Bronchial hyperresponsiveness to methacholine and adenosine 5′-monophosphate, and the presence and degree of atopy in young children with asthma
Article first published online: 24 JAN 2011
© 2011 Blackwell Publishing Ltd
Clinical & Experimental Allergy
Volume 41, Issue 3, pages 338–345, March 2011
How to Cite
Suh, D. I., Lee, J. K., Kim, C. K. and Koh, Y. Y. (2011), Bronchial hyperresponsiveness to methacholine and adenosine 5′-monophosphate, and the presence and degree of atopy in young children with asthma. Clinical & Experimental Allergy, 41: 338–345. doi: 10.1111/j.1365-2222.2010.03664.x
- Issue published online: 7 FEB 2011
- Article first published online: 24 JAN 2011
- Submitted 17 March 2010; revised 18 October 2010; accepted 25 October 2010.
- adenosine 5′-monophosphate (AMP);
- young children
Cite this as: D. I. Suh, J. K. Lee, C. K. Kim and Y. Y. Koh, Clinical & Experimental Allergy, 2011 (41) 338–345.
Background Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma, and is usually measured by bronchial challenges using direct or indirect stimuli. The relationship between atopy and BHR remains to be clarified, particularly in a population selected for asthma. Furthermore, data for young children are limited, although asthma frequently occurs in early childhood.
Objective The aim of this study was to investigate methacholine (direct stimulus) and adenosine 5′-monophosphate (AMP) (indirect stimulus) responsiveness according to the presence and degree of atopy in young children with asthma.
Methods A retrospective analysis of data from 122 preschool children (median age [range]: 5.3 years [4.0–6.8]) presenting with the diagnosis of asthma was performed. These children were characterized by skin-prick tests (SPTs) and bronchial challenges with methacholine and AMP, using a modified auscultation method. The end-point concentration, resulting in audible wheezing and/or oxygen desaturation, was determined for each challenge. Atopy was defined by at least one positive reaction to SPTs, and its degree was assessed using serum total IgE levels, number of positive SPTs, and atopic scores (sum of graded weal size).
Results Atopic patients (n=97) had a significantly lower AMP end-point concentration than non-atopic patients (n=25), whereas the methacholine end-point concentration was not different between the two groups. Among the atopic patients, there was no association between the methacholine end-point concentration and any of the atopy parameters. By contrast, a significant association was found between the AMP end-point concentration and the degree of atopy reflected in serum total IgE and atopic scores (χ2 test for trend, P=0.001, 0.003, respectively).
Conclusion and Clinical Relevance Young children with atopic asthma had a significantly greater AMP responsiveness than those with non-atopic asthma, whereas methacholine responsiveness was not significantly different between the two groups. The degree of atopy appeared to be an important factor in AMP responsiveness, but not in methacholine responsiveness, and thus might be a marker of airway inflammation in asthma.