What is this test?
ANCAs are antibodies against components of certain white blood cells. They can support the assessment of certain types of inflammation of the blood vessels.
Why might it be ordered?
- For kidney, lung, sinus, skin, or nerve symptoms suggestive of systemic vasculitis.
- For follow-up in certain cases of already established ANCA-related disease.
What sample is needed?
A healthcare professional collects a venous blood sample. Depending on the method, the laboratory uses serum or plasma.
How should you prepare?
Tell the laboratory about all medicines, hormone treatments, vitamins and supplements you take. Do not stop or change treatment unless your clinician tells you to. Follow any instructions about fasting and the time of collection.
How should you understand the result?
The pattern and specific PR3 or MPO antibodies have different meanings and are interpreted with the clinical and biopsy data. A positive result means the tested antibodies were detected, but it does not establish a diagnosis on its own. A negative result does not rule out every autoimmune condition.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.