CD8A and posterior cortical atrophy: Results of circulating lymphocytes subpopulations analysed by flow cytometry are presented in Fig. 2A and B. Despite this small decrease in lymphocyte percentage, the proportion of CD4+ (T-lymphocytes helper cells) and CD8+ (T-lymphocytes cytotoxic cells) cells changed in Ex + PCa group when compared with SED + PCa group, with a lower CD4/CD8 ratio (2.64 vs. 2.84, p > 0.05; Fig. 2B).