Interleukin-4 Gene Polymorphisms In Chronic Periodontitis

Periodontal disease is one of the main diseases in oral and its prevalence is high in the world.It is the main cause of the absence of teeth.Periodontal disease is a disease of multiple factor,and the etiopathogenisis is complicated. It is reported recently that the host susceptibility that associated with heredity can influence and alter the reaction of host when microorganism attacks,and determine the progression and severity of the disease,although the broken of the balance between germ,factors of toxin and defense function of host can cause periodontal disease. Recently , host susceptibility is one of the focal point in the periodontal disease investigation Genetic factor simplely can not cause periodontal disease ,but some kind of genetic factors may increase the host, s susceptibility of periodontal disease.The effect of genetic factors in susceptibility of periodontitis has been identified by researchers.Recent years, genetics studies showed that cytokine polymorphism may increase the host, s susceptibility of some chronic inflammation disease for example: juvenile chronic arthritis, systemic lupus erythematosus, asthma, heritage allergy.As the study of biological effect of cytokine(CK) goes further,researchers consider CK as a nonspecific immunity regulatory factor,and plays an important role in periodontitis. Iinterleukin-4(IL-4) gets researchers, attention for its complicated biological function especially the relationship between IL-4 and periodontitis. As the characteristic cytokine of TH2 cell,IL-4 can promote the progression of the inflammatory reaction in which TH2 cell plays main roles through many different pathways. The studies showed that polymorphism can influence the expression of proteins,while so many IL-4 canbefound in periodontitis region.Therefore,it is so important to investigat the influence of IL-4 polymorphism to periodontitis susceptivity Recently,researchers are concentrating on a C to T single nucleotide polymorphism(SNP) at position -590 in the promoter region,and a 70 bp repeat in intron 2 to investigate the relationship between IL-4 polymorphism and periodontitis. This study detects the relationship between IL-4 polymorphism and susceptibility to chronic periodontitis (CP) of Chinese Hannationality people through molecular biology method.Our study use polymerase chain reaction- restriction fragment length polymorphism(PCR-RFLP) to detect the genetype of position -590 of IL-4 promoter region in the blood of peripheral vein of 22 cases of chronic periodontitis and 20 cases healthy controllers.The detection of 70bp repeated sequence in IL-4 intron2 is investigated according to the result of agarose gel electrophoresis of PCR.Data of IL-4 genotypic frequency and allel frequency using SPSS 10.0 software for data analysis, The comparison of means between the two groups use independent sample t test. The data were analyzed by chi-square test.The result indicates that the genotypic frequency of IL-4 -590 C/T in CP group is significantly higher than control group(P<0.05 ,OR = 4,95%CI [1.09;14.62]);the allel frequency of these two groups is significantly different(P<0.05,OR = 2.91,95%CI [1.18;7.15]).The genetype and allele frequency 70bp repeated sequence in IL-4 intron 2 are not significantly different ( P>0.05,OR = 1.71,95%CI [0.45;6.50]; P>0.05 ,OR = 1.86,95%CI [0.77;4.46])between two groups.Conclusions: SNP of -590 position of IL-4 promoter region may infiuence the susceptibility of chronic periodontitis in Chinese of Han nationality, is one of CP genetic risky factors of Han nationnality; the polymorphism of 70bp repeated sequence in IL-4 intron 2 may not infiuence the susceptibility of chronic periodontitis in Chinese of Han nationality.Our investigation of IL-4 gene polymorphism provides new scientific evidence to approach the joint action of all kinds of gene to CP of han nationnality people and the early diagnosis and therapy of CP susceptible population.