Fig. 3

Immunohistochemistry and flow cytometry of the brain tissues from differently treated patients with RE. Three multipanels show a representative pair of histopathological findings (magnification × 200) according to the different immunohistochemical staining and a table that summarized lymphocyte subpopulations in the brain tissues from patients corresponding to the histopathology. Immunostaining for CD45 (anti-CD45, leukocyte common antigen) identifies leukocytes in the brain tissue, and flow cytometry (FC) further determines their type. The distribution of CD19⁺, CD3⁺, CD4⁺ and CD8⁺ cells is expressed as a percentage from the lymphocytic gate (CD45⁺⁺ cells and the side scatter corresponding to lymphocytes) and the activation as a percentage of HLADR⁺ cells from CD4⁺ or CD8⁺ T cells (HLADR⁺/CD3⁺CD4⁺, HLADR⁺/CD3⁺CD8⁺); several brain samples were measured in every patient and the median values and ranges are displayed. Immunoreactivity for astrocytic glial fibrillary acidic protein (anti-GFAP) reveals gliosis. a Low neuroinflammatory activity with scarce inflammatory cells and mild gliosis were found in P1, P2 and P4. Despite the same histopathological pattern, significant differences in CD3⁺, CD8⁺, HLADR⁺/CD3⁺CD4⁺ and HLADR⁺/CD3⁺CD8⁺ lymphocyte subpopulations were identified among these patients (Kruskal-Wallis and Dunn’s test in a post hoc analysis were employed; numbers in bold; details in the text). b High neuroinflammatory activity with lymphocytic infiltrates and severe gliosis was found in P3 and P5; a significantly lower percentage of HLADR⁺/CD3⁺CD8⁺ in the brain tissue of P5 was identified (Mann-Whitney test). c Medium neuroinflammatory activity with isolated inflammatory cells and medium to severe gliosis in the brain tissue exerted P6 and P7; no significant differences in lymphocyte subpopulations were found (Mann-Whitney test)