IgG Anti‐GM1 antibody is associated with reversible conduction failure and axonal degeneration in guillain‐barré syndrome

TLDR

The study aimed to determine the pathophysiological role of IgG anti‑GM1 antibodies in Guillain‑Barré syndrome. It reviewed sequential nerve‑conduction studies of 345 nerves in 34 GBS patients. IgG anti‑GM1 antibodies were significantly correlated with electrodiagnostic patterns, with 16 positive patients classified as AMAN/AMSAN, AIDP, or undetermined; these patients exhibited rapid resolution of conduction slowing and block, distinct from anti‑GM1‑negative AIDP, suggesting reversible conduction failure due to impaired nodal conduction and axonal degeneration driven by immune attack on motor axolemma.

Abstract

Abstract To investigate the pathophysiological role of anti‐GM1 antibody in Gullain‐Barre syndrome (GBS), we reviewed sequential nerve conduction studies of 345 nerves in 34 GBS patients. Statistically significant correlation between IgG anti‐GM1 antibodies and electrodiagnoses was found. Sixteen IgG anti‐GM1‐positive patients were classified as having acute motor sensory axonal neuropathy (AMAN or AMSAN) (12 patients), as having acute inflammatory demyelinating polyneuropathy (AIDP) (3 patientsrpar; ; or as undetermined (1 patient) by electrodiagnostic criteria. Besides axonal features, there was rapid resolution of conduction slowing and block. In 3 patients initially diagnosed as having AIDP, conduction slowing was resolved within days, and 1 of them and 3 AMAN patients showed markedly rapid increases in amplitudes of distal compound muscle action potentials that were not accompanied by prolonged duration and polyphasia. The time courses of conduction abnormalities were distinct from those in IgG anti‐GM1‐negative AIDP patients. Rapid resolution of conduction slowing and block, and the absence of remyelinating slow components, suggest that conduction failure may be caused by impaired physiological conduction at the nodes of Ranvier. Reversible conduction failure as well as axonal degeneration constitutes the pathopsiological mechanisms in IgG anti‐GM1)positive GBS. In both cases, immune‐mediated attack probably occurs on the axolemma of motor fibers.