Background: Interleukin 15 (IL15) promotes activation and proliferation of CD8+ T cells and enhances the differentiation into Th2 cells. A previous study described five polymorphisms in the IL15 gene to be associated with asthma in a haplotype analysis.
Aim: We selected HapMap tagging single nucleotide polymorphisms (SNPs) from IL15 to systematically investigate these IL15 associations in a large population-based sample.
Methods: Genotyping of seven IL15 SNPs was performed using MALDI-TOF MS in a cross-sectional study population of 3099 children from Dresden or Munich (age 9-11 years). All children were phenotyped by standardized and validated protocols for atopic phenotypes. Effects of single SNPs and haplotypes were studied using sas 9.1.3 and haploview. Equivalence tests were performed to prove the significance of negative results.
Results: Neither single IL15 polymorphisms nor haplotype analyses showed associations with asthma or atopy after correction for multiple testing.
Conclusion: These results do not confirm previous case-control studies and suggest that IL15 gene variants do not play an important role in the development for asthma or other atopic disorders.