CASPR2 antibodies

Indication

Suspicion of autoimmune encephalitis and Morvans Syndrome.

Method

Indirect immunofluorescence (IIF) using transfected cells.

Answer

Serum: The result is reported as positive, borderline or negative. A positive result is followed by a titer.

CSF: The result is reported as positive or negative. CSF samples are not titrated.

Interpretation

CASPR2 (Contactin Associated Protein 2) is a subunit of the potassium channel complex (VGKC) and is included in the group of extracellular antigens. Antibodies against CASPR2 may occur in neuromyotonia, autoimmune encephalitis and Morvan Syndrome. There are a relatively few cases published, where 85% have been men and the age of diagnosis has been 46-77 years (median 60 years). There is an association with malignancy, mainly thymoma. Antibody titers can be used to monitor treatment effectiveness.

Generally, treatment with immunotherapy is more effective at autoantibodies directed against extracellular antigens than autoantibodies against intracellular antigens. Follow up with cancer diagnosis is recommended.

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References

LLancaster, Martinez-Hernandez, Dalmau. Encephalitis and antibodies to synaptic and neuronal cell surface proteins. Neurology. 2011 Jul 12;77(2):179-89.  PMID: 21747075

Titulaera et al. Screening for tumours in paraneoplastic syndromes: report of an EFNS Task Force. European Journal of Neurology. Epublished 2010. Eur J Neurol. 2011 January; 18(1): 19–23. PMID: 20880069.

Zuliani, Graus, Giometto, Bien, Vincent. Central nervous system neuronal surface antibody associated syndromes: review and guidelines for recognition. J Neurol Neurosurg Psychiatry 2012;83:638-645. PMID: 22448032

Lancaster E, Huijbers MG, Bar V, et al. Investigations of caspr2, an autoantigen of encephalitis and neuromyotonia. Ann Neurol 2011;69:303-311. PMID 21387375.

Irani SR, Alexander S, Waters P, et al. Antibodies to Kv1 potassium channelcomplex proteins leucine-rich, glioma inactivated 1 protein and contactin-associated protein-2 in limbic encephalitis, Morvan’s syndrome and acquired neuromyotonia. Brain 2010;133:2734-2748. PMID 20663977.

Packages and other tests

View other packages Expanded analysis - Autoantibodies in Autoimmune Pancreatitis (type 2, AIP2) (575), Paraneoplastic Syndromes and Limbic Encephalitis (560, 561 and 562). View other tests AMPA receptor 1 and 2 (GluR1 and GluR2) antibodies, Amphiphysin antibodies, Ma antibodies, Ri (Nova 1/ ANNA-2) antibodies, VGKC (voltage gated potassium channel) antibodies, Yo (PCA-1, Purkinje cells antigen 1) antibodies

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