Interleukin-18 −607C/A Gene Polymorphism in Egyptian Asthmatic Children
- 64 Downloads
Asthma is a multifactorial respiratory disease determined by interactions of multiple disease susceptibility genes and environmental factors. Interleukin (IL)-18 is an important cytokine for initiating and perpetuating the catabolic and inflammatory response in allergic asthma. A number of single nucleotide polymorphisms that influence IL-18 production are found in the gene promoter region.
The aim of this study was to investigate the association of IL-18 −607C/A promoter polymorphism with asthma and whether this polymorphism influenced the severity of asthma in affected children. The influence of this promoter gene polymorphism on total serum IgE level in studied subjects was also investigated.
Subjects and Methods
This study was carried out at the Allergy Clinic of Abu El Reesh Children’s Hospital at Cairo University, Egypt. This study included 40 asthmatic children, subdivided into four groups according to different degrees of asthma severity, and 20 apparently healthy subjects as the control group. All cases were subjected to history taking, clinical examination, and the following laboratory investigations: complete blood count, total serum IgE level assay by ELISA and genomic DNA extraction, and analysis for IL-18 −607C/A promoter gene polymorphism using the PCR-RFLP (restriction fragment length polymorphism) technique.
In the present study the IL-18 −607AA genotype frequency was higher in cases (22.5 %) than in the control group (15 %); however, the difference was not statistically significant (p = 0.773). No statistically significant difference between the degree of asthma severity and IL-18 −607C/A polymorphism was found (p = 0.489). No significant association could be detected upon comparing the frequencies of C and A alleles among the two studied groups (p = 0.366). Also, no significant differences were demonstrated for the allele frequencies when the intermittent with mild [odds ratio (OR) = 2.72, 95 % CI 1.03–2.33, p = 0.067], intermittent with moderate, and severe (OR = 2.8, 95 % CI 1.01–8.5, p = 0.066) asthma groups were compared. The median value of the total serum IgE level in asthmatic cases with the mutant genotype (AA) was significantly higher [360 IU/L (96.6–1,340 IU/L)] than in the control group [119 IU/L (70.6–158.9 IU/L)] (p = 0.033).
No significant statistical difference was encountered regarding the distribution of IL-18 −607C/A genotypes and allele frequencies in asthma patients and healthy controls. Also, there were no significant associations between asthma severity and different genotypes or alleles. The median value of the total serum IgE level in asthmatic cases with the mutant genotype (AA) was significantly higher than in the control group. Thus, IL-18 −607AA genotype frequency might be related to higher total serum IgE.
KeywordsAsthma Asthma Severity Promoter Polymorphism Asthma Group Asthmatic Case
Acknowledgement and Disclosures
The author has no conflicts of interest that are directly relevant to the content of this article.
- 2.El-Hefny A, Nassar S, El-Heneidy F, Said M, El-Beleidy A, El-Marsafy E, Moustafa N, El-Falaky M, Haddad Z. Epidemiology of childhood asthma in Cairo. Med J Cairo Univer. 1994;62:505–18.Google Scholar
- 3.Yamamah G, Abdel Dayemm S, Mohamoud N. Bronchial asthma and hypertension among school children of Giza governorate, screening and epidemiology study. Med J Cairo Univ. 1999;67:229–37.Google Scholar
- 4.Gern JE, Seroogy CM. Role of T regulatory cells in asthma. J Allergy Clin Immunol. 2005;46:996–9.Google Scholar
- 5.Sharma G. Asthma overview (2010). http://emedicine.com. Accessed May 2010, revised Jun 2010.
- 14.Global Initiative for Asthma (GINA) program. Asthma classification, in diagnosis and classification; 2010. pp. 21–3. Available from http://www.ginasthma.org
- 16.Loengard A. Viral-induced asthma; 2008. http://asthma.about.com. Accessed Dec 2011.
- 17.Sawicki G. Asthma symptoms and diagnosis in children; 2010. http://www.uptodate.com. Accessed Jan 2011.
- 20.Aral M, Arican O, Gul M, Sasmaz S, Kocturk SA, Kastal U, Ekerbicer HC. The relationship between serum levels of total IgE, IL-18, IL-12, INF-γ and disease severity in children with atopic dermatitis. Mediat Inflamm. 2006;2006:1–4.Google Scholar
- 26.Khripko OP, Sennikova NS, Lopatnikova JA, Khripko JI, Filipenko ML, Khrapov EA, Gelfgat EL, Yakushenko EV, Kozlov VA, Sennikov SV. Association of single nucleotide polymorphisms in the IL-18 gene with production of IL-18 protein by mononuclear cells from healthy donors. Mediat Inflamm. 2008;18:1–6.CrossRefGoogle Scholar