Inflammatory bowel disease: the role of inflammatory cytokine gene polymorphisms

One year of experience with combined pharmacokinetic/pharmacogenetic monitoring of anti-TNF alpha agents: a retrospective study

Anti-tumor necrosis factor alpha (anti-TNFα) inhibitors are used extensively for the management of moderate to severe inflammatory bowel disease (IBD) in both adult and pediatric patients. Unfortunately, not all patients show an optimal response to induction therapy, while others lose their response over time for reasons yet poorly understood. We report on a pharmacokinetic/pharmacogenetic approach to monitor the therapy with anti-TNFα in a real-world cohort of seventy-nine pediatric patients affected by IBD that was analyzed retrospectively. We evaluated plasma concentrations of infliximab, adalimumab, and related anti-drug antibodies (ADAs), and single nucleotide polymorphisms (SNPs) in genes involved in immune processes and inflammation on the anti-TNFα response. We found a significant association between the SNP in TNFα promoter (-308G>A) and clinical remission without steroids in patients on infliximab therapy. Additionally, a potential connection between HLA-DQA1*05 genetic variant carriers and a higher risk of anti-TNFα immunogenicity emerged.

Adipose tissue-derived mesenchymal stem cells' acellular product extracellular vesicles as a potential therapy for Crohn's disease

The breakdown of gastrointestinal tract immune homeostasis leads to Crohn's disease (CD). Mesenchymal stem cells (MSCs) have demonstrated clinical efficacy in treating CD in clinical trials, but there is little known about the mechanism of healing. Considering the critical roles of macrophage polarization in CD and immunomodulatory properties of MSCs, we sought to decipher the interaction between adipose‐derived MSCs and macrophages, including their cytokine production, regulation of differentiation, and pro‐/anti‐inflammatory function. RNA extraction and next generation sequencing was performed in adipose tissue from healthy control patients' mesentery (n = 3) and CD mesentery (n = 3). Infiltrated macrophage activation in the CD mesentery was tested, MSCs and extracellular vesicles (EVs) were isolated to compare the regulation of macrophage differentiation, cytokines production, and self‐renewal capacities in vitro. CD patients' mesentery has increased M1 macrophage polarization and elevated activation. MSCs and their derived EVs, isolated from inflamed Crohn's mesentery, leads to a rapid differentiation of monocytes to a M1‐like polarized phenotype. Conversely, MSCs and their derived EVs from healthy, non‐Crohn's patients results in monocyte polarization into a M2 phenotype; this is seen regardless of the adipose source of MSCs (subcutaneous fat, omentum, normal mesentery). EVs derived from MSCs have the ability to regulate macrophage differentiation. Healthy MSCs and their associated EVs have the ability to drive monocytes to a M2 subset, effectively reversing an inflammatory phenotype. This mechanism supports why MSCs may be an effective therapeutic in CD and highlights EVs as a novel therapeutic for further exploration.

Data Mining, Network Pharmacology, and Molecular Docking Explore the Effects of Core Traditional Chinese Medicine Prescriptions in Patients with Rectal Cancer and Qi and Blood Deficiency Syndrome

Background

“Zheng” (syndrome) is the basic unit and the basis of traditional Chinese medicine (TCM) treatment. In clinical practice, we have been able to improve the survival time and quality of life for patients with rectal cancer through the treatment of “FuZhengXiaoJi” (strengthening the Qi and reducing accumulation).

Purpose

In this study, we elucidated the core prescriptions for patients with rectal cancer and Qi and blood deficiency syndrome, and we explored the potential mechanisms of the prescriptions using an integrated strategy that coupled data mining with network pharmacology.

Methods

A Bron–Kerbosch (BK) algorithm was applied to find the core prescriptions. The active ingredients, targets, activated signaling pathways, and biological functions of core prescriptions were analyzed using network pharmacology and directly associated proteins were docked using molecular docking technology to elucidate the multicomponent, multitarget, and inter-related components associated with TCM systematically.

Results

Data mining identified 3 core prescriptions, and most of the herbs consisted of “FuZhengXiaoJi” Fang. Network pharmacology identified 15 high-degree active ingredients among the 3 core prescriptions and 16 high-degree hub genes linked with both rectal cancer and the 3 core prescriptions. Additional Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses of these 16 targets showed that the most significant pathways were MAPK, interleukin-17, tumor necrosis factor (TNF), and vascular endothelial growth factor (VEGF) pathways. From the 16 genes, TGFB1, IL1B, IL10, IL6, PTGS2, and PPARG closely interacted with the tumor microenvironment, and PPARG, MYC, and ERBB2 were closely linked to survival. In molecular docking, quercetin, kaempferol, and lauric acid showed good binding energy to each target.

Conclusion

Data mining, network pharmacology, and molecular docking may help identify core prescriptions, high-degree ingredients, and high-degree hub genes to apply to diseases and treatments. Furthermore, these studies may help discover hub genes that affect the tumor microenvironment and survival. The combination of these tools may help elucidate the relationship between herbs acting on “Zheng” (syndrome) and diseases, thus expanding the understanding of TCM mechanisms.

Pharmacogenetic variants of infliximab response in young patients with inflammatory bowel disease

Infliximab is commonly used in inflammatory bowel disease (IBD), however, differences in clinical response among patients are common. Several studies have considered the possibility that these differences are caused by genetic variability even if no unique marker has been yet identified in pediatric patients. We evaluated the impact of two candidate single-nucleotide polymorphisms (SNPs) rs396991 in FCGR3A and rs1800629 in TNFα genes on infliximab response in an Italian cohort of 76 pediatric patients with IBD. Results showed that patients with the variant FCGR3A allele had a reduced clinical response at the end of induction (p value = 0.004), at 22 weeks (p value = 0.001), and at 52 weeks of treatment (p value = 0.01). A significant association between the FCGR3A variant and median infliximab levels measured during maintenance therapy was also observed: patients with wild type genotype had higher infliximab levels compared to patient with variant allele. Furthermore, patients with the variant allele had a higher probability to produce antidrug antibodies (ADAs). No association was found among the TNFα SNP, clinical response, and infliximab levels. This study addressed for the first time in pediatric patients with IBD, the association of FCGR3A SNP, infliximab response, and ADA production.

An immune therapy model for effective treatment on inflammatory bowel disease

Inflammatory bowel disease (IBD) is a disease that causes inflammation throughout the digestive tract. Repeated inflammation and frequent relapses cause intestinal damage and expose the patient to a higher risk. In this work, we proposed an immune therapy model for effective treatment strategy through mathematical modeling for patients with IBD. We evaluated the ability of the patient's immune system to recover during treatment. For this, we defined the interval of healthy individual, and examined the frequency of compartments such as T cells and cytokines considered in the model maintain the normal state. Based on the fact that each patient has a unique immune system, we have shown at the same drug works differently, depending on the individual immune system characteristics for every patient. It is known that IBD is related to an imbalance between pro- and anti- inflammatory cytokines as the cause of the disease. So the ratios of pro- to anti- inflammatory cytokines are used as an indicator of patient's condition and inflammation status in various diseases. We compared the ratios of pro- to anti- inflammatory cytokine according to patient's individual immune system and drugs. Since the effects of biological drugs are highly dependent on the patient's own immune system, it is essential to define the immune system status before selecting and using a biological drug.

INTERACTIONS AMONG INTERLEUKIN-6, C-REACTIVE PROTEIN AND INTERLEUKIN-6 (-174) G/C POLYMORPHISM IN THE PATHOGENESIS OF CROHN'S DISEASE AND ULCERATIVE COLITIS

Inflammatory bowel diseases are multifactorial disorders the clinical manifestation of which depends on the interaction among immune response, genetic and environmental factors. There is growing evidence that cytokines and gene polymorphisms have an important role in disease pathogenesis in various populations although molecular mechanism of their signaling and interactions is not fully understood yet. The present study aimed at exploring the effects of interleukin-6, C-reactive protein and interleukin-6 rs1800795 polymorphism on the development of Crohn’s disease, ulcerative colitis and inflammatory bowel diseases overall and at determining differences between inflammatory bowel disease patients and healthy controls. A total of 132 inflammatory bowel disease patients and 71 healthy blood donors were investigated. In order to assess the clinical relevance of interleukin-6 and C-reactive protein serum concentration and interleukin-6 rs1800795 single nucleotide polymorphism in patients with Crohn’s disease and ulcerative colitis, we performed a cross-sectional, case-control study. Quantitative assessment of serum interleukin-6 and C-reactive protein was performed with solid-phase, enzyme-labeled, chemiluminescent sequential immunometric and immunoturbidimetric assay, respectively. A real-time fluorescence resonance energy transfer-based method on a LightCyclerTM PCR 1.2 was used for genotyping of IL-6 rs1800795 polymorphism. Both interleukin-6 and C-reactive protein serum levels were elevated in Crohn’s disease and ulcerative colitis patients. Positive correlations were observed between C-reactive protein and interleukin-6 serum concentration and ulcerative colitis activity index as measured by modified Truelove-Witt’s severity index scale. C-reactive protein serum level was higher in Crohn’s disease patients without intestinal resection than in Crohn’s disease patients with prior intestinal resection. In ulcerative colitis patients, interleukin-6 and C-reactive protein serum levels were statistically significantly higher in CC interleukin-6 genotype in comparison to GG+GC genotype. Analysis of the promoter region of the interleukin-6 rs1800795 gene polymorphism showed no statistically significant difference in allele frequency either between inflammatory bowel disease patients and healthy controls or between the two inflammatory bowel disease phenotypes and healthy controls. Associations presented in this study give a potentially important insight into the role of interleukin-6 and C-reactive protein signaling and interleukin-6 polymorphism in the pathogenesis of Crohn’s disease and ulcerative colitis disease.

