Characteristics of interleukin (IL)-6 trans-signalling (IL-6TS)-high subjects with COPD (BEAT-COPD (Biomarkers to Target Antibiotic and Systemic Corticosteroid Therapy in COPD Exacerbation) cohort)
| IL-6TS-high | IL-6TS-low | p-value | |
| Subjects n | 24 | 50 | |
| Age years | 69.0±1.8 | 67.8±1.4 | 0.60 |
| Female | 33.3 | 28.0 | 0.75# |
| BMI kg·m−2 | 25.70±0.96 | 25.04±0.63 | 0.32 |
| Current and ex-smokers | 95.83 | 96.00 | 0.97# |
| Pre-FEV1 L | 1.27±0.12 | 1.14±0.07 | 0.26 |
| Post-FEV1 L | 1.29±0.12 | 1.19±0.08 | 0.46 |
| Exacerbations in past year | 3 (1.5–4.0) (n=19) | 2 (2.0–3.0) (n=37) | 0.61 |
| Daily ICS dose μg·day−1 | 1000 (500–1000) (n=18) | 1000 (800–1000) (n=35) | 0.75 |
| Maintenance prednisolone | 10.53 (n=19) | 10.81 (n=37) | 0.97# |
| CRQ total score | 13.64±0.98 | 16.72±0.63 | 0.008 |
| CRQ mastery | 4.07±0.29 | 4.87±0.21 | 0.021 |
| CRQ fatigue | 2.84±0.26 | 3.64±0.18 | 0.049 |
| CRQ emotion | 3.74±0.32 | 4.61±0.18 | 0.088 |
| CRQ dyspnoea | 2.64±0.29 | 3.06±0.19 | 0.26 |
| Blood eosinophils ×1000·μL−1 | 0.24 (0.17–0.37) | 0.22 (0.13–0.39) | 0.32 |
| Blood neutrophils ×1000·μL−1 | 5.35 (4.48–5.90) | 4.74 (4.15–5.78) | 0.24 |
| Serum CRP mg·L–1 | 6.77±2.22 | 4.55±1.10 | 0.088 |
| Serum IL-6 pg·mL–1 | 17.42±7.18 | 12.64±3.14 | 0.024 |
| TCC ×106 cells·g−1 sputum | 7.14 (4.2–15.6) | 2.62 (1.4–4.6) (n=49) | 0.0001 |
| Sputum eosinophils % | 1.00 (0.3–2.5) | 1.75 (0.5–4.3) (n=48) | 0.13 |
| Sputum neutrophils % | 87.13 (72.6–92.6) | 66.25 (44.4–81.7) (n=48) | 0.0004 |
| Sputum macrophages % | 10.11 (5.3–19.7) | 25.00 (12.7–36.4) (n=48) | 0.002 |
| Sputum TNF-α pg·mL–1 | 46.02±56.36 | 2.11±3.11 | <0.00001 |
| Sputum MIP-1α pg·mL–1 | 153.80±52.27 | 44.63±0.37 | <0.00001 |
| Sputum RANTES pg·mL–1 | 7.41±2.34 | 2.28±0.58 | <0.00001 |
| Sputum MMP9 ng·mL–1 | 1008.79±279.40 | 201.32±49.47 | <0.00001 |
| Sputum MMP8 ng·mL–1 | 736.57±229.86 | 127.32±372.61 | <0.00001 |
| Sputum MMP2 ng·mL–1 | 3.11±0.54 | 0.00±0.40 | 0.005 |
Data are presented as geometric mean±se, % or median (interquartile range), unless otherwise stated. Bold type represents statistical significance (p≤0.05). p-values by Kruskal–Wallis test. BMI: body mass index; FEV1: forced expiratory volume in 1 s; ICS: inhaled corticosteroid; CRQ: Chronic Respiratory Questionnaire; CRP: C-reactive protein; TCC: total sputum cell count; TNF: tumour necrosis factor; MIP: macrophage inflammatory protein; MMP: matrix metalloproteinase. #: Chi-squared test.