Five genetic markers in the interleukin 1 family in relation to inflammatory bowel disease

Gut Protective Effect from D-Methionine or Butyric Acid against DSS and Carrageenan-Induced Ulcerative Colitis

Microbiome dysbiosis resulting in altered metabolite profiles may be associated with certain diseases, including inflammatory bowel diseases (IBD), which are characterized by active intestinal inflammation. Several studies have indicated the beneficial anti-inflammatory effect of metabolites from gut microbiota, such as short-chain fatty acids (SCFAs) and/or D-amino acids in IBD therapy, through orally administered dietary supplements. In the present study, the potential gut protective effects of d-methionine (D-Met) and/or butyric acid (BA) have been investigated in an IBD mouse model. We have also built an IBD mouse model, which was cost-effectively induced with low molecular weight DSS and kappa-carrageenan. Our findings revealed that D-Met and/or BA supplementation resulted in the attenuation of the disease condition as well as the suppression of several inflammation-related gene expressions in the IBD mouse model. The data shown here may suggest a promising therapeutic potential for improving symptoms of gut inflammation with an impact on IBD therapy. However, molecular metabolisms need to be further explored.

Interleukin 1β Blockade Reduces Intestinal Inflammation in a Murine Model of Tumor Necrosis Factor-Independent Ulcerative Colitis

BACKGROUND & AIMS

Inflammatory bowel diseases are multifactorial diseases commonly treated with either immunomodulatory drugs or anti-tumor necrosis factor (TNF). Currently, failure to respond to anti-TNF therapy (assessed no earlier than 8-12 weeks after starting treatment) occurs in 20%-40% of patients enrolled in clinical trials and in 10%-20% in clinical practice. Murine models of inflammatory bowel disease provide important tools to better understand disease mechanism(s). In this context and among the numerous models available, Winnie-TNF-knockout (KO) mice recently were reported to show characteristics of ulcerative colitis (UC) that are independent of TNF, and with increased interleukin (IL)1β production.

METHODS

Herein, the efficacy of recombinant IL1-receptor antagonist (anakinra) administration was evaluated in Winnie-TNF-KO mice, used as a UC model of primary anti-TNF nonresponders.

RESULTS

We analyzed gut mucosal biopsy specimens and circulating cytokine profiles of a cohort of 30 UC patients; approximately 75% of primary nonresponders were characterized by abundant IL1β in both the serum and local intestinal tissues. In Winnie-TNF-KO mice, administration of anakinra efficiently reduced the histologic score of the distal colon, which represents the most common site of inflammation in Winnie mice. Furthermore, among lamina propria and mesenteric lymph node-derived T cells, interferon γ-expressing CD8⁺ T cells were reduced significantly after anakinra administration.

CONCLUSIONS

Our study provides new insight and alternative approaches to treat UC patients, and points to anti-IL1 strategies (ie, anakinra) that may be a more effective therapeutic option for primary nonresponders to anti-TNF therapy.

Arginase impedes the resolution of colitis by altering the microbiome and metabolome

Arginase 1 (Arg1), which converts l-arginine into ornithine and urea, exerts pleiotropic immunoregulatory effects. However, the function of Arg1 in inflammatory bowel disease (IBD) remains poorly characterized. Here, we found that Arg1 expression correlated with the degree of inflammation in intestinal tissues from IBD patients. In mice, Arg1 was upregulated in an IL-4/IL-13- and intestinal microbiota-dependent manner. Tie2-Cre Arg1fl/fl mice lacking Arg1 in hematopoietic and endothelial cells recovered faster from colitis than Arg1-expressing (Arg1fl/fl) littermates. This correlated with decreased vessel density, compositional changes in intestinal microbiota, diminished infiltration by myeloid cells, and an accumulation of intraluminal polyamines that promote epithelial healing. The proresolving effect of Arg1 deletion was reduced by an l-arginine-free diet, but rescued by simultaneous deletion of other l-arginine-metabolizing enzymes, such as Arg2 or Nos2, demonstrating that protection from colitis requires l-arginine. Fecal microbiota transfers from Tie2-Cre Arg1fl/fl mice into WT recipients ameliorated intestinal inflammation, while transfers from WT littermates into Arg1-deficient mice prevented an advanced recovery from colitis. Thus, an increased availability of l-arginine as well as altered intestinal microbiota and metabolic products accounts for the accelerated resolution from colitis in the absence of Arg1. Consequently, l-arginine metabolism may serve as a target for clinical intervention in IBD patients.

Autonomically mediated anti-inflammatory effects of electrical stimulation at acupoints in a rodent model of colonic inflammation

BACKGROUND

Acupuncture has been widely accepted for treatments of many diseases. This study was performed to determine effects and mechanisms of electroacupuncture (EA) by chronically implanted electrodes at acupoint ST36 on colonic inflammation induced by TNBS in rats.

METHODS

After intrarectal administration of TNBS, the rats were treated with sham-EA, EA1/EA2 (two sets of parameters) for 3 weeks. Disease activity index (DAI), macroscopic and microscopic lesions, plasma levels of TNF-α, IL-1β and IL-6 were observed as evaluation of inflammatory responses. The autonomic function was assessed by analysis of the heart rate variability.

RESULTS

(a) Vagal activity was significantly increased with both acute and chronic EA1/EA2; (b) DAI was significantly decreased with both chronic EA1 and EA2, and EA2 was more potent than EA1 (P < 0.05); (c) The macroscopic score was 6.4 ± 0.6 with sham-EA and reduced to 4.9 ± 0.1 with EA1 (P < 0.05) and 4.0 ± 0.2 with EA2 (all P < 0.05). The histological score was 4.05 ± 0.58 with sham-EA and remained unchanged (3.71 ± 0.28) with EA1 (P > 0.05) but reduced to 3.0 ± 0.3 with EA2 (P < 0.01); (d) The plasma levels of TNF-α, IL-1β and IL-6 were significantly decreased with EA2.

CONCLUSIONS

Electrical stimulation at ST36 improves colonic inflammation in TNBS-treated rats by inhibiting pro-inflammatory cytokines via the autonomic mechanism.

Resistance mechanisms of Helicobacter pylori and its dual target precise therapy

Helicobacter pylori drug resistance presents a significant challenge to the successful eradication of this pathogen. To find strategies to improve the eradication efficacy of H. pylori, it is necessary to clarify the resistance mechanisms involved. The mechanisms of H. pylori drug resistance can be investigated from two angles: the pathogen and the host. A comprehensive understanding of the molecular mechanisms of H. pylori resistance based on both pathogen and host would aid the implementation of precise therapy, or ideally "dual target precise therapy" (bacteria and host-specific target therapy). In recent years, with increased understanding of the mechanisms of H. pylori resistance, the focus of eradication has shifted from disease-specific to patient-specific treatment. The implementation of "precision medicine" has also provided a new perspective on the treatment of infectious diseases. In this article, we systematically review current research on H. pylori drug resistance from the perspective of both the pathogen and the host. We also review therapeutic strategies targeted to pathogen and host factors that are aimed at achieving precise treatment of H. pylori.

Crohn's Disease and Ulcerative Colitis Show Unique Cytokine Profiles

Introduction

Networks of cytokines have been implicated in both forms of inflammatory bowel disease (IBD): Crohn’s disease (CD) and ulcerative colitis (UC). While CD has associated with T-helper type 1 (Th1) immune responses, UC shows Th2 patterns. Recent studies reported that the inflamed intestinal regions in both CD and UC are significantly infiltrated with a newly described set of T helper, the Th17 cells. These cells have unique cytokine responses. These findings prompted us to further explore the cytokine profiles of CD and UC with a special focus on the Th2 and Th17 related mediators.

Methods

Cytokine transcripts were compared using real-time polymerase chain reaction (PCR) in both inflamed and non-inflamed mucosal specimens from patients with active CD (n=35) or UC (n=20) and without CD or UC (Control, n=54).

Results

In both CD and UC, interleukin (IL)-12 (p40), IL-18, IL-21 and IL-27 transcript levels were higher than in Control. The highest levels of cytokines were found in the diseased areas of CD and UC with only one exception; IL-12 (p40) in CD was more up-regulated in the non-diseased areas compared to diseased CD and Control specimens. CD samples but not UC specimens showed significant IL-17, IL-23, and IL-32 mRNA expression indicating a trend toward Th17 responses. In UC, however, IL-5, IL-13, IL-15 and IL-33 mRNA levels were significantly increased when compared to both CD and Control.

Conclusions

The unique patterns of cytokine networks can help us to better understand the differential expression of their characteristic pathophysiology. In addition, the pharmacological regulation of these small molecules may hold promise to more effective and personalized therapies.

Effect of bacterial and host factors on Helicobacter pylori eradication therapy

INTRODUCTION

A clearer understanding of the factors affecting the cure rate of Helicobacter pylori infection might lead to the development of novel prevention strategies and therapeutic targets.

AREAS COVERED

This review covers two important issues that affect the eradication of H. pylori: bacterial and host factors. Several virulence factors have been shown to be predictors for gastroduodenal diseases. Successful treatment of H. pylori infection also depends on host genetic factors such as CYP2C19 and IL-1B. The latest evidence on host genetic factors is discussed.

EXPERT OPINION

The authors identify three main targets for achieving effective eradication therapy. The first therapeutic target is to identify counter measures for antibiotic-resistant H. pylori strains. Thus, antibiotic susceptibility should be checked in all patients, ideally, before the start of eradication treatment. The second therapeutic target is the inhibition of acid suppression. Maintaining a high intragastric pH for 24 h increases the effectiveness of some antibiotics and the eradication effects for H. pylori. The third therapeutic target is to identify high-risk groups; the CYP2C19 and IL-1B polymorphisms are candidates for significant risk factors. A personalized medical approach will likely increase the cure rate of H. pylori infection.

