TABLE 2.
SUBJECT CHARACTERISTICS AND BRONCHOSCOPIC FEATURES BY ASTHMA PHENOTYPE*
| Subjects with Asthma |
||||
|---|---|---|---|---|
| Healthy Control Subjects | Th2 Signature Low | Th2 Signature High | P Value, Low vs. High | |
| Sample size | 28 | 20 | 22 | — |
| Age, years | 36 ± 9 | 36 ± 11 | 37 ± 12 | 0.98 |
| Gender, M:F (% F) | 12:16 (56) | 6:14 (70) | 11:11 (50) | 0.19 |
| Ethnicity | ||||
| White | 20 | 9 | 9 | 0.98 |
| African American | 0 | 4 | 4 | |
| Hispanic | 3 | 5 | 6 | |
| Asian or Pacific Islander | 5 | 2 | 3 | |
| FEV1, % predicted | 107 (13) | 89 (10) | 85 (13) | 0.85 |
| ΔFEV1 with albuterol (% of baseline) | 2.7 ± 3.4 | 9.7 ± 7.4 | 12.5 ± 9.8 | 0.51 |
| Methacholine PC20 | 64 (22–64) | 0.93 (0.06–7.3) | 0.27 (0.05–1.9) | <0.001 |
| IgE, IU/ml | 27 (3–287); n = 26 | 125 (19–1,194) | 244 (32–2,627) | 0.031 |
| Blood eosinophils, ×109/L | 0.10 ± 0.07 | 0.23 ± 0.21 | 0.37 ± 0.22 | 0.027 |
| BAL eosinophil % | 0.26 ± 0.29; n = 22 | 0.42 ± 0.46; n = 16 | 1.9 ± 1.9; n = 20 | 0.001 |
| RBM thickness, μm | 4.34 ± 1.11; n = 22 | 4.67 ± 0.99; n = 19 | 5.91 ± 1.72; n = 19 | 0.014 |
| ΔFEV1 with fluticasone at 4 wk, L | N/A | 0.03 ± 0.12; (−0.12 to 0.21); n = 6 | 0.35 ± 0.2; (−0.02 to 0.73); n = 10 | 0.004 |
| ΔFEV1 with fluticasone at 8 wk, L | N/A | 0.04 ± 0.12; (−0.11 to 0.26); n = 6 | 0.25 ± 0.23;(−0.18 to 0.52); n = 10 | 0.05 |
Definition of abbreviations: BAL = bronchoalveolar lavage; PC20 = provocative concentration required to cause a 20% decline in FEV1; RBM = reticular basement membrane.
*
Values are presented as mean ± SD or median (range) unless otherwise specified. P values are sidak corrected for multiple testing (across the three groups). For significance testing of PC20 and IgE, data were log transformed for normality. In case of missing data, the number of subjects for whom data exist is noted. P values relative to healthy control subjects are also depicted in Figures 2 and 3.