Dynamics of Colon Monocyte and Macrophage Activation During Colitis

Background: Macrophages are pivotal in coordinating a range of important processes in the intestines, including controlling intracellular infections and limiting damaging inflammation against the microbiota. However, it is not clear how gut macrophages, relative to recruited blood monocytes and other myeloid cells, contribute to the intestinal inflammatory milieu, nor how macrophages and their monocyte precursors mediate recruitment of other immune cells to the inflamed intestine. Methods: Myeloid cell populations isolated from colonic inflammatory bowel disease (IBD) or murine dextran sulphate sodium (DSS) induced colitis were assessed using flow cytometry and compared to healthy controls. In addition, mRNA expression profiles in human and murine colon samples, and in macrophages and monocytes from healthy and inflamed murine colons, were analysed by quantitative PCR (qPCR) and mRNA microarray. Results: We show that the monocyte:macrophage balance is disrupted in colon inflammation to favour recruitment of CD14+HLA-DRInt cells in humans, and Ly6CHi monocytes in mice. In addition, we identify that murine blood monocytes receive systemic signals enabling increased release of IL-1β prior to egress from the blood into the colon. Further, once within the colon and relative to other myeloid cells, monocytes represent the dominant local source of both IL-1β and TNF. Finally, our data reveal that, independent of inflammation, murine colon macrophages act as a major source of Ccl7 and Ccl8 chemokines that trigger further recruitment of their pro-inflammatory monocyte precursors. Conclusions: Our work suggests that strategies targeting macrophage-mediated monocyte recruitment may represent a promising approach for limiting the chronic inflammation that characterises IBD.

Interleukin-4 and Interleukin-10 Gene Polymorphisms in Patients with Inflammatory Bowel Disease

BACKGROUND

Changes in cytokine expression have been frequently found in patients with inflammatory bowel disease (IBD). Cytokine values outside the normal range may be somewhat related to common polymorphisms within cytokine genes.

OBJECTIVE

The present study was designed to investigate the possible association between polymorphisms within Interleukin IL-4 and IL-10 genes and susceptibility to and clinical features of IBD.

METHODS

The study population was composed of 140 healthy controls and 75 patients with IBD (40 patients with Crohn's disease (CD) and 35 patients with ulcerative colitis (UC)). Genotyping was performed using polymerase chain reaction with sequence-specific primers.

RESULTS

Higher frequencies for the C allele of IL-4-590 polymorphism (P < 0.0001; odds ratio [OR], 5.68; 95% confidence interval [95% CI], 3.28-9.83) and for the T allele of IL-4-1098 polymorphism (P = 0.016; OR, 1.83; 95% CI, 1.11-3.02) were observed in the whole group of IBD patients. The IL-4-590 C allele was also significantly overrepresented when IBD patients were subdivided into CD and UC (P < 0.0001; OR, 5.2-6.28). While the IL-4-1098 T allele was present at higher frequencies in patients with UC (P = 0.05; OR, 1.95), but not in CD (P = 0.09). Multiple pairwise comparisons indicated that genotypes of all polymorphisms investigated within IL-4 gene are correlated with IBD, CD, and UC. Haplotype analysis showed that the IL-4-1098/-590 TC haplotype might predispose individuals to IBD, CD, and UC whereas the IL-4-1098/-590 TT and GC haplotypes have a protective effect. On the contrary, neither allele nor genotype frequencies of IL-10 polymorphisms (IL-10-1082 A > G, IL-10-592 A > C, and IL-10-819 T > C) were associated with IBD, CD, or UC.

CONCLUSIONS

The present study suggests that IL-4 polymorphisms might play a role in susceptibility to IBD and its major subtypes in the Iranian population.

Resveratrol and inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract, comprising ulcerative colitis (UC) and Crohn's disease (CD). Progression of IBD leads to long-term impairment of intestinal structure and function. The pathogenesis of IBD is complex, involving environmental, immunological, genetic, microbial, and psychological factors. The conventional therapies and many existing biopharmaceuticals for IBD have limited efficacy or adverse effects. As a promising safe and effective therapy for IBD, resveratrol has been studied widely, as it has shown anti-inflammatory and antioxidant activity. Resveratrol's mechanism of action involves multiple immune responses and signaling pathways; it is absorbed quickly and metabolized into various derivatives. However, the poor water solubility and low bioavailability of resveratrol limit its clinical applications. Further research should attempt to improve the stability and oral bioavailability of resveratrol by modification and various delivery systems.

The Polymorphism rs3024505 (C/T) Downstream of the IL10 Gene Is Associated with Crohn's Disease in Serbian Patients with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), manifesting as Crohn's disease (CD) and ulcerative colitis (UC), is characterized by recurring episodes of inflammation in gastrointestinal tract, in which aberrant production of regulatory cytokine interleukin-10 (IL-10) presumably plays important role. Single nucleotide polymorphisms (SNPs) that affect IL-10 production, such as rs1800896 (G/A) at position -1082 and rs1800871 (C/T) at position -819 in the promoter region of the IL10 gene, have been associated with CD and/or UC, but the results were inconsistent. Another SNP that may alter IL-10 production, rs3024505 (C/T) located immediately downstream of the IL10 gene has been recently identified. T allele of rs3024505 was associated with both UC and CD in Western populations, but the studies from East European countries are lacking. Therefore, our aim was to assess the association of rs3024505, rs1800896 and rs1800871 with Serbian IBD patients. To this end, 107 CD and 99 UC patients and 255 healthy controls were genotyped. As a result, T allele of rs3024505 was associated with CD at allelic, genotypic (GT genotype) and haplotypic (GCCT haplotype) level, suggesting potential role of this variant in susceptibility to CD. In contrast, CD patients carrying C allele of rs3024505 had significantly increased risk of anemia and stricturing/penetrating behavior. No association was observed between rs3024505 and UC or SNPs in IL10 promoter region and any form of IBD. In conclusion, rs3024505 SNP flanking the IL10 gene is associated with susceptibility and severity of disease in Serbian CD patients, further validating its role as a potential biomarker in IBD.

Association of tumor necrosis factor-α and -β gene polymorphisms in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a complex, multifactorial, chronic inflammatory disorder of the gastrointestinal tract in which immune dysregulation caused by genetic and/or environmental factors plays an important role. The aim of this case–control study was to evaluate the association of tumor necrosis factor-alpha (TNF-α) (308) and -β (+252) polymorphisms with susceptibility of IBD. A total of 379 Saudi subjects including 179 IBD patients (ulcerative colitis (UC) =84 and Crohn’s disease (CD) =95) and 200 age- and sex-matched healthy controls were recruited. TNF-α and TNF-β genes were amplified using an amplification refractory mutation systems polymerase chain reaction methodology to detect TNF-α (−308) and -β (+252) polymorphisms. The frequency of the GA genotype of TNF-α (−308G/A) was higher, and the frequencies of the GG and AA genotypes were significantly lower in IBD patients compared with those in controls, indicating that genotype GA-positive individuals are susceptible to IBD and that the GG and AA genotypes exert a protective effect. The frequency of allele A of TNF-α (−308G/A) was significantly higher and that of allele G was lower in IBD patients compared with those in controls, indicating an association of allele A with IBD risk in Saudi patients. On stratification of IBD patients into UC and CD, an almost similar pattern was noticed in both the groups. The results of TNF-β (+252A/G) polymorphisms showed a significant increase in the frequency of the GG genotype in IBD patients, suggesting a positive association of GG genotype with IBD risk. On stratification of IBD patients into UC and CD, the genotype GG of TNF-β was associated with susceptibility risk to UC but not CD. The frequencies of alleles and genotypes of both TNF-α and-β polymorphisms are not affected by sex or type of IBD (familial or sporadic). TNF-α (−308G/A) and TNF-β (+252A/G) polymorphisms are associated with risk of developing IBD in Saudi population.

Variations in inflammatory genes as molecular markers for prediction of inflammatory bowel disease occurrence

OBJECTIVE

Research on inflammatory bowel disease (IBD) has highlighted genes involved in the regulation of inflammatory responses as contributors to disease pathogenesis. This study aimed to evaluate the associations between IBD and variations in NOD2, TLR4, TNF-α, IL-6, IL-1β and IL-1RN genes, and to use the genetic data obtained in predictive modeling.

METHODS

A total of 167 IBD patients and 101 healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism. Using the genotype data attained as the input to various classification algorithms, IBD prediction models were designed. The area under the receiver operating characteristic curve (AUROC) was used to measure their performance.

RESULTS

Significant associations were found between Crohn's disease (CD) and minor NOD2 variants, as well as TLR4 299Gly, TNF-α G-308A, IL-6 G-174C and IL-1RN VNTR A2 variants, while ulcerative colitis (UC) was associated only with IL-1RN VNTR A2 variants. CD and UC showed highly significant difference in the allelic distribution of TNF-α G-308A, where the A allele was found to be related to CD, and the G allele to UC. A combined effect of patients' gender and TLR4 variants was observed among CD patients. When all analyzed genotype and gender data were used, prediction performance achieved a maximum AUROC of 0.690 for CD and 0.601 for UC dataset.

CONCLUSION

Variations in the genes involved in immune regulation are genetic factors of importance in IBD susceptibility that could potentially be used as predictors of disease development.

The effect of turmeric (Curcuma longa) extract on the functionality of the solute carrier protein 22 A4 (SLC22A4) and interleukin-10 (IL-10) variants associated with inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic relapsing disease. Genetic predisposition to the disease reduces an individual's capacity to respond appropriately to environmental challenges in the intestine leading to inappropriate inflammation. IBD patients often modify their diet to mitigate or reduce the severity of inflammation. Turmeric (Curcuma longa L., Zingiberaceae) has historically been used in Chinese, Hindu, and Ayurvedic medicine over several centuries to treat inflammatory disorders. To understand how turmeric may influence the consequences of a genetic predisposition to inappropriate inflammation, we used HEK293 cells to examine the in vitro capacity of turmeric extract and fractions to affect the functionality of two gene variants, solute carrier protein 22 A4 (SLC22A4, rs1050152) and interleukin-10 (IL-10, rs1800896) associated with IBD. We found that a turmeric extract and several chromatographically separated fractions beneficially affected the variants of SLC22A4 and IL-10 associated with IBD, by reducing inappropriate epithelial cell transport (SLC22A4, 503F) and increasing anti-inflammatory cytokine gene promoter activity (IL-10, -1082A). The effect of turmeric on the IL-10 variant was strongly associated with the curcumin content of the extract and its fractions.

Genetic update on inflammatory factors in ulcerative colitis: Review of the current literature

Ulcerative colitis (UC) is one of the main types of inflammatory bowel disease, which is caused by dysregulated immune responses in genetically predisposed individuals. Several genetic factors, including interleukin and interleukin receptor gene polymorphisms and other inflammation-related genes play central role in mediating and modulating the inflammation in the human body, thereby these can be the main cause of development of the disease. It is clear these data are very important for understanding the base of the disease, especially in terms of clinical utility and validity, but summarized literature is exiguous for challenge health specialist that can used in the clinical practice nowadays. This review summarizes the current literature on inflammation-related genetic polymorphisms which are associated with UC. We performed an electronic search of Pubmed Database among publications of the last 10 years, using the following medical subject heading terms: UC, ulcerative colitis, inflammation, genes, polymorphisms, and susceptibility.

Association between polymorphisms in the promoter region of interleukin-10 and susceptibility to inflammatory bowel disease

The aim of this study was to assess the association of polymorphisms in the promoter region of the IL-10 gene with the risk of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Fifteen studies (3,693 cases and 4,574 controls) were included in a meta-analysis of association between IL-10 -1082G/A, -819C/T and -592C/A polymorphisms, and IBD, CD and UC using allele contrast and the recessive, dominant, and additive models. Hardy-Weinberg equilibrium was confirmed for each study. Heterogeneity and study quality were investigated using stratification analyses and sensitivity analyses. Polymorphism -1082G/A showed significant association with CD, with odds ratios (ORs) for the GG + GA genotype and GG versus AA genotype of 1.278 (1.004-1.627) and 1.238 (1.027-1.492) in all subjects. Significant associations were found in the Caucasian subgroup using the allele contrast, dominant, and additive models. C-allele carriers of the -819C/T polymorphism were at increased risk of IBD (OR 1.093, 95% CI 1.004-1.190). Association with the -819C/T polymorphism was also found in Caucasians with CD (C vs. T: OR 1.104, 95% CI 1.010-1.206; CC + CT vs. TT: OR 1.328, 95% CI 1.006-1.754; CC vs. TT: OR 1.339, 95% CI 1.008-1.778), and with UC (CC vs. CT + TT: OR 1.188, 95% CI 1.019-1.385). No significant association was found between the -592C/A polymorphism and IBD, CD or UC. In conclusion, the meta-analysis demonstrated clear association between the IL-10 polymorphisms -1082G/A and -819C/T and the risk of IBD.

Role of genes, the environment and their interactions in the etiology of inflammatory bowel diseases

Few of the studied genes demonstrate association with inflammatory bowel disease (IBD). Three mutations in the nucleotide-binding oligomerization domain 2 gene have consistently shown to be independent risk factors for Crohn's disease, but none of the alleles exhibited high sensitivity or specificity for IBD. Linkage analysis implicated several loci on various chromosomes, and epistasis has been demonstrated. The etiopathogenesis of IBD remains unknown, and environmental contribution to their pathogenesis is evident from genetic studies that demonstrated incomplete monozygotic twins concordandance rate for both Crohn's and ulcerative colitis. Smoking has shown an opposite effect on disease phenotype, with an adverse effect on disease course for Crohn's disease, but a slight beneficial effect in ulcerative colitis. The contribution of infectious agents to susceptibility to IBD appears to be strong. However, the role of nutrition on the etiology and therapy of IBD is not clear. Inconsistencies in environmental risk factors could be due to gene-environment interactions, making it essential to study the role of genetics and environmental contribution to the etiopathology of IBD. Transgenic or knockout mice, such as interleukin-10(-/-), T-cell receptor alpha(-/-), Galphai(2) (-/-) and N-cadherin(-/-), develop colitis-like inflammation similar to humans. Therefore, animal models must be further studied to explore mechanistic interactions.

TNF-alpha gene polymorphisms in Iranian Azari Turkish patients with inflammatory bowel diseases

CONTEXT

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the bowel (IBD) whose causes are not fully known. Emerging data indicate that alterations in cytokine synthesis may play a role in IBD pathogenesis.

AIMS

We aimed to determine the association between tumor necrosis factor-alfa (TNFα) promoter polymorphisms (at positions - 308 and - 1031) and susceptibility to IBD among Iranian Azari Turkish patients.

SETTINGS AND DESIGN

One hundred and one patients with IBD and 100 healthy subjects were analyzed.

MATERIALS AND METHODS

Both polymorphisms in the promoter region of the TNFα gene at positions -1031T/C and -308G/A were detected by polymerase chain reaction-restriction fragment length polymorphism assay. All statistical analyses were calculated with SPSS for Windows 16.0. The Fisher's exact test was used to test for departure from Hardy-Weinberg equilibrium of the genotype frequencies (P > 0.05).

RESULTS

The allele frequency of the TNFα-308G and -1031T were higher in IBD patients but did not reach statistical significance. However, the homozygous TT genotype for the SNP-1031 T > C was significantly higher in UC patients than in healthy controls (P = 0.01) and the heterozygous CT genotype for the SNP -1031 T > C was significantly lower in UC patients than in healthy controls (P = 0.03).

CONCLUSIONS

The TNFα-1031 T allele confers a significant risk for developing UC in Iranian Azeri Turkish patients. Also the frequency of TNFα-1031 C allele was considerably low among patients with UC and it may have protective role among them (OR = 0.43; P = 0.01).

Interleukin-6 is associated with steroid resistance and reflects disease activity in severe pediatric ulcerative colitis

BACKGROUND AND AIM

Approximately one third of patients with acute severe ulcerative colitis (ASC) will fail intravenous corticosteroids (IVCS). Predicting response to IVCS to initiate early salvage therapy remains challenging. The aim of this study was to evaluate the role of serum inflammatory cytokines in ASC and determine their predictive utility with IVCS treatment failure.

METHODS

This preplanned ancillary study, part of the prospective multicenter OSCI study, evaluated pediatric ASC in North America. Serum samples were obtained from 79 children admitted for ASC on the third day of IVCS treatment. Twenty-three (29%) patients required second-line therapy. ELISA-based cytokine arrays were used [TNF-α, IFN-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, and IL-17], selected based on a systematic literature search.

RESULTS

In univariate analysis, only IL-6 was significantly different between responders and non-responders (P=0.003). The risk for IVCS failure increased by 40% per each pg/mL increase in IL-6 level. Factor analysis found IL-6 to be associated with IL-17, suggesting involvement of the T-helper (TH)17 pathway. In a multivariate analysis, disease activity [judged by the Pediatric UC Activity Index (PUCAI)] assumed all the association with the treatment outcome while IL-6 was no longer significant (P=0.32; PUCAI score P<0.001).

CONCLUSIONS

While IL-6 strongly predicted IVCS failure, it likely reflects disease activity and not direct interference with corticosteroid pathway. Nonetheless, IL-6 levels may have a role in predicting IVCS response in severe pediatric UC for treatment decision-making or potentially in medical intervention by virtue of anti-IL-6 antibodies in severe UC.

The association between three promoter polymorphisms of IL-10 and inflammatory bowel diseases (IBD): a meta-analysis

AIM

To assess the relationship of the Interleukin-10 (IL-10) -1082G/A (rs1800896), -819C/T (rs1800871) and -592C/A (rs1800872) polymorphism with inflammatory bowel disease (IBD) by means of meta-analysis.

METHODS

Published data addressing the association between polymorphism of the IL-10 with Crohn's disease (CD) and Ulcerative colitis (UC) were selected from electronic databases. A total of 17 studies including 4132 cases and 5109 controls were included in this meta-analysis which detected whether -1082G/A, -819C/T and -592C/A polymorphism were associated with CD or UC susceptibility.

RESULT

The IL-10 -819C/T and -519C/A variant allele observed a significant association with UC (OR 1.16, 95%CI 1.03-1.31 and OR 1.19, 95%CI 1.03-1.38) not CD while there is no significant association between -1082G/A and UC or CD.

CONCLUSION

The IL-10 -819C/T and -592C/A polymorphisms contribute to susceptibility to UC, but IL-10 -1082G/A polymorphism neither associated with CD nor UC.

Polymorphisms of the cytokine genes TGFB1 and IL10 in a mixed-race population with Crohn's disease

Background

Most Crohn’s disease (CD) genes discovered in recent years are associated with biological systems critical to the development of this disease. TGFB1 and IL10 are cytokines with important roles in CD. The aim of this study was to evaluate the association between CD, its clinical features and TGFB1 and IL10 gene polymorphisms.

Methods

This case–control study enrolled 91 patients and 91 controls from the state of Bahia, Brazil. Five single nucleotide polymorphisms (SNPs) were studied in the TGFB1 gene (codon 10 T > C - rs1800470; codon 25 G > C - rs1800471) and IL10 gene (−1082 A > G - rs1800896; -819 T > C - rs1800871; -592 A > C - rs1800872). An analysis of the genetic polymorphisms was performed using a commercial kit. A comparison of allele frequencies and genotypes was estimated by calculating the odds ratio (OR) with a confidence interval adjusted via the Bonferroni test for a local alpha of 1%. A stratified analysis was applied for gender, race and smoking history. Patients with CD were characterized according to the Montreal classification.

Results

The C allele and CC genotype of the TGFB1 gene rs1800470 were both significantly associated with CD. The stratified analysis showed no confounding factors for the co-variables of gender, race and smoking history. The IL10 gene rs1800896 G allele was significantly associated with age at diagnosis of CD, while the T allele of the IL10 gene rs1800871 was significantly associated with perianal disease. The SNPs rs1800871 and rs1800872 were in 100% linkage disequilibrium.

Conclusions

TGFB1 gene polymorphisms may be associated with susceptibility to the development of CD, and IL10 gene polymorphisms appear to influence the CD phenotype in this admixed population.

Cytokine mucosal expression in ulcerative colitis, the relationship between cytokine release and disease activity

BACKGROUND

Ulcerative colitis (UC) is an inflammatory bowel disease with conflicting evidence from studies on the roles of TNFα, IL-8, TGFβ and other cytokines and characterised by neutrophil infiltration and tissue destruction.

AIM

To compare cytokine profiles of inflamed and non-inflamed mucosa in patients with distal UC, and matched controls.

METHODS

Patients were prospectively recruited, mucosal biopsies at flexible sigmoidoscopy (FS) were taken from UC patients within macroscopically inflamed and non-inflamed proximal mucosa, and from age-sex matched controls undergoing FS. Endoscopic and histological inflammation was graded. Quantitative cytokine analysis for IL-4, TNFα, IL-17A, IL-8, IL-10, TGFβ and IFNγ was carried out on tissue homogenates. Statistical comparison was by Wilcoxon signed rank pair analysis, Mann-Whitney U test and Spearman's correlation.

RESULTS

69 active UC patients (54 paired non-inflamed/inflamed mucosa) and 69 controls were compared. In inflamed mucosa, elevation in IL-8 and reduction in TGFβ was measured compared with non-inflamed mucosa (p<0.001; p<0.02) and control mucosa (p<0.001; p<0.001); IL-8 was positively correlated (rs=0.481, p<0.01) and TGFβ inversely correlated (rs=0.462; p<0.01) with grade of inflammation. TNFα concentration was not significantly different. Comparisons of inflamed with non-inflamed mucosa also demonstrate significant reduction in concentration of IFNγ (p<0.001), IL-4 (p<0.005) and IL-17A (p<0.002).

CONCLUSION

Our findings suggest that IL-8 is elevated and TGFβ is reduced in distal colitis. Lower concentration of IFNγ, IL-4 and IL-17A were also noted. TNFα levels were unchanged. These findings suggest that the inflammatory response in UC may predominantly involve IL-8 mediated neutrophil infiltration and failure of TGFβ mediated tissue healing.

Interleukin-10-1082A/G polymorphism and inflammatory bowel disease susceptibility: a meta-analysis based on 17,585 subjects

A large number of studies have shown that the interleukin-10 (IL-10)-1082A/G polymorphism is implicated in susceptibility to inflammatory bowel disease (IBD). However, the results are inconsistent. We performed this meta-analysis to estimate the association between -1082A/G polymorphism in the IL-10 gene and IBD susceptibility. A total number of 18 case-control studies including 17,585 subjects were identified. No association was found between -1082A/G polymorphism and ulcerative colitis (UC) susceptibility. However, increased risk of Crohn's disease (CD) was associated with -1082A/G polymorphism in the dominant genetic model (GG+GA vs. AA: OR=1.22, 95% CI: 1.02-1.46, P=0.028) and the heterozygote comparison (GA vs. AA: OR=1.28, 95% CI: 1.05-1.55, P=0.015). The results of this meta-analysis provide evidence for the association between IL-10-1082A/G polymorphism and susceptibility of CD. Due to several limitations in the present study, well-designed epidemiological studies with large sample size among different ethnicities should be performed in the future.

Interleukin genes and associations with colon and rectal cancer risk and overall survival

Interleukins are a group of cytokines that contribute to growth and differentiation, cell migration, and inflammatory and anti-inflammatory responses by the immune system. In our study, we examined genetic variation in genes from various anti-inflammatory and proinflammatory interleukins to determine association with colon and rectal cancer risk and overall survival. Data from two population-based incident studies of colon cancer (1,555 cases and 1,956 controls) and rectal cancer (754 cases and 954 controls) were used. After controlling for multiple comparisons, single nucleotide polymorphisms (SNPs) from four genes, IL3, IL6R, IL8, IL15, were associated with increased colon cancer risk, and CXCR1 and CXCR2 were significantly associated with increased rectal cancer risk. Only SNPs from genes within the IL-8 pathway (IL8, CXCR1 and CXCR2) showed a significant association with both colon and rectal cancer risk. Several SNPs interacted significantly with IL8 and IFNG SNPs and with aspirin/non-steroidal anti-inflammatory drug (NSAID), cigarette smoking, estrogen use and BMI. For both colon and rectal cancer, increasing numbers of risk alleles were associated with increased hazard of death from cancer; the estimated hazard of death for colon cancer for the highest category of risk alleles was 1.74 (95% confidence interval [CI] 1.18-2.56) and 1.96 (95% CI 1.28-2.99) for rectal cancer. These data suggest that interleukin genes play a role in risk and overall survival for colon and rectal cancer.

A hospital-based study of clinical and genetic features of Crohn's disease

BACKGROUND/PURPOSE

The aim of this study was to gain a better understanding of the current incidence of Crohn's disease (CD) in Taiwan and examine its clinical/genetic characteristics because there has been a trend toward increased diagnosis in the Asia-Pacific area. The genetic background seen in CD cases in Taiwan seems to be different from that in Western countries.

METHODS

By reviewing the database in the National Taiwan University Hospital, CD patients were identified by clinical, endoscopic, and imaging findings. The clinical characteristics were recorded and analyzed. DNA was extracted from the peripheral blood of patients after obtaining informed consent. Polymerase chain reaction was performed with specific primers followed by direct sequencing to determine the single-nucleotide polymorphisms ATG16L1, CCR6, IL12B, IL23R, LRRK2, TNFSF2, and TNFSF15 CD-associated genes.

RESULTS

Clinical data from 110 CD patients were examined from 1988 to 2008, with a mean follow-up period of 4.5 years. There was a marked increase in new CD diagnosis, especially after 2004. Among the 110 patients, 71 men and 39 women, the age at diagnosis was 30.5±17.8 years (mean±standard deviation). Stenosis occurred in 33.6% (37 of 110) and 40.9% (45 of 110) of patients who underwent surgery. The mortality rate was 2.7%, all because of sepsis. Genetic analysis of 39 patients showed that ATG16L1 and TNFSF15 were associated with susceptibility to CD in Taiwan.

