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Cerebrospinal Fluid Immunoglobulin G (IgG) Index by Electrophoresis

Published: August 9, 2026Updated: August 16, 2026

This test measures the levels of Immunoglobulin G (IgG), a type of antibody found in your cerebrospinal fluid (CSF). It helps assess immune activity in the central nervous system.

Quick summary

["IgG levels in CSF can help diagnose or monitor conditions affecting the brain and spinal cord."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
26947-2
Short code
M pneumo IgG Titr CSF IF
Synonyms
M pneumo IgG Titr CSF IF
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Ref low
8
Ref high
61
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82977
SNOMED
3110003
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like headaches, neurological problems, or signs of inflammation in the brain or spinal cord. It can also be part of evaluating conditions such as multiple sclerosis, infections, or certain cancers like lymphoma.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your back to collect a small amount of CSF through a procedure called a lumbar puncture. You may feel pressure or a mild ache afterward.

What the Test Results Mean

The test compares IgG levels in your CSF to those in your blood. Elevated IgG in CSF alone (without matching blood levels) may suggest conditions like multiple sclerosis or other immune-related disorders in the central nervous system.

Common Conditions Monitored

This test is often used to investigate conditions such as multiple sclerosis, Guillain-Barré syndrome, infections like meningitis, or certain types of brain tumors. It helps differentiate between inflammatory and infectious causes of neurological symptoms.

Reference range

Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A

Specimen: csf

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG profile in CSF

Frequently asked questions

What does a high IgG level in my CSF mean?
A high IgG level in your CSF alone (without proportionally high IgG in your blood) may indicate an immune response within the central nervous system, such as in multiple sclerosis or other demyelinating diseases. Your doctor will consider your symptoms, medical history, and other test results to make a diagnosis.
How is this test different from a blood IgG test?
This test specifically measures IgG in your cerebrospinal fluid, which is the fluid surrounding your brain and spinal cord. Blood IgG tests measure antibodies in your bloodstream. The CSF IgG test helps assess immune activity directly in the central nervous system, which can be distinct from blood-based immune responses.
Can I get this test at home?
No, this test requires a procedure called a lumbar puncture, which is typically done in a hospital or clinic setting by a healthcare professional. You’ll need to be prepared for a short recovery period afterward.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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