台灣慢性牙周病患者之IL-4及IL-18基因多型性

IL-4 and IL-18 gene polymorphisms in Taiwanese with chronic periodontitis

黃偉哲(Wei-Che Huang)

指導教授 ： 蔡吉政

高雄醫學大學/醫學院/醫學研究所/碩士(2008年)

https://doi.org/10.6832/KMU.2008.00028

摘要

中文摘要
背景:
牙周病的產生與宿主本身的免疫調控機制有關，而這些免疫調控機制相關基因對牙周炎的基因易感受性更是被列為重要的致病機轉之一。研究顯示體內血液中的IL-4與IL-18的量對於牙周疾病會造成不同的影響，IL-18會調控干擾素(interferon) 的表現，進而與牙周炎的發生有關，IL-4會促進IgE專一性抗體的分泌量增加，牙周病患者身上發現有高量IgE的表現，顯示IL-18 基因在137G/C與IL-4 基因在-590C/T的基因多型性與發炎反應有密切的相關性，更進一步被提出可能是與牙周病發生的候選基因之一。過去研究發現IL-4在-590C/T的基因多型性與高加索人的aggressive 型態的牙周炎發生有關，且基因型的分佈在不同種族間是有差異，但對台灣族群在牙周炎與IL-4基因多型性的相關性探討仍然非常少。此外，IL-18基因與毒殺細胞的活化有關，而毒殺細胞在口腔的活化已知與牙周病有關，但IL-18的基因多型性與牙周病發生的相關性仍然未知。因此本研究主要的目的就是要了解IL-4與IL-18 之基因多型性與台灣族群罹患牙周病的相關性
研究方法：
我們收集79位健康對照組及109位慢性牙周炎患者，在取得同意書後請受試者完成一份標準化問卷來獲得基本資料、可能的環境暴露資料與干擾因子，並抽取10ml 周邊血液，經萃取其白血球DNA後，以聚合酵素鍊鎖反應(polymerase chain reaction; PCR)配合限制酵素進行PCR產物切割的方法，經洋菜膠電泳分析得到IL-18 -137 G/C與IL-4 -590C/T基因型的資料。相關資料在建檔合併後，經統計分析後來得到其相關性。
結果：
研究對象慢性牙周病組(CP)與健康對照組(H)，在性別方面沒有顯著差異，而年齡方面慢性牙周病組(48.04±7.59)明顯大於健康對照組(43.99±13.8)(p=0.0199)。在物質（菸、酒、檳榔）使用習慣方面，CP組抽菸的頻率明顯高於H組，酒與檳榔則沒有顯著差異。IL-4及IL-8基因多型性在CP及H組的分佈，IL-4 -590C?袍(X2＝0.005，p =0.9462)及IL-18 -137G?彪(X2＝1.014，p =0.3140)在CP及H組間沒有顯著差異。IL-4與IL-18這二組基因多型性彼此之間在慢性牙周病組中的相關性方面，亦沒有明顯相關(X2＝2.049，p =0.1523)。在IL-4及IL-18基因多型性在CP組相對於H組的危險性分析中，無論是IL-4或是IL-18基因多型性皆未達統計上的顯著意義。而在CP組相對於H組的多變項邏輯式回歸分析方面，經過調整其他影響因子後(年齡，性別…)，IL-4 -590C?袍(adjusted OR=1.01，95% CI＝0.49－2.09 )與IL-18 -137G?彪(adjusted OR=1.24，95% CI＝0.59－2.68)皆未達統計上顯著的意義。若以IL-4及IL-18的對偶基因分析，亦沒有統計上顯著差異（X2 ＝1.014，p＝0.3140）。在IL-4與IL-18對偶基因對慢性牙周病之邏輯式回歸分析方面，以IL-4對偶基因C為基準時，其T危險性分析值（OR＝0.533，95％ CI＝0.16－1.71）。而在IL-18方面，若以C為基準時，G(OR＝2.722，95％ CI＝0.76－10.38），二組基因型在慢性牙周病組相對於牙周健康組的相關性上皆未達統計上的顯著意義。而為了解IL-4及IL-18各基因型中抽菸在慢性牙周病相對於健康對照組的關係顯示。在IL-4基因多型性為C/C時抽菸在慢性牙周病 (CP) 相對於 健康對照組 (H) 之相關性達顯著（X2 ＝6.07，p＝0.0138）。而當IL-4基因多型性為(C/T+T/T)時抽菸在慢性牙周病 (CP) 相對於 健康對照組 (H) 之相關性亦達顯著（X2 ＝5.8，p＝0.0161）。
在IL-4基因多型性為C/C或(C/T+T/T)時抽菸在慢性牙周病 (CP) 相對於健康對照組 (H) 之危險性分析方面。當IL-4基因多型性為C/C時，抽菸是慢性牙周病的危險性因子（OR＝2.87，95％ CI ＝1.25－7.09）。而當IL-4基因多型性為(C/T+T/T)時，抽菸亦是慢性牙周病的危險性因子（OR＝3.31，95％ CI ＝1.67－6.93）。
在IL-18方面。當IL-18基因多型性為C/C時抽菸在慢性牙周病 (CP) 相對於 健康對照組 (H) 之相關性達顯著（X2 ＝7.14，p＝0.0075）。而當IL-18基因多型性為(G/C+G/G)時抽菸在慢性牙周病 (CP) 相對於 健康對照組 (H) 之相關性亦達顯著（X2 ＝4.78，p＝0.0288）。
在IL-18基因多型性為C/C或(G/C+G/G)時抽菸在慢性牙周病 (CP) 相對於健康對照組 (H) 之危險性分析方面。當IL-18基因多型性為C/C時，抽菸是慢性牙周病的危險性因子（OR＝2.90，95％ CI ＝1.34－6.66）。而當IL-18基因多型性為(G/C+G/G)時，抽菸亦是慢性牙周病的危險性因子（OR＝5.47，95％ CI ＝1.26－38.43）。

