Demographics and airway macrophage carbon in healthy controls and children with asthma
| Healthy controls | Mild asthma (BTS steps 1 to 2) | Moderate-to-severe asthma (BTS steps 3 to 5) | |
|---|---|---|---|
| n | 47 | 13 | 36 |
| Age (year) | 9.34 (8.9 to 9.7) | 9.41 (9.1 to 9.6) | 11.63*** (9.8 to 13.4) |
| Gender (M/F) | 21/26 | 11/2* | 18/18 |
| Postbronchodilator FEV1 (z-score) | −0.16 (−0.89 to 0.46) | −0.25 (−0.78 to 0.23) | −1.26*** (−1.93 to −0.79) |
| ICS dose (μg BDP equivalent/day) | Not applicable | 0 (0 to 150) | 500 (400 to 750) |
| LABA (n) | Not applicable | 0 | 27 |
| LTRA (n) | Not applicable | 0 | 16 |
| Induced sputum eosinophils (%) | 0 (0 to 0) | 0 (0 to 0.60) | 3.5*** (0.32 to 9.84) |
| Induced sputum neutrophils (%) | 1.75 (0 to 22.5) | 1.00 (0.13 to 16.8) | 16.00** (6.5 to 39.3) |
| Induced sputum airway macrophage carbon (μm2) | 0.37 (0.16 to 0.53) | 0.37 (0.24 to 0.88) | 0.19** (0.08 to 0.26) |
Data are described as median (IQR). Comparison between groups by Kruskal–Wallis test and Dunn's multiple comparisons test. There is a higher proportion of males with mild asthma (p<0.0.5 vs controls, χ2 test). *p<0.05, **p<0.01, ***p<0.001 versus healthy controls.
BDP, beclomethasone dipropionate; BTS, British Thoracic Society; ICS, inhaled corticosteroid; LABA, long acting β2 agonist; LTRA, leukotriene receptor antagonist.