Autoantibody to MOG suggests two distinct clinical subtypes of NMOSD

Area of Science:

• Neuroimmunology
• Autoimmune neurological disorders
• Neuromyelitis Optica Spectrum Disorder (NMOSD)

Background:

• Neuromyelitis optica spectrum disorder (NMOSD) is a severe autoimmune condition affecting the central nervous system.
• Autoantibodies against aquaporin-4 (AQP4) and myelin-oligodendrocyte glycoprotein (MOG) are key biomarkers in NMOSD.
• The clinical and radiological phenotypes associated with dual positivity for AQP4 and MOG autoantibodies remain incompletely understood.

Purpose of the Study:

• To characterize the clinical and radiological features of NMOSD patients with co-existing AQP4 and MOG autoantibodies.
• To compare the disease course and disability in NMOSD patients with dual autoantibody positivity versus MOG autoantibody positivity alone.
• To investigate the potential pathogenic role of MOG autoantibodies in NMOSD.

Main Methods:

• Retrospective analysis of 125 NMOSD patients.
• Serological testing for AQP4 and MOG autoantibodies.
• Clinical data collection including disease course, relapse rate, and disability.
• Magnetic Resonance Imaging (MRI) analysis of brain and spinal cord lesions.
• Ophthalmic examination for retinal nerve fiber layer thickness and optic nerve atrophy.

Main Results:

• 10% of NMOSD patients were double-positive for AQP4 and MOG autoantibodies; 11.2% were MOG-ab single positive.
• Double-positive patients exhibited a multiphase disease course, high relapse rates, and severe disability, with MS-like brain lesions and severe spinal cord edema.
• MOG-ab single-positive patients showed a predominantly monophasic course, milder disability, distinct MRI lesion patterns (spinal cord edema, periventricular brain lesions), and less optic nerve damage.

Conclusions:

• NMOSD patients with both AQP4 and MOG autoantibodies present with a severe phenotype combining features of classic NMOSD and relapsing-remitting MS.
• NMOSD patients with MOG autoantibodies only display an intermediate phenotype between NMOSD and MS.
• The presence of MOG autoantibodies may indicate pathogenicity and influence disease management strategies in NMOSD.