2026 American Academy of Neurology Autoimmune Abstract Website

Charalampia Koutsioumpa¹, Alexander Morrison², Mia Weisman³, Waleed Khan⁴, Srikanth Muppidi⁵, Nizar Chahin⁶, Long Davalos⁷, Alex Diefes³, Reza Seyedsadjadi⁴, Karissa Gable⁸, Mazen Dimachkie⁷, Chafic Karam³, Jeffrey Allen⁹, Bhaskar Roy¹⁰
¹Yale New Haven Hospital, ²The Ohio State University Wexner Medical Center, ³University of Pennsylvania, ⁴Mass General Brigham, ⁵Stanford, ⁶OHSU, ⁷University of Kansas Medical Center, ⁸Duke, ⁹University of Minnesota, ¹⁰Yale University

Objective:

To determine the prevalence, characteristics and treatment course of patients with autoimmune nodopathies in the US.

Background:

Autoimmune nodopathies (AINs) are a rare group of disorders characterized by circulating autoantibodies targeting antigens at the node of Ranvier, usually of the immunoglobulin G4 (IgG4) subclass. About 5-10% of patients with electrodiagnostic features of a demyelinating neuropathy have autoimmune nodopathies. Patients with AINs may present with suggestive clinical features, demonstrate mixed responses to intravenous immunoglobulin (IVIg), but improve with B-cell-depleting therapy.

Design/Methods:

This multi-center study, including over 12 centers in the US, is actively capturing the clinical features and therapeutic responses of patients with AINs.

Results:

To date, we have included 33 patients, with twenty-five (76%) positive for anti-neurofascin 155 (NF155), six (18%) positive for anti-Contactin IgG4 autoantibodies, and two (6%) positive for both autoantibodies. The average age of disease onset was 50.3 ± 19.6 years, and 18 (54.5%) patients were male. 55% had distal and proximal weakness, 36% predominant distal weakness, and 24% had facial weakness. Distal sensory loss, particularly loss of vibration sensation, and ataxia were common. Areflexia was noted in more than 80% of patients. Additional clinical details will be presented. Almost 40% of patients presented acutely or sub-acutely and were initially diagnosed as Guillain-Barré syndrome. Over 90% of this cohort received IVIg, but only 33% had partial benefit. Steroids were used in 50% of cases, neonatal Fc receptor (FcRn) inhibitors in 16% of cases, and PLEX in 20% of cases. Over 70% of patients received rituximab, and most showed objective benefit on clinical examination. Additional treatment details, including extent and durability of response will be presented.

Conclusions:

This collaborative effort across the US is providing new insights into the clinical characteristics of AIN from a large US cohort, as well as critical information on management strategies.