Antineutrophil Cytoplasmic Antibodies (ANCA) Test
Reviewed
Also called: ANCA antibodies, cANCA, pANCA, cytoplasmic neutrophil antibodies, serum anticytoplasmic autoantibodies
An ANCA test looks for antineutrophil cytoplasmic antibodies (ANCA) in a sample of your blood.
Specimen: Blood sample from a vein in your arm
Why this test may be ordered
- To find out if you have autoimmune vasculitis and which type
- To monitor treatment for autoimmune vasculitis
- To help diagnose whether you have ulcerative colitis or Crohn's disease (types of IBD)
Preparation and collection
You usually don't need any special preparations for an ANCA test. Your provider will let you know if you need to do anything to prepare.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
Your provider will consider the results of your ANCA test along with your symptoms and the results of other tests.
- Negative (no ANCAs found): A negative result means that no ANCAs were found in your blood sample. Your symptoms probably aren't caused by vasculitis. Limitation: Your provider will consider the results of your ANCA test along with your symptoms and the results of other tests. Next step: If you have questions about your results, talk with your provider.
- Positive (ANCAs found): A positive result means that ANCAs were found in your blood sample. This may mean you have vasculitis. Limitation: You will often need other blood tests and a biopsy to confirm the diagnosis. Next step: If ANCA antibodies are found, another test may be done on your blood sample to see how much ANCA is in your blood.
- 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
Ask your provider to explain what your test results mean. If you have questions about your results, talk with your provider.
- What do my ANCA test results mean for my health?
- Do I need any additional tests to confirm a diagnosis?
- What type of ANCA was found in my blood?
- How will my results affect my treatment plan?
- Should I be tested for ASCA antibodies if I have symptoms of IBD?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.
U.S. National Library of Medicine: Antineutrophil Cytoplasmic Antibodies (ANCA) Test