| Non-severe asthma | Severe asthma | |
| Sex (F:M) | 7:12 | 14:6 |
| Age (years) | 40.0 (2.4) | 41.4 (2.6) |
| Duration of asthma (years) | 27.4 (3.2) | 27.3 (2.6) |
| Atopy† | 18/19 | 18/20 |
| FEV1 (% predicted) | 84.9 (3.0) | 59.9 (4.7)*** |
| FVC (% predicted) | 93.9 (3.7) | 72.9 (4.9)*** |
| FEV1/FVC ratio | 74.6 (2.1) | 66.9 (2.4)* |
| Bronchodilator response‡ | 9.5 (1.8) | 20.9 (3.9)** |
| Log PC20 (mg/ml) | 0.19 (0.14) | −0.48 (0.17)** |
| Prednisolone dose (mg/day) | 0 | 11.8 (13.7)*** |
| BDP equivalent (μg/day) | 526 (167) | 2530 (292)*** |
| BAL cells | ||
| Total cell count (×106) | 7.32 (0.87) | 5.76 (0.68) |
| Macrophage (%) | 97.1 (0.84) | 93.2 (1.11)** |
| Lymphocyte (%) | 1.27 (0.34) | 2.56 (0.63) |
| Neutrophils (%) | 0.98 (0.29) | 2.58 (0.50)** |
| Eosinophils (%) | 0.63 (0.29) | 1.73 (0.65) |
BAL, bronchoalveolar lavage; BDP, beclometasone dipropionate; F, female; M, male; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; PC20, provocative concentration of methacholine causing a 20% fall in FEV1.
Values are shown as mean (SE).
†Atopy defined as positive skin prick tests to one or more common aeroallergens.
‡Measured as percentage increase in FEV1 after 400 μg salbutamol aerosol.
*p<0.05; **p⩽0.01; ***p⩽0.001 compared with non-severe asthma.