Rethinking neuromyelitis optica (Devic disease).

Area of Science:

• Neuroimmunology
• Autoimmune diseases

Background:

• Neuromyelitis optica (NMO) is distinct from multiple sclerosis (MS) by specific clinical and imaging features.
• NMO often involves severe optic neuritis and myelitis with extensive spinal cord lesions.
• Previous diagnostic criteria excluded brain abnormalities typical of MS.

Purpose of the Study:

• To identify a specific marker for Neuromyelitis Optica (NMO).
• To clarify the relationship between NMO, Japanese opticospinal MS, and other autoimmune conditions.
• To revise diagnostic criteria for NMO.

Main Methods:

• Identification of an immunoglobulin marker (NMO antibody) in NMO patients.
• Testing for the NMO antibody in patients with opticospinal MS, lupus erythematosus, and Sjögren syndrome.
• Review of clinical and imaging data, including brain MRI.

Main Results:

• An NMO-specific antibody targeting aquaphorin-4 was identified.
• This antibody is present in NMO, Japanese opticospinal MS, and some patients with lupus and Sjögren syndrome presenting with optic neuritis and myelitis.
• The presence of atypical brain MRI findings does not exclude NMO if the antibody is present.

Conclusions:

• The NMO antibody is a key diagnostic marker for NMO and related disorders.
• NMO and Japanese opticospinal MS are likely the same disease.
• Revised NMO diagnostic criteria should include patients with the NMO antibody and atypical brain MRI findings.
• Distinguishing NMO from MS is crucial for appropriate treatment selection.