Prophylactic Treatment with Intravenous Immunoglobulin Attenuates Experimental Optic Neuritis in Mice

: Optic neuritis is characterized by optic nerve inflammation, demyelination and axonal loss. Intravenous immunoglobulin (IVIg) has been reported to be effective for steroid-resistant patients. However, there is no report investigating the histopathological efficacy of IVIg in optic neuritis models. In this study, we examined the effects of IVIg on optic neuritis of experimental autoimmune encephalomyelitis (EAE) and experimental autoimmune optic neuritis (EAON). Inflammation, demyelination and axonal loss were assessed in the optic nerve sections. IVIg showed dose-dependent prevention of clinical symptoms in EAON. IVIg provided an anti-inflammatory effect in both EAE and EAON, associated with improved demyelination. Axonal loss in EAE was also significantly attenuated. These results suggest that IVIg has neuroprotective properties in experimental optic neuritis, and is a promising new treatment for optic neuritis.