DIAGNOSTIC TEST 093

MAG Antibodies

Diagnostic test for antibodies against MAG. For suspicion of Inflammatory neuropathy.

Indication

Suspicion of Inflammatory neuropathy

Sample material

Serum

  • Minim. volume: 0,5 mL

CSF

  • Minim. volume: 0,5 mL

Transport

Within Sweden

  • room temperature

International

  • cold

Method

ELISA

Reference interval

Serum

  • < 30 % negative

CSF

  • < 1000 U/mL negative

Result

Serum

  • results are reported as negative, borderline, or positive with a value

CSF

  • results are reported as negative or positive with a value

Interpretation

Myelin-associated glycoprotein (MAG) is a transmembrane glycoprotein that is located in the myelin skins adjacent to the axon. MAG constitutes a very small part (0.1-1%) of the total protein content of myelin.

Several different forms of motor and sensory neuropathies have been shown to be associated with IgM antibodies to MAG. High levels of antibodies against MAG have been observed in demyelinating motor and sensory neuropathies, low levels have been reported in multiple sclerosis, inflammatory neuropathies and motor neuron diseases. About half of the patients with monoclonal IgM gammopathies with associated neuropathy have antibodies against MAG. The antibodies are usually detected in serum but can also be seen in CSF. Borderline result has uncertain clinical relevance.

References

  • Jacobs BC et al. IGOS Consortium. J Peripher Nerv Syst. 2017. International Guillain-Barré Syndrome Outcome Study: protocol of a prospective observational cohort study on clinical and biological predictors of disease course and outcome in Guillain-Barré syndrome. PMID: 28406555
  • Shang P et al. J Neurol. 2021. Axonal variants of Guillain-Barré syndrome: an update. PMID: 32140865
  • Sheikh AB et al. J Neuroimmunol. 2021. Association of Guillain-Barre syndrome with COVID-19 infection: An updated systematic review. PMID: 33895700
  • Van den Bergh PYK et al. J Peripher Nerv Syst. 2021. European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision. PMID: 34085743
  • Wijdicks EF, Klein CJ. Mayo Clin Proc. 2017. Guillain-Barré Syndrome. PMID: 28259232
  • Willison HJ et al. Lancet. 2016. Guillain-Barré syndrome. PMID: 26948435

Included in these panels

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How to order

This test is available worldwide for hospitals, clinics, and physicians.

  1. Print and complete the request form

    Download the request form. Clearly state the name and phone number of the referring hospital, clinic, or physician.

  2. Prepare your samples

    Serum: At least 0.5 mL serum (plain serum tubes without additives).
    CSF: At least 0.5 mL CSF (polypropylene tubes).

  3. Send samples and request form

    Within Sweden
    Samples can be sent at room temperature to:
    Envelopes and smaller boxes:
    Wieslab AB, Box 50117, 20211 Malmö, Sweden

    Larger boxes and frozen samples:
    Wieslab AB, Lundavägen 151, 21224 Malmö, Sweden

    International
    Send samples cold to:
    Wieslab AB, Lundavägen 151, 21224 Malmö, Sweden

Read our sampling instructions for more information

Last updated: 2025-08-18