Antibody to Neisseria meningitidis Group A (IgG) by Immunoassay
This test measures the level of antibodies your body produces in response to exposure to *Neisseria meningitidis* Group A bacteria. These antibodies help your immune system recognize and fight the infection.
["Helps assess immune response to meningococcal vaccination or past infection."]
Key facts at a glance
- LOINC
- 75755-9
- Short code
- MSSA DNA Spec Ql NAA+probe
- Synonyms
- MSSA DNA Spec Ql NAA+probe
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- 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’ve received the meningococcal vaccine (such as MenACWY) or have been exposed to *N. meningitidis* Group A. It can also be part of monitoring for immune response in certain conditions, like complement deficiency or after vaccination.
What to Expect Before the Test
No special preparation is needed. A blood sample will be drawn from a vein, usually in your arm. The process is quick and typically painless. You may feel a slight pinch, but most people tolerate it well.
What the Test Results Mean
Results indicate the presence of IgG antibodies against *N. meningitidis* Group A. A positive result suggests your immune system has recognized the bacteria, while a negative result may mean no detectable antibodies were found, which could prompt further evaluation.
Common Reasons for Testing
This test is often used to confirm immunity after vaccination, evaluate immune function in high-risk individuals (e.g., those with asplenia or complement disorders), or investigate unexplained infections.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
High antibody levels post-vaccination or infection indicate a strong immune response, reducing risk of meningococcal disease. Low or absent levels may signal inadequate immunity, prompting booster doses or additional investigations (e.g., immune function testing).
Short name
Anti-Meningococcal A Antibody (IgG)
Frequently asked questions
How long does it take to get results?
What does a positive result mean?
Can I get this test at home?
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