IL15 gene variants are not associated with asthma and atopy.

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.

STAT1 gene variations, IgE regulation and atopy.

BACKGROUND: Signal transducer and activator of transcription 1 (STAT1), an intracellular signal transducer and activator of transcription centrally involved in many inflammatory pathways, was recently suggested to play an important role in allergy related immune responses. AIM: Thus, we investigated the effect of polymorphisms in the STAT1 gene on the development of atopic sensitization and allergic diseases. METHODS: Haplotype tagging single nucleotide polymorphisms (SNPs) previously described in the STAT1 gene were genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technology in a cross-sectional study population of 3099 German children recruited and phenotyped by the International Study of Asthma and Allergy in Childhood, phase II (ISAAC II). Effects of single SNPs and haplotypes were studied using SAS/Genetics and Haploview. RESULTS: The polymorphism C39134A (rs3771300), located in a potentially cis acting regulatory element in STAT1 intron 24, was inversely related to atopy measured by skin prick test, total and specific serum IgE levels while no effect on atopic disease risk was observed. CONCLUSION: Our results indicate that STAT1 SNP C39134A may protect from atopic sensitization. Because of its location in a highly conserved noncoding sequence near a putative GATA3 binding site, this polymorphism represents an interesting target for further studies.