Fig. 3

IgG and complement mediates extensive astrocytopathy in E5415A model. Extensive loss of AQP4 (a), EAAT2 (b), and GFAP (c) were observed particularly in the inflamed peri-vascular areas (d) positive for Iba1 (f); in contrast, myelin fibers and neurofilament (NF) staining was relatively preserved (e), suggesting a primary astrocytopathy. (g) Myelin pallor was particularly noticeable in the gray matter upon KB staining. (h) MBP staining was virtually intact, but KB and MAG staining was weak, particularly in the cortico-medullary junctions (g−i), and myelin debris could be observed mildly around inflamed sites with KB, MBP, and MAG staining (upper right corner: g−i). These findings suggest insidious early demyelination. (j) Abundant neutrophils were present especially at the lesion border of AQP4-lacking lesions with numerous tissue vacuolations. (k−l) Anti-mouse IgG (k) and anti-rat C5b-9 (l) deposition were observed in the peri-vascular areas. Scale bar = 100 μm (a−l), 40 μm (j), and 20 μm (k−l)