Ronchetti Roberto, Jesenak Milos, Ronchetti Francesco, Rennerova Zuzana
Paediatric Department, University "La Sapienza", Rome, Italy.
Inflamm Allergy Drug Targets. 2010 Jun;9(2):91-6. doi: 10.2174/187152810791292791.
In this paper we shortly discuss epidemiological data on the relationship between asthma and atopy according to recent personal and literature epidemiological publications. The coexistence in several subjects of asthma (and of other "atopic" diseases) and IgE hyperproduction generated the dogma that these two biological conditions are mainly genetic in origin and are linked by a strong casual relationship. In the last decades atopy increased at 5-10 % annual rate and at present atopy prevalence, although variable in different countries, reaches somewhere the prevalence of more than 60 %. Similarly, asthma prevalence increased in the last decades, especially so in western and English speaking countries, reaching in certain countries prevalence values higher than 40 %. For these reasons, although certainly dependent on a genetic predisposition, atopy and asthma can nowadays be considered to be largely determined by environmental factors. Moreover, the analysis of epidemiological data derived from studies conducted worldwide, showed that the prevalence of the two conditions were clearly not correlated so that in certain countries with a 50-60% prevalence of atopy asthma prevalence is lower than 2-6 %, while in other countries asthma prevalence is double than atopy prevalence. Further, in countries with high atopy, the prevalence this conditions is high both in asthmatics and in normal subjects and in the places where asthma prevalence reaches high levels this condition is high both in atopic and non atopic people. In conclusion, epidemiological data show that environmental factors affecting asthma prevalence are different from those affecting atopy prevalence and that subjects bearing one of the two conditions don't show any preferential tendency to develop the other one. From aetiological and pathogenetic point of view asthma and atopy appear to be independent conditions We therefore believe that the association between asthma and atopy demonstrated in almost all the "population studies" (atopy prevalence has always been found 20-30 % higher in asthmatics than in non asthmatic subjects) doesn't prove the existence of a "causal" relationship between the two conditions: this could be a kind of association without causative meaning as is the association between blond hair and blue eyes which in no way can be considered a prove that one of the two conditions is the cause of the other.
在本文中，我们根据近期个人及文献中的流行病学出版物，简要讨论哮喘与特应性之间关系的流行病学数据。在多个个体中，哮喘（以及其他“特应性”疾病）与IgE高产生共存，这形成了一种观念，即这两种生物学状况主要源于遗传，且通过紧密的因果关系相联系。在过去几十年中，特应性以每年5%至10%的速度增长，目前特应性患病率虽然在不同国家有所差异，但在某些地区超过了60%。同样，哮喘患病率在过去几十年中也有所上升，尤其是在西方和英语国家，在某些国家患病率超过了40%。基于这些原因，可以认为尽管特应性和哮喘肯定依赖于遗传易感性，但如今它们在很大程度上是由环境因素决定的。此外，对全球范围内开展的研究所得出的流行病学数据分析表明，这两种状况的患病率显然没有相关性，以至于在某些特应性患病率为50%至60%的国家，哮喘患病率低于2%至6%，而在其他国家，哮喘患病率是特应性患病率的两倍。此外，在特应性高发的国家，哮喘患者和正常受试者中这种状况的患病率都很高，而在哮喘患病率达到高水平的地区，特应性和非特应性人群中这种状况的患病率都很高。总之，流行病学数据表明，影响哮喘患病率的环境因素与影响特应性患病率的环境因素不同，患有这两种状况之一的个体并没有表现出发展为另一种状况的任何优先倾向。从病因学和发病机制的角度来看，哮喘和特应性似乎是独立的状况。因此，我们认为在几乎所有“人群研究”中所证明的哮喘与特应性之间的关联（总是发现哮喘患者中的特应性患病率比非哮喘受试者高20%至30%）并不能证明这两种状况之间存在“因果”关系：这可能是一种没有因果意义的关联，就像金发与蓝眼睛之间的关联一样，绝不能认为这两种状况之一是另一种状况的原因。
