Characteristics of study patients
| N | Value* | Reference range¶ | |
|---|---|---|---|
| EBC, exhaled breath condensate; Feno, fractional exhaled nitric oxide concentration; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; LTB4, leukotriene B4; NA, not applicable or available; PD20, provocative dose of methacholine that caused a 20% fall in FEV1; MDC, macrophage derived chemokine; TARC, thymus and activation regulated chemokine; SD, standard deviation. | |||
| *Results expressed as mean (SD) or median (IQR) unless stated otherwise. | |||
| †Only 80 and 68 patients could successfully perform spirometric tests and methacholine bronchial challenge, respectively. | |||
| ‡Mean (SD) volume of EBC collected was 1.26 (0.44) ml. | |||
| ¶Reference ranges for “inflammatory markers” were established in-house from non-atopic and non-allergic children. | |||
| Clinical characteristics | |||
| Age (years) | 92 | 12.7 (3.4) | NA |
| Male gender, n (%) | 92 | 64 (70) | NA |
| Body mass index (kg/m2) | 92 | 19.0 (3.5) | NA |
| Disease severity score (range 6–30) | 92 | 11 (9–14) | NA |
| Atopic features | |||
| Plasma total IgE concentration (kU/l) | 92 | 611 (271–1256) | ⩽160 for 7 years; ⩽180 for ⩾8 years |
| Specific IgE to D pteronyssinus (kU/l) | 92 | 105 (39–145) | <0.35 |
| Peripheral blood eosinophil (%) | 92 | 8 (5–10) | ⩽3 |
| Absolute eosinophil count (109/l) | 92 | 0.52 (0.35–0.77) | ⩽0.25 |
| Lung function† | |||
| FEV1 predicted (%) | 80 | 92.1 (15.9) | ⩾80 |
| FVC predicted (%) | 80 | 104.8 (17.3) | ⩾80 |
| FEV1/FVC (%) | 80 | 80.0 (9.6) | ⩾80 |
| PD20 (μmol) | 68 | 1.95 (0.58–6.00) | >7.8 |
| Inflammatory markers‡ | |||
| Feno (ppb) | 92 | 72.4 (39.5–117.8) | ⩽30 |
| Plasma TARC concentration (pg/ml) | 92 | 45.0 (26.8–85.3) | ⩽70 |
| Plasma MDC concentration (pg/ml) | 92 | 540 (411–702) | ⩽480 |
| Plasma eotaxin concentration (pg/ml) | 92 | 39.0 (33.5–47.5) | ⩽45 |
| EBC MDC concentration (pg/ml) | 92 | 113 (93–126) | ⩽105 |
| EBC eotaxin concentration (pg/ml) | 92 | 37.0 (33.0–43.3) | ⩽35 |
| EBC LTB4 concentration (pg/ml) | 92 | 39.9 (31.4–47.7) | ⩽35 |