Complete Blood Count (CBC) Test: What You Need to Know
A blood test that detects antibodies against neutrophils, used to diagnose autoimmune blood vessel diseases.
{"This test checks for ANCA antibodies that attack blood vessels","It helps diagnose conditions like granulomatosis with polyangiitis and microscopic polyangiitis","The test uses a blood sample and is often done with other tests"}
Key facts at a glance
- LOINC
- 108998-6
- Short code
- ANCAG
- Synonyms
- ANCA IgG Msmt Ser
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top vacutainer tube; plain serum preferred
- Units
- N/A
- Ref low
- 20
- Ref high
- 30
- Critical range
- 0.5 N/A – —
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (e.g., enzyme-linked immunosorbent assay, chemiluminescent immunoassay, or indirect immunofluorescence) for detection of IgG antibodies against neutrophil cytoplasmic antigens
- CPT
- 86255
- SNOMED
- 39579001
- Specimen volume
- 1-2 mL serum (minimum 0.5 mL)
- Stability
- Serum stable for 7 days at 2-8°C; for prolonged storage, freeze at -20°C or below. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
The complete blood count, or CBC, is a common blood test that measures the different cells in your blood, including red blood cells, white blood cells, and platelets. Your doctor may order it as part of a routine checkup or to help evaluate symptoms such as fatigue, weakness, fever, or unexplained bruising, and to monitor certain conditions and treatments.
The Neutrophil Cytoplasmic IgG Antibody (ANCA) test is a blood test that detects IgG antibodies directed against proteins in neutrophils (a type of white blood cell). These antibodies can attack blood vessels and cause inflammation, leading to conditions known as ANCA-associated vasculitis.
The test is performed by drawing a small sample of blood, usually from a vein in your arm. A healthcare professional will clean the area with an antiseptic, wrap a band around your upper arm, and insert a thin needle to collect the blood into a tube. The sample is then sent to a laboratory, and the entire process typically takes only a few minutes.
A healthcare professional will draw a blood sample from a vein in your arm. The sample is then sent to a laboratory where it is analyzed using techniques like indirect immunofluorescence (IIF) or enzyme-linked immunosorbent assay (ELISA) to detect the presence and type of ANCA antibodies.
In most cases, no special preparation is needed for a CBC, and you can eat and drink normally before the test. However, if your blood sample will be used for other tests at the same time, such as a fasting glucose or cholesterol panel, your doctor may ask you to fast for several hours beforehand. Be sure to tell your provider about any medications or supplements you take.
Generally, no special preparation is needed. You can eat and drink normally before the test. However, always follow any specific instructions provided by your healthcare provider.
The risks associated with a CBC are very small. You may feel a brief sting when the needle goes in, and slight bruising, soreness, or minor bleeding at the puncture site can occur afterward. Serious complications, such as infection or excessive bleeding, are rare. Some people may feel lightheaded during the blood draw, so let the staff know if you feel faint.
The risks are minimal and similar to routine blood tests. You may experience slight bruising, bleeding, or dizziness at the needle site.
Reference range
Negative: <1:10 titer (IIF) or <20 U/mL (ELISA); Equivocal: 20-30 U/mL; Positive: >30 U/mL. Interpretation depends on clinical context; c-ANCA (PR3-ANCA) typically associated with granulomatosis with polyangiitis, p-ANCA (MPO-ANCA) typically associated with microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis.N/A
No special patient preparation required. Fasting is not required. Recent infections, medications, or autoimmune conditions may influence results and should be disclosed to the ordering provider.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The ANCA test is primarily used to diagnose and monitor ANCA-associated vasculitis, including granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). A positive result indicates the presence of these antibodies, supporting the diagnosis when combined with clinical symptoms and other test results. The test can also help differentiate between different types of vasculitis and monitor disease activity during treatment.
Frequently asked questions
What does a positive ANCA result mean?
Can medications affect the test results?
How long does it take to get results?
Do I need this test if I have no symptoms?
Sources
- 1Mayo Clinic - ANCA testSource
- 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