What is the recommended treatment for myelin oligodendrocyte glycoprotein antibody disease (MOGAD)?

Treatment of Myelin Oligodendrocyte Glycoprotein Antibody Disease (MOGAD)

High-dose corticosteroids are the first-line treatment for acute attacks of MOGAD, followed by a prolonged oral corticosteroid taper of at least 3 months with a minimum dose of 12.5 mg/day (or 0.16 mg/kg/day for children) to prevent early relapses. 1, 2

Acute Treatment of MOGAD Attacks

First-Line Treatment

• High-dose intravenous corticosteroids (typically methylprednisolone 1g/day for 3-5 days)
• Follow with oral prednisone taper starting at 1-2 mg/kg/day 3
• Taper should be slow, extending over at least 3 months 2
• Maintain minimum dose of 12.5 mg/day for adults (0.16 mg/kg/day for children) during this period 2

Second-Line/Adjunctive Treatments for Severe or Refractory Cases

• Plasma exchange (PLEX) or immunoadsorption if inadequate response to steroids 3
• Intravenous immunoglobulin (IVIG) 2 g/kg over 5 days (0.4 g/kg/day) 3
• Consider combination of pulse steroids plus IVIG in severe cases 3

Long-Term Immunotherapy for Relapsing MOGAD

First-Line Options

• IVIG (emerging as most effective therapy with 78.6% relapse-free rate) 1, 4
  • Scheduled maintenance dosing
  • Significantly fewer relapses compared to other immunotherapies (HR: 0.1) 4

Alternative Options (in order of evidence-based efficacy)

1. Rituximab (54.2% relapse-free rate) 4

   • Reduces risk of relapsing disease course (HR: 0.21) 5

2. Mycophenolate mofetil (50% relapse-free rate) 4

   • Reduces risk of relapsing disease course (HR: 0.27) 5

3. Low-dose oral corticosteroids (maintenance therapy)

   • Consider for patients who cannot tolerate or access other options

4. Other immunosuppressants to consider:

   • Azathioprine
   • Cyclophosphamide (reserve for severe refractory cases)

Predictors of Relapsing Disease Course

Patients with the following characteristics should be considered for earlier and more aggressive long-term immunotherapy:

• Polyphasic first attack (HR: 2.4) 5
• High CSF protein levels (HR: 2.06) 5
• Severe CSF pleocytosis (>150 cells/mm³) (HR: 3.3) 4
• Pediatric onset before age 9 (HR: 2.69) 4
• Initial presentation with meningoencephalitis (HR: 3.42) 4

Important Clinical Considerations

• 60-70% of MOGAD patients develop a relapsing course 5, 4
• Most relapses (68.6%) occur within the first year, but late relapses can occur up to 15 years after initial presentation 4
• Starting maintenance therapy immediately after the index event significantly reduces relapse risk (HR: 0.26) 5
• MOG antibodies can cause various clinical syndromes including optic neuritis, transverse myelitis, ADEM, and cerebral cortical encephalitis 6
• MOGAD is distinct from multiple sclerosis and AQP4-IgG-positive neuromyelitis optica spectrum disorders 3

Treatment Algorithm

1. Acute attack: High-dose IV methylprednisolone → oral prednisone taper (minimum 3 months)
2. If severe or inadequate response: Add PLEX or IVIG
3. After first attack:
   • Assess for relapse risk factors
   • Consider immediate initiation of maintenance therapy, especially with high-risk features
4. For maintenance therapy:
   • First choice: IVIG (if available and tolerated)
   • Second choice: Rituximab or mycophenolate mofetil
   • Third choice: Low-dose oral corticosteroids

Monitoring

• Regular clinical assessment for new neurological symptoms
• Consider periodic MRI surveillance in high-risk patients
• Monitor for treatment-related side effects
• Reassess MOG antibody status periodically (though clinical relevance of antibody persistence remains under investigation)