[Clinical features of anti-neurofascin-155 antibody positive autoimmune nodopathy in 6 children]

Objective: To analyze the clinical features of anti-neurofascin-155 (NF155) antibody positive autoimmune nodopathy in children. Methods: This was a case series study. A total of 6 children who were diagnosed accurately as anti-NF155 antibody positive autoimmune nodopathy by cell immunofluorescence assay at the Children's Hospital of Fudan University from January 2020 to December 2023 were collected. This study retrospectively analyzed 6 pediatric children's clinical manifestations, laboratory and electrophysiological examination results, and treatment outcomes. Results: Among 6 children with anti-NF155 antibody positive autoimmune nodopathy, there were 4 boys and 2 girls. The onset age of 6 children ranged from 3 years and 8 months to 12 years. All 6 children had extremity weakness (more severe in the distal and the lower extremities than in the upper extremities), 5 children had sensory deficits such as numbness or pain in the extremities, 4 children had tremors and ataxia, 3 children had cranial nerve involvement. Among the 6 children, 4 children had protein-cell separation in cerebrospinal fluid examinations. Among the 6 children, 1 child had central nervous system demyelination, the brain magnetic resonance imaging showed multiple abnormal signals in the bilateral cerebral hemispheres. Four children showed motor and sensory nerve damage in electrophysiological examination, and 2 children only showed motor nerve damage. Three children showed myelin and axonal damage, and 3 children only showed axonal damage. Among the 6 children, 5 children were treated with intravenous immunoglobulin and steroids. Among them, 2 children underwent plasma exchange due to poor efficacy, and subsequently, rituximab was added. There was 1 child changed the treatment with olfatomumab since the symptoms did not significantly improve after using rituximab. After treatment for 4-15 months, 2 children had no clinical symptoms, 1 child had improvement in clinical symptoms, 2 children had no significant improvement in clinical symptoms, and 1 child who did not receive the immunotherapy had no significant change in clinical symptoms. Conclusions: Anti-NF155 antibody positive autoimmune nodopathy in children presents with varying degrees of clinical manifestations. It is mainly characterized by extremity weakness, numbness and pain, often accompanied bytremorsand ataxia. Some pediatric patients may also have central nervous system demyelination. Cerebrospinal fluid and electrophysiological examination are important auxiliary examination methods. If steroid therapy is not effective, plasma exchange and rituximab treatment should be used as soon as possible.