What is the treatment for MOGAD (Myelin Oligodendrocyte Glycoprotein Antibody Disease)?

Treatment of MOGAD (Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease)

Initiate high-dose intravenous methylprednisolone at 1000 mg daily for 3-5 days immediately upon diagnosis, followed by a slow oral prednisone taper starting at 1 mg/kg/day over 2-3 months to prevent early relapses. 1, 2

Acute Attack Management

First-Line Therapy

• High-dose IV methylprednisolone (1000 mg/day for 3-5 days) is the cornerstone of acute treatment and should be started without delay for any MOGAD attack including optic neuritis, transverse myelitis, ADEM, or brainstem encephalitis. 1, 2, 3
• After IV steroids, transition to oral prednisone at 1 mg/kg/day with a prolonged taper over 2-3 months—this extended taper is critical as 50-60% of patients experience relapses during rapid steroid reduction. 1, 2

Second-Line Therapies for Severe or Refractory Cases

• Plasma exchange (5-7 exchanges) or immunoadsorption should be implemented early if there is inadequate response after 3-5 days of IV steroids or if the attack is particularly severe (e.g., bilateral blindness, respiratory insufficiency, severe myelitis). 1, 2, 3
• Intravenous immunoglobulin (IVIG) at 2 g/kg divided over 2-5 days is an effective alternative for patients who cannot undergo plasma exchange or as adjunctive therapy. 1, 3

Long-Term Preventative Therapy

Indications for Maintenance Treatment

• Initiate long-term immunosuppression after a relapsing course is established (typically after a second attack), as approximately 50-65% of MOGAD patients will have a relapsing course. 2, 4
• Consider early preventative therapy even after a first attack in high-risk patients: those with severe CSF pleocytosis (>150 cells/mm³), pediatric onset <9 years of age, or initial presentation with meningoencephalitis. 4

Treatment Options (Listed by Evidence Quality)

• Scheduled intravenous immunoglobulin (IVIG) appears most effective for relapse prevention, with 78.6% of patients remaining relapse-free in recent studies—this represents a significantly lower relapse hazard compared to other immunotherapies (HR: 0.1). 4
• Rituximab is widely used with 54.2% of patients remaining relapse-free, making it a reasonable first-line steroid-sparing agent. 2, 4
• Mycophenolate mofetil kept 50% of patients relapse-free and represents another viable option. 4
• Prospective trials are underway for IL-6 receptor inhibitors and neonatal Fc receptor inhibitors, which may become future standard treatments. 3

Monitoring and Follow-Up Strategy

Clinical Surveillance

• Conduct clinical assessments every 3-6 months to evaluate treatment response and detect early relapse signs. 1
• Monitor for steroid-dependent course, characterized by frequent flare-ups after methylprednisolone withdrawal—this pattern necessitates earlier initiation of steroid-sparing agents. 5

Antibody Monitoring

• Retest MOG-IgG antibodies 6-12 months after the initial attack to assess prognosis, as antibody disappearance may indicate monophasic disease (though this is more common in pediatric ADEM cases). 6, 2
• If MOG-IgG becomes negative but clinical suspicion remains high, re-test during acute attacks, treatment-free intervals, or 1-3 months after plasma exchange/IVIG, as antibody levels fluctuate with disease activity and treatment. 1, 2
• Do not base long-term treatment decisions solely on antibody disappearance, as transient seronegativity can occur even in relapsing patients, and some patients experience their first relapse 5-15 years after initial presentation. 6, 4

Critical Treatment Pitfalls to Avoid

Medication Errors

• Never use interferon-beta or natalizumab—these multiple sclerosis disease-modifying therapies are ineffective or potentially harmful in MOGAD and can increase relapse rates. 1, 2
• Avoid medications with known risk of worsening neurological symptoms in the context of demyelinating disease. 1

Steroid Management Errors

• Do not taper steroids rapidly—MOGAD has an exceptionally high risk of flare-ups with quick steroid cessation, unlike many other neuroinflammatory conditions. 1, 2
• The 2-3 month taper duration is evidence-based and should not be shortened even if the patient appears clinically stable. 1

Diagnostic Pitfalls

• Ensure MOG-IgG was detected by cell-based assay using full-length human MOG, as this is the gold standard—other assay methods have unacceptable false-positive rates. 2
• Recognize that CSF may show neutrophilic pleocytosis (present in 64% of cases with pleocytosis) and typically lacks oligoclonal bands (absent in 87-88% of cases), which can mimic CNS infection and lead to misdiagnosis. 6, 1, 5, 2
• Be aware that MOGAD lesions lack Dawson's fingers (absent in 95-99% of cases) and U-fiber involvement (absent in 94%), helping distinguish it from MS. 6