Cytokine gene polymorphisms in Turkish patients with inflammatory bowel disease

OBJECTIVE: Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the bowel, the causes of which are not fully known. Ethnic differences in disease prevalence, familial aggregation of the disease and studies of twins provide the most important evidence to suggest that genetic factors play a role in the pathogenesis of inflammatory bowel disease (IBD). The aim of this study was to examine the allelic polymorphisms that can determine the immune response levels in tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1B), interleukin-1 receptor antagonist ( IL-1RN) and interleukin-10 (IL-10) genes and to investigate their roles in the inflammatory pathway in IBD. MATERIAL AND METHODS: The study included 120 patients with UC and 70 patients with CD who were diagnosed either endoscopically or histopathologically. The control group comprised 105 healthy individuals who stated that they had never had any bowel disease during their life span. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method for polymorphisms in the TNFalpha gene at positions -308 and -238, the IL-10 gene at positions -1082 and -627, the IL-1B gene at -511 regions and the variable number of tandem repeat (VNTR) method for polymorphism in the intron 2 of the IL-1RN gene were performed. The results were analyzed on agarose gel electrophoresis. RESULTS: No significant differences were found in the allele and genotype frequencies of the polymorphisms in the IL-1B, IL10, TNFalpha and IL-1RN genes between the patients with UC and CD and controls. CONCLUSIONS: The results suggest that these polymorphisms were not important risk factors in the susceptibility to IBD in Turkish patients.     

IL-17基因多态性与中国汉族人群炎症性肠病的关系

目的:研究IL-17A和IL-17F的5个多态性位点与中国汉族人炎症性肠病之间的关系.方法:采用病例-对照研究方法,收集确诊的溃疡性结肠炎(ulcerative colitis,UC)和克罗恩病(Crohn’s disease,CD)患者共350例(UC270例;CD80例),健康对照组268例,收集外周血标本2mL,提取DNA,运用LDR(ligasedetection reaction allelic)技术进行多态性检测.采用SPSS17.0软件进行数据分析.结果:CD患者中IL-17F(rs763780,7488T/C)突变等位基因C的频率明显高于对照组(13.8%vs8.4%,P=0.044,OR=1.74,95%CI1.01-2.99).在亚型分析中,rs763780基因多态性与CD病变范围有关,突变等位基因C在CD回结肠型患者中的频率明显高于对照组(P=0.02).IL-17A(rs2275913,G-197A)与UC患者疾病的严重程度有弱相关性,含有突变基因A的患者倾向于临床轻型.IL-17F(rs763780,7488T/C)多态性与U C患者发病年龄之间有弱相关性,T/C基因型患者趋向于年轻型(P=0.046).结论:IL-17F rs763780基因多态性与CD易感性之间有弱相关性,在亚组分析中发现rs763780与CD的病变范围和UC的发病年龄有关.IL-17A rs2275913基因多态性与UC疾病严重程度呈负相关.     

Cytokine gene polymorphisms in inflammatory bowel disease.

BACKGROUND: Concordance rates in siblings and twins provide strong evidence that genetic susceptibility is important in the pathogenesis of inflammatory bowel disease. The number and identity of susceptibility genes is largely uncertain. Cytokine genes are attractive candidate loci. AIMS: To study allelic frequencies of polymorphisms of the interleukin-1 receptor antagonist (IL-1RA) gene and the tumour necrosis factor alpha gene in patients with inflammatory bowel disease. SUBJECTS: One hundred and twenty nine North European caucasoid patients with ulcerative colitis, 120 patients with Crohn's disease, and 89 healthy controls. METHODS: Genotyping was performed by polymerase chain reaction. A variable number of tandem repeats (VNTR) in the IL-1RA gene and a single base pair polymorphism in the TNF alpha gene promoter region (TNF-308) were analysed. RESULTS: No significant differences in IL-1RA VNTR allelic frequencies were noted between Crohn's disease (allele 1: 72.6%, allele 2: 24.7%, allele 3: 2.6%), ulcerative colitis (72.6%, 24.3%, 3.1%, respectively), and controls (76.9%, 20.8% and 2.3%). Some 42.4% of patients with ulcerative colitis and 43.4% patients with Crohn's disease were carriers of allele 2, compared with 34.8% healthy subjects. The TNF2 allele was modestly reduced in Crohn's disease (13.2%), compared with healthy subjects (21.3%; p = 0.04), and ulcerative colitis (21.6%). CONCLUSIONS: The associations demonstrated are modest: these polymorphisms are unlikely to be important determinants of overall disease susceptibility.     

Comparison of TPMT and NUDT15 polymorphisms in Chinese patients with inflammatory bowel disease

AIM To observe gene polymorphisms of TPMT and NUDT15, and compare their predictive value for azathioprine(AZA)-induced leukopenia in inflammatory bowel disease(IBD).METHODS This study enrolled 219 patients diagnosed with IBD in Xiangya Hospital, Central South University, Changsha, China from February 2016 to November 2017. Peripheral blood of all patients was collected to detect their genotypes of TPMT and NUDT15 by pyrosequencing at the Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya Hospital. Eighty patients were treated with AZA according to the disease condition. During the first month, patients who received AZA underwent routine blood tests and liver function tests once a week. The endpoint of the study was leukopenia induced by AZA. By analyzing patient characteristics, genotypes and leukopenia induced by drug use, we found the risk factors associated with AZA-induced leukopenia.RESULTS There were 219 patients with IBD(160 men and 59 women), including 39 who were confirmed with ulcerative colitis(UC), 176 with Crohn's disease(CD) and 4 with undetermined IBD(UIBD). There were 44 patients(20.1%) with mutant genotype of NUDT15(C/T); among them, 16 received AZA, and 8(50%) developed leukopenia. There were 175 patients(79.7%) with wild genotype of NUDT15(C/C); among them, 64 received AZA, and 11(17.2%) developed leukopenia. A significant difference was found between NUDT15 C/T and its wild-type C/C(P = 0.004). There were only 3 patients with TPMT mutant genotype of A/G(1.4%) who participated in the research, and 1 of them was treated with AZA and developed leukopenia. The remaining 216 patients(98.6%) were found to bear the wild genotype of TPMT(A/A); among them, 79 patients received AZA, and 18(22.8%) developed leukopenia, and there was no significant difference from those with A/G(P = 0.071). The frequency of TPMT mutation was 1.4%, and NUDT15 mutation rate was significantly higher and reached 20.1%(P = 0.000). Therefore, NUDT15 gene polymorphism was obviously a better biomarker than TPMT gene polymorphism in the prediction of AZA-induced leukopenia.CONCLUSION Mutation rate of NUDT15 in Chinese IBD patients is higher than that of TPMT. NUDT15 polymorphism is a better predictor for AZA-induced leukopenia than TPMT polymorphism.     

Association of vitamin D receptor gene polymorphisms in Iranian patients with inflammatory bowel disease

Background and Aims: The vitamin D receptor (VDR) gene maps to a region on chromosome 12 shown to be linked to inflammatory bowel disease (IBD). Many studies have recognized the relation of VDR gene polymorphisms with inflammatory and autoimmune disorders. Determining the frequency of these polymorphisms and their possible relation with IBD can improve understandings about the genetic background of these diseases. The objective of this study was to assess the association of VDR gene polymorphisms (Apa I, Taq I, Bsm I, Fok I) with IBD in Iran. Methods: In this case control designed study 150 patients with ulcerative colitis, 80 patients with Crohn's disease and 150 Age and Sex matched healthy controls from Iranian origin were enrolled. These patients were referred to a tertiary center during a two‐year period (2004–2006). Assessment of VDR gene polymorphisms was performed by the polymerase chain reaction—restriction fragment length polymorphism (PCR‐RFLP) method. The genotype–phenotype association for these polymorphisms was analyzed. Results: Only the frequency of the Fok I polymorphism was significantly higher in ulcerative colitis and Crohn's groups. The frequency of the polymorphic allele f was higher in ulcerative colitis and Crohn's patients comparing with controls (P = 0.011 and P < 0.001, respectively). The f/f genotype was also significantly more frequent (P < 0.001), while the F/F genotype was less presented in Crohn's patients compared to controls (P < 0.001). No genotype–phenotype association was observed with any mutations. Conclusions: This study suggests a probable association of the Fok I polymorphism in VDR receptor gene and Crohn's susceptibility in Iranian population.     

Association of MYO9B gene polymorphisms with inflammatory bowel disease in Chinese Han population

AIM: To explore the association of MYO9B gene polymorphisms with clinical phenotypes and intestinal permeability of individuals with inflammatory bowel disease (IBD) in China.METHODS: A total of 442 IBD patients and 402 healthy volunteers were genotyped for two single nucleotides (rs962917 and rs1545620) using the ligase detection reaction and polymerase chain reaction. Allelic and genotype frequency analyses were performed for the two groups. Intestinal permeability was evaluated using lactulose (L) and mannitol (M) excretion. The association of MYO9B gene polymorphisms with intestinal permeability between the normal and high intestinal permeability groups was analyzed.RESULTS: Overall, there was no significant difference in the genotypic and allelic frequencies of MYO9B between IBD patients and controls. Although no association was found with ulcerative colitis in the comparison between the subgroups, the frequencies of rs962917 and rs1545620 were different in the Crohn’s disease (CD) subgroup with ileocolitis (CC vs CT and TT, P = 0.014; and AA vs AC and CC, P = 0.022, respectively). rs1545620 variants appear to be the genetic susceptibility factor for perianal disease in CD patients (AA vs AC CC, P = 0.029). In addition, the L/M ratio was significantly higher in IBD patients than in controls (0.065 ± 0.013 vs 0.020 ± 0.002, P = 0.02), but no association was found between the MYO9B gene and the L/M ratio in IBD patients.CONCLUSION: MYO9B gene polymorphisms may influence the sub-phenotypic expression of CD in China. No association between these MYO9B polymorphisms and intestinal permeability in IBD patients was found.     

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.     

Association of polymorphic alleles of CTLA4 with inflammatory bowel disease in the Japanese

AM: To examine an association between the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene that plays a role in downregulation of T-cell activation and inflammatory bowel disease consisting of ulcerative colitis (UC) and Crohn's disease (CD) in the Japanese. METHODS: We studied 108 patients with UC, 79 patients with CD, and 200 sex-matched healthy controls, with respect to three single nucleotide polymorphisms (SNPs) in CTLA4, such as C-318T in the promoter region, A+49G in exon 1 and G+6230A in the 3' untranslated region (3'-UTR) by a PCR-restriction fragment length polymorphism method, and to an (AT)n repeat polymorphism in 3'-UTR by fragment analysis with fluorescence-labeling on denaturing sequence gels. Frequency of alleles and genotypes and their distribution were compared statistically between patients and controls and among subgroups of patients, using X2 and Fisher exact tests. RESULTS: The frequency of "A/A" genotype at the G+6230A SNP site was statistically lower in UC patients than in controls (3.7% vs 11.0%, P= 0.047, odds ratio (OR) = 0.311). Moreover, the frequency of "G/G" genotype at the A+49G SNP site was significantly higher in CD patients with fistula (48.6%) than those without it (26.2%) (P = 0.0388, OR=2.67). CONCLUSION: The results suggest that CTLA4 located at 2q33 is a determinant of UC and responsible for fistula formation in CD in the Japanese.     

Association of Fas-670 gene polymorphism with inflammatory bowel disease in Chinese patients

AIM: Recent studies suggest that Fas-mediated apoptosis is involved in the pathogenesis of inflammatory bowel disease (IBD). It has been hypothesized that either increased apoptosis of intestinal epithelium or decreased apoptosis of lamina propria lymphocytes may induce inflammation of' gut. The aim of this study was to determine whether the Fas gene promoter polymorphism at position-670 was associated with IBD in Chinese patients. METHODS: Fifty unrelated Chinese patients with IBD (38 patients with ulcerative colitis and 12 with Crohn's disease) and 124 healthy controls were genotyped for the Fas-670 polymorphism by PCR-restriction fragment length polymorphism method. The PCR product was digested by Mva I restriction enzyme. RESULTS: Distribution of the Fas-670 gene polymorphism was 33% for the AA genotype, 52% for the AG genotype and 15% for the GG genotype in 124 healthy subjects. In patients with IBD, 30% was for the AA genotype, 42% for the AG genotype and 28% for the GG genotype respectively. However, there was no significant difference in the genotype (P= 0.1498), allele frequencies (P= 0.3198) and carriage frequencies (P = 0.4133) between healthy controls and IBD patients. Furthermore, we did not find any difference between the left-sided colitis and total colitis (P = 0.8242). CONCLUSION: Fas-670 polymorphism is not associated with IBD in Chinese patients.     

炎症性肠病患者抑制性杀伤细胞免疫球蛋白样受体基因多态性分析

目的 分析炎症性肠病(inflammatory bowel disease,IBD)患者抑制性杀伤细胞免疫球蛋白样受体(killer cell immunoglobulin-like receptor,iKIR)基因多态性,探讨iKIR基因多态性与IBD的关联性.方法 收集100例溃疡性结肠炎(UC)、52例克罗恩病(CD)患者和106名种族匹配的健康对照者外周血DNA标本,采用序列特异性引物聚合酶链反应(PCR-SSP)方法,分析上述对象iKIR基因位点的多态性,计算iKIR基因表型频率和基因频率,比较IBD患者与健康对照者间的差异.结果 iKIR基因(包括KIR2DL1、KIR2DL2、KIR2DL3、KIR2DL4、KIR2DL5、KIR3DL1、KIR3DL2、KIR3DL3)在IBD患者和健康对照组均有不同程度的表达.UC患者KIR2DL1和KIR2DL3表现型频率比健康对照组显著降低(P=0.001),而KIR2DL2、KIR2DL4、KIR2DL5、KIR3DL1、KIR3DL2和KIR3DL3表现型频率与健康对照组比较差异无统计学意义(P＞0.05).CD患者KIR2DL1表现型频率比健康对照组显著降低(P=0.007),而其余iKIR基因表现型频率与健康对照组比较差异无统计学意义(P＞0.05).结论 KIR2DL1和KIR2DL3表现型频率在UC患者中显著下降,提示其与UC的易感性有密切关系; 而KIR2DL1基因可能与CD易感性密切相关.     

Fecal microbial dysbiosis in Chinese patients with inflammatory bowel disease

AIM To analyze the alterations of fecal microbiota in Chinese patients with inflammatory bowel disease(IBD).METHODS Fecal samples from 15 patients with Crohn's disease(CD)(11 active CD, 4 inactive CD), 14 patients with active ulcerative colitis(UC) and 13 healthy individuals were collected and subjected to 16 S ribosomal DNA(rDNA) gene sequencing. The V4 hypervariable regions of 16 S rDNA gene were amplified from all samples and sequenced by the Illumina Mi Seq platform. Quality control and operational taxonomic units classification of reads were calculated with QIIME software. Alpha diversity and beta diversity were displayed with R software.RESULTS Community richness(chao) and microbial structure in both CD and UC were significantly different from those in normal controls. At the phyla level, analysis of the microbial compositions revealed a significantly greater abundance of Proteobacteria in IBD as compared to that in controls. At the genera level, 8 genera in CD and 23 genera in UC(in particular, the Escherichia genus) showed significantly greater abundance as compared to that in normal controls. The relative abundance of Bacteroidetes in the active CD group was markedly lower than that in the inactive CD group. The abundance of Proteobacteria in patients with active CD was nominally higher than that in patients with inactive CD; however, the difference was not statistically significant after correction. Furthermore, the relative abundance of Bacteroidetes showed a negative correlation with the CD activity index scores.CONCLUSION Our study profiles specific characteristics and microbial dysbiosis in the gut of Chinese patients with IBD. Bacteroidetes may have a negative impact on inflammatory development.     

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.     

CTLA4 gene and Graves' disease: association of Graves' disease with the CTLA4 exon 1 and intron 1 polymorphisms,but not with the promoter polymorphism

OBJECTIVE: Recent studies have shown that Graves' disease (GD) is linked to and associated with alleles of the cytotoxic T lymphocyte antigen-4 (CTLA4) locus. However, the true pathogenic polymorphism(s) at this locus remains uncertain. Moreover, the association studies of the promoter CTLA4(-318)C/T polymorphism in white GD populations have produced conflicting results. Therefore, we have analysed three CTLA4 single nucleotide polymorphisms, including promoter CTLA4(-318)C/T, exon 1 CTLA4(49)A/G and intron 1 CTLA4(1822)C/T in our GD cohort from the UK. PATIENTS AND METHODS: We studied 301 white patients with GD and 349 healthy ethnically matched local controls. Amongst GD probands, 129 had significant thyroid-associated orbitopathy (TAO; NOSPECS class III or worse). The CTLA4(-318)C/T, CTLA4(49)A/G and CTLA4(1822)C/T polymorphisms were genotyped by using the restriction enzymes MseI, Bst71I and HaeIII, respectively. RESULTS: We found no association between GD and alleles of CTLA4(-318)C/T. GD was found to be associated with the G allele of CTLA4(49)A/G[P = 5.9 x 10(-6), odds ratio (OR) 1.65] and the T allele of CTLA4(1822)C/T (P = 7.7 x 10(-6), OR 1.64). The frequencies of these alleles were significantly higher in GD probands with significant TAO than in those without TAO (G allele: P = 0.001, OR 1.68; T allele: P = 0.001, OR 1.70). CONCLUSIONS: The promoter CTLA4(-318)C/T polymorphism is not in linkage disequilibrium with the pathogenic polymorphism(s) at the CTLA4 locus. The alleles of both the exon 1 CTLA4(49)A/G and the intron 1 CTLA4(1822)C/T polymorphisms are associated with GD, which is stronger in patients with TAO.     

Vaccinations in patients with inflammatory bowel disease

Treatment of inflammatory bowel disease (IBD) frequently requires administration of immunosuppressive therapies, which increases susceptibility to a number of infectious pathogens. However, many infections can be prevented by correct and appropriate utilization of vaccinations. While several guidelines have been published on vaccination schedules in patients with IBD, vaccination rates remain suboptimal and even lower than those in the general population. This is due to many factors including poor awareness of the importance of vaccines by gastroenterologists and general practitioners as well as potential prejudices of patients regarding the safety and benefits of vaccines. With the aim of increasing awareness about the key role of immunization in the management of patients with IBD, the present review examines the existing literature relating to the main vaccinations and their application in these patients. We also summarize current evidence in order to provide clinicians with an easy source of reference for the principal recommendations for prevention of infectious diseases in patients with IBD. In addition, the recommendations about traveling for IBD patients are briefly explored. Lastly, since it is important for gastroenterologists to be aware of recommendations on vaccination, we recommend implementing educational programs to ensure compliance with current guidelines.     

Hyperhomocysteinemia and prevalence of polymorphisms of homocysteine metabolism-related enzymes in patients with inflammatory bowel disease

OBJECTIVES: Patients with inflammatory bowel disease (IBD) have an increased risk of thrombotic complications. Moreover, a hypercoagulable state has been hypothesized as a contributing factor in the pathogenesis of IBD. Recently, a growing amount of interest has focused on mild-to-moderate hyperhomocysteinemia as a risk factor for thromboembolic disease. We aimed to evaluate the prevalence of hyperhomocysteinemia in patients with IBD and to investigate the contribution of genetic defects in the enzymes involved in homocysteine (Hcy) metabolism and vitamin status in determining increased levels of plasma total Hcy (tHcy). METHODS: The concentrations of tHcy, folate, and vitamin B12 as well as the prevalence of methylenetetrahydrofolate reductase (MTHFR) 677C to T mutation and the 68-bp insertion at exon 8 of cystathionine beta-synthase (CBS) were measured in patients with IBD and healthy controls. RESULTS: In all, 17 out of 64 IBD patients (26.5%) and four out of 121 (3.3%) controls had hyperhomocysteinemia with a statistically significant difference (p < 0.0001). No significant difference was found between IBD patients and controls with regard to the prevalence of homozygotes for the C677T variant (TT) of MTHFR or the prevalence of heterozygotes for the CBS-gene mutation (IN). Among the IBD patients the only independent factor significantly associated with hyperhomocysteinemia was folate deficiency (p = 0.0002), regardless of the MTHFR or the CBS genotype. CONCLUSIONS: IBD patients have a higher prevalence of hyperhomocysteinemia than do healthy controls. Folate deficiency is the only independent risk factor in developing hyperhomocysteinemia.