Test Code SFIG Cerebrospinal Fluid IgG Index Profile, Serum and Spinal Fluid
Specimen Required
Both serum and spinal fluid are required. Spinal fluid must be obtained within 7 days of serum collection.
Two individual serum samples are required.
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: 2 Plastic vials
Specimen Volume: 2 mL in 2 plastic vials, each vial containing 1 mL
Collection Instructions: Centrifuge and aliquot serum into 2 plastic vials within 2 hours of collection.
Specimen Type: Spinal fluid
Container/Tube: Sterile vial
Specimen Volume: 1 mL
Collection Instructions: Label specimen as SFINC.
Useful For
Aiding in the diagnosis of multiple sclerosis and other central nervous system inflammatory conditions
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
SFINC | IgG Index, CSF | No | Yes |
SFIGS | IgG, S | No | Yes |
ALBS1 | Albumin, S | Yes, (order ALB) | Yes |
Method Name
SFINC, SFIGS: Nephelometry
ALBS1: Photometric
Reporting Name
CSF IgG Index ProfileSpecimen Type
CSFSerum
Specimen Minimum Volume
Serum 1 mL in 2 plastic vials, each vial containing 0.5 mL
Spinal fluid: 0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
CSF | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 14 days | ||
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 28 days | ||
Ambient | 7 days |
Reference Values
CSF index: 0.00-0.85
CSF IgG: 0.0-8.1 mg/dL
CSF albumin: 0.0-27.0 mg/dL
Serum IgG
0-4 months: 100-334 mg/dL
5-8 months: 164-588 mg/dL
9-14 months: 246-904 mg/dL
15-23 months: 313-1,170 mg/dL
2-3 years: 295-1,156 mg/dL
4-6 years: 386-1,470 mg/dL
7-9 years: 462-1,682 mg/dL
10-12 years: 503-1,719 mg/dL
13-15 years: 509-1,580 mg/dL
16-17 years: 487-1,327 mg/dL
≥18 years: 767-1,590 mg/dL
Serum albumin
≥12 months: 3,500-5,000 mg/dL
Reference values have not been established for patients who are <12 months of age.
CSF IgG/albumin: 0.00-0.21
Serum IgG/albumin: 0.0-0.4
CSF IgG synthesis rate: 0-12 mg/24 hours
Interpretation
Cerebrospinal fluid (CSF) IgG synthesis rate indicates the rate of increase in the daily CSF production of IgG in milligrams per day. A result greater than 12 mg/24h is elevated.
A CSF index greater than 0.85 is elevated and indicative of increased synthesis of IgG.
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. Thompson AJ, Banwell BL, Barkhof F, et al: Diagnosis of multiple sclerosis: 2017 revisions of the McDonald criteria. Lancet Neurol. 2018 Feb;17(2):162-73. doi: 10.1016/S1474-4422(17)30470-2
5. Gurtner KM, Shosha E, Bryant SC, et al: CSF free light chain identification of demyelinating disease: comparison with oligoclonal banding and other CSF indexes. Clin Chem Lab Med. 2018 Jun 27;56(7):1071-1080. doi: 10.1515/cclm-2017-0901
6. Rifai N, Norvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, 6th ed. Elsevier; 2018
Day(s) Performed
Monday through Friday
Report Available
2 to 5 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest 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
82040
82042
82784 x 2
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
SFIG | CSF IgG Index Profile | 14116-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
INDEX | IgG Index, CSF | 14117-6 |
ALB_S | Albumin, S | 1751-7 |
IGG_S | IgG, S | 2465-3 |
AIGAS | IgG/Albumin, S | 6782-7 |
IGG_C | IgG, CSF | 2464-6 |
ALB_C | Albumin, CSF | 1746-7 |
AIGAC | IgG/Albumin, CSF | 2470-3 |
SRATE | Synthesis Rate, CSF | 14116-8 |