Science News: Anti-LGI4 Antibody Is a Novel Juxtaparanodal Autoantibody for Chronic Inflammatory Demyelinating Polyneuropathy

Submitted by: Pritikanta Paul, MD
Edited by: Nakul Katyal, M

Zhang X, Kira JI, Ogata H, et al. Anti-LGI4 antibody is a novel juxtaparanodal autoantibody for chronic inflammatory demyelinating polyneuropathy. Neurol Neuroimmunol Neuroinflamm. 2023;10(2):e200081. Published 2023 Jan 11. doi:10.1212/NXI.0000000000200081

Summary: In this single-centered study, 113 anti-NF155 and anti-CNTN1 antibody–negative chronic inflammatory demyelinating polyneuropathy (CIDP) patients were enrolled and the reactivity of sera from these patients against mouse dorsal root ganglion (DRG) and sciatic nerves was surveyed. The objective of this was to identify novel nodal autoantibodies in CIDP. Western blotting, indirect immunofluorescence, and cell-based RNA interference assays were used to identify target antigens. Sera from four patients reacted to juxtaparanodal regions of nodes of Ranvier in the sciatic nerve fibers and DRG satellite glia. Majority of these antibodies were IgG4 type. The identified candidate antigen was leucine-rich repeat LGI family member 4 (LGI4). The authors noted, patients with anti-LGI4 antibody positivity tended to have relatively old age at onset with subacute presentation involving both motor and sensory and very high levels of CSF protein. Intravenous immunoglobulin (IVIG) was only partially effective.

The authors concluded a small proportion of patients with CIDP have IgG4 antibodies against LGI4 have subacute onset of symptoms mimicking Guillain-Barré syndrome but have severe sensory impairment in addition to weakness.

Comments: This study identifies a novel nodal autoantibody in CIDP . That adds to our knowledge on autoimmune nodopathies, and warrants further studies to elaborate on these findings.