Test guide
CSF Immunoglobulin G (IgG) Index
CSF stands for cerebrospinal fluid. IgG stands for immunoglobulin G. It is a type of antibody. Antibodies are proteins that your immune system makes to fight germs . A CSF IgG index measures the levels of IgG in your cerebrospinal fluid.
What it is for
A CSF IgG index is used to check for diseases of the central nervous system . It is often used to help diagnose multiple sclerosis (MS). MS is a chronic (long-lasting) autoimmune disorder that attacks the outside covering of your nerves. Most people with MS have higher than normal levels of IgG. But a CSF IgG test alone can't diagnose MS. Source: MedlinePlus, National Library of Medicine. Medical test information is public domain. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.
Limitations
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
Also known as
- cerebrospinal fluid IgG level, cerebrospinal fluid IgG measurement, CSF IgG level, IgG (Immunoglobulin G) spinal fluid, IgG synthesis rate
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