Background: Childhood onset immune-mediated polyneuropathy, such as chronic inflammatory demyelinating polyneuropathy (CIDP), is rare. A newly described subclass of immune-mediated neuropathies related to antibodies against the nodal or paranodal proteins of the peripheral nerve represents a distinct clinical syndrome. Anti-NF155 autoimmune nodopathy (AN) in adults may cause tremor, cranial nerve involvement, rapid and severe progression, younger age of onset, and poor response to intravenous immunoglobulin (IVIG). Studies on anti-NF155 AN in the pediatric population are limited.
Objectives: The aim of this case series is to describe the clinical course and treatment response of pediatric patients with anti-NF155 AN.
Methods: Antibodies against neurofascin-155 were detected in four pediatric patients with new onset immune mediated sensorimotor neuropathy with mixed axonal and demyelinating features. Data were collected from clinical, laboratory, radiologic, and electrophysiologic examinations. Descriptive statistics were applied.
Results: Age at symptom onset ranged from nine through thirteen years. All patients exhibited primarily distal weakness and impaired pinprick sensation and proprioception, with three also demonstrating impaired vibration sense. Clinical symptoms included tremor (n=2) and ataxia (n=3). The mean time from symptom onset to identification of anti-NF155 AN was 36 months (range 6–84 months). The maximum modified Rankin scale scores ranged from 2 to 4. MRI showed spinal nerve root enhancement (n=3) and cranial nerve enhancement (n=2). CSF protein was elevated (n=3), showing cytoalbuminologic dissociation. All patients were initially treated with IVIG, and only one patient remained on IVIG alone as maintenance immunotherapy. Two patients began Rituximab for persistent weakness – one four months and the other two years after initial IVIG, and both demonstrated superior response with Rituximab. The fourth patient started Rituximab empirically following antibody identification and demonstrated clinical improvement in strength and sensory deficits.
Conclusions: Anti-NF155 AN in pediatric patients resembles the adult presentation, with distal weakness, sensory neuropathy, ataxia, and tremor, though it typically follows a milder course. Partial response to IVIG may be seen, but the addition of Rituximab often leads to superior outcomes, emphasizing the importance of early clinical recognition and antibody detection.