What it measures
Antibodies against a set of proteins found in cell nuclei, such as Ro, La, Sm and RNP. They are autoantibodies, meaning antibodies made against the body's own cells. The test is usually run after a positive ANA test, to see which antibodies are behind it.
Why people test it
- A follow-up to a positive antinuclear antibody (ANA) test.
- Measured when lupus, Sjögren's syndrome, scleroderma or a related condition is suspected.
- Investigating symptoms such as joint pain, rashes, dry eyes or a dry mouth.
Typical range
There is no numeric range. The result is reported as positive or negative, and a positive result names the antibodies found. Labs differ in which antibodies their panel covers, and the report shows the lab's own list.
Finger-prick or vein?
Providers offer this test only from a vein sample, taken at a clinic.