Fig. 6.

Immunohistology of brain lesions of children ADS. Tissues corresponding to brain lesions of three patients with ADS/RADS, either MOG+ (n = 2) or MOG− (n = 1). One lesion from a patient with RADS MOG+ (b, c), another lesion from a patient with a monophasic ADEM (ADS MOG+) (d–f), or a RADS MOG− (g–i), were stained to detect IgG, IgM, and the myelin protein MBP (confocal microscopy) or the activated microglia/macrophage marker CD68, or the complement factor C1q (bright field microscopy) (scale bars 20 μm.) a In the tissue section from patient 1, immunofluorescence (IF) staining of MBP in green and IgM in red shows the non-overlapping presence of MBP and IgM in the parenchyma; inset: a higher magnification shows a microglia/macrophage containing MBP. b IF of MBP in green and IgG in red shows co-localization of both signals in the parenchyma; inset: a higher magnification shows a microglia/macrophage with inclusions stained with MBP and IgG. c C1q staining in brown appears intracellular within microglia/macrophages; left inset: a higher magnification of an activated microglia/macrophage labeled with CD68, right inset: a higher magnification shows a microglia/macrophage with intracytoplasmic labeling of C1q. d IF of MBP in green and IgM in red shows conserved architecture of tissue and no or scarce IgM. e MBP in green and IgG in red show overlapping signals in the parenchyma of patient 2; inset: a higher magnification shows a microglia/macrophage with inclusions of mixed MBP and IgG. f C1q staining in brown within brain lesions appears intracellular; in the bottom right corner, a higher magnification shows a microglia/macrophage with intracytoplasmic labeling of C1q. g IF of MBP in green reveals myelin vacuolization and IgM in red shows scarce presence of IgM in the tissue and coating membranes of phagocytic cells. h MBP in green and IgG in red show scarce amount of IgG in tissue and absence of colocalization of MBP and IgG. i No C1q labeling is appreciable within this lesion. In all IF, nuclei are stained in blue with DAPI