Haplotype analysis of the interleukin-18 gene in Czech patients with allergic disorders

• Published in: Human immunology 2010-06, Vol.71 (6), p.592-597
• Main Authors: Izakovicova Holla, Lydie, Hrdlič ková, Barbara, Schüller, Marcel, Buckova, Dana, Kindlova, Dagmar, Izakovic, Vincent, Vasku, Anna
• Format: Article
• Language: English
• Subjects: Adult; Allergic diseases; Allergy and Immunology; Asthma; Case-Control Studies; Czech Republic; DNA Mutational Analysis; Female; Genes, Lethal; Genetic Association Studies; Genetic Predisposition to Disease; Haplotype; Haplotypes; Humans; Hypersensitivity - genetics; Hypersensitivity - immunology; Hypersensitivity - physiopathology; IL-18; Interleukin-18 - genetics; Male; Middle Aged; Polymorphism; Polymorphism, Single Nucleotide
• ISSN: 0198-8859; 1879-1166
• DOI: 10.1016/j.humimm.2010.03.004

Abstract The interleukin-18 ( IL-18 ) gene on chromosome 11q22 has been suggested as a susceptibility factor for allergies. To test for a possible role of IL-18 polymorphisms in Czech population, case-control study including 958 subjects (633 allergic patients and 325 healthy controls) was performed. An allele-specific polymerase chain reaction was used to analyze variants at positions −607 C/A (rs1946518) and −137 G/C (rs187238) in the promoter region together with the polymerase chain reaction–restriction fragment length polymorphism method for the detection of polymorphism at position −140 C/G (previously −133 C/G, rs360721) in intron 1 of the IL-18 gene. The −1297 C/T (rs360719) polymorphism was genotyped by real-time–polymerase chain reaction, using a predevelopment TaqMan allele discrimination assay. There were no significant differences in distribution of alleles or genotypes in any of four single nucleotide polymorphisms in the IL-18 gene between controls and patients. However, subsequent analysis revealed a significant difference in haplotype frequencies between the allergic patients and healthy subjects ( p < 0.01). Haplotype formed by −1297 C/−607 A/−137 C/−140 C alleles occurred significantly more frequently in patients than controls (0.0433 vs 0.0129; p < 0.0003; pcorr < 0.01, OR = 3.37; 95% CI = 1.59–7.14). In contrast, there was no relationship among the IL-18 variants and total serum IgE level. Our results indicate that promoter polymorphisms in the IL-18 gene act in interaction and could play a role in allergic disorders.