We report a child with an early and severe manifestation of an Aquaporin-4 (AQP-4) positive Neuromyelitis Optica Spectrum Disorder (NMOSD) who had a refractory disease course despite aggressive immunotherapy and underwent autologous hematopoietic stem cell transplant (AHSCT).

Case report featuring clinical presentation, laboratory, neuroimaging result, discussion of medical decision-making, and specific treatment protocol used for AHSCT.

A 2-year-old girl presented with left-hand weakness and abnormal gait. CSF and serum AQP-4 antibody were positive. She had highly active disease with 7 hospitalizations (5 of which she underwent PLEX) for exacerbations involving holocord edema, bilateral optic neuritis, and parenchymal brain lesions.

She was initially placed on rituximab but had rapid B cell repopulation. She was transitioned to mycophenolate mofetil with addition of monthly Tocilizumab but still had relapses. While her attacks continued to be partially responsive to acute therapies, serial imaging revealed increasing myelomalacia and optic nerve atrophy.

She subsequently underwent a myeloablative AHSCT without significant complication. Unfortunately, a week after full engraftment, she started to have worsening visual symptoms with an enhancing lesion of the optic chiasm. She received plasma exchange and IV steroids with significant clinical improvement. In the 6 months following AHSCT, she has only been admitted once for headache and neutropenia, with no relapses and stable neuroimaging. Anti-AQP4 titers at 5 months post-transplant decreased over 10-fold from > 1:100,000 to 1:10,000.

AHSCT has been increasingly utilized in refractory cases of adult NMOSD, showing good efficacy, tolerability, and potential for enduring disease remission. The long-term efficacy and safety of this treatment in children is unknown and requires further investigation.