Test Catalog

Test Id : MAGES

Myelin-Associated Glycoprotein Autoantibodies, IgM, Serum

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

Evaluating peripheral neuropathy

 

Evaluating paraproteinemic neuropathy

Method Name
A short description of the method used to perform the test

Enzyme-Linked Immunosorbent Assay (ELISA)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

MAG IgM, S

Aliases
Lists additional common names for a test, as an aid in searching

Anti-MAG

MAG

DADS

IgM Neuropathy

Paraprotein Neuropathy

Distal Acquired Demyelinating Symmetric Neuropathy

Specimen Type
Describes the specimen type validated for testing

Serum

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 1 mL

Forms

If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.5 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 28 days
Frozen 28 days
Ambient 72 hours

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

Evaluating peripheral neuropathy

 

Evaluating paraproteinemic neuropathy

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

Autoantibodies directed against myelin-associated glycoprotein (MAG) are associated with sensory motor demyelinating peripheral neuropathy. A distal acquired demyelinating symmetric (DADS) neuropathy phenotype is the most commonly associated presentation. Patients typically have a slowly progressive symmetric sensory ataxia with/without distal weakness and an IgM monoclonal gammopathy of undetermined significance (MGUS). Nerve conductions studies typically demonstrate a characteristic progressive sensory predominant mixed axonal and demyelinating neuropathy with reduced distal conduction velocities that are greater distally. In general, patients with a DADS neuropathy show limited treatment responses to intravenous immunoglobulin and more aggressive immunotherapy may be needed. MAG antibody titers do not correlate with disease severity nor treatment responses. The presence of MAG antibodies is not exclusively diagnostic of an acquired neuropathy and results must be interpreted in the correct clinical and electrophysiological context. MAG antibodies are present in approximately 50% to 70% of those with an IgM M-protein and a DADS neuropathy phenotype. However, MAG antibodies may also be identified in those with an IgM M-protein and a chronic inflammatory demyelinating polyneuropathy (CIDP) presentation as well as in other IgM paraproteinemic disorders that present with neuropathy including in myeloma, lymphoplasmacytic lymphoma (Waldenstrom macroglobulinemia) and amyloid light chain (AL)-IgM primary amyloidosis. Higher MAG antibody titers (>10,000 BTU) are better predictors of an electrophysiological DADS phenotype whereas low titer MAG antibodies may be associated with a more diverse group of neuropathies. Detection of MAG IgM antibody by enzyme-linked immunosorbent assay based on human MAG (100 kDa) antigen is significantly more sensitive and specific than MAG western blot and immunofluorescence assays using primate antigen.

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.

<1500 Buhlmann Titer Unit

Interpretation
Provides information to assist in interpretation of the test results

A positive result is consistent with anti-myelin-associated glycoprotein neuropathy.

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

This test is not diagnostic and should be interpreted in the correct clinical context. Myelin-associated glycoprotein antibodies may be found in those without neuropathy, IgM M-protein, or paraproteinemic neuropathy.

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

1. Kuijf ML, Eurelings M, Tio-Gillen AP, et al: Detection of anti-MAG antibodies in polyneuropathy associated with IgM monoclonal gammopathy. Neurology. 2009 Sep;73(9):688-695

2. Katz JS, Saperstein DS, Gronseth G, Amato AA, Barohn RJ: Distal acquired demyelinating symmetric neuropathy. Neurology. 2000 Feb;54(3):615-620

3. Magy L, Kabore R, Mathis S, et al: Heterogeneity of polyneuropathy associated with anti-MAG antibodies. J Immunol Res. 2015;2015:450391

Method Description
Describes how the test is performed and provides a method-specific reference

Microwells are precoated with human myelin-associated glycoprotein (MAG) antigen. The calibrators, controls, and diluted patient samples are added to the wells and autoantibodies recognizing the MAG antigen bind during the first incubation. After washing the wells to remove all unbound proteins, purified horseradish peroxidase-labeled anti-human IgM conjugate is added. The conjugate binds to the captured human autoantibody and the excess unbound conjugate is removed by a further wash step. The bound conjugate is visualized with 3,3',5,5' tetramethylbenzidine (TMB) substrate, which gives a blue reaction product, the intensity of which is proportional to a concentration of autoantibody in the sample. Acid is added to each well to stop the reaction. This produces a yellow end-point color, which is read at 450 nm.(Package insert: anti-MAG Autoantibodies ELISA. Buhlmann Laboratories AG; 10/2018)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Tuesday, Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 5 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

28 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

83520

LOINC® Information

Test Id Test Order Name Order LOINC Value
MAGES MAG IgM, S 39087-2
Result Id Test Result Name Result LOINC Value
Result LOINC Value Tooltip
607034 MAG IgM, S 39087-2

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports