CSF Immunoglobulin G (IgG) Index

CSF Immunoglobulin G (IgG) index is a laboratory test used to measure the level of IgG immunoglobulin in the cerebrospinal fluid (CSF), a clear fluid that surrounds the brain and spinal cord in the brain. IgG is an important protein in the immune system that helps fight off infections and other diseases. The IgG index is one of several methods used to evaluate the status of the immune system.

Preparation

No special preparation is required before a CSF IgG Index test. However, it's important to inform your doctor of any medications you are taking, as some medications can alter the results of the test.

Procedure

The CSF IgG Index test is conducted on a sample of cerebral spinal fluid (CSF), which is obtained by a lumbar puncture (spinal tap). In the procedure, a needle is inserted between two vertebrae in the lower back, and a small sample of the CSF is withdrawn. The sample is then tested for the level of IgG immunoglobulin.

Types

The CSF IgG Index is often used in combination with other tests such as the CSF-IgM Index, the CSF/serum albumin ratio, and total protein levels, to make a more comprehensive evaluation.

Risks

The procedure for obtaining a CSF sample is generally safe, although there may be some minor side effects such as headaches, mild pain in the lower back, or dizziness. Rarely, there may be a risk of infection or a headache that persists for a few days.

Why?

The CSF IgG Index is used to evaluate the immune status of a person, as it can detect changes in IgG levels that may be caused by certain diseases or disorders. For example, a low IgG index may indicate a reduced immune response, while a higher IgG index may indicate an active immune response.

When?

The CSF IgG Index may be ordered to help diagnose and evaluate certain neurological conditions such as multiple sclerosis or Guillain-Barré syndrome, or to help evaluate the effectiveness of treatments for such conditions.