Abstract
Several studies have shown an inverse relationship between day care attendance and the development of atopy or serum IgE levels. CD14 is a pattern recognition molecule for bacterial endotoxin and a gene-environmental interaction between the CD14 gene polymorphisms and endotoxin exposure has been shown to affect the development of atopy and allergic diseases. Interleukin 4 receptorα (IL4R) gene is a key gene for IgE production and it has been shown to modify the effect of day care on interferon-γ production in infants. We investigated the interactive relationships between day care attendance and the genetic polymorphisms, and their effect on serum total and specific IgE levels. School children living in a city in Japan participated in this study. Day care attendance in the first 2 years of life (day care) and other possible confounding factors were examined using a questionnaire. We determined total and 8 specific IgE levels in the sera, and genotyped CD14 -550C/T and IL4R Ile50Val. After correction for confounding factors, the interaction between day care and CD14 -550C/T was significant for total IgE and mite-specific IgE, as well as for atopy. The interaction between day care and IL4R Ile50Val was significant for total IgE and mite-specific IgE, but that between CD14-550C/T and IL4R Ile50Val was not significant for any phenotypes. The effect of day care on the total and specific serum IgE levels was affected by genetic backgrounds.
