Ancaabtitrserif
A blood test that detects antibodies targeting white blood cells, used to diagnose certain autoimmune diseases affecting blood vessels.
{"Measures antibodies (ANCA) that may attack your own white blood cells","Helps diagnose conditions like vasculitis that cause blood vessel inflammation","Results are reported as titers showing antibody concentration","A simple blood draw is all that's needed for this test","Results help doctors monitor disease activity and treatment response"}
Key facts at a glance
- LOINC
- 51924-9
- Short code
- ANCA-T
- Synonyms
- ANCA Ab Titr Ser IF
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube without anticoagulant
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Critical range
- 0.5 N/A – —
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–99 years
- Method
- Indirect Immunofluorescence (IIF) using ethanol-fixed and formalin-fixed neutrophil substrates; titer determined by serial dilution
- CPT
- 86256
- SNOMED
- 39579001
- Specimen volume
- 1-2 mL serum (minimum 0.5 mL)
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The Neutrophil Cytoplasmic Antibody (ANCA) test is a blood test that looks for specific antibodies in your blood. These antibodies (called antineutrophil cytoplasmic antibodies) are proteins that your immune system may produce by mistake. They target neutrophils, which are a type of white blood cell that helps fight infections. The test uses a special technique called immunofluorescence to detect these antibodies and measure their strength, which is reported as a "titer" (such as 1:20 or 1:160).
Why do I need this test?
Your doctor may order this test if you have symptoms that suggest an autoimmune condition affecting your blood vessels, such as unexplained fever, skin rash, joint pain, kidney problems, or breathing difficulties. This test is particularly useful for diagnosing conditions called vasculitis, where the immune system attacks blood vessels and causes inflammation. It can also help distinguish between different types of vasculitis and monitor how well treatment is working.
How is the test performed?
A healthcare professional will draw a small amount of blood from a vein in your arm using a needle. You may feel a brief pinch or sting. The blood sample is then sent to a laboratory where technicians will analyze your serum (the liquid part of your blood) using immunofluorescence techniques. The test looks for two main patterns: c-ANCA (cytoplasmic) and p-ANCA (perinuclear), which can indicate different conditions. Results are typically available within a few days.
What do the results mean?
Results are reported as a titer, which shows how much the blood sample can be diluted before the antibodies can no longer be detected. A higher titer (like 1:160) means more antibodies are present. A positive result suggests your immune system may be attacking your own blood vessels, but your doctor will interpret the results along with your symptoms and other tests to make a diagnosis. Sometimes the test may be positive even without active disease, so results should always be discussed with your healthcare provider.
Reference range
Negative: <1:20 (or <1:10 depending on laboratory). Positive results reported as titer with pattern: c-ANCA (cytoplasmic) or p-ANCA (peripheral) or atypical ANCAN/A
No fasting required. Avoid hemolyzed or lipemic specimens as they may interfere with immunofluorescence interpretation. Inform clinician of any recent infections, as infections can transiently elevate ANCA titers.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Do I need to fast before this test?
Are there any risks from the blood test?
What happens if my result is positive?
How long does it take to get results?
Will I need to repeat this test?
Sources
- 1
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy