Association between polymorphisms in the Toll-like receptor 4, CD14, and CARD15／NOD2 and inflammatory bowel disease in the Greek population

AIM: Crohn's disease (CD) and ulcerative colitis (DC) are multifactorial diseases with a significant genetic background. Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune response such as CD14 or Toll-like receptor 4 (TLR4), are involved in their pathogenesis. In further exploring the genetic background of these diseases, we investigated the variations in the CARD15/NOD2 gene (Arg702Trp, Gly908Arg and Leu1007fsinsC), and polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) as well as in the promoter of the CD14 gene (T/C at position -159) in Greek patients with CD and UC. METHODS: DNA was obtained from 120 patients with CD, 85 with UC and 100 healthy individuals. Genotyping was performed by allele specific PCR or by PCR-RFLP analysis. RESULTS: The 299Gly allele frequency of the TLR4 gene and the T allele and TT genotype frequencies of the CD14 promoter were significantly higher in CD patients only compared to healthy individuals (P= 0.026<0.05; P= 0.0048<0.01 and P= 0.047<0.05 respectively). Concerning the NOD2/CARD15 mutations the overall presence in CD patients was significantly higher than that: in UC patients or in controls. Additionally, 51.67% of the CD patients were carriers of a TLR4 and/or CD14 polymorphic allele and at least one variant of the NOD2/CARD15, compared to 27% of the UC patients. It should be pointed out that both frequencies significantly increased as compared with the 10% frequency of multiple carriers found in healthy controls. A possible interaction of the NOD2/CARD15 with TLR4 and especially CD14, increased the risk of developing inflammatory bowel disease (IBD). CONCLUSION: Our results indicate that co-existence of a mutation in either the TLR4 or CD14 gene, and in NOD2/CARD15 is associated with an increased susceptibility to developing CD compared to UC, and to developing either CD or UC compared to healthy individuals.     

Toll-like receptor 4 and NOD2／CARD15 mutations in Hungarian patients with Crohn＇s disease： Phenotype-genotype correlations

AIM: To determine common NOD2/CARD15 mutations and TLR4 D299G polymorphism in Hungarian patients with CD. METHODS: A total of 527 unrelated patients with CD (male/female: 265/262, age: 37.1 (SD 7.6) years) and 200 healthy subjects were included. DNA was screened for possible NOD2/CARD15 mutations by denaturing high-performance liquid chromatography (confirmed by direct sequencing). TLR4 D299G was tested by PCR-RFLP. RESULTS: NOD2/CARD15 mutations were found in 185 patients (35.1%) and in 33 controls (16.5%,P<0.0001). SNP8/R702W (10.8% vs 6%, P= 0.02), SNP13/3020insC (19.4% vs 5%, P<0.0001) and exon4 R703C (2.1% vs 0%, P= 0.02) mutations were more frequent in CD, while the frequency of SNP12/G908R was not increased. The frequency of TLR4 D299G was not different (CD: 9.9% vs controls: 12.0%). Variant NOD2/CARD15 allele was associated with an increased risk for CD (ORhet=1.71, 95%CI=1.12-2.6, P= 0.0001, ORtwo-risk alleles = 25.2, 95%CI =4.37- ,P<0.0001), early disease onset (carrier: 26.4 years vs non-carrier: 29.8 years, P=0.0006), ileal disease (81.9% (?) 69.5%, OR = 1.99, 95%CI = 1.29-3.08, P= 0.02, presence of NOD2/CARD15 and TLR4: 86.7% vs 64.8%), stricturing behavior (OR = 1.69,95%CI = 1.13-2.55, P= 0.026) and increased need for resection (OR=1.71, 95%CI: 1.13-2.62, P= 0.01), but not with duration, extra-intestinal manifestations, familial disease or smoking. TLR4 exhibited a modifier effect: age of onset in wt/TLR4 D299G carriers: 27.4 years vs NOD2mut/TLR D299G: 23 years (P = 0.06), in NOD2mut/wt: 26.7 years. CONCLUSION: These results confirm that variant NOD2/ CARD15 (R702W, R703C and 3020insC) alleles are associated with earlier disease onset, ileal disease, stricturing disease behavior in Hungarian CD patients. In contrast, although the frequency of TLR4 D299G polymorphism was not different from controls, NOD2/TLR4 mutation carriers tended to present at earlier age.     

CARD15/NOD2 polymorphisms do not explain concordance of Crohn''s disease in Swedish monozygotic twins

BACKGROUND: CARD15/NOD2 polymorphisms are associated with Crohn's disease. There is a high concordance for disease and disease phenotype in monozygotic twin pairs with Crohn's disease. AIM: We studied CARD15/NOD2 polymorphisms in a Swedish, population-based cohort of monozygotic twins with Crohn's disease to assess whether these variants explain disease concordance. SUBJECTS AND METHODS: Twenty-nine monozygotic twin pairs (concordant n=9, discordant n=20) with Crohn's disease and 192 healthy controls were investigated for the CARD15/NOD2 variants Arg702Trp, Gly908Arg and Leu1007fsinsC. RESULTS: CARD15/NOD2 mutations were found in 5/38 (13%) twins with Crohn's disease, corresponding to a total allele frequency of 6.6%. Only 2/9 concordant twin pairs carried any of the variants and the remaining seven were wild type genotype. The total allele frequency was 4.4 times higher (95% confidence interval 1.0-21.5, p=0.06) in concordant twins than in discordant ones, 11.1% versus 2.5%. In healthy controls the total allele frequency was 2.6%. CONCLUSIONS: CARD15/NOD2 polymorphisms contribute but do not alone explain concordance of Crohn's disease in monozygotic twins and, at least in a Swedish population, other polymorphisms are required. The low occurrence of CARD15/NOD2 mutations in the study and other Northern European populations suggests that these variants are of less importance in Northern Europe.     

OCTN and CARD15 gene polymorphism in Chinese patients with inflammatory bowel disease

AIM： To investigate the single nucleotide polymorphism （SNPs） distribution of NOD2/CARD15 （R702W, G908R）, OCTN1 1672CFT and OCTN2-207G/C in Chinese patients with inflammatory bowel disease （IBD）. METHODS： A total of 61 patients with Crohn＇s disease （CD）, 151 patients with ulcerative colitis （UC）, and 200 unrelated healthy controls were genotyped. Genotyping was performed by sequence specific primer polymerase chain reaction （PCR-SSP） or by restriction fragment length polymorphism （PCR-RFLP） analysis. RESULTS： Among the subjects in our study groups, including patients with CD, UC and healthy controls, none had OCTN and CARD15 variants and very rare IBD family history was found in our patients with the percentage of 0 （0/61 with CD） and 1.3% （2/151 with UC）. CONCLUSION： Our results indicate that although OCTN or CARD15 variation is associated with susceptibility to IBD in Western populations, these might be rare and may not be associated with susceptibility to IBD in Chinese patients.     

Polymorphisms in interleukin-10 gene according to mutations of NOD2/CARD15 gene and relation to phenotype in Spanish patients with Crohn＇s disease

AIM:To examine the contribution of interleukin-10(IL-10)gene polymorphisms to Crohn's disease(CD)phenotype,and the possible genetic epistasis betweenIL-10 gene polymorphisms and CARD15/NOD2 genemutations.METHODS:A cohort of 205 Spanish unrelated patientswith Crohn's disease recruited from a single centerwas studied.All patients were rigorously phenotypedand followed-up for at least 3 years(mean time,12.5years).The clinical phenotype was established prior togenotyping.RESULTS:The correlat on of genotype-Viennaclassification groups showed that the ileocolonic locationwas significantly associated with the-1082G allele in theNOD2/CARD15 mutation-positive patients(RR=1.52,95%CI,1.21 to 1.91,P=0.008).The multivariate analysisdemonstrated that the IL-10 G14 microsatellite allelein the NOD2/CARD15 mutation positive patients wasassociated with two risk factors,history of appendectomy(RR=2.15,95%CI=1.1-4.30,P=0.001)and smokinghabit at diagnosis(RR=1.29,95%CI=1.04-4.3,P=0.04).CONCLUSION:In Spanish population from Madrid,inCD patients carrying at least one NOD2/CARD15 mutation,the-1082G allele is associated with ileocolonic disease and the IL-10G14 microsatellite allele is associated withprevious history of appendectomy and smoking habit atdiagnosis.These data provide further molecular evidencefor a genetic basis of the clinical heterogeneity of CD.     

NOD2/CARD15基因多态性与克罗恩病患者相关性研究

目的NOD2/CARD15基因是人类的第一个克罗恩病(CD)易感基因,其间的3个单核苷酸多态性(SNPs)与白种人CD有显著性相关,但与日本人无关。本研究旨在证实这3个SNPs是否与浙江地区人群的CD易感性有关。方法血样来自浙江地区32例CD患者,110例溃疡性结肠炎患者及292例健康对照者。通过PCRSSP方法直接检测野生型及NOD2/CARD15基因的3个多态性(Arg702Trp,Gly908Arg,Leu1007fsinsC)。结果没有发现1例CD患者纯合子或杂合子的SNPs突变,同样在溃疡性结肠炎患者和健康人中也未能检测到。结论本研究表明一些存在于特定人群的CD易感基因可能在其他人群中不存在,白种人CD患者相关的易感基因NOD2/CARD15常见的3个SNPs与浙江地区CD人群无关。     

CARD15 in inflammatory bowel disease and Crohn''s disease phenotypes: An association study and pooled analysis

BACKGROUND: Three major polymorphisms of the Caspase-Activation Recruitment Domain containing protein 15 gene have been described to be associated with Crohn's disease. Genotype-phenotype studies reported in literature provide conflicting data on disease localisation and behaviour. We investigated the relation of Caspase-Activation Recruitment Domain containing protein 15 with inflammatory bowel disease and Crohn's disease phenotypic characteristics in a large Dutch cohort and performed a pooled analysis on inflammatory bowel disease patients and Crohn's disease phenotypic characteristics reported in association studies. METHODS: We genotyped 781 cases and 315 controls for the R702W, G908R and 1007fsinsC variants and for six microsatellite markers in and close to Caspase-Activation Recruitment Domain containing protein 15. In the pooled analysis data of 7201 inflammatory bowel disease patients and 3720 controls from 20 studies were included. RESULTS: Association was found for Crohn's disease with R702W and 1007fsinsC, including several disease characteristics, and not for ulcerative colitis. In the pooled analysis all three common Caspase-Activation Recruitment Domain containing protein 15 variants showed strong association with Crohn's disease (p<0.00001; odds ratio varying from 3.0 for single heterozygotes to 14.7 for compound heterozygotes) and not with ulcerative colitis. Phenotype analysis showed association with small bowel involvement, stricturing and penetrating disease. CONCLUSION: Caspase-Activation Recruitment Domain containing protein 15 is associated with Crohn's disease and not with ulcerative colitis. All three common Crohn's disease-associated variants are associated with small bowel involvement, the G908R and 1007fsinsC alleles also being associated with a complicated disease course.     

克罗恩病CARD15/NOD2基因突变的研究

目的 发现与中国人克罗恩病（CD）发病相关的单核苷酸多态性（SNP）及其与临床特点的关系.方法 临床资料完整的CD、溃疡性结肠炎（UC）患者及健康体检者各30例.提取人血白细胞基因组DNA,PCR扩增NOD2基因第4、8、11外显子,纯化后直接测序.结果 5例CD患者有SNP改变,其中2例为P268S,1例为R459R,2例为P268S和R459R,而在UC患者和健康人中各检测到1例R459R.所有研究对象未发现R702W、G908R及3020insC改变.CD有4例P268S,与UC和健康体检者比较差异有统计学意义（χ^2=8.037,P＜0.05）.4例P268S CD患者病变均在回肠（χ^2=9.231,P=0.01）,发病年龄小于20岁（χ^2=10.769,P＜0.01）,并发肠腔狭窄而需手术（χ^2=7.972,P＜0.01）,2例有P268S和R459R的患者病情较重,多次复发.结论 P268S可能是CARD15/NOD2基因中与中国人CD相关的SNP,与患者发病年龄、病变部位及肠腔狭窄明显相关,与患者性别及病变严重程度无关.     

NOD2/CARD15, NOD1/CARD4, and ICAM-1 gene polymorphisms in Turkish patients with inflammatory bowel disease

Purpose The genetic susceptibility of people with certain NOD2/CARD15, NOD1/CARD4, and ICAM-1 gene variants to inflammatory bowel disease is still under investigation. The aim of this study was to investigate polymorphisms in the NOD2/CARD15 (R702W, G908R, and 3020insC), NOD1/CARD4 (E266K, D372N), and ICAM-1 (G241R, K469E) genes, which are known to be associated with inflammation, in Turkish patients with inflammatory bowel disease and healthy control groups. Methods The genotypes of 70 patients with endoscopically and histopathologically diagnosed Crohn's disease (38 men, 32 women; mean age, 38.8 ± 1.3), 120 patients with ulcerative colitis (67 men, 53 women; mean age, 41.7 ± 1.3) and 106 healthy control subjects (37 men, 69 women; mean age, 35.7 ± 1.4), who stated that they had never had any prior bowel disease history, were compared. A polymerase chain reaction-restriction fragment length polymorphism analysis was performed for two variants of the ICAM-1 gene, the three main variants of the NOD2/CARD15 gene, and the E266K variant of the NOD1/CARD4 gene, and DNA sequencing was used for the D372N polymorphism of the NOD1/CARD4 gene. Results In this study, the three previously described Crohn's disease-predisposing variants of the NOD2/CARD15 gene and the polymorphisms examined in the NOD1/CARD4 and ICAM-1 genes were not found to be associated with ulcerative colitis or Crohn's disease. Conclusions These findings suggest that the polymorphisms observed in the NOD2/CARD15, NOD1/CARD4, and ICAM-1 genes are not genetic susceptibility factors for Crohn's disease or ulcerative colitis in Turkey.     

NOD2/CARD15基因R702W、G908R及L1007fs多态性与广西壮族人群炎症性肠病的相关性

目的:探讨我国广西壮族人群NOD2/CARD15基因R702W、G908R及L1007fs的遗传多态性与炎症性肠病的相关性.方法:分别收集2007-02/2010-10在广西地区无亲缘关系的壮族(n=70)和汉族(n=76)IBD患者及壮族(n=80)和汉族(n=84)正常对照者的肠黏膜组织.采用酚氯仿法提取各组织样本DNA,采用聚合酶链反应-限制性片段长度多态性分析(PCR-RFLP)方法对NOD2/CARD15基因R702W、G908R及L1007fs进行检测,统计基因型及等位基因频率,分析上述3个多态性位点与广西壮族人群炎症性肠病的相关性.结果:广西壮族和汉族IBD患者与正常对照者均未发现NOD2/CARD15基因R702W、G908R及L1007fs突变型基因型,所有多态性位点上的基因型全部为野生型纯合子,其基因型频率和等位基因频率分布在IBD患者和正常对照者中差异无统计学意义(P>0.05).结论:NOD2/CARD15基因R702W、G908R及L1007fs多态性与广西壮族人群炎症性肠病无明显相关性.     

Role of CARD15, DLG5 and OCTN genes polymorphisms in children with inflammatory bowel diseases

AIM: To investigate the contribution of variants of CARD15, OCTN1/2 and DLG5 genes in disease predispo- sition and phenotypes in a large Italian cohort of pediatric patients with inflammatory bowel diseases (IBD). METHODS: Two hundred patients with Crohn’s disease (CD), 186 ulcerative colitis (UC) patients, 434 par- ents (217 trios), and 347 healthy controls (HC) were studied. Polymorphisms of the three major variants of CARD15, 1672C/T and -207G/C SNPs for OCTN genes, IGR2096a_1 and IGR2198a_1 SNPs for the IBD5 locus, and 113G/A variant of the DLG5 gene were evaluated. Potential correlations with clinical sub-phenotypes were investigated. RESULTS: Polymorphisms of CARD15 were significantly associated with CD, and at least one variant was found in 38% of patients (15% in HC, OR = 2.7, P < 0.001). Homozygosis for both OCTN1/2 variants was more com- mon in CD patients (1672TT 24%, -207CC 29%) than in HC (16% and 21%, respectively; P = 0.03), with an in- creased frequency of the TC haplotype (44.8% vs 38.3% in HC, P = 0.04). No association with the DLG5 variant was found. CD carriers of OCTN1/2 and DLG5 variants more frequently had penetrating disease (P = 0.04 and P = 0.01), while carriers of CARD15 more frequently had ileal localization (P = 0.03). No gene-gene interaction was found. In UC patients, the TC haplotype was morefrequent (45.4%, P = 0.03), but no genotype/phenotype correlation was observed. CONCLUSION: Polymorphisms of CARD15 and OCTN genes, but not DLG5 are associated with pediatric on- set of CD. Polymorphisms of CARD15, OCTN, and DLG5 genes exert a weak influence on CD phenotype.     

Prevalence of mutations of the NOD2/CARD15 gene and relation to phenotype in Spanish patients with Crohn disease

Background: We assessed the prevalence of R702W, G908R, and L1007fs coding mutations in the NOD2/CARD15 gene and the genotype–phenotype relation in Spanish patients with Crohn disease. Methods: A cohort of 204 unrelated patients with Crohn disease and 140 healthy controls were studied. The phenotype was established before commencement of genotyping. Genotyping of the R702W, G908R, and L1007fs gene polymorphisms of NOD2/CARD15 was performed by two independent laboratories using different techniques. In the case of discordant results, specific sequencing of DNA strands was performed. Results: At least one mutation was present in 32.8% of patients compared to 10.7% in controls (OR?=?4.08, 95% CI 2.21 to 7.50). In patients with Crohn disease, the frequency of R702W, G908R, and L1007fs carriers was 13.7%, 8.3%, and 14.2%, respectively. Compound heterozygotes and homozygotes occurred in 3.4% and 2.9% of patients and in none of the controls. The correlation of genotype–Vienna classification showed a significant association with ileal disease (RR?=?1.61, 95% CI 1.21–2.15, P?=?0.001) and an inverse association with colonic localization (RR?= 0.29, 95% CI 0.11–0.80, P?=?0.007). There was a significant association between G908R carriership and previous appendectomy, surgical interventions, and stricturing behavior. A gene‐dosage effect on phenotypic characteristics was not observed. Conclusions: In a Spanish population from Madrid, mutations of the NOD2/CARD15 gene were a marker of susceptibility to Crohn disease and were associated with ileal disease. Carriers of the G908R mutation showed a stricturing disease behavior, history of appendectomy, and surgical interventions over the course of the disease.     

Role of matrix metalloproteinase, tissue inhibitor of metalloproteinase and tumor necrosis factor-α single nucleotide gene polymorphisms in inflammatory bowel disease

AIM:To study the (functional) relevance of single nucleotide polymorphisms (SNPs) in genes encoding matrix metalloproteinases (MMP)-1,-2,-3,-9,tissue inhibitors of metalloproteinases (TIMP)-1,-2 and tumor necrosis factor (TNF)-α in the etiopathogenesis of inflammatory bowel diseases (IBD),that may enhance susceptibility and/or disease severity. METHODS:Genomic DNA from 134 Crohn's disease (CD),111 ulcerative colitis (UC) patients and 248 control subjects was isolated from resected intestinal tissue or blood. Allelic composition at SNP loci was determined by PCR-RFLP or tetra primer ARMS PCR. RESULTS:The TIMP-1 genotype TT in women and T in men at SNP +372 T/C was found to increase CD susceptibility (39% vs 23.8%,P=0.018 and 67.9% vs 51.6%,P=0.055,respectively),while women with this genotype were less prone to development of fistulae during follow-up (41.4% vs 68.3%,P=0.025). Male IBD or CD patients carrying the TIMP-1 +372 T-allele expressed lower levels of TIMP-1 in surgically resected macroscopically inflamed tissue (0.065 < P < 0.01). The 5T5T genotype at MMP-3 SNP -1613 5T/6T increased the chance of stenotic complications in CD during follow-up (91.2% vs 71.8%,P = 0.022) but seemed to protect against colonic involvement of this disease at first endoscopic/radiologic examination (35.3% vs 59.5%,P=0.017). CONCLUSION:Allelic composition at the examinedSNPs in genes coding for TIMP-1 and MMP-3 affect CD susceptibility and/or phenotype,i.e.,fistulizing disease,stricture pathogenesis and first disease localisation. These findings reinforce the important role of these proteins in IBD.     

