The effects of systemic inflammation on the pathogenesis of Alzheimer’s disease (AD) are not clarified, both beneficial and deleterious effects being reported. Allergy is accompanied by a systemic inflammatory response and some epidemiological studies have reported a positive association between a history of allergy/asthma and dementia. To investigate whether chronic airway allergy influences the inflammatory status in the brain, AD-like pathology, and behaviour in relation to AD, we induced chronic airway allergy in triple transgenic AD (3xTgAD) and wildtype (WT) mice by repeated exposure to ovalbumin (OVA) as allergen. Behavioural tests relevant for hippocampus-dependent behaviour were performed. We found that allergy significantly increased the brain levels of immunoglobulin (Ig) G, IgE. In 3xTgAD mice, allergy increased the levels of decay accelerating factor and decreased the phosphorylation of p38. In contrast, allergy increased the levels of interleukin (IL)-1β and complement component 1q (C1q) in WT mice. Bronchoalveolar lavage fluid analysis confirmed eosinophilia in both genotypes, but the basal levels of eosinophils were lower in 3xTgAD mice. In summary, allergy induced predominantly anti-inflammatory effects in 3xTgAD mice, and pro-inflammatory effects in WT mice, thus being another potential factor to be considered when studying AD pathogenesis.

全身性炎症对阿尔茨海默氏病（AD）发病机理的影响尚不清楚，据报道有有益和有害作用。过敏伴随全身性炎症反应，一些流行病学研究报告说，过敏/哮喘病史与痴呆症之间存在正相关关系。为了研究慢性气道过敏是否会影响大脑的炎症状态，AD样病理以及与AD相关的行为，我们通过反复暴露于卵清蛋白中诱导了三重转基因AD（3xTgAD）和野生型（WT）小鼠的慢性气道过敏（ OVA）作为过敏原。进行了与海马依赖行为有关的行为测试。我们发现过敏明显增加了免疫球蛋白（Ig）G，IgE的大脑水平。在3xTgAD小鼠中，变态反应增加了衰变促进因子的水平，并降低了p38的磷酸化。相反，变态反应增加了野生型小鼠的白介素（IL）-1β和补体成分1q（C1q）的水平。支气管肺泡灌洗液分析证实了两种基因型均嗜酸性粒细胞增多，但3xTgAD小鼠的嗜酸性粒细胞基础水平较低。总之，变态反应主要在3xTgAD小鼠中引起抗炎作用，而在WT小鼠中引起促炎作用，因此是研究AD发病机理时要考虑的另一个潜在因素。但3xTgAD小鼠的嗜酸性粒细胞基础水平较低。总之，变态反应主要在3xTgAD小鼠中引起抗炎作用，在WT小鼠中引起促炎作用，因此是研究AD发病机理时要考虑的另一个潜在因素。但3xTgAD小鼠的嗜酸性粒细胞基础水平较低。总之，变态反应主要在3xTgAD小鼠中引起抗炎作用，而在WT小鼠中引起促炎作用，因此是研究AD发病机理时要考虑的另一个潜在因素。