Relationship between serum IgE and airway responsiveness in adults with asthma.
BACKGROUND
General population studies have shown a relationship between total serum IgE levels and airway responsiveness, but this association has not been documented in patients with asthma.


OBJECTIVE
The study assesses the cross-sectional relationship between IgE levels and airway responsiveness in 208 subjects who had had emergency department treatment for asthma at least 2 years earlier.


METHODS
All participants completed a standardized respiratory questionnaire and underwent spirometry, allergy skin testing, and a dose-response methacholine challenge test.


RESULTS
After adjusting for age and gender, the percentage of patients with asthma and airway responsiveness (provocative concentration causing a 20% fall in forced expiratory volume in 1 second [PC20] < or = 8 mg/ml) increased from 52% in the lower quintile of IgE to 72% in the upper quintile (p < 0.01). After adjusting for age, gender, baseline percent predicted forced expiratory volume in 1 second, and smoking, the association between IgE (both in quintiles and continuous) and PC20 appeared consistent and statistically significant (p < 0.01). This association was stronger in patients who were not given inhaled steroid (odds ratio for twice the concentration of IgE, 1.42; 95% confidence interval, 1.09 and 1.84), than in patients treated with inhaled steroid (odds ratio, 1.10; 95% confidence interval, 0.82 and 1.50). Eosinophilia and skin reactivity were associated with PC20 although to a lesser extent.


CONCLUSIONS
These findings strengthen the role played by IgE in facilitating the development of bronchial responsiveness in patients with asthma.
Sunyer
J
J
Department d'Epidemiologia i Salut Pública, Universitat Autònoma de Barcelona, Spain.
Antó
J M
JM
Sabrià
J
J
Roca
J
J
Morell
F
F
Rodríguez-Roisin
R
R
Rodrigo
M J
MJ
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000402:Airway Obstruction / Q000503:physiopathology; D001249:Asthma / Q000276:immunology* / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage; D008875:Middle Aged; D012882:Skin Tests
D016210:Methacholine Chloride; D007073:Immunoglobulin E