Promoter polymorphism of the IL-18 gene is associated with atopic asthma in Tunisian children.
Several lines of evidence point to a relevant role of IL-18 in the process of asthma. Some studies suggest that the polymorphism in the gene of IL-18 can be involved in many inflammatory and atopic diseases such as asthma. The aim of our study is to estimate the frequency of the IL-18-607 C/A (rs 1946518) promoter polymorphism in Tunisian children with asthma. We investigated whether the presence of this polymorphism -607 C/A was associated with asthma or atopy and whether this polymorphism influenced the severity of asthma in affected children. We examined also the relationship between the IL-18 gene polymorphism and the serum total IgE level. The IL-18/-607 C/A polymorphism was analysed by polymerase chain reaction and restriction fragment-length polymorphism (PCR-RFLP) analysis. A total of 105 asthma patients and 112 controls as part of the whole children population were studied in a case-control study. Among the 105 children with asthma, 40 were also studied for linkage analyses with their respective parents. We noted that the A allele was associated with statistically significant increases in the risk of asthma in the case-control study (odd ratio (OR) = 1.55, 95% confidence interval (CI) 1.03-2.33. Moreover, the A allele was also associated with atopic asthma (P = 0.008), but not with asthma severity. The transmission disequilibrium test (TDT) analysis in this family study did not suggest a preferential transmission of the IL-18/ -607 C/A polymorphism to affected children. There is no correlation between the IgE level and the IL-18 -607 C/A promoter polymorphism. Our data indicate that IL-18 -607 C/A promoter polymorphism is associated with susceptibility to developing asthma in Tunisian population.
Lachheb
J
J
Homeostasis and Cell Dysfunction Unit Research, Medicine University of Tunis, Tunis, Tunisia. lachheb.jihene@yahoo.fr
Chelbi
H
H
Ammar
J
J
Hamzaoui
K
K
Hamzaoui
A
A
D001249:Asthma / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D020382:Interleukin-18 / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D014416:Tunisia; D044465:White People / Q000235:genetics
D020382:Interleukin-18; D007073:Immunoglobulin E