Complete Blood Count (CBC)
A blood test to detect IgM antibodies against neutrophils in your blood, used to help diagnose certain autoimmune diseases affecting blood vessels.
{"This test looks for IgM antibodies that attack your own white blood cells (neutrophils)","It helps doctors diagnose conditions like vasculitis (blood vessel inflammation)","A simple blood draw is all that's needed","Results are reported as positive or negative","Your doctor will explain what your result means for your specific situation"}
Key facts at a glance
- LOINC
- 17356-7
- Short code
- ANCA-IgM
- Synonyms
- ANCA IgM Ser Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red top serum separator tube (SST) or plain red top tube
- Units
- N/A
- Critical range
- 0.5 N/A – —
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Indirect Immunofluorescence Assay (IFA)
- CPT
- 86256
- SNOMED
- 39534006
- Specimen volume
- 1-2 mL serum
- Stability
- Stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
What is a complete blood count (CBC) test and what does it measure?
The Neutrophil Cytoplasmic IgM Antibody test is a blood test that detects the presence of IgM antibodies directed against proteins in neutrophils (a type of white blood cell). These antibodies are also called ANCA (Anti-Neutrophil Cytoplasmic Antibodies). When your immune system mistakenly produces antibodies that attack your own cells, it's called an autoimmune response.
Why might my doctor order a complete blood count (CBC) test for me?
Your doctor may order this test if you have symptoms that suggest an autoimmune disease affecting your blood vessels (vasculitis), such as unexplained fever, skin rashes, joint pain, kidney problems, or breathing difficulties. This test helps your doctor determine if your symptoms are caused by an autoimmune condition.
How is a complete blood count (CBC) test performed?
A healthcare professional will draw a small blood sample from a vein in your arm. The blood is then sent to a laboratory where technicians look for the presence of IgM antibodies against neutrophils. You don't need to fast or make any special preparations for this test.
What do the results of my complete blood count (CBC) test mean?
Results are typically reported as either 'Positive' or 'Negative'. A positive result means that IgM antibodies against neutrophils were found in your blood, which may indicate an autoimmune disease. A negative result means no antibodies were detected. However, results must be interpreted together with your symptoms and other test results by your healthcare provider.
Are there any risks or side effects from having a complete blood count (CBC) test?
The risks are minimal and similar to any routine blood test. You may experience slight bruising or soreness at the needle site. Some people may feel dizzy or lightheaded during or after the blood draw.
Reference range
Negative (No cytoplasmic IgM neutrophil antibodies detected). Positive results reported as titer.N/A
No special patient preparation required. Fasting is not necessary.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to diagnose and monitor autoimmune vasculitis disorders, including Granulomatosis with Polyangiitis (formerly Wegener's granulomatosis), Microscopic Polyangiitis, and Eosinophilic Granulomatosis with Polyangiitis (formerly Churg-Strauss syndrome). A positive result, especially when combined with clinical symptoms, can help confirm the diagnosis. The test may also be used to monitor disease activity during treatment.
It's important to note that a positive result doesn't always mean you have a disease. Some infections, medications, or other conditions can cause a positive result. Your doctor will consider your complete medical history and other test results when interpreting this test.
Frequently asked questions
Do I need to fast before this test?
How long does it take to get results?
What is the difference between IgM and IgG antibodies?
Can this test diagnose vasculitis on its own?
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