Table I.
Characteristics of Study Participants.
| Total (N=52) | Allergic Asthma (N=38) | Non-allergic Asthma (N=14) | P value1 | |
|---|---|---|---|---|
|
| ||||
| Bronchoscopy age (year)2 | 5.7 [4.5–7.2] | 6.3 [4.8–8.3] | 4.3 [2.7–6.9] | 0.07 |
|
| ||||
| Male3 | 63% (33/52) | 71% (27/38) | 43% (6/14) | 0.06 |
|
| ||||
| African American3 | 29% (15/52) | 34% (13/38) | 14% (2/14) | 0.16 |
|
| ||||
| Total IgE (IU/ml)2 | 111 [66–188] | 255 [163–399] | 12 [6–23] | <0.001 |
|
| ||||
| Asthma Medications3 | ||||
| Inhaled corticosteroid | 100% (52/52) | 100% (38/38) | 100% (14/14) | 1.0 |
| Long-acting beta-agonist | 62% (32/52) | 68% (26/38) | 43% (6/14) | 0.13 |
| Anti-leukotriene | 60% (31/52) | 68% (26/38) | 36% (5/14) | <0.05 |
|
| ||||
| Inhaled corticosteroid dose (mcg)2 | 479 [382–602] | 571 [437–746] | 298 [205–433] | <0.01 |
|
| ||||
| Modified Asthma Predictive Index (≤ 5 yr.)3 | (N=26) | (N=16) | (N=10) | |
| Atopic dermatitis | 35% (9/26) | 44% (7/16) | 20% (2/10) | 0.21 |
| Family history of asthma | 88% (23/26) | 94% (15/16) | 80% (8/10) | 0.29 |
| Blood eosinophilia (≥4% of total WBC) | 44% (11/25) | 47% (7/15) | 40% (4/10) | 0.74 |
|
| ||||
| Asthma Control Test / Childhood Asthma Control Test2 (≥ 4 yr.) |
(N=40) 13 [11–15] |
(N=32) 13 [11–15] |
(N=8) 15 [12–18] |
0.59 |
|
| ||||
| Airflow limitation (>5 yr.) | ||||
| FEV1 (% predicted)2 |
(N=26) 80% [73–89%] |
(N=22) 80% [72–89%] |
(N=4) 82% [58–116%] |
0.88 |
| FEV1/FVC ratio4 |
(N=26) 0.75 [0.65–0.81] |
(N=22) 0.72 [0.60–0.81] |
(N=4) 0.76 [0.74–0.83] |
0.29 |
|
| ||||
| Bronchodilator response (%)4 |
(N=14) 16% [11–31%] |
(N=11) 13% [9–30%] |
(N=3) 29% [14–34%] |
0.90 |
|
| ||||
| Blood eosinophilia (≥4%)3 | 57% (29/51) | 70% (26/37) | 21% (3/14) | <0.01 |
| Absolute eosinophil count (cells per μL)4 | 420 [200–760] | 630 [320–830] | 270 [120–430] | <0.05 |
|
| ||||
| Echovirus / human rhinovirus3 | 38% (19/50) | 33% (12/36) | 50% (7/14) | 0.27 |
| Other viruses3, 5 | 0% (0/50) | 0% (0/36) | 0% (0/14) | 1.0 |
|
| ||||
| Any bacteria3 | 29% (14/49) | 20% (7/35) | 50% (7/14) | <0.05 |
| Streptococcus pneumoniae3 | 10% (5/49) | 9% (3/35) | 14% (2/14) | 0.55 |
| Other bacteria3, 6 | 24% (12/49) | 14% (5/35) | 50% (7/14) | <0.01 |
|
| ||||
| BAL Cells (≥1%)3 | (N=23) | (N=16) | (N=7) | |
| Eosinophils (%) | 22% (5/23) | 31% (5/16) | 0% (0/7) | 0.09 |
| Neutrophils (%) | 87% (20/23) | 88% (14/16) | 88% (6/7) | 0.91 |
| Lymphocytes (%) | 87% (20/23) | 88% (14/16) | 88% (6/7) | 0.91 |
|
| ||||
| Age at 1st wheeze (mo.)2 |
(N=39) 9.2 [6.1–14] |
(N=28) 8.9 [5.5–14] |
(N=11) 10 [3.7–27] |
0.53 |
|
| ||||
| Hospitalization for asthma within past 12 months (≥1 visit).3 |
(N=42) 67% (28/42) |
(N=32) 75% (24/32) |
(N=10) 40% (4/10) |
<0.05 |
|
| ||||
| Clinical History3, 7 | ||||
| Atopic dermatitis | 25% (9/36) | 36% (9/25) | 0% (0/11) | <0.05 |
| Food allergy | 60% (29/48) | 80% (29/36) | 0% (0/12) | <0.001 |
| Past pneumonia | 73% (36/49) | 69% (25/36) | 85% (11/13) | 0.06 |
Sample size varies based on available data.
1
Allergic versus non-allergic asthmatics.
2
Geometric mean [95% confidence interval].
3
Percentage of subjects (prevalence);
4
Median [interquartile range].
5
See online data supplement for details.
6
Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pyogenes, and Staphylococcus aureus.
7
Based on documentation available in the medical record. Inhaled corticosteroid dose expressed as fluticasone equivalents.