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IL-18 Gene Promoter Polymorphisms (il-18 + gene_promoter_polymorphism)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Association between IL-18 gene promoter polymorphisms and inflammatory bowel disease in a Japanese population

INFLAMMATORY BOWEL DISEASES, Issue 12 2005
T Takagawa MD
Abstract Background: Interleukin-18 (IL-18) is a pleiotropic cytokine that induces the production of interferon (IFN)-, and also to regulate Th2 cytokines. Recently, association studies between IL-18 gene promoter polymorphisms and several Th1- or Th2-mediated inflammatory diseases were reported. In inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), recent evidence suggests that IL-18 is involved in the pathogenesis. Methods: Using DNA direct sequencing, we investigated IL-18 gene promoter polymorphisms at ,607C/A and ,137G/C. Allele, genotype, and haplotype frequencies were determined in 210 Japanese patients with UC, 205 patients with CD, and 212 controls. Results: In UC, the ,137C allele frequency was significantly higher in the proctitis-type patients than in controls (Pc = 0.0068). The ,137 genotype frequency was also significantly different in the proctitis-type patients than in controls (Pc = 0.032). No other allele and genotype frequencies were significantly associated with UC after Bonferroni correction. Furthermore, the frequency of haplotype 2 (,607A, ,137C), which had a lower promoter activity and IFN-, mRNA level than the other haplotypes as previously reported, was significantly higher in the proctitis-type patients than in controls (Pc = 0.01). In CD, we could not find any significant differences. Conclusions: IL-18 gene promoter polymorphisms may not be associated with disease susceptibility but related to the extent of disease in UC. [source]

Promoter polymorphism of IL-18 gene in pulmonary tuberculosis in South Indian population

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 5 2007
M. Harishankar
Summary Interleukin-18 (IL-18) plays a vital role in both innate and acquired immunity. We analysed polymorphisms at ,607(C/A) and ,137(G/A) in the promoter region of IL-18 gene by allele-specific polymerase chain reaction in normal healthy subjects (n = 173) and patients with pulmonary tuberculosis (n = 165). Allele, genotype and haplotype frequencies did not differ significantly between normal healthy subjects and patients. The results suggest that the IL-18 gene promoter polymorphisms are not associated with susceptibility or resistance to pulmonary tuberculosis in south Indian population of Dravidian descent. [source]

IL-18 gene promoter ,137C/G and ,607C/A polymorphisms in Chinese Han children with type 1 diabetes mellitus

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 2 2007
G. P. Dong
Summary Type 1 diabetes mellitus (T1DM) is a heterogeneous autoimmune disease, and both environmental and genetic factors play a role in its pathogenesis. Interleukin (IL)-18 is a potent pro-inflammatory cytokine capable of inducing interferon-gamma production that is associated with the development of T1DM. The gene for IL-18 is located on chromosome 11q22.2-q22.3 and has been reported to be associated with a susceptibility to T1DM. To test the putative involvement between IL-18 gene polymorphism and predisposition to T1DM, we conducted a case-control study in Chinese Han children. The single nucleotide polymorphisms at position ,607(C/A) and ,137(C/G) in the promoter region of the IL-18 gene were analysed by sequence-specific primers-polymerase chain reaction in 118 patients with T1DM and 150 healthy controls. (1) The allele frequency of ,607A was 41.2% and 53.0%, respectively, in patients and in control subjects (P = 0.01), but the allele frequency of ,137C/G was not statistically significant (P = 0.37). (2) The distribution of CC genotype at position ,607 was significantly different between patients and normal controls (P = 0.03), while the distribution of AA genotype in patients was significantly lower than that in the controls (P = 0.03). (3) Furthermore, there was a significant increase in haplotype (,137C/,607G) and genotype combination (,137GG/ ,607CC) in patients compared with controls (P = 0.03 and P = 0.04, respectively). The results of this study show that IL-18 gene promoter polymorphisms confer susceptibility to T1DM in Chinese Han children. Moreover, subjects carrying AA genotype at position ,607 of the promoter of IL-18 gene may be a low risk of T1DM development. [source]