Neuromyelitis optica spectrum disorder (NMOSD)

Important caveat

NMOSD is a serious, relapsing, antibody-mediated CNS autoimmune disease in which preventable relapses cause permanent vision loss, paralysis, and autonomic dysfunction. The dominant intervention is guideline-directed care from a neuroimmunology subspecialist — most commonly with one of the four FDA-approved monoclonal antibodies (eculizumab, ravulizumab, inebilizumab, satralizumab) or off-label rituximab, with acute relapses treated by IV methylprednisolone pulses and plasma exchange. MS DISEASE-MODIFYING THERAPIES CAN WORSEN NMOSD. This is the single most important safety thread. Interferon-beta, natalizumab, and fingolimod — all standard MS DMTs — have been documented to worsen AQP4+ NMOSD. Several other MS DMTs are at minimum unsafe or unstudied. Distinguishing NMOSD from MS at diagnosis (via AQP4-IgG serology, MRI pattern recognition, and the 2015 IPND criteria) is therefore not academic — it is the safety-critical decision that determines whether a patient is started on the correct disease-targeted therapy. If you have been diagnosed with MS and have features that overlap with NMOSD (severe optic neuritis, especially bilateral; LETM on MRI; area postrema syndrome), ask explicitly whether AQP4-IgG and MOG-IgG serology have been checked. If you have been diagnosed with NMOSD and are being offered an MS DMT, ask explicitly why — the standard of care for AQP4+ NMOSD does not include interferon-beta, natalizumab, or fingolimod. ECULIZUMAB AND RAVULIZUMAB REQUIRE MENINGOCOCCAL VACCINATION. Both C5 complement inhibitors carry an FDA boxed warning for meningococcal infection. Vaccination against Neisseria meningitidis serogroups A, C, W, Y AND serogroup B is required prior to starting therapy (ideally ≥2 weeks before the first dose, with antibiotic prophylaxis if therapy must start sooner). Breakthrough meningococcal infection — including in vaccinated patients — has occurred and can be rapidly fatal. Fever in a patient on eculizumab or ravulizumab is an emergency, not a wait-and-see symptom. INEBILIZUMAB AND RITUXIMAB CARRY INFECTION AND HYPOGAMMAGLOBULINEMIA RISKS. Both deplete CD20 (rituximab) or CD19 (inebilizumab) B-cells, with extended duration. IgG levels can decline over time, raising opportunistic infection risk. PML (progressive multifocal leukoencephalopathy) is a documented rare risk with rituximab. Vaccination status (especially against pneumococcus, influenza, COVID-19, and meningococcus where indicated) should be addressed before B-cell depletion when possible. SATRALIZUMAB CARRIES INFECTION AND LIPID/LIVER EFFECTS. Anti-IL-6R blockade can blunt acute-phase responses including fever, masking infection presentations. MOGAD IS NOW A SEPARATE DISEASE per the 2023 international consensus criteria. Clinical course differs (more often monophasic, better recovery profile), and treatment responses differ — including treatments that are standard in AQP4+ NMOSD that are not necessarily the right answer in MOGAD. None of the five peptides on this page have NMOSD-specific evidence. None should substitute for, delay, or be added to a maintenance regimen without explicit sign-off from the prescribing neuroimmunologist. The Guthy-Jackson Charitable Foundation and the Sumaira Foundation are patient-organization resources oriented around NMOSD specifically; AAN and ECTRIMS publish clinician-facing guidance. WADA athletes: BPC-157 (S0) prohibited at all times. Pregnancy: NMOSD pregnancy requires neurology + maternal-fetal medicine coordination; relapse rate may increase postpartum; eculizumab and ravulizumab are continued during pregnancy in most cases with careful neonatal monitoring; rituximab has B-cell-repletion timing considerations; inebilizumab and satralizumab pregnancy data are emerging.