Fig. 4

Analysis of T lymphocyte subsets. Percentage of CD4 T cells (identified in the gate of CD3+ T cells as CD4+) (a), CD8 T cells (identified as CD3+ CD4- T cells) (d), and the ratio of the percentage of CD4 and CD8 T cells (g) were shown in PBMC from young (circles) and elderly (triangles) donors, control (white symbols) and TBI patients (black symbols). Percentage of CD4 (b) and CD8 (e) T cells and the ratio CD4/CD8 T cells (h) were displayed by separating TBI patients according to injury severity assessed as GCS score. GCS score was correlated with the percentages of CD4 (c), CD8 T cells (f), and with the ratio CD4/CD8 (i) in young TBI patients. Correlations were assessed by Spearman correlation coefficients. Dashed lines represent 95% confidence intervals. Statistical significance is shown as p and r values. * p < 0.05; ** p < 0.01; *** p < 0.001 TBI vs. control aged-matched subjects. §§ p < 0.01; §§§ p < 0.001 young vs. elderly control subjects