Koppelman G H, Jansen D F, Schouten J P, van der Heide S, Bleecker E R, Meyers D A, Postma D S
Department of Pulmonary Rehabilitation, Beatrixoord, Haren, The Netherlands.
Clin Exp Allergy. 2003 Feb;33(2):170-5. doi: 10.1046/j.1365-2222.2003.01591.x.
Multiple population studies have shown the presence of a sibling effect on atopic disease. However, it is unclear if the sibling effect is also of importance in subjects who are genetically at high risk for the development of atopy.
To study the presence of a sibling effect on markers of atopy (serum total IgE, specific IgE, skin tests) and asthma (bronchial hyper-responsiveness to histamine) in families ascertained through a parent with asthma.
First-degree offspring in 200 asthma families were studied (n = 541). Mixed effects regression models were used to account for the dependence of the observations within a family, and to adjust for possible confounding variables.
Multiple regression analysis showed that having older siblings was inversely related to atopy, defined as >/= 2, >/= 3, >/= 4, or >/= 5 skin tests (P = 0.07-0.009). In addition, family size (number of siblings) had a significant protective effect on the presence of specific IgE to common aeroallergens (P = 0.03). Exposure to cigarette smoke in the first 3 years of life significantly increased the risk of having specific IgE to common aeroallergens (P = 0.04). No sibling effect was detected for serum total IgE or bronchial hyper-responsiveness to histamine.
This study shows a protective sibling effect on the presence and severity of atopy but not on bronchial hyper-responsiveness in children who are genetically at risk. The identification of the sibling effect in high-risk families stresses the need to understand the basis of this effect, in order to design future prevention programmes.
多项人群研究表明存在同胞效应与特应性疾病有关。然而，尚不清楚同胞效应在遗传上有特应性疾病高风险的个体中是否也很重要。
研究在通过患有哮喘的父母确诊的家庭中，同胞效应与特应性指标（血清总IgE、特异性IgE、皮肤试验）和哮喘（对组胺的支气管高反应性）之间的关系。
对200个哮喘家庭中的一级后代进行研究（n = 541）。使用混合效应回归模型来考虑家庭内观察值的依赖性，并对可能的混杂变量进行调整。
多元回归分析表明，有年长同胞与特应性呈负相关，特应性定义为皮肤试验≥2、≥3、≥4或≥5次阳性（P = 0.07 - 0.009）。此外，家庭规模（同胞数量）对常见气传变应原特异性IgE的存在有显著的保护作用（P = 0.03）。生命最初3年接触香烟烟雾显著增加了对常见气传变应原产生特异性IgE的风险（P = 0.04）。未检测到血清总IgE或对组胺的支气管高反应性存在同胞效应。
本研究表明，在有遗传风险的儿童中，同胞效应具有保护作用，可降低特应性的存在和严重程度，但对支气管高反应性无此作用。在高危家庭中识别同胞效应强调了理解这种效应基础的必要性，以便设计未来的预防方案。
