Department of Pediatrics, Seoul National University Hospital, Jongno-gu, Seoul, Korea.
Clin Exp Allergy. 2011 Mar;41(3):338-45. doi: 10.1111/j.1365-2222.2010.03664.x. Epub 2011 Jan 24.
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.
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.
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).
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).
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.
支气管高反应性（BHR）是哮喘的一个特征，通常通过使用直接或间接刺激的支气管挑战来测量。特应性与 BHR 之间的关系仍需阐明，特别是在选择哮喘人群时。此外，尽管哮喘在幼儿期经常发生，但针对幼儿的数据有限。
本研究旨在调查患有哮喘的幼儿中特应性的存在和程度与乙酰甲胆碱（直接刺激）和腺苷 5'-单磷酸（AMP）（间接刺激）反应性之间的关系。
对 122 名患有哮喘的学龄前儿童（中位年龄[范围]：5.3 岁[4.0-6.8]）的回顾性数据分析。这些儿童通过皮肤点刺试验（SPT）和乙酰甲胆碱和 AMP 支气管挑战进行特征描述，使用改良听诊法。确定每个挑战导致可听喘鸣和/或氧饱和度降低的终点浓度。特应性定义为至少有一个 SPT 阳性反应，其程度使用血清总 IgE 水平、阳性 SPT 数量和特应性评分（分级风团大小总和）进行评估。
特应性患者（n=97）的 AMP 终点浓度明显低于非特应性患者（n=25），而两组之间的乙酰甲胆碱终点浓度没有差异。在特应性患者中，乙酰甲胆碱终点浓度与任何特应性参数之间均无关联。相比之下，AMP 终点浓度与反映在血清总 IgE 和特应性评分中的特应性程度之间存在显著关联（χ²趋势检验，P=0.001，0.003）。
患有特应性哮喘的幼儿的 AMP 反应性明显大于非特应性哮喘的幼儿，而两组之间的乙酰甲胆碱反应性没有显著差异。特应性程度似乎是 AMP 反应性的一个重要因素，但不是乙酰甲胆碱反应性的重要因素，因此可能是哮喘气道炎症的标志物。
