CD8A and amyotrophic lateral sclerosis: In contrast, ALS patients exhibited increased proportions of CD4+ (12.10%, IQR 7.96–15.86) and CD8+ T cells (10.32%, IQR 7.46–12.55) expressing the activation marker HLA-DR in the CSF and in the case of CD8+ T cells also in PB (1.87%, IQR 1.03–3.51) compared with controls (CD4+HLA-DR+ CSF 6.83%, IQR 5.18–10.33, P = 0.001; CD8+HLA-DR+ PB 0.92%, IQR 0.71–1.24, P = 0.003; CD8+HLA-DR+ CSF 6.90%, IQR 4.44–9.41, P = 0.012; Fig. 1A).