Changes in Bronchial Hyperresponsiveness in Children with Asthma

Kim, Gun Ha; Seo, Kang Jin; Byeon, Jung Hye; Song, Dae Jin; Yoo, Young; Choung, Ji Tae; Koh, Young Yull

Abstract

PURPOSE: The aim of this study was to investigate changes in bronchial hyperresponsiveness, total IgE, blood total eosinophil counts and serum eosinophil cationic protein (ECP), after treatment with inhaled corticosteroids or leukotriene modifiers in children with asthma.
METHODS
Methacholine bronchoprovocation tests were repeated at 12 months of follow-up in 37 children with atopic asthma and eight children with non-atopic asthma, who regularly attended the Allergy Clinic of Korea University Anam Hospital and Seoul National University Hospital over one year from their initial visit. A serum total IgE, peripheral blood eosinophil counts, and serum ECP levels were measured on their initial visits and at 12 months of follow-up.
RESULTS
Following six to 12 months of inhaled corticosteroids or leukotriene modifiers treatment, the geometric mean (range of 1 SD) of methacholine PC20 was significantly changed in the atopic asthma group [2.20 mg/mL (0.41-11.82) vs. 6.69 mg/mL (1.25-35.87), P=0.000] but not in non-atopic asthma group [2.41 mg/mL (0.90-6.42) vs. 2.46 mg/mL (0.62-9.78), P=0.065]. Blood total eosinophil counts and serum ECP levels decreased significantly over one year in atopic asthma, while these changes were not observed in non-atopic asthma. Significantly higher FEV1 %predicted values (98.3+/-6.6%) were noted at 12 month follow-up compareed to the initial values (92.9+/-11.4%, P=0.023) in the non-atopic asthma group.
CONCLUSION
Inhaled corticosteroids or leukotriene modifiers treatment resulted in a significantly decreased bronchial hyperresponsiveness in children with atopic asthma. This effect was reflected primarily by reduced blood eosinophilic inflammation. The persistence of bronchial hyperresponsiveness in children with non-atopic asthma might be related with genetic factors or airway remodeling other than eosinophilic inflammation.