CD4 and triple-A syndrome: Compared to the stable AAA group, the proportions of naïve CD4 T-cells, resting memory CD4 T-cells, activated memory CD4 T-cells, and activated dendritic cells were significantly greater in the ruptured AAA group, whereas the proportions of regulatory T-cells and M0, M1, and M2 macrophages, respectively, were significantly lower in the ruptured AAA group (Figure 5E).