DIAGNOSTIC TEST 833

LGI-1 Antibodies (IgG)

Diagnostic test for antibodies against LGI1. For suspicion of autoimmune encephalitis.

Indication

Suspicion of autoimmune encephalitis

Sample material

Serum

  • Minim. volume: 0.5 mL

CSF

  • Minim. volume: 0.5 mL

Transport

Within Sweden

  • room temperature

International

  • cold

Method

Cell-based assay (CBA), Indirect immunofluorescence (IIF)

Reference interval

Serum

  • <1:10 negative

CSF

  • negative

Result

Results are reported as negative or positive. A positive result is followed by a titer (serum).

Interpretation

LGI-1 is a subunit in the potassium channel complex (VGKC). Antibodies against LGI-1 have been reported in classical autoimmune encephalitis and epilepsy. Antibodies against LGI-1 are the second most common in autoimmune encephalitis, following antibodies against NMDAR. Antibodies against LG-1 are detected more often in men, with the median age when diagnosed being 60 years (30-80 years). LGI-1 antibodies are associated with tumors (lung, thymoma, and other tumor forms). Screening for cancer diagnosis is recommended.

Antibodies against LGI-1 are graded as Lower-risk antibodies with a frequency of <10% of underlying cancer, and a positive result yields 0 points PNS score, according to Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes.

References

  • Leypoldt F et al. Ann N Y Acad Sci. 2015. Autoimmune encephalopathies. PMID: 25315420
  • Dalmau J et al. Physiol Rev. 2017. Autoantibodies to Synaptic Receptors and Neuronal Cell Surface Proteins in Autoimmune Diseases of the Central Nervous System. PMID: 28298428
  • Dalmau J et al. Lancet Neurol. 2019. An update on anti-NMDA receptor encephalitis for neurologists and psychiatrists: mechanisms and models. PMID: 31326280
  • Graus F et al. Neurol Neuroimmunol Neuroinflamm. 2021. Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes. PMID: 34006622
  • Flanagan EP et al. JAMA Neurol. 2023 Autoimmune Encephalitis Misdiagnosis in Adults. PMID: 36441519

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