Role of matrix metalloproteinase, tissue inhibitor of metalloproteinase and tumor necrosis factor-α single nucleotide gene polymorphisms in inflammatory bowel disease

AIM: To study the (functional) relevance of single nucleotide polymorphisms (SNPs) in genes encoding matrix metalloproteinases (MMP)-1, -2, -3, -9, tissue inhibitors of metalloproteinases (TIMP)-1, -2 and tumor necrosis factor (TNF)-α in the etiopathogenesis of inflammatory bowel diseases (IBD), that may enhance susceptibility and/or disease severity.METHODS: Genomic DNA from 134 Crohn's disease (CD), 111 ulcerative colitis (UC) patients and 248 control subjects was isolated from resected intestinal tissue or blood. Allelic composition at SNP loci was determined by PCR-RFLP or tetra primer ARMS PCR.RESULTS: The TIMP-1 genotype ∏ in women and T in men at SNP +372 T/C was found to increase CD susceptibility (39% vs 23.8%, P = 0.018 and 67.9% vs 51.6%, P = 0.055, respectively), while women with this genotype were less prone to development of fistulae during follow-up (41.4% vs 68.3%, P = 0.025). Male IBD or CD patients carrying the TIMP-1 +372 T-allele expressed lower levels of TIMP-1 in surgically resected macroscopically inflamed tissue (0.065 ＜ P ＜ 0.01). The 5TST genotype at MMP-3 SNP -1613 5T/6T increased the chance of stenotic complications in CD during followup (91.2% vs 71.8%, P = 0.022) but seemed to protect against colonic involvement of this disease at first endoscopic/radiologic examination (35.3% vs 59.5%, P = 0.017).CONCLUSION: Allelic composition at the examined SNPs in genes coding for TIMP-1 and MMP-3 affect CD susceptibility and/or phenotype, i.e., fistulizing disease,stricture pathogenesis and first disease localisation.These findings reinforce the important role of these proteins in IBD.     

NOD2,IL23R and ATG16L1 polymorphisms in Lithuanian patients with inflammatory bowel disease

AIM:To investigate the frequency of NOD2, IL23R and ATG16L1 genetic variants in a case-control panel for inflammatory bowel disease (IBD) from Lithuania.METHODS: One hundred and eighty unrelated IBD pa- tients [57 Crohn‘s disease (CD) and 123 ulcerative colitis (UC)] and 186 healthy controls were genotyped for the following known genetic susceptibility variants:NOD2-Arg702Trp (rs2066844), Gly908Arg (rs2066845) and Leu1007insC (rs2066847), as well as IL23R-Arg381Gln (rs11209026) and ATG16L1-Thr300Ala (rs2241...     

Association between NOD2/CARD15 gene polymorphisms and Crohn’s disease in Chinese Zhuang patients

AIM:To assess the relationship between the P268S,JW1 and N852S polymorphisms and Crohn’s disease(CD)susceptibility in Zhuang patients in Guangxi,China.METHODS:Intestinal tissues from 102 Zhuang[48CD and 54 ulcerative colitis(UC)]and 100 Han(50 CD and 50 UC)unrelated patients with inflammatory bowel disease and 72 Zhuang and 78 Han unrelated healthy individuals were collected in the Guangxi Zhuang Autonomous Region from January 2009 to March 2013.Genomic DNA was extracted using the phenol chloroform method.The P268S,JW1 and N852S polymorphisms were amplified using polymerase chain reaction(PCR),detected by restriction fragment length polymorphism(RFLP),and verified by gene sequencing.RESULTS:Heterozygous mutation of P268S in the NOD2/CARD15 gene was detected in 10 CD cases(six Zhuang and four Han),two Han UC cases,and one Zhuang healthy control,and P268S was strongly associated with the Chinese Zhuang and Han CD populations(P=0.016 and 0.022,respectively).No homozygous mutant P268S was detected in any of the groups.No significant difference was found in P268S genotype and allele frequencies between UC and control groups(P>0.05).Patients with CD who carried P268S were likely to be≤40 years of age(P=0.040),but were not significantly different with regard to race,lesion site,complications,and other clinical features(P>0.05).Neither JW1 nor N852S polymorphisms of the NOD2/CARD15gene were found in any of the subjects(P>0.05).CONCLUSION:P268S polymorphism may be associated with CD susceptibility in the Zhuang population in the Guangxi Zhuang Autonomous Region,China.In contrast,JW1 and N852S polymorphisms may not be related to CD susceptibility in these patients.     

