Figure 5. Aged mice and aged patients display altered circulating levels of neutrophil-associated cytokines after stroke. Levels of the neutrophil-associated cytokines IL-6 (A) and CXCL1 (B) in serum from young (3 month) and aged (20-22 month) animals 24 hours after sham or stroke surgery. Data was analyzed by two-way ANOVA, followed by Sidak’s multiple comparisons test. n=3/4 mice per group. Levels of the inflammatory cytokines IL-6 and IL-8 were measured in serum from stroke patients or transient ischemic attack controls 24 hours after stroke onset. Comparison of control (n=17) and stroke (n=143) levels of IL-6 (C, Mann-Whitney, p=0.0014) and IL-8 (D, Mann-Whitney, p =0.0017). (B) Linear correlation between ischemic stroke patient age and levels of IL-6 (E, R2 = 0.04, p=0.01, n= 143) and IL-8 (F, R2=0.14, p=<0.0001, n=143) 24 hours after stroke onset. *p≤0.05, **p=<0.01, ***p=<0.001, ****p=<0.0001.