 2014 international recommendations (Agmon-Levin et al.) name IFA as the reference method while acknowledging automated platforms. Labs report the screen as negative or positive at a set dilution, then reflex to a titer and an ICAP-nomenclature pattern. Screening dilutions differ. Mayo screens at 1:80 and reports below 1:80 as negative. Labcorp's current IFA reports negative below 1:80, borderline at 1:80 and positive above 1:80, while some other Labcorp profiles report titers from 1:40. Healthy-donor frequencies from 15 laboratories were 31.7% at 1:40, 13.3% at 1:80, 5.0% at 1:160 and 3.3% at 1:320 (Tan et al., 1997). US NHANES found ANA in 11.0%, 11.4% and 16.1% of people at a 1:80 screen in 1988-1991, 1999-2004 and 2011-2012. The 2019 EULAR/ACR SLE classification criteria use ANA at 1:80 or higher on HEp-2 cells, or an equivalent test, as an entry criterion; pooled sensitivity was 97.8%. Solid-phase assays (ELISA, multiplex) report an index or units with lab-specific cutoffs. For example, Mayo's ELISA calls 1.0 U or less negative, 1.1-2.9 weakly positive, 3.0-5.9 positive and 6.0 or more strongly positive. These assays can miss cytoplasmic and mitotic patterns that IFA shows. A positive screen is usually followed by tests for specific antibodies (dsDNA, ENA) chosen by the clinical picture.

LOINC 42254-3 (primary), 8061-4, 59069-5, 47383-5. Specimen: serum.

Sources

  1. Antinuclear Antibodies, HEp-2 Substrate, IgG, Serum (test NAIFA), Mayo Clinic Laboratories
  2. Antinuclear Antibodies (ANA), Serum (test ANA2, ELISA), Mayo Clinic Laboratories
  3. ANA by IFA, Reflex to Titer and Pattern (test 164947), Labcorp
  4. Antinuclear antibody (ANA) testing options, Labcorp
  5. ANA Screen, IFA, with Reflex to Titer and Pattern (test code 249), Quest Diagnostics
  6. Range of antinuclear antibodies in "healthy" individuals, Arthritis & Rheumatism (1997)
  7. International recommendations for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies, Annals of the Rheumatic Diseases (2014)
  8. 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus, EULAR and ACR (2019)
  9. Increasing Prevalence of Antinuclear Antibodies in the United States, Arthritis & Rheumatology (2022)
  10. LOINC codes and long common names verified with the NLM Clinical Tables LOINC search, U.S. National Library of Medicine

AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.

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