台灣漢族華人牙周炎和TLR4基因多型性相關性

An Investigation on the Association between TLR4 Gene Polymorphism and Periodontal Disease in a Taiwan Han Population

王天佑(Tian-You Wang)

指導教授 ： 何坤炎

高雄醫學大學/口腔醫學院/牙醫學研究所/碩士(2012年)

摘要

背景：
　　牙周炎是一種發炎性疾病，會影響且破壞牙齒周遭支持組織，包括：牙齦、齒槽骨、牙周韌帶…等。形成牙周炎過程是複雜且多基因參與，且由多種環境因子和基因共同影響宿主免疫反應系統和致病菌的交互作用。Toll-like receptor的基因多型性會影響宿主對於牙周致病菌的先天免疫反應系統。本研究的目標是探討台灣漢民族TLR4的基因多型性和牙周炎之間的關聯性。

材料與方法：
抽取122位慢性牙周炎患者、84位侵犯性牙周炎患者及64位牙周健康者20ml靜脈血之白血球來萃取DNA。以Real Time TaqMan probe PCR技術檢測Toll-like receptor4 (rs2197914)T>C基因多型性。統計分析以卡方檢定分析基因型、性別、抽菸有無在各組間的差異，以邏輯回歸分析基因型和罹患牙周炎風險相關性。
同時檢驗研究樣本中基因型分布是否符合Hardy-Weinberg equilibrium定律。

結果：
TLR4基因型和座基因分布頻率在慢性牙周炎、侵犯性牙周炎和牙周健康者三個族群中並無統計學上顯著差異。以對數回歸分析總樣本基因型和牙周炎的關係，TT基因型罹患侵犯性牙周炎的風險是CT/CC的1.95倍，但未達統計學上顯著性(OR=1.95, p = 0.0884, 95%CI = 0.231-1.104)。但若區分出抽菸和未抽菸族群，在未抽菸者中，TT基因型罹患侵犯性牙周炎的風險為CT+CC基因型的2.66倍，達統計上顯著差異(OR=2.66, p = 0.0383, 95%CI = 0.144 - 0.929)。 在抽菸者中，基因型和牙周炎間的關聯性皆未達統計上差異。

結論：
本篇研究結果顯示在台灣漢民族未有抽菸習慣族群中，TLR4基因多型性中的TT基因型比CT/CC基因型有較高罹患侵犯性牙周炎的風險。然而，關於此TLR4基因多型性與牙周炎相關的作用機轉仍需更進一步研究討論。

關鍵字

TLR4 ； 基因多型性 ； 牙周炎 ； 抽菸

並列摘要

Objectives:
Periodontitis is an inflammatory disease that affecting the periodontal connective supporting tissues. Gene polymorphisms of Toll-like receptor could affect the host’s ability to respond to microbial pathogens. This study aimed to investigate the possible association between TLR4 gene polymorphism and periodontal disease in a Taiwan Han population.
Material and methods:
Genomic DNA was obtained from the peripheral blood of 122 patients with chronic periodontitis (CP), 84 patients with (aggressive periodontitis (AgP) and 64 periodontally healthy subjects (HC). The genotype of TLR4 SNP was performed using the TaqMan SNP genotyping assay (Applied Biosystems Inc. (ABI), Foster City). The probe fluorescence signals were detected with a TaqMan Assay for Real-Time PCR (7500 Real Time PCR System, Applied Biosystems Inc. ABI). X2 analysis was used to test the deviation of genotype frequencies from Hardy Weinberg equilibrium. The data were analyzed by ANOVA, chi-square test and logistic regression analysis with JMP 6.0 (SAS, Cary, NC, USA).
Results:
There were no statistical differences in the frequencies of genotypes and alleles between CP, AgP and HC (p = 0.6811, X2 = 2.298). Genotypes of all study subjects were further divided into C-allele and non-C-allele carriers. The logistic regression analysis adjusted for gender, alcohol drinking, cigarette smoking, betel nut chewing and age. The association of allele carries between AgP and HC did not reach significance (OR=1.95, p = 0.0884, 95%CI = 0.231-1.104). Subjects were further stratified by smoking habit. The association of allele carries showed statistical differences between AgP and HC in non-smoking subjects (OR = 2.66, p = 0.0383, 95%CI = 0.144-0.929).
Conclusion:
The results of our study showed that TT genotype of TLR4 polymorphism was associated with an increase risk of aggressive periodontitis (AgP) in Taiwanese population without smoking habits. The genetic effect of TT genotype was masked by smoking habit in subjects of aggressive periodotitis. However, further research for the function of TLR4 polymorphism is necessary.

並列關鍵字

TLR4 ； gene polymorphism ； periodotitis ； smoking

參考文獻

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