Antineutrophil Cytoplasmic Antibodies (ANCA) Test
Reviewed
This test looks for antineutrophil cytoplasmic antibodies (ANCA) in your blood. These antibodies attack healthy white blood cells and can be a sign of autoimmune vasculitis or inflammatory bowel disease (IBD).
Preparation and collection
You usually don't need any special preparations. Your provider will let you know if you need to prepare if the test is done with other blood tests.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- A positive ANCA test does not confirm autoimmune vasculitis; other tests and a biopsy are often needed.
- ANCA test results are not always an accurate way to measure how much disease you have when monitoring treatment.
- For IBD, if neither ANCA nor ASCA antibodies are found, you may still have IBD.
What to do next
If you have questions about your results, talk with your provider. Your provider will consider your ANCA test results along with your symptoms and the results of other tests.
Evidence source
U.S. National Library of Medicine: Antineutrophil Cytoplasmic Antibodies (ANCA) Test