Test Code CASF IgG/Albumin Ratio, Spinal Fluid
Reporting Name
IgG/Albumin Ratio, CSFUseful For
Assessment of cerebrospinal fluid (CSF) IgG/albumin ratio in the absence of a paired CSF and serum specimen
Performing Laboratory

Specimen Type
CSFOrdering Guidance
The cerebrospinal fluid (CSF) index in which the CSF IgG/albumin ratio is compared to the serum IgG/albumin ratio aids in the diagnosis of individuals with multiple sclerosis. See SFIN / Cerebrospinal Fluid (CSF) IgG Index, Serum and Spinal Fluid.
Specimen Required
Collection Container/Tube: Sterile vial
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
CSF | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 14 days |
Reference Values
CSF IgG: 0.0-8.1 mg/dL
CSF albumin: 0.0-27.0 mg/dL
CSF IgG/albumin: 0.00-0.21
Day(s) Performed
Monday through Friday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
82042
82784
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
CASF | IgG/Albumin Ratio, CSF | 2470-3 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
IGG_C | IgG, CSF | 2464-6 |
ALB_C | Albumin, CSF | 1746-7 |
AIGAC | IgG/Albumin, CSF | 2470-3 |
Clinical Reference
1. Tourtellotte WW, Walsh MJ, Baumhefner RW, Staugaitis SM, Shapshak P: The current status of multiple sclerosis intra-blood-brain-barrier IgG synthesis. Ann NY Acad Sci. 1984;436:52-67
2. Bloomer LC, Bray PF: Relative value of three laboratory methods in the diagnosis of multiple sclerosis. Clin Chem. 1981 Dec;27(12):2011-2013
3. Hische EA, van der Helm HJ: Rate of synthesis of IgG within the blood-brain barrier and the IgG index compared in the diagnosis of multiple sclerosis. Clin Chem. 1987 Jan;33(1):113-114
4. Swanson JW: Multiple sclerosis: update in diagnosis and review of prognostic factors. Mayo Clin Proc. 1989 May;64(5):577-586
5. Markowitz H, Kokmen E: Neurologic diseases and the cerebrospinal fluid immunoglobulin profile. Mayo Clin Proc. 1983 Apr;58(4):273-274
Method Description
The cerebrospinal fluid (CSF) and albumin are determined by immunonephelometry on a Siemens Nephelometer II. CSF IgG and albumin, and CSF IgG/albumin ratios are reported.(Instruction manual: Siemens Nephelometer II Operations. Siemens, Inc; Version 2.3, 2008; Addendum to the Instruction Manual 2.3, 08/2017)
Report Available
Same day/1 to 2 daysReject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Method Name
Nephelometry