Table 3.
Proportions of T-cell subsets in different age groups
| Percentages of T-cell subsets (%) | Youngest old (61–70 years; n = 34) | Middle old (71–80 years; n = 53) | Oldest old (≥81 years; n = 40) | P-value |
|---|---|---|---|---|
| T cells (CD3+CD45+)/lymphocytes | 68.40 (60.00–75.55) | 65.50 (57.50–73.05) | 62.90 (50.10–71.10) | 0.176 |
| CD4+ cells/T cells | 57.75 (49.22–62.87) | 53.80 (40.80–61.10) | 49.55 (39.98–59.50) | 0.111 |
| CD8+ cells/T cells | 35.80 (30.25–41.45) | 41.50 (32.55–51.30) | 48.30 (35.50–54.30)a | 0.013 |
| CD4+CD25+CD127dim+cells/T cells | 6.50 (5.00–7.65) | 7.00 (5.55–8.35) | 6.55 (4.78–8.35) | 0.659 |
| CD4+CD28+ cells/T cells | 53.40 (41.60–61.60) | 48.60 (37.75–59.30) | 44.30 (32.70–56.90)a | 0.045 |
| CD4+CD28− cells/T cells | 2.30 (0.70–4.65) | 2.60 (1.05–5.60) | 5.10 (1.95–11.97)a,b | 0.019 |
| CD4+CD45RA+ cells/T cells | 13.2 (8.00–20.65) | 13.80 (6.55–17.65) | 8.85 (3.15–16.98)a | 0.030 |
| CD4+CD45RA− cells/T cells | 44.10 (32.95–47.75) | 39.70 (31.15–44.3) | 39.90 (32.13–49.45) | 0.359 |
| CD8+CD28+ cells/T cells | 19.30 (14.15–26.45) | 18.30 (14.75–23.70) | 18.60 (13.90–25.18) | 0.723 |
| CD8+CD28− cells/T cells | 13.80 (10.70–20.10) | 19.80 (11.50–30.75)a | 24.90 (19.10–34.45)a | 0.001 |
| CD8+CD45RA+ cells/T cells | 14.3 (8.90–18.90) | 13.1 (10.05–19.35) | 18.20 (9.20–22.65) | 0.291 |
| CD8+CD45RA− cells/T cells | 21.20 (15.60–28.60) | 23.70 (17.1–29.85) | 27.70 (20.55–35.95) | 0.055 |
Data are represented as median (interquartile range). P-value was calculated among the three groups and statistically significant P-values are marked in bold.
a P < 0.05 compared with the youngest-old group.
b P < 0.05 compared with the middle-old group.