CD40LG and optic neuritis: Additionally, no significant differences in the frequency of disease manifestations were detected in other MOG-Ig isotype groups (MOG-IgM, MOG-IgG/A, MOG-IgG/M), except for a difference in optic neuritis frequency comparing isolated MOG-IgA with isolated MOG-IgG (35/55 [64%]) (eFigure 2 in Supplement 1).