Cerebrospinal Fluid Immunoglobulin G (IgG) Measurement by Immunoassay
This test measures the amount of Immunoglobulin G (IgG), a type of antibody found in your cerebrospinal fluid (CSF). It helps assess immune activity in the brain and spinal cord.
["IgG in CSF can help diagnose or monitor conditions affecting the central nervous system."]
Key facts at a glance
- LOINC
- 109777-3
- Short code
- M pneumo IgG Msmt CSF
- Synonyms
- M pneumo IgG Msmt CSF
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
What Does This Test Measure?
IgG is a key part of your immune system, produced by your body to fight infections. In the CSF, it plays a role in protecting the brain and spinal cord. This test specifically looks at the concentration of IgG in the fluid surrounding these areas, which can differ from blood IgG levels due to the blood-brain barrier and immune responses.
Why Might You Need This Test?
Doctors may order this test if you have symptoms like headaches, neurological issues, or signs of inflammation in the brain or spinal cord. It can help identify conditions such as multiple sclerosis, infections, or autoimmune diseases that affect the central nervous system.
How Is the Sample Collected?
A small amount of CSF is collected through a procedure called a lumbar puncture (spinal tap). This involves inserting a needle into your lower back to draw fluid from the spinal canal. The sample is then sent to a lab for testing.
What Are Common Uses?
This test is often used to diagnose or monitor conditions like multiple sclerosis, where IgG can be elevated in the CSF. It may also help identify other inflammatory or infectious processes in the central nervous system.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Elevated IgG in CSF can indicate an immune response in the brain or spinal cord, such as in multiple sclerosis, Guillain-Barré syndrome, or certain infections. Low or normal levels may suggest no significant immune activity, but further evaluation is needed to rule out other conditions. Always discuss results with your healthcare provider.
Short name
IgG in CSF
Frequently asked questions
What does an abnormal IgG level in CSF mean?
How long does it take to get results from this test?
Can I eat or drink before this test?
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