結論：
IL-4之-590C?袍基因多型性與IL-18 -137G?彪基因多型性間並無交互作用，IL-4之-590C?袍基因多型性或是IL-18之-137G?彪與慢性牙周病的發生無關。然而若是探討IL-4及IL-18各基因型與抽菸在慢性牙周病相對健康組的關係，我們可以知道，若是有IL-4-590T與IL-18-137G基因型，再加上抽菸因子的話，其危險性將大於IL-4-590C及IL-18-137C。原先單獨討論基因多型性與慢性牙周病二者關連所發現在統計上不顯著的結果，可能因為樣本數仍不夠多導致基因影響不足以達到顯著，然而若是經由抽菸因子的放大，我們可以明顯的發現各基因型間不同的差異性。

關鍵字

IL-4基因 ； IL-18基因 ； 慢性牙周病 ； 基因多型性

並列摘要

Abstract
Background:
Host immune response has been considered as an important disease associated factor of periodontitis, especially the cytokines produced from the infection site with oral pathogens. Cytokine has been proposed that genotypes reflective of polymorphisms in cytokine genes can predispose individuals to disease by enhancing inflammatory processes. Cytokine, interleukin (IL)-18 regulates the expression of the proinflammatory cytokine interferon (IFN)-gamma and to be associated with the destruction of periodontal tissue. However, few studies provided the association between IL-18 polymorphisms and periodontitis. The-590 (C-->T) polymorphism of the IL4 gene is associated with high levels of IgE in asthmatic families. The concentration of IgE in gingival tissue was found to be elevated in patients with periodontitis. IL-4 gene locus (-590 C/T) contributes to the interindividual susceptibility for aggressive periodontitis in a German population. The frequencies of the IL-4 genotypes were different between different ethnics. Few or no study in Taiwan reported such relationship between IL-4 genotypes and periodontitis. Our aim was to evaluate whether the IL-4 and IL-18 gene polymorphisms are associated with peridontitis in a Taiwanese population.
Material and Methods:
After the inform consent, 10 ml peripheral blood was collected from participants. We surveyed each participant with a standardized questionnaire about possible risk factors including smoking habits, and statistically analyzed the data about the effect of single nucleotide polymorphisms (SNP) or interaction between SNPs and environmental factors on the development of periodontitis. DNA was extracted from peripheral blood of 100 health controls and 100 chronic periodontitis, Genotyping has been performed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. The JMP statistical software was used to determine the association by ??2-test, ANOVA and logistic regression analysis.

Results:
The major category of ethnicity was Taiwanese . No differences in demographic data, frequencies of habitual drinker, and betel quid chewing were found between CP and H patients. Frequency distributions in IL-4 -590C?袍(??2 =0.005, p=0.9462) and IL-18 -137G?彪 (??2 = 1.014, p=0.3140) polymorphisms were not significantly different between CP and H groups.
The risk for CP compared with controls was not significantly different in the carriers with IL-4 -590(C/T+T/T) genotype than in those with -590 C/C genotype (OR = 1.02, 95%CI = 0.55-1.91). After adjusted with the possible confounding factors, -590C?袍 polymorphisms remained not significant different between CP and healthy controls(adjusted OR = 1.01, 95%CI = 0.49-2.09).
A similar result was also found in IL-18 gene polymorphism . The risk for CP compared with controls was not significantly different in the carriers with IL-18 -137(G/C+G/G) genotype than in those with -137 C/C genotype (OR = 1.41, 95%CI = 0.73-2.79). After adjusted with the possible confounding factors, -137G?彪 polymorphisms remained not significantly different between CP and healthy controls(adjusted OR = 1.24, 95%CI = 0.59-2.68).
However, the odds ratio(OR) of developing CP in smoking(vs. non-smoking) IL-4 -590C/C or IL-18 -137C/C individuals was 2.87 or 2.90 respectively, p<0.05 ; the OR of developing CP in smokers (vs. non-smikers) of IL-4 -590C/T+T/T or IL-18 -137G/C+G/G was 3.31 or 5.47 respectively, p<0.05 . The smokers (vs. non-smokers) with the compositions of IL-4 -590C/C and IL-18-137C/C still had higher susceptibility (OR=2.50) to CP . The OR of smokers(vs. non-smokers ) of the combinations of IL-4 -590 C/T+T/T and IL-18 -137 G/C+G/G for developing CP was 5.14 . But these composite data were not statistically significantly different.This OR of 2.50 was lower than the OR of every single genotype (2.87,3.31,2.90,5.47) suggesting that individuals with IL-4 -590C/C and IL-18 -137C/C as compared with the other studied genotypes could be less susceptible to CP , particularly in smokers.
Conclusions:
This study demonstrated no association between IL-4 -590C?袍 and IL-18 -137G?彪 and the risk of susceptibility for CP in Taiwanese.Smokers(vs. non-smokers) might have a trend to increase OR for developing CP in individuals of IL-4 -590C/T+T/T(vs C/C) or in individuals of IL-18 -137G/C+G/G (vs. C/C) , However, this suggestion needs to have studies with a larger sample size of smoking IL-4 -590 C/T+T/T and/or IL-18 -137G/C+G/G subjects expecially healthy control to obtaine a more defined conclusion. Further research in larger numbers of subjects might be necessary to prove the definitive association of these polymorphisms with CP.

並列關鍵字

genetic susceptibility ； cytokine ； IL-4 ； IL-18 ； periodontitis ； PCR-RFLP

參考文獻

參考文獻

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