No simple answers for the Finnish and Russian Karelia allergy contrast: Methylation of <scp>CD</scp>14 gene

• Published in: Pediatric Allergy and Immunology
• Main Authors: Khoo, Siew‐Kim, Mäkelä, Mika, Chandler, David, Schultz, En Nee, Jamieson, Sarra E., Goldblatt, Jack, Haahtela, Tari, LeSouëf, Peter, Zhang, Guicheng
• Other Authors: Asthma Foundation of Western Australia, National Health and Medical Research Council, BrightSpark Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: Immunology; Immunology and Allergy; Pediatrics, Perinatology and Child Health; karelian
• Online Access: http://dx.doi.org/10.1111/pai.12612; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fpai.12612; https://onlinelibrary.wiley.com/doi/pdf/10.1111/pai.12612

Abstract Background Finnish and Russian Karelian children have a highly contrasting occurrence of asthma and allergy. In these two environments, we studied associations between total serum immunoglobulin E (IgE) with methylation levels in cluster of differentiation 14 ( CD 14 ). Methods Five hundred Finnish and Russian Karelian children were included in four groups: Finnish children with high IgE (n = 126) and low IgE (n = 124) as well as Russian children with high IgE (n = 125) and low IgE (n = 125). DNA was extracted from whole blood cells and pyrosequenced. Three CpG sites were selected in the promoter region of CD 14 . Results Methylation levels in two of the three CpG sites were higher in the Finnish compared to Russian Karelian children. In the promoter area of CD 14 , the Finnish compared to Russian children with low IgE had a significant (p &lt; 0.0001) increase in methylation levels at the Amp5Site 2. Likewise, the Finnish compared to Russian children with high IgE had a significant (p = 0.003) increase in methylation levels at the Amp5Site 3. In Russian children with low vs. high IgE, there were significant differences in methylation levels, but this was not the case on the Finnish side. In the regression analysis, adding the methylation variation of CD 14 to the model did not explain the higher asthma and allergy risk in the Finnish children. Conclusions The methylation levels in the promoter region of CD 14 gene were higher in the Finnish compared to Russian Karelian children. However, the methylation variation of this candidate gene did not explain the asthma and allergy contrast between these two areas.