Identification of NOD2/CARD15 mutations in Malaysian patients with Crohn's disease

OBJECTIVE: The NOD2/CARD15 gene has been identified as an important susceptibility gene for Crohn's disease (CD) but the three common disease predisposing mutations (DPM) found in developed countries have not been identified in Asian populations. The aim of our study was to look for the DPM in our multiracial population and to discover whether there were any differences in the three major ethnic groups; Malay, Chinese and Indian. METHODS: Blood samples from consecutive CD patients and healthy controls were obtained and analyzed for the three common mutations (R702W, G908R, 1007fs) but in addition to this, we also looked for the SNP5 and JW1 variants which are associated with CD in Ashkenazi Jews. A polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) technique was used to identify the mutations, which was confirmed by sequencing. The baseline socio‐demography and clinical characteristics of the CD patients were recorded. RESULTS: Overall 45 patients (three Malays, 15 Chinese, 26 Indians and one other) with confirmed CD and 300 controls were recruited. The three common DPM were not observed in either the CD patients or the controls. Neither the SNP5 nor the JW1 mutation was found in any of the controls. However, the SNP5 mutation was identified in six (13.3%) Indian CD patients and the JW1 mutation in eight CD patients who are different from those carrying the SNP5 mutation: one Malay (33.3%), two Chinese (13.3%), one other (Portuguese) and four Indians (15.4%). The presence of SNP5 was strongly associated with CD in the Indian population and that of JW1 was strongly associated with CD overall and in each of the major ethnic groups. There was a trend towards a younger age of onset and stricturing disease in patients carrying the JW1 mutation. CONCLUSION: These findings suggest the presence of novel DPM in the NOD2/CARD15 gene in Asian patients with CD.     

NOD2/CARD15 gene mutations in North Algerian patients with inflammatory bowel disease

AIM: To analyse allelic frequency of NOD2 gene variantsand to assess their correlation with inflammatory bowel disease(IBD) in Algeria.METHODS: We studied 132 unrelated patients diagnosed with IBD, 86 with Crohn's disease(CD) and 46 with ulcerative colitis(UC). Data was prospectively collected between January 2011 and December 2013. The demographic and clinical characteristics were recorded for all the patients. A group of 114 healthy unrelated individuals were selected as controls. All groups studied originated from different regions of North Algeria and confirmed the Algerian origin of their parents and grandparents. Informed and written consent was obtained from each of the participants. All individuals were genotyped for the three CDassociated NOD2 variants(p.Arg702 Trp, p.Gly908 Arg and p.Leu1007 fsins C mutations) using the polymerase chain reaction-restriction fragment length polymorphism method. Allele and genotype frequencies in patients and control subjects were compared by χ2 test and Fisher's exact test where appropriate. Odds ratios(OR) and 95% confidence intervals(95%CI) were also estimated. Association analyses were performed to study the influence of these variants on IBD and on clinical phenotypes.RESULTS: The p.Arg702 Trp mutation showed the highest frequency in CD patients(8%) compared to UC patients(2%)(P = 0.09, OR = 3.67, 95%CI: 0.48-4.87) and controls(5%)(P = 0.4, OR = 1.47, 95%CI: 0.65-3.31). In CD patients allelic frequencies of p.Gly908 Arg and p.Leu1007 fsins C variants compared to HC were 3% vs 2%(P = 0.5, OR = 1.67, 95%CI: 0.44-6.34); 2% vs 1%(P = 0.4 OR = 2.69 95%CI: 0.48-14.87 respectively). In UC patients, allelic frequencies of p.Gly908 Arg and p.Leu1007 fsins C variants compared to HC were 1% vs 2%(P = 1, OR = 1.62, 95%CI: 0.17-4.74) and 2% vs 1%(P = 0.32, OR = 0.39, 95%CI: 0.05-2.87). The total frequency of the mutated NOD2 chromosomes was higher in CD(13%), than in HC(8%) and UC(5%). In addition, NOD2 variants were linked to a particular clinical sub-phenotype in CD in this Algerian cohort. As expected, the three NOD2 variants showed a significant association with CD but did not reach statistical significance, despite the fact that the allele frequency of NOD2 variants was in the range found in most of the European populations. This might be due to the non-exposure of the NOD2 carriers to environmental factors, required for the expression of the disease.CONCLUSION: Further analyses are necessary to study genetic and environmental factors in IBD in the Algerian population, using larger patient groups.     

