Table 1

Subject characteristics

BaselineBefore expeditionAfter expedition
Subjects (M/F)13/5
Age (years)39.6±11.3
Inhaled steroids, n (%)13 (72%)16 (89%)
 High dose2 (11%)3 (17%)
 Medium dose3 (17%)8 (44%)
 Low dose8 (44%)5 (28%)
LABA, n (%)12 (67%)15 (83%)
SABA alone, n (%)5 (28%)2 (11%)
LTRA, n (%)6 (33%)5 (28%)
Pre-BD FEV1 (% pred)92.0±21.590.2±12.083.6±10.3†
Pre-BD FVC (% pred)116.0±14.4116.8±14.4102.7±15.9††
FEV1/FVC (%)66.0±14.566.0±12.069.5±9.5
FeNO (ppb)17.2–27.8–35.314.4–18.1–24.3‡8.0–13.5–23.8
History of allergy18 (100%)
Total IgE (kU/L)45.2–93.1–228.3
Sputum analysis
Total cell count (×106/mL)0.4–0.8–1.40.6–0.9–1.91.0–1.7–1.8
Eosinophils (%)0.0–2.0–6.30.0–0.0–0.0§0.0–0.0–0.0*
Neutrophils (%)2.3–9.5–20.816.8–30.5–51.840.0–51.0–74.0**
Macrophages (%)77.0–87.0–95.844.0–64.0–85.026.0–45.0–54.0**
Lymphocytes (%)0.0–0.0–1.00.0–1.0–8.02.0–5.0–7.0**
  • Lung function parameters, ACT and are represented as median and IQR (lower quartile-median-upper quartile).

  • Total IgE was measured by ImmunoCAP. Sputum differential cell counts were prepared by cytocentrifugation.

  • FeNO measurements at baseline and before expedition were performed using the Niox Flex (Aerocrine) and after expedition using the NObreath analyser (Bedfont Scientific Ltd).

  • *p<0.01, **p<0.001 (Dunn's multiple comparison test compared with before expedition).

  • †p=0.004, ††p=0.0001 (paired t test compared with before expedition).

  • ‡p=0.002 (Wilcoxon signed rank test compared with baseline).

  • §p<0.001 (Dunn's multiple comparison test compared with baseline).

  • ACT, Asthma Control Test; BD, bronchodilator; FeNO, fractional expired nitric oxide; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; LABA, long-acting β2 agonist; SABA, short-acting β2 agonist; LTRA, leukotriene receptor antagonist.