Bronchial allergen challenges in children – safety and predictors
Article first published online: 20 JAN 2013
© 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd
Pediatric Allergy and Immunology
Volume 24, Issue 1, pages 19–27, February 2013
How to Cite
To cite this article: Bronchial allergen challenges in children – safety and predictors. Pediatr Allergy Immunol 2012: 00: 000–000., , , , , .
- Issue published online: 20 JAN 2013
- Article first published online: 20 JAN 2013
- Manuscript Accepted: 30 OCT 2012
- bronchial allergen challenge;
- allergen-specific IgE;
- methacholine challenge;
- exhaled nitric oxide
In allergic asthma, the diagnosis of house dust mite (HDM) allergy is mainly based on the patient's history, allergy testing by the skin prick test (SPT) or the levels of allergen-specific IgE. We retrospectively analysed data from 350 bronchial provocations with HDM and related it to the following parameters: specific IgE, bronchial hyperresponsiveness (BHR) to methacholine testing (MCT) and exhaled NO (eNO).
Approximately 350 patients (5–18 yr of age) with allergic asthma and a positive SPT to HDMs were included. To define the sensitivity and specificity for the detection method of an early asthmatic response (EAR), a receiver-operating characteristic (ROC) curve was plotted. The accuracy was measured by the area under the ROC curve (AUC). A logistic regression model was used to predict the individual probability of a positive challenge. The results of the regression model were validated in a prospective group of n = 75 patients.
The following cut-off values showed the best combination of sensitivity and specificity: specific IgE Dermatophagoides farinae 19.6 kU/l (AUC, 0.88), PD20FEV1 0.13 mg methacholine (AUC, 0.73) and eNO 20.1 ppb (AUC, 0.71). The following equation predicted the individual probability of a positive challenge in the retrospective and prospective group: p = 1.[1 + exp[−(−1.78 + 2.46.10log D. far − 1.25.10logPD20 metha)]]−1, (AUC = 0.88).
The value of using the specific IgE and MCT as predictors was confirmed in a large number of patients. We also showed, for the first time, that the eNO predicted the EAR. The logistic regression model is repeatable with a good accuracy.