Newly emerging type B insulin resistance (TBIR) during treatment with eculizumab for AQP4-IgG-positive neuromyelitis optica spectrum disorder (NMOSD): fatal outcome.

Background: Aquaporin-4 immunoglobulin G (AQP4-IgG) antibody-positive neuromyelitis optica spectrum disorders (NMOSD) are frequently associated with other autoimmune disorders, including systemic lupus erythematosus (SLE). Eculizumab (ECU) is a highly effective long-term treatment for NMOSD. However, ECU is known to increase significantly the risk of infection with encapsulated bacteria and sepsis.