Phenotypic analysis of leukocytes in blood and CSF from control, PI, and EAE-diseased rats. (A, B, C, D) Immunocytochemical identification of blood leukocytes. The percentages of CD3+ T cells, CD68+ monocytes, and to some extent CD45RA+ B cells decrease, while the percentage of MPO+ neutrophils increases strongly in both PI and EAE animals in comparison to the control group (Ctr), (Dunnett’s test, * P < 0.05, ** P < 0.01, *** P < 0.001). The percentages of MPO+, CD3+, and CD68+ cells in the blood are also statistically different between PI animals and animals with EAE at day 11. One-tailed t-test for unequal variance, §§ P < 0.01, §§§ P < 0.001. (E) Few cells are present in the CSF of control and PI rats. The number of cells increases significantly in the CSF of EAE-diseased animals. Dunnett’s test, P < 0.001 (***). (F) The main population of cells in the CSF of EAE-diseased rats is CD3 positive and a significant proportion of MPO+ cells is also present. In A-D and F, the percentages of leukocytes that were CD3+, MPO+, CD68+, CD45RA+ cells, are given for individual animals, with the mean ± SEM. In E, data are expressed as mean ± SEM, (n).