CONCLUSION

Recently, the incidence of CD diagnosis in Taiwan has markedly increased. ATG16L1 and TNFSF15 are associated with CD in Taiwan.

Cytokine gene polymorphism in microscopic colitis association with the IL-6-174 GG genotype

OBJECTIVES

Microscopic colitis (MC) is a chronic inflammatory disease with unknown pathogenesis. Very little is known about polymorphisms in the cytokine genes in MC. We have investigated the occurrence of well-characterized polymorphisms of interleukins (IL-6, IL-1β, IL-1 receptor antagonist, IL-10) and CD14 in MC. We also determined the serum IL-6 levels.

METHODS

We genotyped 81 patients with MC and 178 controls for polymorphisms of IL-6-174, IL-1β-511, IL-1β-3953, IL-1 receptor antagonist, IL-10-1082 and CD14-159. Serum concentration of IL-6 was measured in 72 patients.

RESULTS

Genotype GG of IL-6-174 was more prevalent in MC compared with the controls (P=0.030; odds ratio: 1.941; confidence interval: 1.078-3.495), and the frequency of allele G of IL-6-174 was higher in MC (0.55 vs. 0.47; P=0.036; odds ratio: 1.514; confidence interval: 1.041-2.203). However, after correction for multiple comparisons, the difference became nonsignificant. IL-6 genotype and the serum IL-6 concentration showed no association. The concentration of IL-6 was higher in patients with collagenous colitis than in those with lymphocytic colitis (median 1.73 vs. 1.34 pg/ml, P=0.011). No association between polymorphisms of other cytokine genes and MC was seen.

CONCLUSION

The IL-6-174 gene polymorphism has a possible association with MC, as the IL-6 GG genotype was more frequent in patients with the disease. As this genotype may be linked with an enhanced IL-6 production, we speculate that this polymorphism can influence the pathogenesis of MC by evoking a proinflammatory bias in the mucosal cytokines. The enhanced concentration of IL-6 in collagenous colitis compared with lymphocytic colitis supports a difference in the pathogenetic mechanisms between the two subgroups of MC.

The effect of IL-10 genetic variation and interleukin 10 serum levels on Crohn's disease susceptibility in a New Zealand population

Interleukin (IL)-10 has important effects in immunoregulation and inflammation, and previous studies have provided evidence for the involvement of IL-10 in the pathogenesis of Crohn's disease (CD). In this study, we investigated whether genetic variants of the IL-10 gene were associated with CD in a New Zealand population. Three single nucleotide polymorphisms (SNPs) in the promoter region of IL-10 (rs1800871, rs1800872, and rs1800896) and a flanking SNP, rs3024505, were genotyped in a well-characterized New Zealand dataset consisting of 342 CD cases and 610 controls. Furthermore, we measured serum IL-10 levels in a number of the CD patients and controls and examined whether a relationship existed between these polymorphisms and serum IL-10 levels. We demonstrated an association with CD for SNPs rs3024505 and rs1800896, and phenotypic analysis indicated an association of rs3024505 with an early age at first diagnosis, stricturing CD behavior, and requirement for bowel resection. We also observed that IL-10 concentration was significantly higher in CD patients than in the controls and that the T allele of rs1800896, the A allele of rs1800871, and the T allele of rs1800872 were associated with increased serum IL-10 levels.

Relationship between the polymorphism of tumor necrosis factor-α-308 G>A and susceptibility to inflammatory bowel diseases and colorectal cancer: a meta-analysis

Inflammatory bowel disease (IBD) and colorectal cancer (CRC) are common health problems worldwide. Tumor necrosis factor (TNF) is a type of cytokine that induces inflammation and inhibits tumorigenesis. Several studies have assessed the relationship between the polymorphism of TNF-α-308 G>A and the susceptibility to IBD and CRC; however, the results have been controversial. In addition, the hypothesis whether the increased risk of CRC in IBD patients could be partly ascribed to the polymorphism of TNF-α-308 G>A was unclear. Therefore, we conducted this meta-analysis to confirm these associations. Pooled odd ratios (ORs) and 95% confidence intervals (95% CIs) were calculated on the basis of data from 14, 18, and 7 studies from a total of 27 studies for the associations between the polymorphism of TNF-α-308 G>A and ulcerative colitis, Crohn's disease (CD) and CRC. In Europeans, the AA genotype increased the risk of ulcerative colitis (UC) (OR, 2.041; 95% CI, 1.261-3.301) and CD (OR, 1.730; 95% CI, 1.168-2.564) significantly, without obvious heterogeneity and publication bias. Meanwhile, the GA genotype increased the risk of UC in Asians (OR, 2.360; 95% CI, 1.269-4.390) significantly. However, no significant association was observed for CRC in any ethnic population. The results of this meta-analysis suggested that the polymorphism of TNF-α-308 G>A participates in modifying the susceptibility to UC and CD in Europeans and Asians. The increased risk of CRC in IBD patients should be clarified as the combined effects of polymorphisms in TNF-α and other cytokines, and the interaction with environmental factors, in future studies.

Meta-analysis: polymorphisms in TNF-alpha gene promoter and Crohn's disease

BACKGROUND

Tumour necrosis factor alpha (TNF-alpha) is involved in the pathogenesis of Crohn's disease (CD). However, results on the association between the polymorphisms in TNF-alpha promoter and the risk of CD are inconsistent.

AIM

To perform a quantitative synthesis for the genetic polymorphisms in TNF-alpha promoter and CD risk.

METHODS

Databases were searched (up to 2009) and 31 studies were included. Risks of CD associated with the polymorphisms in TNF-alpha promoter were assessed.

RESULTS

Overall, individuals with -1031 TC+CC genotype had a slightly increased risk to develop CD compared with individuals with -1031 TT genotype (OR, 1.32; 95% CI, 1.03-1.70). In the further stratified analysis, we found Asians with the -1031T>C, -863 C>A and -857 C>T variant polymorphisms have almost one and a half CD risk compared with other genotypes (OR, 1.58; 95% CI, 1.16-2.15; OR, 1.55; 95% CI, 1.18-2.02; OR, 1.54; 95% CI, 1.19-1.99 respectively). We did not find -308 G>A variant associated with CD location and disease behaviours in stratified analysis.

CONCLUSIONS

TNF-alpha polymorphisms in the promoter region might be used as a biomarker for CD risk prediction. Larger studies with mixed ethnicity subjects and stratified by clinical and sub clinical characteristics are needed to validate our findings.

Genetic risk factors for inflammatory bowel disease in a North-eastern Mexican population

The purpose of this study was to assess the role of Helicobacter pylori and several genetic polymorphisms in relation to inflammatory bowel disease (IBD). We studied 44 unrelated patients with IBD and 75 subjects with no history of IBD as controls. Using pyrosequencing technology, we identified gene polymorphisms in IL-10, TNF-A, ILB-31, and TLR4. H. pylori status was determined by serology. Individuals homozygous for IL10-592 A or IL10-1082 A genotypes show significantly lower occurrence of IBD (P=0.03 and P<0.01, respectively). Individuals heterozygous at IL10-1082 have significantly increased occurrence of IBD, both ulcerative colitis and Crohn's disease (P<0.01). There was no difference in the prevalence of H. pylori infection between cases and controls. This study provides evidence that variation in IL10 is correlated with IBD occurrence in this Mexican population.

The polymorphism rs3024505 proximal to IL-10 is associated with risk of ulcerative colitis and Crohns disease in a Danish case-control study

Background

Crohns disease (CD) and ulcerative colitis (UC) are characterized by a dysregulated inflammatory response to normal constituents of the intestinal flora in the genetically predisposed host. Heme oxygenase-1 (HO-1/HMOX1) is a powerful anti-inflammatory and anti-oxidant enzyme, whereas the pro-inflammatory interleukin 1β (IL-1β/IL1B) and anti-inflammatory interleukin 10 (IL-10/IL10) are key modulators for the initiation and maintenance of inflammation. We investigated whether single nucleotide polymorphisms (SNPs) in the IL-1β, IL-10, and HO-1 genes, together with smoking, were associated with risk of CD and UC.

Methods

Allele frequencies of the IL-1β T-31C (rs1143627), and IL-10 rs3024505, G-1082A (rs1800896), C-819T (rs1800871), and C-592A (rs1800872) and HO-1 A-413T (rs2071746) SNPs were assessed using a case-control design in a Danish cohort of 336 CD and 498 UC patients and 779 healthy controls. Odds ratio (OR) and 95% confidence interval (95% CI) were estimated by logistic regression models.

