Clinical Significance:
The antinuclear antibody (ANA) test is key to the diagnosis of lupus. It may help to tell the difference between lupus and other autoimmune diseases when diagnostic criteria are unclear. See medical history for a list of diagnostic criteria.
- If a person has 4 or more diagnostic criteria for lupus, the ANA test alone may be enough to make the diagnosis.
- If a person has 3 criteria (not including a positive ANA test), a positive ANA test may help clarify the diagnosis. A negative ANA test may help rule out lupus.
- If a person has 2 or fewer criteria, the ANA test is probably not appropriate and may only confuse the issue. Many people who do not have lupus have a positive ANA test.
A test for antinuclear antibodies (ANA) is done to help:
- Diagnose systemic lupus erythematosus
- Distinguish between SLE and rheumatoid arthritis when the diagnosis is unclear
- Diagnose other suspected autoimmune diseases
