Cerebrospinal Fluid Myelin-Associated Glycoprotein (MAG) Antibody Profile (Screening)
This test measures antibodies against myelin-associated glycoprotein (MAG), a protein found in the central nervous system. It helps identify potential demyelinating disorders, such as chronic inflammatory demyelinating polyneuropathy (CIDP).
["This test may be used if you have symptoms of nerve damage or unexplained weakness, numbness, or fatigue."]
Key facts at a glance
- LOINC
- 102085-8
- Short code
- CNS Demyelinating ds Panel SerPl FC
- Synonyms
- CNS Demyelinating ds Panel SerPl FC
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- flow-cytometry
- 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
What Is Myelin-Associated Glycoprotein (MAG)?
Myelin is the protective sheath covering nerve fibers in the body. When the immune system mistakenly attacks this myelin, it can lead to nerve damage and symptoms like weakness, numbness, or balance issues. MAG is one of the proteins in myelin that this test detects antibodies against.
Why Might This Test Be Ordered?
Your healthcare provider may recommend this test if you have symptoms like persistent muscle weakness, tingling, or balance problems that don’t improve with other treatments. It’s also sometimes used in people with a history of autoimmune diseases or those suspected of having a rare nerve disorder.
How Is the Sample Collected?
A small amount of cerebrospinal fluid (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 your spinal canal. You may feel pressure or mild discomfort during the procedure.
What Does a Positive Result Mean?
A positive result means your blood contains antibodies targeting MAG, which may suggest an underlying demyelinating condition. However, this alone doesn’t confirm a diagnosis. Further testing and clinical evaluation are needed to determine the cause of your symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Understanding the Role of MAG Antibodies
Short name
MAG Antibody Screen (CSF)
Frequently asked questions
How often will I need to retest if my results are positive?
What are the most common symptoms associated with this test result?
Will this test affect my daily activities or treatments?
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