IgG, Serum
Use
Aiding in the diagnosis of multiple sclerosis and other central nervous system inflammatory conditions as a part of a profile. Elevation of IgG in the cerebrospinal fluid (CSF) of patients with inflammatory diseases of the central nervous system (CNS), such as multiple sclerosis, neurosyphilis, acute inflammatory polyradiculoneuropathy, and subacute sclerosing panencephalitis may be due to local (intrathecal) synthesis of IgG. Elevations of CSF IgG or the CSF/serum IgG ratio may also occur because of permeability of the blood brain barrier, and hence, a correction using albumin measurements in CSF and serum is appropriate.
Special Instructions
Only orderable as part of a profile. For more information see SFIG / Cerebrospinal Fluid IgG Index Profile, Serum and Spinal Fluid.
Limitations
The cerebrospinal fluid (CSF) IgG index can be elevated in other inflammatory demyelinating diseases, such as neurosyphilis, acute inflammatory polyradiculoneuropathy, and subacute sclerosing panencephalitis. To increase sensitivity of the test for detection of demyelinating conditions, a study using approximately 1300 patient samples was performed, resulting in a change to the medical decision point for the CSF IgG index from 0.85 to 0.70.
FDA ApprovedNew York Approved
Methodology
Immunoassay (Nephelometry)
Biomarkers
LOINC Codes
- 2465-3
- 2465-3
- 6782-7
- 1756-6
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Plastic vial
Collection Instructions
Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.
Causes for Rejection
Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 28 days |
| Frozen | 28 days |