2026 American Academy of Neurology Autoimmune Abstract Website

Objective:

To highlight autoimmune nodopathy mimicking GBS and the need for early diagnostic reassessment and targeted therapy.

Background:

Autoimmune nodopathies are immune-mediated neuropathies that can resemble Guillain-Barré syndrome (GBS), making diagnosis challenging. They are associated with IgG4 antibodies targeting nodal and paranodal proteins including NF186, NF155, CNTN1, and Caspr1. In 2021, the EAN/PNS classified autoimmune nodo-paranodopathy as a distinct subtype of polyneuropathy. These disorders often follow an aggressive course with cranial nerve involvement and demonstrate minimal response to IVIG, while B-cell–targeted therapies such as rituximab are more effective. We present a case of acute-onset, severe pan-nodopathy that initially mimicked GBS, ultimately associated with new-onset SLE. Although the mechanisms underlying this form of polyautoimmunity remain poorly understood, increased awareness is critical to enable early recognition and appropriate management, helping to prevent a potentially life-threatening disease course.

Design/Methods:

An 18-year-old woman with new-onset SLE, nephrotic syndrome, and pneumonia presented with rapidly progressive ascending weakness and bulbar involvement. Initial findings suggested GBS, and IVIG was initiated. Despite treatment, she deteriorated within three days to quadriplegia with respiratory failure requiring intubation. Electrodiagnostic studies showed a progressive sensorimotor axonal polyneuropathy with severe active denervation, and biopsy demonstrated mild axonal loss.

Results:

Given her rapid decline and poor response to IVIG, therapy was escalated to plasma exchange, corticosteroids, mycophenolate mofetil, hydroxychloroquine, and cyclophosphamide. Serologic testing identified pan-neurofascin (NF155/NF186) IgG4 antibodies, confirming autoimmune nodopathy. Rituximab was initially unavailable, so ofatumumab was initiated in the meanwhile with marked clinical improvement over subsequent weeks.

Conclusions:

Autoimmune nodopathies may mimic GBS but often show continued progression and poor response to IVIG. Early recognition is essential, as management requires escalation to targeted immunotherapy. This case underscores the importance of reassessing the diagnosis in patients with presumed GBS who fail to improve or have an atypical course.