CSF Immunoglobulin G (IgG) Index
Reviewed
A CSF IgG index measures the level of immunoglobulin G (IgG) in your cerebrospinal fluid. It is used to help diagnose conditions affecting the central nervous system, especially multiple sclerosis (MS).
Preparation and collection
You don't need any special preparations, but you may be asked to empty your bladder and bowels before the test.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- A CSF IgG test alone cannot diagnose multiple sclerosis or any other condition.
- There is no specific test for multiple sclerosis.
- Results must be interpreted by a healthcare professional in the context of your symptoms and other tests.
- The test does not provide a definitive diagnosis; additional testing is often needed.
What to do next
If you have questions about your results, talk with your provider. You may need other tests to help diagnose or rule out a condition. While there is no cure for multiple sclerosis, there are treatments available to relieve symptoms and help keep it from getting worse.
Evidence source
U.S. National Library of Medicine: CSF Immunoglobulin G (IgG) Index