| 摘要: | 研究背景：有研究證實發炎反應參與了腦中風的致病機制，介白素在這一連串的發炎反應中扮演重要的角色。本研究嘗試觀察介白素-18基因多型性與介白素-18濃度是否為腦梗塞的危險因子，並探討其三者間的獨立與交互作用。
材料方法：研究對象為258位40歲以上，選擇新光醫院為就醫場所之首次罹患腦梗塞的男女病患及年齡及性別配對之493位非罹患腦梗塞的門診個案或社區民眾。利用結構式問卷以標準化流程收集研究對象之基本人口學特性，及相關環境暴露與疾病等資料。將儲存血清測量介白素-18，介白素-18使用酵素連結免疫吸附法(Enzyme-linked immunoassay,ELISA)進行測量。依介白素-18之第一三分位(T1, ≦326.2 pg/ml)做為分界點，將介白素-18≦326.2 pg/ml者定義為參考組，介白素-18>326.2 pg/ml者定義為危險組。探討之介白素-18基因多型性位點為112014759C/A、112034500A/G、rs1946518(−607C/A)，利用聚合酶連鎖反應(Polymerase chain reaction,PCR)將萃取出的DNA增幅後，再以限制片段長度多型性(Restriction Fragment Length Polymorphism, RFLP)及tetra-primer ARMS-PCR方式進行基因型判定。介白素-18基因多型性、介白素-18濃度及危險因子對罹患腦梗塞的風險以邏輯式迴歸或條件式邏輯式迴歸分析。
結果：病例組的IL-18濃度顯著比對照組低(236.3 pg/ml v.s 341.5 pg/ml,P<0.001)。
在112014759C/A位點中，之C/A+C/C基因型相對於A/A基因型對發生腦梗塞的風險估計在沒有高血壓者呈顯著保護性(OR=0.25,P<0.01)，在有高血壓者呈顯著危險性(OR=3.46,P<0.01)，而其他特殊危險分層結果皆沒有顯著意義。在112034500A/G位點中，G/A+G/G基因型相對於A/A基因型對發生腦梗塞的風險估計在正常IL-18者、沒有抽菸習慣者、高密度脂蛋白膽固醇正常者、有高血壓者、有高血糖者及腰圍過胖者身上，皆呈現顯著保護性(OR=0.42、0.28、0.32、0.40、0.17及0.17,P<0.05)。在rs1946518(−607C/A)位點中，C/A+A/A基因型相對於A/A基因型對發生腦梗塞的風險估計，在罹患過低高密度脂蛋白膽固醇者身上呈現顯著保護性(OR=0.24, P<0.05)，其他特殊危險分層結果皆沒有達到顯著意義。
結論：本研究結果顯示傳統危險因子如運動習慣、高血壓、高血糖、過低高密度脂蛋白膽固醇在本研究中仍為腦梗塞之重要危險因子。病例組IL-18濃度顯著的低於對照組。112014759C/A、112034500A/G、rs1946518(−607C/A)等位基因及基因型會有IL-18偏高的現象，但沒有達到統計上顯著意義。在幾個不同的分層中，不同位點的基因型對腦梗塞都呈現顯著的保護性。
Background：Inflammatory markers has been considered as the contributors to ischemic stroke(IS). Interleukin(IL), one of inflammation marker, are play an important role in the pathogenesis of IS. We aims to clarify the role of three IL-18 polymorphisms (112014759C/A,112034500A/G,rs1946518(−607C/A)) and protein concentrations in IS, according the case-control study in Taiwanese.
Materials and Methods：We included 493 healthy community-based adults and 258 IS patients aged over 40 years at baseline. Those IS patients were hospitalized in the Shin Kong Wu Ho-Su Memorial Hospital. Information about demographic characteristics and exposures of disease and risk factors were collected by questionnaire. Serum IL-18 were assessed by ELISA. Serum IL-18 concentration were divided into two parts, lower risk group is defined equal or less than 326.2 pg/ml, higher risk ones is defined as the higher risk ones. By Polymerase chain reaction(PCR), Restriction Fragment Length Polymorphism(RFLP), and tetra-primer amplification refractory mutation system PCR(tetra-primer ARMS-PCR), we determine 112014759C/A, 112034500A/G, and rs1946518(−607C/A) polymorphisms. Logistic regression for unmatched data and conditional Logistic regression for matched data were used.
Results：The level of serum IL-18 in all stroke patients was significantly lower than that of controls(236.3 pg/ml v.s 341.5 pg/ml, P<0.001). The 112014759C/A, C/A+C/C genotype was significant decreased risk to IS in no hypertension subjects. The genotype also had a significant risk with IS in hypertension subjects only, compared with A/A genotype (OR=0.25,3.46,P<0.01). The 112034500A/G, G/A+G/G genotype , comparing with A/A genotype , was significant decreased risk with IS in those subjects with the normal levels of IL-18, and high density lipoprotein-cholesterol (HDL-C), without smoking habit, and with hypertension, hyperglycemia, and obesity (OR=0.42,0.32,0.28,0.40,0.17, 0.17,P<0.05). The rs1946518(−607C/A), C/A+A/A genotype, compared with C/C genotype, had significant decrease risk with IS in those subjects with lower HDL-C level(OR=0.24, P<0.05), and the other stratification were not significant.
Conclusion：In our study, exercise, hypertension, diabetes, and low density lipoprotein-cholesterol(LDL-C) were significant risk factors of IS. The level of serum IL-18 in all stroke patients was significantly lower than that of controls. The three SNP (112014759C/A, 112034500A/G, rs1946518(−607C/A)), their allele and genotype both raised the IL-18 concentration but non-significant. There was a significant protective effect between genotype and IS in several subgroups. |
