Neuromyelitis Optica

Previously known as Devic disease and once regarded as a variant of multiple sclerosis

Associated with a specific antibody marker (NMO-IgG) targeting the water channel aquaporin-4 in 80% of cases, and with antibodies to myelin oligodendrocyte glycoprotein (MOG-IgG) in a third of NMO-IgG seronegative patients

Optic neuritis and acute myelitis with MRI changes that extend over at least three segments of the spinal cord

Isolated myelitis or optic neuritis may also occur

MRI of the brain typically does not show widespread white matter involvement, but such changes do not exclude the diagnosis

Eculizumab

• FDA approved

• A complement inhibitor that reduced the annualized relapse rate from 35% to 2% compared to placebo

• Requires prior immunization against meningococcus

Inebilizumab

• FDA-approved

• A humanized anti-CD19 antibody that depletes B cells

• Reduced relapse rate compared to placebo in a randomized trial

Alteratives include

• Rituximab

  • Two 1-g intravenous infusions spaced by 2 weeks, or four weekly infusions of 375 mg/m²

  • Re-dosing may occur every 6 months or when CD19/20-positive or CD27-positive lymphocytes become detectable

• Mycophenolate mofetil, 500–1500 mg orally twice daily, titrated until the absolute lymphocyte count falls below 1500/mcL

• Azathioprine, 2.5–3 mg/kg orally

Corticosteroids used for acute relapses

Plasma exchange given when severe relapses do not respond to corticosteroids