ErratumDoes the “Hygiene Hypothesis” Provide an Explanation for the High Prevalence of Multiple Sclerosis in Sardinia?
ErratumDoes the “Hygiene Hypothesis” Provide an Explanation for the High Prevalence of Multiple Sclerosis in Sardinia?
复制标题
勘误“卫生假说”能否为撒丁岛多发性硬化症的高患病率提供解释？
作者：
S. Sotgiu;M. Pugliatti;A. Sotgiu;A. Sanna;G. Rosati
“卫生假说”描述了一种假设的情况，其中TH1（防御宿主免受细菌和病毒感染）和TH2（防御寄生虫感染）免疫应答之间的平衡是关键的，并且其中在婴儿期减少感染应激源的结果是增加自身免疫（TH1介导的）和过敏（TH2介导的）。许多流行病学观察证实，过敏性和自身免疫性疾病在“发达”国家显著增加，与儿童感染呈负相关。然而，最近已经揭示，与变态反应相关的免疫元件也广泛参与自身免疫性脱髓鞘的发病机制，并且TH2和TH1介导的感染改善了疾病的过程，证实了变态反应根源也是导致自身免疫性疾病升级的原因，并且两者具有共同的免疫学特征。在意大利撒丁岛，与生活在同一地中海地区的其他人群相比，MS和I型糖尿病的频率在过去几十年中急剧增加。初步观察使我们相信，环境变化有利于MS风险的上升，从而支持卫生假说。然而，该地区MS患病率分布的数据表明，除环境外，还必须充分考虑其他机制。我们最近的流行病学研究显示，在同一个萨萨里省的农村和城市地区之间的MS患病率存在显着差异，但与卫生假说的预期相反，MS患病率在农村显着较高，遗传上“古老”，西化过程不太明显的地区。在此基础上，我们认为，除了与异戊二烯相关的因素外，遗传学可能是撒丁岛人对MS高度易感性的一个更相关的决定因素。
The "hygiene hypothesis" describes a hypothetical scenario in which the balance between TH1 (defending host against bacterial and viral infections) and TH2 (defending against parasitic infections) immune responses is pivotal and in which the consequence of reducing the infectious stressors during infancy is increased autoimmunity (TH1-mediated) and allergy (TH2-mediated). Many epidemiological observations confirm that allergic and autoimmune diseases are significantly increased in the "developed" countries and negatively associated with childhood infections. However, it has been recently revealed that immune elements associated with allergy are extensively involved also in the pathogenesis of autoimmune demyelination and that TH2- and TH1-mediated infections ameliorate the course of the disease confirming that the allergic root is also responsible for the escalation of autoimmune disorders, and both have a common immunological denominator. In the Italian island of Sardinia, MS and type-I diabetes frequencies have sharply increased in the last decades compared to other populations living in the same Mediterranean area. Initial observation led us to believe that environmental changes favoured the MS risk rise, thus sustaining the hygiene hypothesis. However, data on MS prevalence distribution in this territory suggest that other mechanisms than environment have also to be taken into great account. Our recent epidemiological studies reveal significant differences in the MS prevalence between rural and urban areas within the same province of Sassari but, contrarily to what expected from the hygiene hypothesis, MS prevalence is significantly higher in rural, genetically "archaic", areas where the westernalization process has been less pronounced. On this basis we believe that, beside hygiene-related factors, genetics could represent a more relevant determinant of Sardinian high susceptibility to MS.