Can bacterial endotoxin exposure reverse atopy and atopic disease?
Can bacterial endotoxin exposure reverse atopy and atopic disease?
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DOI：
10.1016/j.jaci.2004.08.004
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发表时间：
2004-11-01
影响因子：
14.2
通讯作者：
Pearce, N
中科院分区：
文献类型：
--
作者：
Douwes, J;Le Gros, G;Pearce, N
研究表明，儿童期内毒素暴露与特应性和特应性哮喘的风险降低有关。人们通常认为这些影响只发生在生命的早期。然而，最近的流行病学研究表明，免疫偏离可能发生在整个生命。假设免疫系统在生命的最初几年后没有固定，我们假设内毒素暴露不仅可以在整个生命的任何时候抑制特应性致敏和疾病的发展，而且还可以逆转这一过程。卫生假说的这种新的扩展主要是基于几个流行病学观察的间接证据，这些观察表明，高度暴露于内毒素的成年人的特应性减少，这不太可能单独用保护作用来解释。此外，一些动物研究表明内毒素可能下调预先存在的气道嗜酸性粒细胞增多和高反应性。然而，目前几乎没有直接证据表明内毒素可以逆转特应性和过敏性疾病。通过观察性研究和随机试验来验证这一假设，最终可能会开发出治疗过敏性疾病（如过敏性哮喘、花粉热和湿疹）的新疗法。
Studies have shown that endotoxin exposure in childhood is associated with a reduced risk of atopy and atopic asthma. It is commonly assumed that these effects only occur in early life. However, recent epidemiologic studies suggest that immune deviation might take place throughout life. Assuming that the immune system is not fixed after the first years of life, we hypothesize that endotoxin exposure might not only inhibit the development of atopic sensitization and disease at any time throughout life but might also reverse this process. This novel extension of the hygiene hypothesis is primarily based on the indirect evidence of several epidemiologic observations showing a reduction in atopy in adults highly exposed to endotoxin that is unlikely to be explained by protective effects alone. In addition, some animal studies demonstrated the potential of endotoxin to downregulate pre-existing airway eosinophilia and hyperreactivity. However, there is currently little direct evidence that endotoxin might reverse atopy and allergic diseases. Observational studies and randomized trials to test this hypothesis could ultimately lead to the development of novel treatments for atopic diseases, such as allergic asthma, hay fever, and eczema.