Repeated follow-up of AQP4-IgG titer by cell-based assay in neuromyelitis optica spectrum disorders (NMOSD)

Introduction Neuromyelitis optica spectrum disorder (NMOSD) is characterized by the presence of serum anti-aquaporin 4 (AQP4) antibody. However, the significance of changes in the serum titer as a marker of disease severity or relapse prediction is unknown. Methods We collected clinical data and serum antibody titers by cell-based assay from 45 NMOSD patients for whom more than one titer measurement taken in 6–12 month interval periods was...