Biomarkers for neuromyelitis optica

• Anti-AQP4 antibody is a sensitive diagnostic biomarker for neuromyelitis optica (NMO).
• Other candidate biomarkers for NMO are majorly involved in Th17 pathway and astrocytic damages.
• IL-6 is associated with anti-AQP4 antibody generation.
• GFAP levels in CSF demonstrate correlations with clinical severity of NMO relapses.
• Blocking IL-6 receptor by tocilizumab may be a potential treatment for NMO patients.

Neuromyelitis optica (NMO) is an acquired, heterogeneous inflammatory disorder, which is characterized by recurrent optic neuritis and longitudinally extensive spinal cord lesions. The discovery of the serum autoantibody marker, anti-aquaporin 4 (anti-AQP4) antibody, revolutionizes our understanding of pathogenesis of NMO. In addition to anti-AQP4 antibody, other biomarkers for NMO are also reported. These candidate biomarkers are particularly involved in T helper (Th)17 and astrocytic damages, which play a critical role in the development of NMO lesions. Among them, IL-6 in the peripheral blood is associated with anti-AQP4 antibody production. Glial fibrillary acidic protein (GFAP) in CSF demonstrates good correlations with clinical severity of NMO relapses. Detecting these useful biomarkers may be useful in the diagnosis and evaluation of disease activity of NMO. Development of compounds targeting these biomarkers may provide novel therapeutic strategies for NMO. This article will review the related biomarker studies in NMO and discuss the potential therapeutics targeting these biomarkers.