What it measures
Antinuclear antibodies (ANA) are antibodies against parts of the nucleus of the body's own cells. They are found in most people with lupus and in several other autoimmune conditions, but also at low levels in many healthy people, especially with age.
Why people test it
- Measured when joint pain, rashes, mouth ulcers or tiredness suggest an autoimmune condition such as lupus.
- Used as a first screen, followed by more specific antibody tests when positive.
- Part of an autoimmune liver screen, with mitochondrial and smooth muscle antibodies.
Typical range
The result is reported as positive or negative, usually with a titre (how far the sample can be diluted and still show antibodies) and a pattern, such as speckled or homogeneous. Labs use their own methods and cut-offs, and the report shows the lab's wording.
Finger-prick or vein?
A finger-prick sample is often enough, as antibody tests need only a small amount of serum. A vein sample is taken where a lab or a larger panel needs more blood.