CD4 and post-traumatic stress disorder: However, because the number of PBMCs increased in PTSD patients, when we calculated the absolute number of various lymphocyte subsets, we noted that the numbers of CD4+ T cells (Figure 2B), CD8+ T cells (Figure 2C), B cells (Figure 2D), NK cells (Figure 2E) and NKT cells (Figure 2F) increased significantly.