Test Catalog

Test ID: MSP3    
Multiple Sclerosis (MS) Profile, Serum and Spinal Fluid

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosing multiple sclerosis, especially helpful in patients with equivocal clinical or radiological findings

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Kappa free light chain will be performed by nephelometry on all samples. When kappa free light chain results are 0.0600 mg/dL or more, the oligoclonal banding tests will be performed at an additional charge. If the time of testing exceeds the specimen stability for oligoclonal banding tests only kappa free light chain will be performed. Kappa free light chain will only be performed up to specimen stability.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease characterized by visual, motor, and sensory disturbances. The diagnosis of MS is dependent on clinical, radiological, and laboratory findings. The detection of increased intrathecal immunoglobulin (Ig) synthesis is the basis for current diagnostic laboratory tests for MS. These tests include the kappa free light chains in cerebrospinal fluid (CSF) and CSF oligoclonal band detection.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.


Medical decision point: 0.1000 mg/dL



<2 bands

Interpretation Provides information to assist in interpretation of the test results

When result is 0.1000 mg/dL or more, the kappa free light chain concentration measured in cerebrospinal fluid (CSF) is at or greater than the threshold associated with demyelinating disease. This is a positive result. These findings, however, are not specific for multiple sclerosis (MS) because CSF-specific immunoglobulin synthesis may also be detected in patients with other neurologic diseases (infectious, inflammatory, cerebrovascular, autoimmune, and paraneoplastic). Clinical correlation is recommended. Automatic reflexing to oligoclonal bands will occur.


When result is less than 0.0600 mg/dL, the kappa free light chain concentration measured in CSF is lower than the threshold associated with demyelinating disease. This is a negative result. Testing for oligoclonal banding is not performed. Clinical correlation is recommended.


When result is 0.0600 to 0.0999 mg/dL, the kappa free light chain concentration measured in CSF is slightly elevated but not above the medical decision point of 0.1000 mg/dL associated with demyelinating disease. This is a borderline result. Reflexing to oligoclonal bands will be automatically performed and clinical correlation is recommended.


When the oligoclonal band assay detects 2 or more unique IgG bands in the CSF, the result is positive.


CSF is used in the diagnosis of MS by identifying increased intrathecal IgG synthesis qualitatively (oligoclonal bands). The presence of 2 or more unique CSF oligoclonal bands was reintroduced as one of the diagnostic criteria for MS in the 2017 revised McDonald criteria. These findings, however, are not specific for MS as CSF-specific IgG synthesis may also be found in patients with other neurologic diseases including infectious, inflammatory, cerebrovascular, and paraneoplastic disorders. Clinical correlation is recommended.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Increased intrathecal Ig synthesis may occur in other inflammatory central nervous system diseases, and therefore, these assays are not specific for multiple sclerosis.

Supportive Data

In a cohort of 1307 patients analyzed in 2018, where 159 had demyelinating disease, the Mayo Clinic oligoclonal banding test had a clinical sensitivity of 74% and clinical specificity of 89%, ROC AUC of 0.813, when 2 or more unique cerebrospinal fluid (CSF) bands are used as a cutoff for positive. This, kappa free light chain test, when considered positive at a concentration greater than or equal to 0.1000 mg/dL as a medical decision point, has a sensitivity of 70% with a specificity of 87%. The differences between the 2 tests are not statistically significant and the 2 tests show comparable performance with shorter turn-around-time for results, and an objective quantitative result.


The MSP3 panel combines the ease of use and interpretation of the quantitative measurement of kappa free light chains in CSF and allies it to the traditional interpretation of oligoclonal bands for optimized efficiency in laboratory testing for demyelinating diseases and improved test utilization.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Andersson M, Alvarez-Cermeno J, Bernardi G, et al: Cerebrospinal fluid in the diagnosis of multiple sclerosis: a consensus report. J Neurol Neurosurg Psychiatry. 1994 Aug;57(8):897-902

2. 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

3. Thompson AJ, Banwell BL, Barkhof F, et al: Diagnosis of multiple sclerosis: 2017 revisions of the McDonald criteria. Lancet Neurol. 2018 Feb;17(2):162-173

4. 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;56:1071-1080

5. Saadeh R, Pittock S, Bryant S, et al: CSF Kappa Free Light Chains as a Potential Quantitative Alternative to Oligoclonal Bands in Multiple Sclerosis. In: American Academy of Neurology Annual Meeting. 2019 Philadelphia, PA