Table 1.
Characterization of the study population. Comparisons between groups regarding the vaccine response to the influenza vaccine
| Variable | TOTAL N = 60 |
Non-Responders N = 33 |
Responders N = 27 |
p |
|---|---|---|---|---|
| Age (years) | 79 [70–87] | 80 [67–88] | 77 [71–86] | 0.806 |
| Male sex, n (%) | 24 (40) | 15 (46) | 9 (33) | 0.340 |
|
CD4 + T-cell count (cells/mm 3 ) |
799 [614–1103] | 715 [533–1236] | 825 [749–1008] | 0.281 |
|
CD8 + T-cell count (cells/mm 3 ) |
473 [279–685] | 439 [159–671] | 486 [384–698] | 0.185 |
| CD4 + /CD8 + ratio | 1.8 [1.2–2.3] | 1.9 [1.2–2.3] | 1.6 [1.1–2.7] | 0.704 |
| sj/β TREC ratio | 32 [0–50] | 31 [0–55] | 34 [7–50] | 0.615 |
| Thymic failure a | 19 (32) | 12 (36) | 7 (27) | 0.441 |
| CMV titre (AU/μL) | 25.4 [13.3–40.3] | 25.4 [12.4–39.0] | 24.6 [13.8–43.0] | 0.973 |
| LBP (ng/μL) | 12.7 [10.2–14.1] | 13.0 [10.1–15.3] | 12.7 [11.4–13.5] | 0.564 |
| hsCRP (mg/L) | 2.8 [1.6–5.0] | 2.3 [1.2–4.8] | 3.1 [2.2–5.0] | 0.330 |
| B2M (μg/mL) | 2.5 [2.1–3.5] | 2.7 [2.4–3.7] | 2.3 [2.0–3.3] | 0.156 |
| D-dimers (μg/L) | 705 [438–1183] | 875 [445–1425] | 620 [438–918] | 0.082 |
| IL-6 (pg/mL) | 3.5 [2.4–4.6] | 3.4 [2.3–4.9] | 3.6 [2.6–4.5] | 0.691 |
| sCD163 (ng/L) | 1034 [844–1293] | 1034 [792–1224] | 1084 [878–1477] | 0.222 |
| % Lymphocytes | 26.2 [23.2–33.1] | 24.9 [22.4–32.0] | 29.0 [25.0–34.1] | 0.063 |
| % Monocytes | 6.5 [5.4–7.6] | 6.6 [5.4–7.9] | 6.5 [5.4–7.5] | 0.894 |
| % Neutrophils | 59.6 [54.1–65.7] | 62.8 [54.4–66.9] | 58.0 [52.4–62.5] | 0.089 |
| % Basophils | 0.2 [0.2–0.4] | 0.3 [0.2–0.4] | 0.2 [0.1–0.3] | 0.258 |
| % Eosinophils | 3.4 [2.2–4.2] | 3.2 [1.7–4.5] | 3.7 [3.2–4.2] | 0.094 |
| Platelets (x10e9/L) | 223 [180–294] | 233 [181–294] | 197 [170–296] | 0.650 |
| MCV (fL) | 90.2 [86.1–93.6] | 90.6 [85.5–93.5] | 90.0 [86.6–95.1] | 0.876 |
| MPV (fL) | 9.4 [7.9–10.1] | 9.3 [7.8–10.3] | 9.40 [8.1–10.0] | 0.716 |
| ESR (mm/h) | 12 [6–22] | 14 [6–21] | 10 [6–24] | 0.921 |
| PLR | 117 [87–164] | 134 [88–166] | 113 [82–144] | 0.377 |
| NLR | 2.3 [1.6–2.9] | 2.6 [1.7–3.0] | 1.9 [1.5–2.4] | 0.056 |
| Comorbidities (number b ) | 3 [2–5] | 3 [2–5] | 3 [2–5] | 0.874 |
| Barthel index c | 87 [70–100] | 85 [70–100] | 90 [70–100] | 0.838 |
| < 20 | 3 (5) | 1 (3.8) | 2 (6.1) | |
| 20–35 | 2 (3.3) | 1 (3.8) | 1 (3) | |
| 40–55 | 5 (8.3) | 3 (11.5) | 2 (6.1) | |
| ≥ 60 | 32 (53.3) | 14 (53.8) | 18 (54.5) | |
| 100 | 18 (30) | 8 (29.6) | 10 (30.3) |
Continuous variables are expressed as median values [IQR], and categorical variables are expressed as the number of cases (%). Comparisons between the groups were made using the nonparametric Mann–Whitney U test for continuous variables and the χ2 or Fisher exact test for categorical variables. Variables with a p value < 0.1 are shown in italics. Variables with a p value < 0.05 were considered statistically significant and are shown in bold. Note: CMV Cytomegalovirus, LBP Lipopolysaccharide Binding Protein, hsCRP High sensitivity C-Reactive Protein, B2M β2-microglobulin, sCD163 soluble CD163, MCV Mean corpuscular volume, MPV Mean platelet volume, ESR erythrocyte sedimentation rate, PLR Platelet to lymphocyte ratio, and NLR Neutrophil to lymphocyte ratio. (a) Thymic failure is defined as an sj/β TREC ratio < 10. bDetails of comorbidities recorded are shown in Additional file 5: Table S5. c100 is totally independent and < 20 is totally dependent