INDIVIDUAL TEST 833
LGI-1 Antibodies (IgG)
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
Last updated: 2024-08-12
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ENSKILD ANALYS 833
LGI-1-antikroppar (IgG)
Indikation
Misstanke om autoimmun encefalit
Provmaterial
Serum
- Minim. volym: 0,5 mL
Likvor
- Minim. volym: 0,5 mL
Transport
Inom Sverige
- rumstemperatur
Internationellt
- kylt
Metod
Cell-based assay (CBA), indirekt immunofluorescens (IIF)
Referensintervall
Serum
- <1:10 negativt
Likvor
- negativt
Resultat
Resultat anges som negativt eller positivt. Positivt resultat titreras (serum).
Tolkning
LGI-1 är en subenhet i kaliumkanalskomplexet (VGKC). Antikroppar mot LGI-1 har rapporterats förekomma vid klassisk autoimmun encefalit och epilepsi. Antikroppar mot LGI-1 anses vara de näst vanligast förekommande vid autoimmun encefalit efter antikroppar mot NMDAR. Autoantikroppar mot LG-1 påvisas något oftare hos män. Ålder vid diagnoshar en median på 60 år(30-80 år). LGI-1 antikroppar är associerade med tumörer (lung, tymom men även andra tumörformer). Antikroppstitrar kan användas för att följa behandlingseffektivitet. Uppföljning med cancerdiagnostik rekommenderas.
Antikroppar riktade mot LGI-1 bedöms vara Lower-risk antibodies med en förekomst på <10% för en underliggande cancer och positivitet ger 0 poäng i PNS score enligt Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes.
Referenser
- 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
Senast uppdaterat: 2024-08-12