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HelpTest Code IGG-SYN IgG Synthesis, CSF
Useful For
Measurement of the CSF proteins, albumin and IgG, are directed mainly towards the demonstration of two common disorders, namely blood-brain barrier damage and selective elevation of IgG due to local synthesis within the CNS.
Synonyms/Keywords
Immunoglobulin G and albumin in spinal fluid; Immunoglobulin G (IgG) in and albumin in CSF; also IgG and albumin in serum, CSF IgG Synthesis Rate
Specimen Requirements
| Fasting Required | Specimen Type | Preferred Container/Tube | Acceptable Container/Tube | Specimen Volume | Specimen Minimum Volume (allows for 1 repeat) |
Pediatric Minimum Volume (no repeat) |
|---|---|---|---|---|---|---|
| No | Spinal Fluid (CSF) and Serum |
Screw cap, sterile, leakproof tubes for CSF
Red Top Tube (RTT) for serum |
Plastic tube for CSF
Serum Separator Tube (SST) |
1.0 mL for CSF
0.5 mL for serum |
0.5 mL for CSF
0.3 mL for serum |
0.5 mL for CSF
0.3 mL for serum |
Collection/Processing Instructions
CSF must be collected without red cells. This will elevate both the CSF albumin and IgG because of serum contamination.
Both CSF and serum are needed for analysis. Separate labels and accession numbers are generated for blood and CSF samples:
- On first accession, one aliquot tube/label is required for the CSF sample and testing.
- When this test order is placed, a separate accession with the test code "IGGSYN-S" will reflex for the serum testing. 2 aliquot tubes/labels are required for the serum sample and testing
Serum sample must be drawn within 24 hours of spinal fluid collection. If serum is not collected within 24 hours of CSF collection, please call Customer Service to discuss the case with a Clinical Chemist.
Separate serum from cells within 2 hours of collection
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| CSF (spinal fluid) | Refrigerated | 7 days |
| Serum | Refrigerated | 7 days |
| Frozen | 3 months |
Rejection Criteria
| Hemolysis and/or the presence of intact RBCs in the CSF specimen |
|---|
| For CSF - frozen samples |
Test Components
CSF IgG/Albumin Ratio, IgG Index, IgG Synthesis Rate, Serum IgG and Albumin, CSF IgG and Albumin
Interpretations
An increase in the CSF IgG with a corresponding increase in the CSF IgG/Albumin Ratio suggests that the IgG is produced locally. Increases of IgG and total protein without corresponding increases in the ratio indicate damage to the blood-brain barrier.
In rare instances, the CSF albumin can be elevated and the IgG normal. This can mean the blood-brain barrier has become permeable to albumin, but not IgG, which is a larger molecule. Guillian-Barre Syndrome, which has been associated with influenza immunization shots, will give similar results. The total protein will also be elevated in this syndrome. The difference here is that the albumin is derived from breakdown of the CNS tissues.
This test may be used to aid in the diagnosis of Multiple sclerosis, Systemic lupus Erythematosus, Neurosarcoidosis, Syphilis, and CNS Lymphoma.
Reference Range Information
| Performing Location | Reference Range |
|---|---|
| Marshfield |
IgG (CSF): 0-6.6 mg/dL Albumin (CSF): 15-32 mg/dL IgG/Albumin ratio: 0.00-0.27 Serum Albumin (> 1 year): 3300-5000 mg/dL Serum IgG (Adult): 617-1344 mg/dL CSF IgG Index: 0.30-0.70 CSF IgG Synthesis Rate: 0.0-8.0 mg/day |
Marshfield Labs Performing Department
Marshfield Labs Immunodiagnostics
Performing Information
| Performing Location | Day(s) Test Performed | Analytical Time | Methodology/Instrumentation |
|---|---|---|---|
| Marshfield | Monday through Friday | 6-8 hours | Turbidimetric method/The Binding Site Optilite analyzer |
CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 82784 | CSF IgG | |||
| 82784 | Serum IgG | |||
| 82042 | CSF Albumin | |||
| 82040 | Serum Albumin |
Outreach CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 82784 | CSF IgG | |||
| 82784 | Serum IgG | |||
| 82042 | CSF Albumin | |||
| 82040 | Serum Albumin |
Ordering Applications
| Ordering Application | Description |
|---|---|
| Cerner | IgG Synthesis, CSF |
| COM | IgG - Synthesis Rate |