Characterization of a Subtype of Autoimmune Encephalitis With Anti–Contactin-Associated Protein-like 2 Antibodies in the Cerebrospinal Fluid, Prominent Limbic Symptoms, and Seizures

Abstract

In this cohort study, anti-CASPR2 antibodies in the CSF are associated with a subtype of autoimmune encephalitis with prominent limbic involvement and seizures that is rarely associated with cancer. Conversely, patients with NMT and MoS have anti-CASPR2 antibodies only in the serum but not in the CSF and frequently present with a malignant thymoma. The anti-CASPR2 antibodies found in these patients targeted the discoidin and laminin G1 domains of CASPR2 and always included IgG4 autoantibodies.