[Treatment of NMO]

Area of Science:

• Neurology
• Immunology
• Neuroimmunology

Context:

• Current diagnostic criteria for neuromyelitis optica (NMO) require simultaneous optic neuritis and myelitis, potentially delaying early diagnosis.
• A significant number of patients may have the underlying disease process without meeting these strict criteria.
• The proposed new criteria aim to capture a broader range of patients with NMO spectrum disorders.

Purpose:

• To propose simplified diagnostic criteria for NMO, focusing on specific spinal cord lesions or the presence of anti-aquaporin-4 (AQP4) antibodies.
• To introduce a new nomenclature, 'autoimmune astrocytopathy,' to better reflect the disease mechanism targeting astrocytes.
• To re-evaluate existing clinical trial data and propose a treatment algorithm for NMO management.

Summary:

• The study suggests new diagnostic criteria for NMO: either a long contiguous spinal cord lesion (LCL) spanning three or more segments or long segmental spinal cord atrophy, or the presence of anti-aquaporin-4 (AQP4) antibodies.
• Reanalysis of Japanese interferon beta-1b trial data in patients with multiple sclerosis (MS) and MRI evidence of LCL showed no efficacy.
• A treatment algorithm is proposed, starting with high-dose steroids, followed by plasma exchange if needed, and then immunosuppressants (Mizoribine, Tacrolimus, Azathiopurine) or advanced therapies like Mitoxantrone or Rituximab for refractory cases.

Impact:

• The proposed criteria could enable earlier and more accurate diagnosis of NMO spectrum disorders.
• The new term 'autoimmune astrocytopathy' may improve understanding of the disease's underlying autoimmune attack on astrocytes.
• The outlined treatment algorithm provides a structured approach to managing NMO, emphasizing the need for evidence-based clinical trials.