Anti-Neutrophil Cytoplasmic Antibody (ANCA) Serum Test (Quantitative)
This test measures the presence and level of antibodies called ANCA in your blood. ANCA are linked to certain autoimmune conditions that affect blood vessels, such as vasculitis.
["This blood test helps identify inflammation or immune system activity in blood vessels that may signal an underlying condition requiring further evaluation."]
Key facts at a glance
- LOINC
- 20904-9
- Short code
- N caninum Ab Ser Ql IF
- Synonyms
- N caninum Ab Ser Ql IF
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- if
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like unexplained fever, weight loss, skin rashes, joint pain, or organ damage that could be linked to vasculitis. It’s also used to monitor treatment progress in people already diagnosed with ANCA-associated vasculitis.
What to Expect Before the Test
No special preparation is needed, but avoid strenuous activity 24 hours before testing. Fasted blood draws are not required, but timing may vary by lab. Inform your provider about any medications or supplements you’re taking.
What the Test Results Mean
Results are reported as a concentration level of ANCA antibodies in your serum. Positive results suggest an increased risk of vasculitis, but additional testing (like biopsy or clinical correlation) is needed to confirm a diagnosis.
Common Reasons for Positive Results
Positive ANCA test results can occur in conditions like granulomatosis with polyangiitis (GPA), microscopic polyangiitis, or eosinophilic granulomatosis with polyangiitis (EGPA). False positives may occur in infections or other autoimmune diseases, so results should be interpreted with clinical context.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
ANCA tests are critical for diagnosing and managing vasculitis, a group of rare but serious conditions where inflammation damages blood vessels. Early detection allows for timely treatment to prevent organ damage. While ANCA doesn’t always indicate vasculitis, it’s a key marker for guiding further evaluation and treatment decisions.
Short name
ANCA Serum Test
Frequently asked questions
How long does it take to get ANCA test results?
Can ANCA test results change over time?
Does diet affect ANCA test results?
Sources
- 1
- 2Lab Tests OnlineSource
- 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 16, 2026. · Read our editorial policy