Autoimmune nodopathy with anti-NF186 antibodies following SARS-CoV-2 infection: a case report.

BACKGROUND

Autoimmune nodopathy is a distinct entity characterized by antibodies targeting nodal/paranodal proteins like neurofascin-186 (NF186), leading to conduction defects and neurological dysfunction. This report highlights a unique case of autoimmune nodopathy with anti-NF186 antibodies following SARS-CoV-2 infection.

CASE PRESENTATION: A 47-year-old female developed acute limb numbness and weakness ten days post-COVID-19 diagnosis, which progressed to respiratory muscle paralysis necessitating mechanical ventilation. Initial treatments with intravenous immunoglobulin and steroids were ineffective. Diagnosis of autoimmune nodopathy with anti-NF186 antibodies was confirmed through clinical examination, electromyography (EMG), and serum antibody testing using cell-based assays. The patient showed partial improvement with plasma exchange therapy and achieved stability after rituximab treatment, consistent with the typical treatment response pattern for anti-NF186 autoimmune nodopathy. Notably, re-infection with SARS-CoV-2 did not exacerbate her symptoms, and a gradual recovery of muscle strength was observed over time, with the patient regaining substantial independence in daily activities by November 2023.

CONCLUSIONS

This case represents the first reported occurrence of anti-NF186 autoimmune nodopathy following SARS-CoV-2 infection, underscoring the potential link between viral triggers and autoimmune neurological disorders. It emphasizes the importance of testing for specific nodal/paranodal antibodies in post-COVID neurological presentations and highlights the superior efficacy of plasma exchange and B-cell depleting therapies over conventional treatments in managing nodopathies.