Immune-related biomarkers in the neuromyelitis optica spectrum disorder; pathogenesis and therapeutic approaches.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system that mostly affects the optic nerves and spinal cord. About eighty percent of patients have antibodies that are directed against the water channel aquaporin-4 (AQP4)-IgG, which is expressed on astrocytes. This protein was shown to be both a biomarker and a pathogenic cause of NMOSD. Researchers have discovered that antibodies against myelin oligodendrocyte glycoprotein (MOG) IgG can serve as a biomarker for a distinct condition known as MOG antibody-associated disease (MOGAD). This condition shares some similarities with AQP4-IgG-positive NMOSD, but it has distinct differences in terms of its underlying causes, clinical characteristics, response to treatment, and prognosis. Identifying AQP4 antibodies in the blood serum confirms the diagnosis of seropositive NMOSD. Nevertheless, it remains uncertain if there is a correlation between AQP4-IgG levels and disease activity, severity, responsiveness to medication, or long-term effects. Furthermore, there is still a need to establish and confirm biomarkers specifically for patients diagnosed with seronegative NMOSD. This study primarily examines the immunological aspects of NMOSD, which might have significant consequences for clinical practice. These implications include the possible use of new biomarkers to aid in the early and correct diagnosis of NMOSD, as well as the development of current treatment options to enhance the long-term prognosis of NMOSD patients.