Papillitis associated with IgLON5 autoimmunity: A novel clinical phenotype.

OBJECTIVES:To describe papillitis as a clinical phenotype of IgLON5 autoimmunity. METHODS:We retrospectively reviewed patients with IgLON5 autoimmunity who had optic neuropathy, optic neuritis, or optic disc edema. Sera from patients with recurrent papillitis were tested for IgLON5 antibodies. RESULTS:We found two elderly males presenting with papillitis in the presence of IgLON5 antibodies. CSF pleocytosis was present and partial vision improvement occurred in one patient despite immunotherapy. Sera from 18 patients with recurrent papillitis were negative for IgLON5 antibodies. CONCLUSION:Papillitis could be a manifestation of IgLON5 disease, with or without accompanying cognitive, sleep, and movement disorders.