Baseline cohort characteristics
| Cohort | Severe asthma | Mild and moderate asthma | Non-asthma | Cystic fibrosis |
| All patients | n=51 | n=20 | n=20 | n=13 |
| Male, sex, N (%) | 29 (56.9) | 11 (55.0) | 12 (60.0) | 7 (53.8) |
| Race, N (%) | ||||
| White | 23 (45.1) | 10 (50.0) | 18 (90.0) | 13 (100.0) |
| Black | 12 (23.5) | 5 (25.0) | 0 (0.0) | 0 (0.0) |
| Asian | 2 (3.9) | 1 (5.0) | 0 (0.0) | 0 (0.0) |
| More than one | 11 (21.6) | 4 (20.0) | 1 (5.0) | 0 (0.0) |
| Unknown | 3 (5.9) | 0 (0.0) | 1 (5.0) | 0 (0.0) |
| Ethnicity: Hispanic/Latinx | 9 (17.6) | 6 (30.0) | 1 (5.0) | 2 (15.4) |
| Age, years (mean±SD) | 10.9±4.2 | 11.9±3.6 | 11.9±3.6 | 12.9±3.6 |
| Total IgE titre (log) | 2.2±1.0 | 2.4±0.4 | 2.6±0.4 | 1.7±0.8 |
| Used inhaled corticosteroids, N (%) | 51 (100.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |