溃疡性结肠炎患者中肿瘤坏死因子相关凋亡诱导配体基因多态性及单倍型分析

目的 探讨肿瘤坏死因子相关凋亡诱导配体(Trail)基因多态性及单倍型与溃疡性结肠炎(UC)的关系.方法 收集UC患者331例,健康对照者832名,PCR扩增Trail目的基因后,直接测序检测Trail基因3非编码区(G1525A/G1588A/C1595T)三种单核苷酸多态性,并分析Trail单倍型与UC的关系.结果 与对照组相比较,Trail G1525A突变等位基因A和基因型GA+ AA的频率在UC组中明显降低(P值均＜0.01);UC组Trail G1588A和C1595T两位点突变等位基因A和T的频率明显低于对照组,且差异有统计学意义(P值均＜0.01).轻和中度UC患者Trail C1595T突变等位基因T和CT+ TT基因型频率为49.15％和64.51％,重度UC患者分别为72.37％和84.21％,两组比较差异均有统计学意义(OR值分别=2.710和2.935,95％CI:1.598～4.596和1.188～7.249,P值均＜0.05).重度UC患者Trail G1525A突变等位基因A的频率为48.69％,较轻和中度UC患者(35.16％)增加(OR=1.750,95％CI:1.082～2.830,P=0.021).UC组中AAT单倍型频率显著低于对照组(43.09％比58.41％,95％CI:1.549～2.229,P＜0.01);GAT单倍型频率在UC组中明显增高(10.15％比0.18％,95％CI:0.005～0.051,P＜0.01).结论 Trail基因多态性及单倍型与UC易感性密切相关.     

TRAIL基因多态性与特发性血小板减少性紫癜的相关性研究

目的 探讨TRAIL基因第五外显子3’-UTR区1525G/A、1595C/T与特发性血小板减少性紫癜的相关性.方法 采用病例对照的方法,选择ITP患者132例,正常对照者130例,提取外周血基因组DNA,采用PCR-RFLP法分析TRAIL基因1525G/A、1595C/T位点的基因型,计算基因型和等位基因频率,进行x2检验.结果 TRAIL基因第五外显子3’-UTR区1525G、1595C等位基因频率ITP组高于正常对照组,但是两组比较1525G/A、1595C/T位点基因型分布无统计学差异(P=0.367),两组间等位基因频率比较无统计学差异(P=0.262).结论 TRAIL基因第五外显子3’-UTR区1525G/A、1595C/T位点基因多态与ITP的遗传易感性没有相关性.     

TRAIL基因多态性与卵巢癌的相关性探讨

目的探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)基因第五外显子3’-UTR区多态性与卵巢癌发生的相关性。方法选择175例上皮性卵巢癌患者(观察组)和170例健康体检者(对照组),采用PCR-RFLP法分析两组TRAIL基因第五外显子3’-UTR区1525G/A、1595C/T位点的基因型,比较观察组和对照组及观察组中高分化、中分化、低分化卵巢癌患者基因型和等位基因频率。结果观察组GG/CC、GA/CT基因型频率明显高于对照组,AA/TT频率明显低于对照组,P均<0.05;观察组G/C等位基因频率明显高于对照组,A/T频率明显低于对照组,P均<0.05。观察组高分化、中分化、低分化基因型频率及等位基因频率两两比较均有统计学差异,P均<0.05。结论 TRAIL基因第五外显子3’-UTR区1525G/A、1595C/T位点基因多态与卵巢癌的遗传易感性相关,携带1525G、1595C基因者卵巢癌发病风险增加。     

肿瘤坏死因子相关凋亡诱导配体单核苷酸多态性及其血清水平在食管癌检验中的应用

目的 探讨食管癌检验中肿瘤坏死因子相关凋亡诱导配体(TRAIL)单核苷酸多态性及其血清水平的应用。方法 回顾性选取2020年2月至2021年2月本院食管癌患者156例为观察组,健康体检人员50例为对照组。统计分析两组基因型与等位基因频率、血清TRAIL(sTRAIL)水平,并统计分析观察组不同病理分期、细胞分化程度患者的TRAIL基因型及血清sTRAIL水平。结果 观察组患者基因型1525GG/1588GG/1595CC、1525GA/1588GA/1595CT的比率均高于对照组,1595AA/1588AA/1595TT的比率低于对照组(P<0.05),等位基因1525G/1588G/1595C的比率高于对照组,1525A/1588A/1595T的比率低于对照组(P<0.05),血清sTRAIL水平低于对照组(P<0.05),Ⅰ～Ⅱ期患者的血清sTRAIL水平高于Ⅲ～Ⅳ期患者(P<0.05),基因型1525GG/1588GG/1595CC、1525GA/1588GA/1595CT、1595AA/1588AA/1595TT患者的血清sTRAIL水平逐渐升高(P&l...     

细胞毒T淋巴细胞相关抗原4基因多态性与汉族溃疡性结肠炎患者的相关性研究

目的　研究细胞毒T淋巴细胞相关抗原4(CTLA- 4)基因外显子1的49位点A/G和启动子- 318位点C/T多态性与溃疡性结肠炎(UC)的相关性。方法　采用序列特异性引物聚合酶链反应(PCR -SSP)方法,检测82例中国湖北汉族溃疡性结肠炎患者(UC)以及204 例健康对照者CTLA- 4 基因外显子1的49位点A/G和启动子-318位点C/T的基因型和单倍型。结果　UC患者CTLA -4 A+49G和C- 318T基因型与正常对照组间差异无统计学意义(P>0.05),且与性别无关。在单倍型分析中,UC患者CTLA -4单倍型2,3(C-318 G49/T-318 A49)显著低于正常人群(26%比41%,P<0.05,OR=0.4918,95%CI:0.2784~0.8688)。结论　UC患者CTLA- 4 基因A+49G和C -318T单倍型2,3 与UC呈负相关。     

转化生长因子-β1及肿瘤坏死因子相关凋亡诱导配体基因多态性与结节性甲状腺疾病相关性研究

目的 探讨转化生长因子(TGF)-β1 +869T/C和肿瘤坏死因子相关凋亡诱导配体(TRAIL)+1525 G/A的基因多态性在结节性甲状腺疾病患者中的分布及其相关性.方法 选择2007年9月至2009年9月于内蒙古科技大学包头医学院第一附属医院内分泌科确诊的结节性甲状腺疾病患者544例作为研究对象,其中包括136例结节性甲状腺肿患者(结甲组),132例甲状腺瘤患者(腺瘤组),146例Graves病患者(GD组),130例桥本甲状腺炎患者(HT组),同时另选择135例健康体检者作为对照组.所有对象清晨空腹采2ml静脉血,采用聚合酶链式反应-单链构象多态分析(PCR-SSCP)、聚合酶链式反应-限制性内切酶片段长度多态性(PCR-RFLP)技术检测TGF-β1+869 T/C和TRAIL+ 1525A/G基因多态性.结果 ①TGF-β1+869T/C:结甲组的CC基因型[47.0％ (64/136)]、C等位基因频率[63.2％(172/272)]均高于对照组[16.3％(22/135)、45.2％(122/270)],组间比较差异有统计学意义(x2=30.76、17.79,P均＜0.05).腺瘤组CC基因型[42.4％(56/132)]、C等位基因频率[59.1％(156/264)]均高于对照组,组间比较差异有统计学意义(x2=24.40、10.34,P均＜0.05).携带C等位基因的人群患结节性甲状腺肿的风险是携带T等位基因的2.086倍[比值比(OR)=2.086;95％可信区间(CI):1.480～2.943];携带C等位基因的人群患腺瘤的风险是携带T等位基因的1.752倍(OR=1.752;95％CI:1.244～2.469).②TRAIL+1525G/A:结甲组GG基因型[40.4％(55/136)]、G等位基因频率[62.9％(171/272)]均高于对照组[11.9％(16/135)、48.5％(131/270)],组间比较差异有统计学意义(x2=9.176、11.307,P均＜0.05).腺瘤组GG基因型[53.0％(70/132)]及等位基因频率[73.1％(193/264)]均高于对照组,组间比较差异有统计学意义(x2=9.806、33.82,P均＜0.05).携带G等位基因的人群患结节性甲状腺肿的风险是携带A等位基因的1.796倍(OR=1.796,95％CI:1.275～ 2.531);携带G等位基因的人群患腺瘤的风险是携带A等位基因的2.884倍(OR=2.884,95％CI:2.009 ～ 4.142).结论 TGF-β1+869T/C、TRAIL+1525G/A多态性可能与结节性甲状腺疾病的发病有关,TGF-β1的C等位基因和TRAIL的G等位基因可能是结节甲状腺疾病的易感基因.     

肿瘤坏死因子相关凋亡诱导配体基因1525位点的多态性与结节性甲状腺疾病的关系

目的 探讨肿瘤坏死因子相关凋亡诱导配体基因(TRAIL)1525位点多态性与结节性甲状腺疾病的关系.方法 125例甲状腺疾病患者来自于内蒙古包头医学院第一附属医院内分泌科,其中结节性甲状腺肿(结甲)患者67例,甲状腺腺瘤患者58例.患者中男54例、女71例,平均年龄为(41.05±14.42)岁.结甲患者接毒性或非毒性进行分组,甲状腺腺瘤患者按高功能或非高功能分组.正常对照人群100例,来自本院同期体检者,其中男47例,女53例,平均年龄为(42.35±16.52)岁.根据知情同意的原则,采集两组人群的静脉血,采用聚合酶链反应-限制性内切酶片段长度多态性(PCR-RLFP)方法进行TRAIL基因多态性测定,计算TRAIL基因的基因型(纯合子GG、杂合子GA、突变纯合子AA)和等位基因频率(G、A),比较相对风险度(比值比,OR).结果 结甲组TRAIL基因1525位点基因型(GG:40.3％,AG:44.8％,AA:14.9％)、等位基因频率(G:62.7％,A:37.3％)与对照组(GG:17.0％,AG:65.0％,AA:18.0％;G:49.5％,A:50.5％)比较,差异有统计学意义(x2值分别为11.376、5.633,P＜0.01或＜0.05);腺瘤组1525位点基因型(GG:44.8％,AG:38.0％,AA:17.2％)、等位基因频率(G:63.8％,A:36.2％)与对照组比较,差异有统计学意义(x2值分别为15.342、6.054,P＜0.01或＜ 0.05).结甲组TRAIL基因1525位点等位基因频率风险度与对照组的比较,OR=1.714(P＜ 0.05),95％可信区间(CI):1.097 - 2.679;腺瘤组TRAIL基因1525位点等位基因频率风险度与对照组的比较,OR=1.797(P＜0.05),95％CI:1.124～2.874.毒性与非毒性结节组、高功能与非高功能腺瘤组TRAIL基因1525位点基因型、等位基因频率比较,差异无统计学意义(x2值分别为3.714,2.792;1.103,2.020;P均＞0.05).结论 TRAIL 基因1525位点多态性与结节性甲状腺疾病发生关系密切.     

线粒体DNA变异与老年2型糖尿病患者易感性的相关性

目的 研究湖北地区老年2型糖尿病(T2DM)患者中线粒体基因突变的发生率及其相关性.方法 采用PCR-RFLP、基因测序技术,对175例老年T2DM患者和200例糖耐量正常的健康老年对照组进行检测.结果 MIND1 3316(G→A)、MTTL1 3243(A→G)、MIND13394( T→C)、MIND14216(T→C) MIND14164(A→G)和MIND2 5178( T→C)变异率分别为3.26％、2.72％、1.71％、4％、34.9％;对照组检出3316(G→A)突变2例(0.99％)、4164 5例(0.99％)、5718(T→C)变异64例(32.3％),未检出3394、4216的点突变;两组间3394(T→C)变异率差别有统计学意义(P＜0.05);且T2DM组5178A基因型血清TC水平低于5178C基因型(P＜0.05),但TG、LDL-C、HDL-C、apoA、apoB、Lp(a)水平两组无统计学意义.结论 3394( T→C)与老年T2DM患者的易感性有一定关联,5178(T→C)变异与湖北地区老年汉族人T2DM的脂代谢相关.     

IL-1β和IL-1Ra基因单核苷酸多态性同溃疡性结肠炎的相关性

目的探讨白细胞介素113（IL-1β）和白细胞介素1受体结抗剂（IL-1Ra）基因单核苷酸多态性（SNP）与溃疡性结肠炎（UC）易感性的关系。方法应用聚合酶链式反应顺序特异性引物法（PCR—SSP），检测2005年5月至2006年8月在哈尔滨医科大学附属第一医院就诊的56例UC患者和44例同期健康体检者的IL-1β（-511T／C）位点、IL-1β（＋3962T／C）位点和IL-1Ra（11100C／T）位点的SNP，分析两组基因型频率和等位基因频率差异；并分析两组差异显著基因的单倍体分型以及基因型与表型的关系。结果（1）UC组IL-1β＋3962位点TC杂合子基因型频率及T等位基因频率明显高于对照组，差异有显著性（P=0．000，P=0．02）。OR值分析表明IL-1β＋3962位点为TC基因型的人群患UC的风险性是TT或CC基因型人群的2．4倍。（2）单倍体分型显示，含有IL-1β＋3962T等位基因（IL-1β511C3962T）的H1单倍型和含有野生型等位基因（IL-1β511C3962C）的H2单倍型在两组中频率的比较差异具有显著性。（3）IL-1β＋3962位点各基因型在UC患者不同病情轻重之间的分布比较以及不同发病部位之间的分布比较差异无显著性；（4）IL-1β-511位点和IL-1Ra 11100位点基因型频率和等位基因频率在两组人群中的分布差异无显著性。结论①IL-1β＋3962位点CT基因型频率及T等位基因频率增高可能与UC易感性有关，但与UC患者病情轻重及发病部位无关。②IL-1β保留511位点和IL-1RA 11100位点的SNP与UC易感性无关。     

CD40基因单核苷酸多态性及单倍型与缺血性脑卒中的相关性研究

目的研究CD40基因单核苷酸多态性及其单倍型与缺血性脑卒中易感性之间的关系;同时分析CD40基因型及血清水平与缺血性脑卒中的相关性。方法选择缺血性脑卒中患者202例(脑卒中组),健康体检者199例(对照组),应用单碱基延伸的PCR技术和DNA测序法对CD40基因rs1883832C/T、rs1569723A/C和rs4810485G/T单核苷酸多态性进行基因分型,同时采用ELISA法检测血清CD40水平。结果脑卒中组与对照组CD40基因rs1883832C/T位点基因型和等位基因频率比较,差异有统计学意义(P<0.01)。等位基因频率的相对风险分析发现,rs1883832T等位基因携带者患缺血性脑卒中的风险是C等位基因的1.557倍(P=0.002);携带rs1883832T等位基因的缺血性脑卒中患者血清CD40水平显著高于不携带者(P<0.05)。联合基因型分析发现,脑卒中组T-C-T单倍型携带者较对照组明显增加了发病风险(P=0.033)。结论 CD40基因rs1883832C/T多态性和T-C-T单倍型与缺血性脑卒中的发病具有相关性,其中T等位基因可能是缺血性脑卒中的遗传易感基因,携带T等位基因的个体可能通过促进CD40的高度表达进而增加了缺血性脑卒中的发病风险。     

CTLA4 gene polymorphisms in Dutch and Chinese patients with inflammatory bowel disease

BACKGROUND: Inflammatory bowel diseases (IBDs) are characterized by chronic intestinal inflammation as a result of an exaggerated T-cell response. CTLA4, a receptor of activated T cells, has an inhibitory function in regulating T-cell activation. Since CTLA4 gene polymorphisms have been associated with several autoimmune diseases, the aim was to study these gene polymorphisms in patients with IBD in two different populations. METHODS: The C-318T polymorphism in the promoter region and A+49G polymorphism in exon I of the CTLA4 gene were investigated by a PCR-SSP method. We studied 139 unrelated patients with ulcerative colitis (UC), 163 patients with Crohn disease (CD) and 174 healthy controls of Dutch Caucasian origin as well as 35 patients with UC and 62 healthy controls from the Chinese Han population. RESULTS: No significant differences in the distribution of allele, genotype and haplotype frequencies were observed between C-318T and A+49G gene polymorphisms and IBD in Dutch Caucasians and UC in the Chinese Han population. Although the haplotypes of the C-318T and A+49G polymorphisms were distributed differently between Dutch Caucasian and Chinese Han populations, there were no differences in the subgroups of patients with CD classified according to age, localization and behaviour in the Vienna classification and in those with UC classified according to age at onset, disease extension and presence of colectomy in the Dutch patients. However, the CTLA4-318 genotype CC was more frequent in patients with CD over 40 years (93%) than in younger patients (74%) (P = 0.045). CONCLUSION: C-318T and A+49G CTLA4 gene polymorphisms and their haplotypes are not associated in Dutch Caucasian patients with IBD and in Chinese patients with UC.     

CTLA4 Gene Polymorphisms in Dutch and Chinese Patients with Inflammatory Bowel Disease

Background: Inflammatory bowel diseases (IBDs) are characterized by chronic intestinal inflammation as a result of an exaggerated T-cell response. CTLA4, a receptor of activated T cells, has an inhibitory function in regulating T-cell activation. Since CTLA4 gene polymorphisms have been associated with several autoimmune diseases, the aim was to study these gene polymorphisms in patients with IBD in two different populations. Methods: The C-318T polymorphism in the promoter region and A+49G polymorphism in exon 1 of the CTLA4 gene were investigated by a PCR-SSP method. We studied 139 unrelated patients with ulcerative colitis (UC), 163 patients with Crohn disease (CD) and 174 healthy controls of Dutch Caucasian origin as well as 35 patients with UC and 62 healthy controls from the Chinese Han population. Results: No significant differences in the distribution of allele, genotype and haplotype frequencies were observed between C-318T and A+49G gene polymorphisms and IBD in Dutch Caucasians and UC in the Chinese Han population. Although the haplotypes of the C-318T and A+49G polymorphisms were distributed differently between Dutch Caucasian and Chinese Han populations, there were no differences in the subgroups of patients with CD classified according to age, localization and behaviour in the Vienna classification and in those with UC classified according to age at onset, disease extension and presence of colectomy in the Dutch patients. However, the CTLA4-318 genotype CC was more frequent in patients with CD over 40 years (93%) than in younger patients (74%) ( P = 0.045). Conclusion: C-318T and A+49G CTLA4 gene polymorphisms and their haplotypes are not associated in Dutch Caucasian patients with IBD and in Chinese patients with UC.     

纤维蛋白原Bβ链七个位点基因单体型与脑梗死的关系

目的研究纤维蛋白原(Fib)Bβ-1420G/A、-993C/T、1689T/G、BsmAIG/C、16I/D、345C/T、HinfIA/C位点基因多态性及其构建的单体型与血浆Fib功能表达及脑梗死的关系。方法选择首次急性脑梗死患者90例(脑梗死组),健康体检者859例(对照组),填写临床调查量表,测定血液生化指标和血浆Fib浓度、纤维蛋白单体聚合反应速率(FMPV)、FMPV/最大吸光度(A_(max))等指标,同时检测FibBβ链7个位点的基因型,并筛选其常见单体型行相关性分析。结果脑梗死组FibBβ链7个基因多态性位点中仅Bβ-1420AA基因型频率明显高于对照组,差异有统计学意义(P<0.01),H1、H2、H3、H4、H5、H6、H7常见单体型在2组的频率分布差异有统计学意义(χ~2=110.47,P<0.01)。以脑梗死为因变量回归分析,筛选出FMPV、FMPV/A_(max)、FibHinfI、H2、H4、H6;以FMPV为因变量,筛选出收缩压、血糖、I6I/D位点;以A_(max)为因变量,筛选出H5单体型;以FMPV/A_(max)为因变量,筛选出脑梗死、饮酒史、Fib-1420G/A(P<0.05)。结论 FMPV和Bβ-1420变异纯合子及HinfI变异基因型是发生脑梗死的重要危险因素;FibBβ链基因多态性位点及其各种单体型在脑梗死发病中并非仅通过影响血浆Fib功能表达而发挥作用。     

亚甲基四氢叶酸还原酶基因677和1298位点多态性与溃疡性结肠炎的相关性

目的 探讨亚甲基四氢叶酸还原酶(MTHFR)基因C677T和A1298C位点多态性与浙江汉族人群溃疡性结肠炎(UC)的关系.方法 采用限制性片段长度多态性PCR(PCR-RELP)法,在274例UC患者和726例正常对照者中检测MTHFR C677T及A1298C基因多态性分布差异.结果 UC患者中,MTHFR C677T突变等位基因(T)和基因型(CT+TT)频率与正常对照组相比差异无统计学意义(P＞0.05);而MTHFR A1298C突变等位基因(C)和基因型(AC+CC)频率均高于正常对照组(35.77%比29.96%,P=0.013;52.19%比44.90%,P=0.039).另外,MTHFR 677纯合子突变基因型(TT)、突变等位基因(T)以及677CT/1298AC复合基因型频率在广泛性结肠炎患者中明显高于远端结肠炎(37.66%比14.72%,P=0.0002;49.35%比32.99%,P=0.0004;29.87%比15.23%,P=0.006);重度UC患者的MTHFR 1298位点突变等位基因(C)频率显著低于(轻+中)度患者(18.97%比33.88%,P=0.022).结论 MTHFR C677T及A1298C基因多态性与浙江汉族UC明显相关.

Abstract：

Objective To investigate the association between the genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and ulcerative colitis (UC) of Han ethnic population in Zhejiang, China. Methods Two hundred and seventy-four consecutive patients with UC and 726 healthy controls (HC) were studied. The genetic polymorphisms of MTHFR (C677T and A1298C) were genotyped using PCR-RELP methods. Results The frequencies of variant allele and genotype in MTHFR A1298Cgene were higher in UC patients than in the HC (35.77% vs 29. 96%, P =0. 013; 52. 19% vs 44. 90%,P=0.039; respectively). However, there were no significant discrepancies of the allele and genotype frequencies in the MTHFR C677T gene between the UC patients and the HC (P ＞ 0. 05 ). In addition, the MTHFR 677Tr homozygote, T allele and 677CT/1298AC compound genotype were more prevalent in patients with extensive colitis than in those with distal colitis (37. 66% vs 14. 72% ,P = 0. 0002; 49. 35% vs 32.99% ,P =0. 0004; 29. 87% vs 15.23% ,P =0. 006; respectively). Furthermore,the variant allele in the MTHFR A1298C gene (C) in severe UC patients was significantly lower than in mild and moderate UC patients (18.97% vs 33. 88% ,P =0. 022). Conclusion The genetic polymorphisms of MTHFR C677T and A1298C are obviously associated with Han ethnic population with UC in Zhejiang province.     

Allelic variations of the multidrug resistance gene determine susceptibility and disease behavior in ulcerative colitis

BACKGROUND AND AIMS: The MDR1 gene encodes P-glycoprotein 170, an efflux transporter that is highly expressed in intestinal epithelial cells. The MDR1 exonic single nucleotide polymorphisms (SNPs) C3435T and G2677T have been shown to correlate with activity/expression of P-glycoprotein 170. METHODS: This was a case-control analysis of MDR1 C3435T and G2677T SNPs in a large well-characterized Scottish white cohort (335 with ulcerative colitis [UC], 268 with Crohn's disease [CD], and 370 healthy controls). We conducted 2-locus haplotype and detailed univariate and multivariate genotypic-phenotypic analyses. RESULTS: The MDR1 3435 TT genotype (34.6% vs 26.5%; P = .04; odds ratio [OR], 1.60; 95% confidence interval [95% CI], 1.04-2.44) and T-allelic frequencies (58.2% vs 52.8%; P = .02; OR, 1.28; 95% CI, 1.03-1.58) were significantly higher in patients with UC compared with controls. No association was seen with CD. The association was strongest with extensive UC (TT genotype: 42.4% vs 26.5%; P = .003; OR, 2.64; 95% CI, 1.34-4.99; and T allele: 63.9% vs 52.8%; P = .009; OR, 1.70; 95% CI, 1.24-2.29), and this was also confirmed on multivariate analysis ( P = .007). The G2677T SNP was not associated with UC or CD. These 2 SNPs lie in linkage disequilibrium in our population (D', .8-.9; r 2 , .7-.8). Two-locus haplotypes showed both positive (3435T/G2677 haplotype: P = .03; OR, 1.44) and negative (C3435/2677T haplotype: P = .002; OR, .35) associations with UC. Homozygotes for the haplotype 3435T/G2677 were significantly increased in UC ( P = .017; OR, 8.88; 95% CI, 1.10-71.45). CONCLUSIONS: Allelic variations of the MDR1 gene determine disease extent as well as susceptibility to UC in the Scottish population. The present data strongly implicate the C3435T SNP, although the 2-locus haplotype data underline the need for further detailed haplotypic studies.     

Association between IL-18 gene promoter polymorphisms and inflammatory bowel disease in a Japanese population

BACKGROUND: Interleukin-18 (IL-18) is a pleiotropic cytokine that induces the production of interferon (IFN)-gamma and also to regulate Th2 cytokines. Recently, association studies between IL-18 gene promoter polymorphisms and several Th1- or Th2-mediated inflammatory diseases were reported. In inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), recent evidence suggests that IL-18 is involved in the pathogenesis. METHODS: Using DNA direct sequencing, we investigated IL-18 gene promoter polymorphisms at -607C/A and -137G/C. Allele, genotype, and haplotype frequencies were determined in 210 Japanese patients with UC, 205 patients with CD, and 212 controls. RESULTS: In UC, the -137C allele frequency was significantly higher in the proctitis-type patients than in controls (Pc = 0.0068). The -137 genotype frequency was also significantly different in the proctitis-type patients than in controls (Pc = 0.032). No other allele and genotype frequencies were significantly associated with UC after Bonferroni correction. Furthermore, the frequency of haplotype 2 (-607A, -137C), which had a lower promoter activity and IFN-gamma mRNA level than the other haplotypes as previously reported, was significantly higher in the proctitis-type patients than in controls (Pc = 0.01). In CD, we could not find any significant differences. CONCLUSIONS: IL-18 gene promoter polymorphisms may not be associated with disease susceptibility but related to the extent of disease in UC.