Table 2 Sputum characteristics.
| Control subjects | COPD patients | |||
|---|---|---|---|---|
| Non‐smoking | Smoking | Steroid free | Steroid treated | |
| (n = 9) | (n = 10) | (n = 9) | (n = 8) | |
| Sputum weight (g) | 4.3 (2.5–7.5) | 4.4 (1.0–7.4) | 3.1 (1.7–9.1) | 2.5 (1.4–4.9) |
| Squamous cells (%) | 18 (6–30) | 12.5 (3–54) | 19 (9–47) | 13 (0–45) |
| Viability (%) | 59 (27–79) | 61 (39–77) | 75 (25–87) | 74 (37–90) |
| 106 cells/g‡ | 0.5 (0.3–1.8) | 0.6 (0.1–2.4) | 0.9 (0.3–3.2) | 1.2 (0.5–11.7) |
| Neutrophils | ||||
| % | 52.0 (16.0–77.6) | 38.3 (4.6–87.0) | 57.6 (12.0–91.4) | 87.3 (5.2–95.0) |
| ×106/g | 0.29 (0.08–1.41) | 0.19 (0.02–0.81) | 0.47 (0.11–2.74) | 1.03 (0.02–10.67) |
| Macrophages | ||||
| % | 35.8 (14.0–58.4) | 35.4 (8.0–74.8) | 33.8 (6.6–77.0) | 8.3 (3.6–62.4) |
| ×106/g | 0.29 (0.07–0.65) | 0.35 (0.04–1.8) | 0.13 (0.06–0.87) | 0.23 (0.04–0.56) |
| Lymphocytes | ||||
| % | 2.8 (0.2–4.8) | 1.9 (02–10.0) | 1.4 (0.0–5.0) | 1.2 (0.0–4.6) |
| ×106/g | 0.01 (0.00–0.04) | 0.01 (0.00–0.24) | 0.01 (0.00–0.05) | 0.015 (0.00–0.12) |
| Eosinophils | ||||
| % | 0.0 (0.0–3.6) | 0.1 (0.0–6.2) | 0.0 (0.0–2.0) | 0.3 (0.0–49.6) |
| ×106/g | 0.0 (0.0–0.02) | 0.0 (0.0–0.09) | 0.0 (0.0–0.02) | 0.005 (0.0–0.35) |
| Epithelial cells | ||||
| % | 9.8 (0.8–28.2) | 10.2 (1.4–66.4) | 5.8 (1.0–39.4) | 1.1 (0.0–31.4) |
| ×106/g | 0.06 (0.0–0.17) | 0.11 (0.01–0.35) | 0.06 (0.02–0.83) | 0.035 (0.0–0.19) |
| IL‐8 positive samples | 5/9 | 8/10 | 9/9 | 8/8 |
| IL‐8 (ng/ml)‡ | 0.11 (0.08–2.81) | 0.42 (0.08–4.59) | 1.17 (0.28–25.0)* | 5.75 (0.91–14.40)*† |
| TNFα positive samples | 2/9 | 4/10 | 4/10 | 5/8 |
| TNFα (pg/ml)‡ | 1.0 (1.0–3.3) | 1.0 (1.0–8.9) | 1.0 (1.0–25.8) | 4.5 (1.0–307.8) |
Values are expressed as median (range).
Differences between groups were tested using the Kruskal‐Wallis H test and, if appropriate (p<0.05), subsequent analysis of subgroups was performed by the Mann‐Whitney U test.
*p<0.05 v non‐smoking controls; †p<0.05 v smoking controls.
‡Statistical differences between study groups were calculated based on all samples. In case of non‐detectable samples, the lower detection level of the assay was used (80 pg/ml for IL‐8, 1 pg/ml for TNFα).