Double Anti-NMO and Anti-MOG Positivity in a Patient With Metastatic Renal Carcinoma: First Reported Case

Area of Science:

• Neuroimmunology
• Onconeural autoimmunity
• Central nervous system (CNS) demyelination

Background:

• Neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein-associated disease (MOGAD) are CNS demyelinating disorders.
• These conditions are characterized by autoantibodies targeting aquaporin-4 (AQP4) and MOG, respectively.
• Dual positivity for AQP4-IgG and MOG-IgG antibodies is rare and presents diagnostic and therapeutic challenges.

Purpose of the Study:

• To report the first case of dual AQP4-IgG and MOG-IgG positivity in a patient with metastatic renal carcinoma.
• To highlight the diagnostic and therapeutic complexities associated with this rare presentation.

Main Methods:

• Case presentation of a 49-year-old male with metastatic renal carcinoma and progressive neurological symptoms.
• Investigation included lumbar puncture and autoantibody testing for AQP4-IgG and MOG-IgG.
• Diagnostic confirmation of a demyelinating process with dual seropositivity.

Main Results:

• The patient presented with neurological symptoms initially presumed to be tumor progression.
• Dual seropositivity for AQP4-IgG and MOG-IgG antibodies was identified.
• Treatment with high-dose corticosteroids and rituximab led to clinical and radiological stability.

Conclusions:

• This case underscores the rare co-occurrence of AQP4-IgG and MOG-IgG positivity in a patient with metastatic renal carcinoma.
• The underlying pathogenesis remains unclear, potentially involving genetic predisposition and autoimmune coactivation.
• Emphasizes the need for personalized treatment strategies and further research for managing such complex cases.