Results

Carriers of rs3024505, a marker polymorphism flanking the IL-10 gene, were at increased risk of CD (OR = 1.40, 95% CI: 1.06-1.85, P = 0.02) and UC (OR = 1.43, 95% CI: 1.12-1.82, P = 0.004) and, furthermore, with risk of a diagnosis of CD and UC at young age (OR = 1.47, 95% CI: 1.10-1.96) and OR = 1.35, 95% CI: 1.04-1.76), respectively). No association was found between the IL-1β, IL-10 G-1082A, C-819T, C-592A, and HO-1 gene polymorphisms and CD or UC. No consistent interactions between smoking status and CD or UC genotypes were demonstrated.

Conclusions

The rs3024505 marker polymorphism flanking the IL-10 gene was significantly associated with risk of UC and CD, whereas no association was found between IL-1β or HO-1 gene polymorphisms and risk of CD and UC in this Danish study, suggesting that IL-10, but not IL-1β or HO-1, has a role in IBD etiology in this population.

IL-1beta-511 and IL-1RN*2 polymorphisms in inflammatory bowel disease: An Italian population study and meta-analysis of European studies

BACKGROUND

Several studies have tried to find possible associations between genetic polymorphisms and inflammatory bowel disease prevalence and/or phenotype. Our objectives were to test the frequency and phenotypic association of two polymorphisms of the interleukin-1 pathway, IL-1beta-511 and IL-1RN*2, in inflammatory bowel disease patients and controls from an Italian population, and to compare our data with previously published similar studies in Europe.

METHODS

We screened 290 inflammatory bowel disease patients (178 ulcerative colitis and 112 Crohn's disease) and 106 controls for IL-1beta-511 and IL-1RN*2 polymorphisms by polymerase chain reaction (PCR)-based methods. The prevalence of the IL-1beta-511 and IL-1RN*2 polymorphisms in European inflammatory bowel disease patients was calculated by a meta-analysis of previously published studies using the Mantel-Haenszel method.

RESULTS

No correlation between the IL-1 polymorphisms and inflammatory bowel disease prevalence was found in our study population. Crohn's disease patients with the IL-1beta-511 mutation had a higher rate of complicated disease. A trend for an association between the IL-1RN*2 mutation and a higher risk for inflammatory bowel disease has been found only in studies with Northern European populations.

CONCLUSIONS

The IL-1beta-511 mutation can be associated with complex disease behaviour in Italian Crohn's disease patients. The IL-1RN*2 mutation may play a role in Northern European people with inflammatory bowel disease.

Increased susceptibility to dextran sulfate sodium induced colitis in the T cell protein tyrosine phosphatase heterozygous mouse

T cell protein tyrosine phosphatase (TC-PTP / PTPN2) is an enzyme that is essential for the proper functioning of the immune system and that participates in the control of cell proliferation, and inflammation. We previously observed that TC-PTP^−/− mice display various immunodeficiencies, hypersensitivity to LPS and die within three weeks of birth due to anemia and widespread inflammation. A recent analysis of the Wellcome Trust Case Control Consortium (WTCC) genome wide scan data, reported in 2007, indicated a potential role for TC-PTP in inflammatory bowel disease (IBD). To further investigate the potential role of TC-PTP in IBD, we studied heterozygous TC-PTP mutant mice challenged with dextran sulfate sodium (DSS) in their drinking water. In comparison to control animals, we observed significant changes in the colon mucosa of DSS-treated TC-PTP^+/− mice, in the ratio of colon to body weight, as well as an up-regulation of mRNA transcripts for IL-6, IL-23, 1L-12β, IFN-γ, TNF-α. Moreover, up-regulation of serum IL-6 levels in DSS-treated TC-PTP^+/− mice confirms that mice with a single copy of the TC-PTP gene display increased susceptibility to systemic inflammation due to bowel epithelial erosion resulting from DSS challenge. Our findings support the lack of modulation of Janus kinases 1 and 3 (Jak1, Jak3), and the downstream signal transducer and activator of transcription 1,3 and 5 (Stat1, Stat3, Stat 5) by PTPN2 in the development of IBD like condition. Pathological and molecular analysis reveal that the deficiency of TC-PTP results in pro-inflammatory condition in the bowel of heterozygous TC-PTP^+/− mice. These novel findings in TC-PTP hemi-deficiency support the hypothesis that TC-PTP is an important regulator of inflammatory cytokine signaling and that it may be implicated in the pathophysiology of IBD.

Early-onset Crohn disease is associated with male sex and a polymorphism in the IL-6 promoter

AIMS

Pediatric onset of Crohn disease (CD) is characterized by male sex predominance while adult-onset disease demonstrates female sex predominance. It has been postulated that this phenomenon may be genetically determined or due to an effect of estrogen on age of onset. Interleukin (IL)-6 modulates the TH17 pathway, and the IL-6 promoter is modulated by estrogen, possibly linking genetically determined inflammation and the presence of estrogen. The aim of our study was to investigate whether differences in IL-6 promoter genotype could explain male sex in earlier disease onset.

PATIENTS AND METHODS

We genotyped 333 patients with CD and 100 controls, 162 pediatric-onset patients (age of onset 18 years and younger) for the IL-6-174 polymorphic site. Genotype, sex, and age of onset were compared.

RESULTS

Males with IL-6-174GG genotype (the wild-type allele) had an increased risk for a younger age of onset compared to males with IL-6-174GC or CC genotype (G --> C genotype), hazard ratio (HR) 1.49, P = 0.02, 95% confidence interval (CI) 1.07-2.09. Females with GG genotype were not found to have an increased risk for a younger age of onset compared with females with G --> C genotype, HR 1.01, P = 0.96, 95% CI 0.72-1.41.

CONCLUSIONS

Males with IL-6-174GG genotype are prone to develop CD at a younger age than males with the IL-6-174G --> C genotype. Our study suggests that age of onset may be modified by the IL-6-174GG genotype and this modification is sex dependent. This may be due to increased transcription of IL-6, an effect that may be repressed by estrogen in females.

Association of the -31C/T functional polymorphism in the interleukin-1beta gene with the intractability of Graves' disease and the proportion of T helper type 17 cells

Interleukin (IL)-1beta is a proinflammatory cytokine and has been implicated in the pathogenesis of several autoimmune diseases. To evaluate the hypothesis that the functional -31C/T polymorphism (rs1143627) in the gene encoding IL-1beta is associated with the intractability and the severity of autoimmune thyroid diseases, we genotyped this polymorphism in 64 patients with intractable Graves' disease (GD), 28 GD patients in remission, 49 patients with Hashimoto's disease (HD) who developed hypothyroidism (severe HD), 28 untreated euthyroid HD patients (mild HD) and 59 healthy volunteers. The -31T allele, which is related to the high producibility of IL-1beta, was significantly more frequent in patients with intractable GD than in those with GD in remission (P = 0.0017; odds ratio 2.8; 95% confidence interval 1.5-5.3), although there was no difference in this frequency between two groups of HD patients. We showed additionally that the proportion of IL-17-producing T helper type 17 (Th17) cells, whose differentiation and proliferation are promoted by IL-1beta, was higher in autoimmune thyroid disease patients with the T allele than in those with CC genotypes. In conclusion, our data indicated that the T allele of -31C/T polymorphism in the IL1B gene was involved in the intractability of GD, and this involvement may arise through the differentiation and proliferation of Th17 cells.

Fatty acids, IL6, and TNFalpha polymorphisms: an example of nutrigenetics in Crohn's disease

OBJECTIVES

The aim of this work was to study the interaction between genetic polymorphisms (single-nucleotide polymorphisms, SNPs) of pro- and anti-inflammatory cytokines and fat intake on the risk of developing Crohn's disease (CD) or modifying disease activity.

METHODS

Seven SNPs in interleukin 1 (IL1), tumor necrosis factor alpha (TNFalpha), lymphotoxin alpha (LTalpha), and IL6 genes were analyzed in 116 controls and 99 patients with CD. The type of fat intake was evaluated, and the interaction between SNPs and dietary fat in modulating disease activity was analyzed.

RESULTS

Individuals who were homozygous for the IL6-174G/C polymorphism had a six-fold higher risk for CD (odds ratio (OR)=6.1; 95% confidence interval (95% CI)=1.9-19.4), whereas the TT genotype on the TNFalpha-857C/T polymorphism was associated with more active disease (OR=10.4; 95% CI=1.1-94.1). A high intake of total, saturated, and monounsaturated fats, as well as a higher ratio of n-6/n-3 polyunsaturated fatty acid (PUFA), was associated with a more active phenotype (P<0.05). Furthermore, there was an interaction between dietary fat intake and SNPs, with a high intake of saturated and monounsaturated fats being associated with active disease, mainly in patients carrying the variant alleles of the 857 TNFalpha polymorphism (OR=6.0, 95% CI=1.4-26.2; OR=5.17; 95% CI=1.4-19.2, respectively) and the 174 IL6 polymorphism (OR=2.95; 95% CI=1.0-9.1; OR=3.21; 95% CI=1.0-10.4, respectively). Finally, low intake of n-3 PUFA and high n-6/n-3 PUFA ratio in patients with the TNFalpha 857 polymorphism were associated with higher disease activity (OR=3.6; 95% CI=1.0-13.0; OR=5.92; 95% CI=1.3-26.5, respectively).

CONCLUSIONS

These results show that different types of fat may interact with cytokine genotype, modulating disease activity.

Clinical application of cytokine-related gene polymorphism analysis using a newly developed DNA chip in critically ill patients

OBJECTIVES

To investigate the usefulness of analysis of single nucleotide polymorphism (SNP) using a newly developed DNA chip assay involving single base extension(SBE) and subsequent hybridization in cytokine-related genes in critical care patients.

DESIGN AND METHODS

Genotyping was performed in 76 ICU patients admitted to the ICU. First, the DNA samples from 58 patients were subjected to PCR and SBE conditioning for DNA. Second, another 18 patients were subjected to genotyping for SNPs in IL-6 -596G/A, -572C/G, -174G/C, TNF-alpha -308G/A, -238G/A, IL-1beta -511C/T and -31T/C by both TaqMan and DNA chip method, and by DNA direct sequencing prospectively.

RESULTS

First, PCR and SBE condition were established with initial sample sets, which were consistent with results by TaqMan method. Second, no difference was observed between two assay methods in prospective validation set.

CONCLUSIONS

The genotyping assay using the new chip was developed and its usefulness was confirmed.

Polymorphisms of PTPN11 coding SHP-2 as biomarkers for ulcerative colitis susceptibility in the Japanese population

OBJECTIVE

To identify genetic determinants of inflammatory bowel disease (IBD), we examined an association between polymorphisms of both the programmed cell death 1 gene (PDCD1) and the src homology 2 domain-containing tyrosine phosphatase 2 gene (PTPN11) and susceptibility to IBD.

METHODS

Study subjects comprised 114 patients with ulcerative colitis (UC), 83 patients with Crohn's disease, and 200 healthy control subjects. Five single nucleotide polymorphisms (SNPs) in PDCD1 and PTPN11 were detected by polymerase chain reaction restriction fragment length polymorphism. Subsequently, haplotypes composed of the two SNPs in PTPN11 were constructed.

RESULTS

The frequencies of the Hap 1 haplotype and its homozygous Hap 1/Hap 1 diplotype of PTPN11 were significantly increased in UC patients compared to control subjects (P = 0.011 and P = 0.030, respectively). While no association was found for PDCD1 for UC or CD and none for PTPN11 for CD.

CONCLUSION

PTPN11 is a genetic determinant for the pathogenesis of UC, and haplotyping of PTPN11 may be useful as a genetic biomarker to identify high-risk individuals susceptible to UC.

Sequence variants in IL10, ARPC2 and multiple other loci contribute to ulcerative colitis susceptibility

Inflammatory bowel disease (IBD) typically manifests as either ulcerative colitis (UC) or Crohn's disease (CD). Systematic identification of susceptibility genes for IBD has thus far focused mainly on CD, and little is known about the genetic architecture of UC. Here we report a genome-wide association study with 440,794 SNPs genotyped in 1,167 individuals with UC and 777 healthy controls. Twenty of the most significantly associated SNPs were tested for replication in three independent European case-control panels comprising a total of 1,855 individuals with UC and 3,091 controls. Among the four consistently replicated markers, SNP rs3024505 immediately flanking the IL10 (interleukin 10) gene on chromosome 1q32.1 showed the most significant association in the combined verification samples (P = 1.35 x 10(-12); OR = 1.46 (1.31-1.62)). The other markers were located in ARPC2 and in the HLA-BTNL2 region. Association between rs3024505 and CD (1,848 cases, 1,804 controls) was weak (P = 0.013; OR = 1.17 (1.01-1.34)). IL10 is an immunosuppressive cytokine that has long been proposed to influence IBD pathophysiology. Our findings strongly suggest that defective IL10 function is central to the pathogenesis of the UC subtype of IBD.

Role of the protein C pathway in the extraintestinal thrombosis associated with murine colitis

BACKGROUND & AIMS

Chronic inflammatory bowel diseases (IBD) are associated with an increased risk for thromboembolism. Although thrombosis is known to contribute to the morbidity and mortality of patients with IBD, the underlying mechanisms that contribute to the genesis of a hypercoagulable state during intestinal inflammation remain poorly defined. The objective of this study was to determine whether the protein C pathway contributes to the enhanced extraintestinal thrombosis that is associated with dextran sodium sulfate (DSS)-induced colitis in mice.

METHODS

Microvascular thrombosis was induced in cremaster muscle microvessels of normal and colitic mice using a light/dye injury model. DSS colitis enhanced thrombus formation in cremaster arterioles of wild-type mice.

RESULTS

The DSS-induced thrombosis response was greatly attenuated in transgenic mice over expressing the endothelial protein C receptor. Activated protein C (APC), administered to colitic WT mice immediately prior to photoactivation, also afforded protection against thrombosis, and an anti-APC antibody enhanced thrombus formation.

CONCLUSIONS

These findings indicate that elevated APC levels, derived from either endogenous or exogenous sources, confer protection against the extraintestinal thrombosis that accompanies colonic inflammation.

Single nucleotide polymorphism in the tumor necrosis factor-alpha gene affects inflammatory bowel diseases risk

AIM: To investigate the role that single nucleotide polymorphisms (SNPs) in the promoter of the tumour necrosis factor-alpha (TNF-α) gene play in the risk of inflammatory bowel diseases (IBDs) in a New Zealand population, in the context of international studies.

METHODS: DNA samples from 388 patients with Crohn’s disease (CD), 405 ulcerative colitis (UC), 27 indeterminate colitis (IC) and 201 randomly selected controls, from Canterbury, New Zealand were screened for 3 common polymorphisms in the TNF-α receptor: -238 G→A, -308 G→A and -857C→T, using a Taqman^R assay. A meta-analysis was performed on the data obtained on these polymorphisms combined with that from other published studies.

RESULTS: Individuals carrying the -308 G/A allele had a significantly (OR = 1.91, χ² = 17.36, P < 0.0001) increased risk of pancolitis, and a 1.57-fold increased risk (OR = 1.57, χ² = 4.34, P = 0.037) of requiring a bowel resection in UC. Carrying the -857 C/T variant decreased the risk of ileocolonic CD (OR = 0.56, χ² = 4.32, P = 0.037), and the need for a bowel resection (OR = 0.59, χ² = 4.85, P = 0.028). The risk of UC was reduced in individuals who were smokers at diagnosis, (OR = 0.48, χ² = 4.86, P = 0.028).

CONCLUSION: TNF-α is a key cytokine known to play a role in inflammatory response, and the locus for the gene is found in the IBD3 region on chromosome 6p21, known to be associated with an increased risk for IBD. The -308 G/A SNP in the TNF-α promoter is functional, and may account in part for the increased UC risk associated with the IBD3 genomic region. The -857 C/T SNP may decrease IBD risk in certain groups. Pharmaco- or nutrigenomic approaches may be desirable for individuals with such affected genotypes.

Advance in the relationship between inflammatory bowel disease and tumor necrosis factor polymorphisms

The pathogenesis of inflammatory bowel disease (IBD), including ulcerative and Crohn's disease, is still not entirely clarified till today, and it is probably associated with tumor necrosis factor (TNF), which is influenced by its polymorphisms. The allele frequency, genotype frequency and carrier frequency of TNF affect the susceptibility and clinical manifestation of IBD, presenting differences in ethnics and regions, and produce significant effect on the development and prognosis of disease.

Human leucocyte antigen and TNFalpha polymorphism association in microscopic colitis

OBJECTIVES

Coeliac disease (CD) is common in patients with microscopic colitis (MC). The human leucocyte antigen (HLA)-DR3-DQ2 haplotype is strongly associated with CD, and there is evidence for an association with MC. We analysed the genetic background of MC by assessing the haplotypes of HLA-DR3-DQ2 and HLA-DR4-DQ8. In addition, TNFalpha gene polymorphism (-308) associated with susceptibility to several autoimmune diseases was studied.

METHODS

Eighty patients with MC including 29 with collagenous colitis (CC) and 51 with lymphocytic colitis (LC) were typed for HLA-DR3-DQ2, and HLA-DR4-DQ8 molecule encoding genes using either an allele-specific PCR, or hybridization with sequence-specific oligonucleotides. Duodenal biopsies (N=78) confirmed the diagnosis of CD in 15 (18.8%) patients. TNFalpha(308) alleles were analyzed in 78 patients with MC (27 with CC and 51 with LC). A control group of 3627 patients was used in the HLA study and 178 patients in the TNFalpha study.

RESULTS

HLA-DR3-DQ2 haplotype was more frequent in patients with MC (43.8%) including both subgroups (LC, 44.8%; CC, 43.1%; P<0.001), and MC with CD (86.7%; P<0.001) and without CD (33.3%; P=0.003), compared with the controls (18.1%). Similarly, the TNF2 carrier rate was higher in MC (46.2%; P<0.001) including both CC (44.4%; P=0.031) and LC (47.1%; P=0.001), and both MC patients with CD (66.7%; P=0.001) and without CD (39.3%; P=0.019), compared with the controls (23%).

CONCLUSION

Both CC and LC are associated with the HLA-DR3-DQ2 haplotype and with TNF2 allele carriage. These associations are present also in MC patients without CD. The shared predisposing HLA-DR3-DQ2 haplotype and the high prevalence of CD in patients with MC suggest an epidemiological overlap, and probably some similarities in the pathogenesis of CD and MC.

Tumor necrosis factor-alpha polymorphisms in ulcerative colitis-associated colorectal cancer

OBJECTIVES

Ulcerative colitis (UC) is characterized by chronic recurrent mucosal inflammation. Genetic studies in UC have indicated linkage to chromosome 6 in the region of the tumor necrosis factor-alpha (TNF-alpha) gene, a potent proinflammatory cytokine. TNF-alpha production is influenced by multiple factors including the type of immune cell and its level of activation. However, several single nucleotide polymorphisms (SNP) in the promoter region of TNF-alpha have been correlated with either increased or decreased production, indicating that regulation of TNF-alpha is in part genetic. Because UC patients are at increased risk for developing colorectal cancer (CRC), we investigated if there was an association between SNPs in the promoter of the TNF-alpha gene and UC-CRC.

METHODS

DNA was extracted from formalin-fixed, paraffin-embedded tissue from 114 UC-CRC cases and 114 UC-no CRC controls. Controls were frequency matched on duration and extent of colitis, age, ethnicity, and gender. All 228 tissue samples were analyzed for five TNF-alpha promoter polymorphisms (-238[G-->A], -308[G-->A], -857[C-->T], -863[C-->A], and -1031[T-->C]) using PCR and sequencing.

RESULTS

The -308(G-->A) SNP was significantly associated with UC-CRC cases at both the allele and genotype level (P < 0.0001). No other SNPs were significantly associated with UC-CRC.

CONCLUSION

We report a novel finding of a strong association between the -308(G-->A) SNP and UC-CRC. Complete elucidation of the mechanism of UC-CRC carcinogenesis will require investigation of other genes involved in modulating inflammation, but our results suggest that some UC patients may have additional genetic predispositions toward developing UC-CRC.

Dextran sulfate sodium enhances interleukin-1 beta release via activation of p38 MAPK and ERK1/2 pathways in murine peritoneal macrophages

Interleukin (IL)-1 beta is a pro-inflammatory cytokine that has been shown to play a pivotal role in the onset of inflammatory bowel disease (IBD), however, the molecular mechanisms underlying the production of IL-1 beta in IBD are not fully understood. We investigated dextran sulfate sodium (DSS)-induced IL-1 beta production and caspase-1 activities in murine peritoneal macrophages (pM phi). Further, the activation status of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK1/2), and c-Jun NH(2)-terminal kinase (JNK1/2), as well as their upstream target kinases, were examined by Western blotting. In addition, mRNA expression was assessed by RT-PCR and CXC chemokine ligand 16 (CXCL16) protein was detected by immunocytochemistry. DSS-treated pM phi released IL-1 beta protein in a time-dependent manner without affecting mRNA levels during 3-24 h, and caspase-1 activity peaked at 5 min (29-fold). IL-1 beta release and caspase-1 activity induced by DSS were significantly inhibited by a MAPK kinase 1/2 inhibitor, a p38 MAPK inhibitor, and NAC, however, not by JNK1/2 or a protein kinase C inhibitor. In addition, DSS strikingly induced the phosphorylation of p38 MAPK and ERK1/2 within 2 and 10 min, respectively. DSS also induced intracellular generation of reactive oxygen species (ROS). Pre-treatment with anti-CXCL16 for 24 h, but not anti-scavenger receptor-A, anti-CD36, or anti-CD68 antibodies, significantly suppressed DSS-induced IL-1 beta production. Our results suggest that DSS triggers the release of IL-1 beta protein from murine pM phi at a post-translational level through binding with CXCL16, ROS generation, and resultant activation of both p38 MAPK and ERK1/2 pathways, and finally caspase-1 activation.

Molecular pathogenesis of inflammatory bowel disease: genotypes, phenotypes and personalized medicine

Crohn's disease (CD) and ulcerative colitis (UC), also known as inflammatory bowel diseases (IBD), are characterized by chronic inflammation of the gastrointestinal tract. IBD is among the few complex diseases for which several genomic regions and specific genes have been identified and confirmed in multiple replication studies. We will review the different loci implicated in disease risk in the context of three proposed mechanisms leading to chronic inflammation of the gut mucosa: 1) deregulation of the innate immune response to enteric microflora or pathogens; 2) increased permeability across the epithelial barrier; and 3) defective regulation of the adaptive immune system. As our knowledge of genetic variation, analytical approaches and technology improves, additional genetic risk factors are expected to be identified. With the identification of novel risk variants, additional pathophysiological mechanisms are likely to emerge. The resulting discoveries will further our molecular understanding of IBD, potentially leading to improved disease classification and rational drug design. Moreover, these approaches and tools can be applied in the context of variable drug response with the goal of providing more personalized clinical management of patients with IBD.

Association of TNF-alpha/LTA polymorphisms with Crohn's disease in Koreans

Polymorphisms of the proinflammatory and immunoregulatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and lymphotoxin-alpha (LTA), have been shown to affect their production and be associated with Crohn's disease. However, the actual alleles associated with the disease are variable among populations. The aim of this study was to test whether TNF-alpha and LTA polymorphisms were associated with Crohn's disease risk in Korean samples. Genotyping for five TNF-alpha promoter polymorphisms (-1031, -863, -857, -308, and -238) and two LTA polymorphisms (intron 1 and Thr60Asn) were performed on 289 Korean patients with Crohn's disease and 399 unrelated healthy controls. Carriers of an individual polymorphism of TNF-alpha at -857T, showed statistically significant association with Crohn's disease (adjusted OR=1.64, 95% CI=1.11-2.41, P=0.013). Following haplotype analysis, carriers of the haplotype consisted of the -1031C, -863A, and -857C alleles showed statistically significant association with Crohn's disease (adjusted OR=1.54, 95% CI=1.02-2.32, P=0.040). Significantly reduced frequencies were seen for the carriers of the LTA Thr60Asn polymorphism in patients (OR=0.62; 95% CI=0.42-0.93, P=0.019), suggesting a protective effect on Crohn's disease. Our data support the hypothesis that the TNF-alpha/LTA genotypes play an important role in the pathogenesis of Crohn's disease in Koreans.

Cytokine tumor necrosis factor-alpha A promoter gene polymorphism at position -308 G-->A and pediatric inflammatory bowel disease: implications in ulcerative colitis and Crohn's disease

OBJECTIVES

Our pilot study aimed to determine the effect of tumor necrosis factor-alpha (TNF-alpha) 308 G-->A promoter single-nucleotide polymorphism in pediatric inflammatory bowel disease (IBD), its influence on inflammatory activity and the clinical manifestations.

METHODS

We obtained genomic DNA from 164 subjects, 82 with long-standing IBD aged 8 to 18 years: 46 with Crohn disease (CD) and 36 with ulcerative colitis (UC). Eighty-two healthy children served as the control population. Genotyping was determined by using a restriction enzyme-based assay. TNF-alpha 308 G-->A polymorphism was assessed in terms of inflammatory (C-reactive protein [CRP]) and disease activity. The latter was assessed by the Pediatric Crohn's Disease Activity Index (PCDAI) and the Truelove index for CD and UC, respectively.

RESULTS

Significant differences in TNF-alpha 308 A polymorphism were found between the IBD group and controls (P < 0.05) and the UC group and controls (P < 0.001). No differences were noted between TNF-alpha 308 A polymorphism and clinical characteristics in UC. The frequency of the -308 A allele of TNF was not different in CD compared with that in the control group. The frequency of TNF-alpha 308 A genotype was significantly higher in CD patients with predominantly stenosing/penetrating disease compared with patients without complications (P < 0.001) and healthy controls (P < 0.01). In CD patients, those carrying TNF -308 A had a significant increase in CRP (P < 0.05) and the PCDAI (P < 0.05). In CD, CRP levels strongly correlated with the PCDAI (r = 0.6150, P < 0.001). In UC, significant differences among the mean levels of CRP (P < 0.05) and disease activity (P < 0.001) related to TNF-alpha 308 A polymorphism were found. Allele distribution (odds ratio, 12.9; CI, 1.18-140.81, P < 0.001) and CRP serum levels (odds ratio, 1.020; CI, 1.00-1.04, P < 0.001) were independently associated with CD complications.

CONCLUSIONS

Although not necessarily dictating IBD initiation, the TNF-alpha 308 A polymorphism may play a role in modifying the CD phenotype. The polymorphism may influence disease activity as well as more intense inflammatory activity in both forms of IBD and may modify the progression of chronic digestive tract inflammation.

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.