Is neuromyelitis optica without AQP4-IgG a T-cell mediated disease? insights from checkpoint inhibitor immune-related adverse events.

A 30-year-old female presented with recurrent opticospinal demyelinating attacks after introduction of nivolumab to treat Hodgkin's lymphoma. Paraneoplastic, neuronal surface, and demyelinating antibodies were negative from the serum and/or cerebrospinal fluid. Oligoclonal bands were negative and she met clinical criteria for NMOSD without AQP4-IgG. She could not tolerate plasmapheresis due to transfusion-related acute lung injury but responded well to corticosteroids and discontinuation of nivolumab. The precipitation of typical NMOSD without AQP4-IgG syndrome by a checkpoint inhibitor suggests a possible T-cell mediated pathogenesis. This may help explain why this patient group lacked response to B-cell therapies in NMOSD clinical trials.