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Breis et al. Neuroimmunol Neuroinflammation 2020;7:330-4 Neuroimmunology
DOI: 10.20517/2347-8659.2020.14 and Neuroinflammation

Letter to Editor Open Access

Anti-CASPR2 antibodies clinical significance and its
main phenotypes

Letícia Caroline Breis, Marco Antônio Machado Schlindwein, Marcus Vinicius Magno Gonçalves

Department of Medicine, University of the Region of Joinville, Joinville, Santa Catarina 89202-207, Brazil.
Correspondence to: Marco Antônio Machado Schlindwein, Department of Medicine, University of the Region of Joinville, Rua
Ministro Calogenas, 439, Bucarein, Joinville, Santa Catarina 89202-207, Brazil. E-mail: marcoschlindwein02@gmail.com

How to cite this article: Breis LC, Schlindwein MAM, Gonçalves MVM. Anti-CASPR2 antibodies clinical significance and its main
phenotypes. Neuroimmunol Neuroinflammation 2020;7:330-4. http://dx.doi.org/10.20517/2347-8659.2020.14

Received: 4 Feb 2020 Accepted: 7 Apr 2020 Available online: 6 Jun 2020

Science Editor: Athanassios P. Kyritsis Copy Editor: Jing-Wen Zhang Production Editor: Jing Yu

Contactin associated protein 2 (CASPR2) is cellular adhesion molecule (CAMs) part of the neuroxins
family. It is a transmembrane protein with its C-terminal portion interacting with an ankyrin protein called
[1]
4.1B and also a PDZ binding motif .
It is localized along the axon, especially in the synaptic terminal and in the juxta-paranodal portion in the
node of Ranvier. It is found in neurons on the basal ganglia and other motor areas, limbic system, sensitive
pathways, and appears richly expressed in the temporal lobe, especially in inhibitory GAD65 positive
[1-3]
neurons . CASPR2 forms with Contactin-2 part of the VGKC complex, where it has the function of
[1-3]
clustering Kv1 channels at the juxta-paranodal [Figure 1].
[4]
Antibodies against CASPR2 have been described in various forms of clinical presentation [Figure 2],
part of this great variation is believed to be associated with great variation in epitopes, although antibodies
against the discoidin domain and laminin G1 are found in every patient [1,5,6] . As well the overlapping
found between peptides of CASPR2 and LGI1 could explain the variation of phenotype when exposure
[7,8]
to the same VGKC complex antigens . Additionally the HLA DRB1*11:01 implicated in CASPR2 is not
[7]
associated with LGI1 .
The pathogenesis in anti-CASPR2 disease is believed to occur due to a block on the interaction between
[6,9]
CASPR2 and Contactin-2 [Figure 3], and the disrupting the Kv1 channels expression. In some cases,
[10]
there is reduced expression such as in the dorsal root ganglia and in others inducing an increase

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