Objective To summarize the clinical characteristics, antibody spectrum and neuroelectrophysiological features of autoimmune nodopathy(AN), and to explore the phenotypic differences among different antibody-positive subgroups.

Methods The clinical and electrophysiological data of patients definitely diagnosed with AN in Beijing Tiantan Hospital, Capital Medical University, from October 2018 to January 2026 were retrospectively analyzed.

Results A total of 33 patients with AN were included. Antibody examination results showed that, anti-neurofascin(NF)155 antibody was the most prevalent, detected in 17 patients(51.50%), followed by anti-contactin-1(CNTN1) antibody in 8 patients(24.24%). Anti-NF186 antibody(4 cases, 12.12%), anti-contactin-associated protein 1(Caspr1) antibody(2 cases, 6.06%) and dual-target antibody positivity(2 cases, 6.06%) were relatively uncommon. The main clinical manifestations of AN patients included symmetric distal paresthesia of the extremities(32 cases, 96.97%), limb weakness(31 cases, 93.93%) and sensory ataxia(25 cases, 75.76%). Different antibody-positive subgroups presented distinct phenotypic features: patients with positive anti-NF155 antibody had a relatively younger age of onset, chronic onset and a high incidence of tremor, which was dominated by immunoglobulin(Ig)G4 subclass antibodies; patients with positive anti-CNTN1 antibody had a relatively advanced age of onset, mostly presented with acute or subacute onset, and were prone to complicated nephrotic syndrome; patients with positive anti-NF186 antibody had relatively mild nerve conduction damage; patients with anti-Caspr1 antibody manifested acute or subacute onset, with relatively elevated cerebrospinal fluid protein level and 24-h intrathecal IgG synthesis rate. The prominent neuroelectrophysiological manifestations of AN included decreased motor and sensory nerve conduction velocities, prolonged distal latency, frequent non-compressive conduction block and abnormal temporal dispersion. Definite sensory nerve action potentials could not be elicited in more than half of the patients.

Conclusions Patients with AN show high heterogeneity in clinical and neuroelectrophysiological characteristics, and different antibody-positive subgroups correspond to specific clinical and neuroelectrophysiological phenotypes.