Pediatric Respirology Unit, Department of Pediatrics, Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Allergy. 2009 Nov;64(11):1597-601. doi: 10.1111/j.1398-9995.2009.02057.x. Epub 2009 Apr 14.
Asthma phenotypes are well described among children. However, there are few studies comparing airway inflammation in different clinical presentations of pediatric asthma. We tested the hypothesis that nonatopic asthma is associated with a predominant noneosinophilic inflammation in the airways, as assessed by induced sputum. The objective of this study was to evaluate the cytological characteristics of induced sputum (IS) in atopic (AA), nonatopic asthmatics (NAA) and nonatopic nonasthmatic children (NANA).
Of 90 selected children, 77 met eligibility criteria for performing IS and were classified as: AA, n = 28, NAA, n = 29 and NANA, n = 19. Subjects answered to a set of ISAAC-based questions and were skin-tested for common aeroallergens. A defined series of exclusion criteria was applied.
Induced sputum was obtained from 54 (70.1%) subjects (21 AA, 20 NAA and 13 NANA). Demographic data and mean FEV(1) were similar in the three groups. The proportion of eosinophils [median, inter quartile range (IQR)] was significantly higher in the sputum of AA [(6.0.)12)] compared with NAAs [0 (2)] and NANAs [0 (1)], P < 0.001. The proportion of children with sputum eosinophilia (eos > 3%) was also significantly higher in AA (71.4%) when compared with NAA (28.6%); none of the NANA had sputum eosinophilia. Nonatopic asthmatic children had significantly higher proportions and absolute number of neutrophils than AA and controls.
The results suggest that nonatopic children present IS with a cell pattern that is predominantly neutrophilic while eosinophilia is the hallmark of airway inflammation in the majority of atopic wheezing children not treated with inhaled steroids.
儿童哮喘表型已有详细描述。然而，比较不同临床表型儿科哮喘气道炎症的研究较少。我们通过诱导痰来检测非特应性哮喘气道炎症是否主要为非嗜酸性粒细胞炎症的假说。本研究旨在评估诱导痰（IS）细胞学特征在特应性（AA）、非特应性哮喘（NAA）和非特应性非哮喘儿童（NANA）中的特点。
在 90 名入选儿童中，有 77 名符合进行 IS 标准，分为 AA 组（n = 28）、NAA 组（n = 29）和 NANA 组（n = 19）。所有儿童均回答了一组基于 ISAAC 的问题，并进行了常见变应原的皮肤点刺试验。还应用了一系列明确的排除标准。
54 名（70.1%）儿童成功获得诱导痰（IS），其中 21 名 AA、20 名 NAA 和 13 名 NANA。三组的人口统计学数据和平均 FEV1 相似。AA 组诱导痰中嗜酸性粒细胞比例[中位数，四分位距（IQR）]明显高于 NAA 组[0（2）]和 NANA 组[0（1）]，P < 0.001。AA 组痰嗜酸性粒细胞增多（EOS > 3%）的儿童比例也明显高于 NAA 组（71.4%）；NANA 组无一例出现痰嗜酸性粒细胞增多。非特应性哮喘儿童的中性粒细胞比例和绝对值明显高于 AA 组和对照组。
结果表明，非特应性儿童的 IS 表现为以中性粒细胞为主的细胞模式，而吸入性类固醇治疗的大多数特应性喘息儿童气道炎症的特征是嗜酸性粒细胞增多。