克罗恩病相关的NOD2及β-防御素-2基因多态性对β-防御素-2表达的影响

目的探讨克罗恩病（Crohndisease,CD）相关的NOD2及人β-防御素-2（humanbeta—defensin2,hBD-2）基因多态性对hBD-2转录活性的影响及主要机理。方法将hBD-2报告基因质粒和NOD2真核表达载体共转染至HEK293T细胞,用脂多糖（LPS）和TNF—α分别孵育刺激后测定hBD-2转录活性变化。结果LPS对hBD-2转录活性有抑制作用（P=0．020）,TNF—α可相对升高hBD-2转录活性,呈剂量依赖性（P=0．004）;LPS作用时,NOD2（P268S）改变前后hBD-2的转录活性差异有统计学意义（P=0．008）;hBD-2（-233）改变前后hBD-2的转录活性差异无统计学意义（P=0．053）。在TNF-α（5ng／m1）刺激时,NOD2（P268S）改变前后hBD-2的转录活性差异无统计学意义（P=0．064）;hBD-2（-233）改变前后hBD-2的转录活性差异有统计学意义（P=0．006）;NF—κB抑制剂可显著下调hBD-2转录的激活（P〈0．001）。结论NOD2（P268S）改变能够降低hBD-2的内源性表达;hBD-2（-233）改变导致hBD-2诱生性表达的减少;NF—κB通路可能是hBD-2诱导表达的主要路径。     

Prevalence of SLC22A4, SLC22A5 and CARD15 gene mutations in Hungarian pediatric patients with Crohn＇s disease

AIM: To investigate the frequency of the common NOD2/CARD15 susceptibility variants and two functional polymorphisms of OCTN cation transporter genes in Hungarian pediatric patients with Crohn's disease (CD). METHODS: A cohort of 19 unrelated pediatric and 55 unrelated adult patients with Crohn's disease and 49 healthy controls were studied. Genotyping of the three common CD-associated CARD15 variants (Arg702Trp, Gly908Arg and 1007finsC changes) with the SLC22A4 1672C-->T, and SLC22A5 -207G-->C mutations was performed by direct sequencing of the specific regions of these genes. RESULTS: At least one CARD15 mutation was present in 52.6% of the children and in 34.5% of the adults compared to 14.3% in controls. Surprisingly, strongly different mutation profile was detected in the pediatric versus adult patients. While the G908R and 1007finsC variants were 18.4% and 21.1% in the pediatric group, they were 1.82% and 11.8% in the adults, and were 1.02% and 3.06% in the controls, respectively. The R702W allele was increased approximately two-fold in the adult subjects, while in the pediatric group it was only approximately 64% of the controls (9.09% in the adults, 2.63% in pediatric patients, and 4.08% in the controls). No accumulation of the OCTN variants was observed in any patient group versus the controls. CONCLUSION: The frequency of the NOD2/CARD15 susceptibility variants in the Hungarian pediatric CD population is high and the profile differs from the adult CD patients, whereas the results for SLC22A4 and SLC22A5 mutation screening do not confirm the assumption that the carriage of these genotypes means an obligatory susceptibility to CD.