CD4 and infection: Compared with the stable group, the infection group was characterized by significantly lower cell counts of CD3+ T cells (1141.11 ± 537.85 vs. 628.52 ± 469.07, P < 0.001), CD8+ T cells (471.15 ± 242.78 vs. 284.68 ± 243.10, P < 0.001), CD4+ T cells (598.42 ± 322.91 vs. 301.36 ± 228.33, P < 0.001), NK cells (223.26 ± 204.71 vs. 123.40 ± 104.91, P < 0.001) and B cells (162.00 ± 113.84 vs. 67.17 ± 66.67, P < 0.001) (Supplementary Table 2).