Normal | Mild-to-moderate asthma | Refractory asthma | |
Subjects n | 13 | 25 | 27 |
Male | 6 | 12 | 14 |
Atopic % | 3±23 | 11±44 | 14±52 |
Total IgE# | 16.2 (0.6) | 172 (1.1) | 354 (0.6) |
Age yrs¶ | 38 (23–49) | 42 (18–72) | 44 (21–69) |
Age at onset of symptoms yrs¶ | NA | 14 (1–36) | 16 (1–58) |
Nocturnal symptoms n | 0 | 6 | 10 |
FEV1 % pred | 96.6±5.9 | 94.2±7.4 | 62±21.1 |
FEV1/FVC % | 79.6±7.8 | 78.0±6.7 | 69.0±13 |
Single flow NO concentration ppb, 50 mL·s−1# | 16.5 (0.18) | 24.6 (0.31) | 31.7 (0.28) |
Maximal bronchial NO output nL·min−1# | 39.3 (0.2) | 54.3 (0.4) | 64.3 (0.4) |
Sputum eosinophil count %+ | 0 (0–1.3) | 6.3 (0–65.8) | 7.8 (0–53.3) |
Sputum neutrophil count % | 57.3±24.9 | 54.9±25.5 | 62.0±27.2 |
Total sputum cell count ×103# | 0.4 (0.9) | 1.5 (0.8) | 1.8 (0.5) |
PC20 mg·mL−1# | >16 | 0.4 (0.6) | 0.4 (0.7) |
Number on oral steroids | 0 | 0 | 6 |
Data are presented as mean±sd, unless otherwise indicated. Ig: immunoglobulin; FEV1: forced expiratory volume in one second; % pred: per cent predicted; FVC: forced vital capacity; NO: nitric oxide; PC20: provocative concentration causing a 20% fall in FEV1; NA: not available. #: geometric mean (log sd); ¶: mean (range); +: median (range).