What is the treatment for Myelin Oligodendrocyte Glycoprotein (MOG) antibody disease?

Treatment of Myelin Oligodendrocyte Glycoprotein (MOG) Antibody Disease

The first-line treatment for acute attacks in MOG antibody disease is high-dose intravenous methylprednisolone followed by a slow oral steroid taper, with plasma exchange or intravenous immunoglobulin as second-line options for severe attacks or inadequate steroid response. 1, 2

Acute Treatment

First-Line Treatment

• High-dose intravenous methylprednisolone (IVMP)
  • Leads to favorable outcomes in the majority of patients 2
  • Typically 1000 mg daily for 3-5 days 1
  • Should be followed by oral steroid taper for up to 3 months to prevent early relapses 2
  • Slow tapering is critical as MOG-IgG positive patients have a high risk of flare-ups after steroid cessation 3

Second-Line Treatments

For patients with severe attacks or inadequate response to steroids:

• Plasma exchange (PLEX) 3, 1, 2
• Intravenous immunoglobulin (IVIG) 3, 1, 2
  • Particularly effective in children 3

Maintenance/Preventative Treatment

When to Start Maintenance Therapy

• After first relapse to prevent further relapses and permanent sequelae 2
• Consider for patients with a definitive relapsing disease course 4

First-Line Maintenance Options

1. Rituximab 1, 2

   • B-cell depleting therapy that has shown efficacy in retrospective studies
   • Often preferred in adults with relapsing disease

2. Mycophenolate mofetil 2, 5

   • Immunosuppressive agent that has shown benefit in preventing relapses

3. Azathioprine 2

   • Alternative immunosuppressive option

4. Monthly IVIG 2

   • Particularly effective in pediatric patients

Treatment Escalation for Breakthrough Relapses

If relapses occur despite first-line maintenance therapy:

1. Switch to rituximab or IVIG (if not already used) 2
2. Consider combination of rituximab and IVIG 2
3. Add maintenance oral steroids as a last resort 2

Special Considerations

Monitoring

• MOG-IgG serum concentrations depend on disease activity and treatment status 1
• Antibodies may transiently disappear after plasma exchange or during immunosuppression 1
• If initially negative but MOG disease is still suspected, consider retesting:
  • During acute attacks
  • During treatment-free intervals
  • 1-3 months after plasma exchange or IVIG 1

Treatment Response

• MOG-IgG positive patients are particularly responsive to antibody-depleting treatments for acute attacks 3
• Patients with optic neuritis tend to show marked improvement with high-dose steroids 6
• Patients with myelitis also respond well to steroids but may have less improvement if left untreated compared to optic neuritis 6

Relapse Risk

• Recent data suggests a higher relapse rate than previously reported, with most relapses occurring within one year of diagnosis 7
• The median time to first relapse in one study was 9.5 months (range 2-120) 5

Pitfalls and Caveats

• Avoid MS-specific treatments like interferon-beta or natalizumab, which may increase relapse rates in MOG antibody disease 1
• Early identification of MOG antibody disease is crucial for appropriate treatment selection 1
• Do not discontinue maintenance therapy too early, as relapses can occur even after prolonged periods of stability
• Be aware that MOG-IgG may become undetectable during treatment but this does not necessarily indicate disease resolution 3
• Consider that some patients may have co-existing autoantibodies (e.g., NMDAR antibodies) that might require additional treatment considerations 5

While evidence for treatment is largely based on retrospective studies and expert consensus, early aggressive treatment of acute attacks and appropriate maintenance therapy for relapsing disease appear to improve long-term outcomes in MOG antibody disease.