RETRACTED: The maturation of the fetal and neonatal immune system (Retracted article. See vol. 138, pg. 2548, 2008)

The prevalence of allergic diseases has risen markedly since the 1960s, particularly in the developed countries of the Western world. These diseases manifest initially during infancy and childhood and are apparently becoming more persistent in successive birth cohorts. The importance of genetic susceptibility in the disease process is widely recognized, and it is further recognized that the ultimate expression of the disease is the result of complex interactions between genetic and environmental factors, with nutrition representing 1 main variable, neither of which have yet been comprehensively characterized. There is increasing evidence that the level of complexity inherent in the pathogenesis of allergic diseases may be even greater than is currently contemplated, as an additional set of crucial factors appear to be involved. Notably, it appears likely that the ultimate effects of the ''gene-environment" interaction within individuals may also be related to the developmental status of the relevant target tissues at the time the interactions occur. Examples of the latter, discussed below, are elements of innate and adaptive immune function and aspects of food allergy and of airway function relevant to atopic asthma.