AQP4 and experimental autoimmune encephalomyelitis: We reported that spinal cord of mice which received IgG isolated from sera of AQP4–IgG-seropositive patients had AQP4 loss and astrocytic activation (not observed in mice which received IgG from healthy subjects or AQP4–IgG-seronegtive patients), but no glia fibrillary acidic protein (GFAP) loss, inflammatory cell infiltration, demyelination, or any clinical weakness documented by the experimental autoimmune encephalomyelitis (EAE) score (19).