Association between the IL1B -31C > T polymorphism and Helicobacter pylori infection in Asian and Latin American population: A meta-analysis

BACKGROUND

Host genetic factors that control the production of cytokines, including interleukin-1β (IL-1β), possibly affect susceptibility to many Helicobacter pylori-related diseases. There is a complex interplay between H. pylori infection, the subsequent production of certain cytokines, and H. pylori-related diseases. We conducted a meta-analysis to clarify the association between the IL1B -31C > T polymorphism and H. pylori infection, and possible subsequent pathogenic mechanisms.

METHODS

Published literature contained within PubMed, Embase, and the Cochrane Library was used in our meta-analysis. Data were analyzed with the STATA 13.1 software package using pooled odds ratios (ORs) with 95% confidence intervals (95% CI). Egger's regression test, Begg's rank correlation test, and Begg's funnel plot were used to test publication bias.

RESULTS

A total of 12 case-control studies comprising 5827 subjects (3335 cases and 2492 controls) were available for our meta-analysis. The IL1B -31C > T polymorphism was associated with an increased risk of H. pylori infection in Asian and Latin American population (TT + CT vs. CC, OR = 1.29, 95% CI = 1.14-1.46; TT vs. CT + CC, OR = 1.23, 95% CI = 1.09-1.39; TT vs. CC, OR = 1.43, 95% CI = 1.22-1.67; T allele vs. C allele, OR = 1.19, 95% CI = 1.10-1.29). A significant association was also found for all genetic models in various subgroups (cancer and no-cancer, hospital- and population-based).

CONCLUSION

Our meta-analysis demonstrated that IL1B -31C > T polymorphism might increase H. pylori infection risk in Asian and Latin American population. Further studies with different ethnicities and larger sample size are required to validate this result.

Significance of IL-1RA Polymorphism in Iranian Patients with Inflammatory Bowel Disease

BACKGROUND AND AIM

Interleukin (IL)-1 family members play an important role in the pathogenesis of inflammatory bowel disease (IBD). There are conflicting results regarding the association of IL-1 gene cluster single nucleotide polymorphisms (SNPs) with IBD and its clinical features. The aim of this study was to examine IL-1α -889 C/T, IL-1β -511 C/T, IL-1β +3962 C/T, IL-1R Pst-I1970 C/T, and IL-1RA Mspa-I11100 C/T SNPs in Iranian patients.

METHODS

In this study, SNPs of IL-1 family members were investigated in 75 patients with IBD (40 CD and 35 UC), using polymerase chain reaction with sequence-specific primers method.

RESULTS

IL-1β -511 CC genotype was significantly less present in UC compared to controls, while IL-1RA Mspa-I11100 CC was significantly associated with both Crohn's disease (CD) and ulcerative colitis (UC). IL-1α -889 TT genotype was more frequently associated with extraintestinal manifestations. A significant association was observed between IL-1β +3962 TT genotype and the disease activity in IBD. IL-1RA Mspa-I11100 CC was significantly less frequent in CD patients who need immunosuppressive therapy. IL-1RA Mspa-I11100 CT was associated with earlier age of onset in IBD, while TT genotype was associated with higher age of onset in IBD.

CONCLUSIONS

IL-1 SNPs seem to be associated with IBD and could affect the disease severity as well.

To be or not to be: The host genetic factor and beyond in Helicobacter pylori mediated gastro-duodenal diseases

Helicobacter pylori (H. pylori) have long been associated with a spectrum of disease outcomes in the gastro-duodenal system. Heterogeneity in bacterial virulence factors or strains is not enough to explain the divergent disease phenotypes manifested by the infection. This review focuses on host genetic factors that are involved during infection and eventually are thought to influence the disease phenotype. We have summarized the different host genes that have been investigated for association studies in H. pylori mediated duodenal ulcer or gastric cancer. We discuss that as the bacteria co-evolved with the host; these host gene also show much variation across different ethnic population. We illustrate the allelic distribution of interleukin-1B, across different population which is one of the most popular candidate gene studied with respect to H. pylori infections. Further, we highlight that several polymorphisms in the pathway gene can by itself or collectively affect the acid secretion pathway axis (gastrin: somatostatin) thereby resulting in a spectrum of disease phenotype

Polymorphisms in genes related to inflammation, NSAID use, and the risk of prostate cancer among Danish men

The etiology of prostate cancer (PC) remains mostly unknown, but increasing evidence suggests that chronic inflammation in the prostate is associated with an increased risk of PC. Epidemiological studies have suggested that use of nonsteroidal anti-inflammatory drugs (NSAIDs) may protect against PC. Inborn variations in genes involved in the inflammatory response may modulate the risk of PC and interact with NSAIDs. The aims of this study were 1) to evaluate whether polymorphisms and haplotypes of the inflammation-related genes COX-2, Il1B, NFKB1, and PPARG are associated with risk of PC; 2) to investigate gene-environment interactions between polymorphisms and NSAID use; and 3) to examine whether the studied polymorphisms were associated with the aggressiveness of PC. The study population consisted of 370 cases of PC and 370 risk-set matched (age) controls nested within the prospective Danish "Diet, Cancer, and Health" cohort. Carriers of the variant deletion allele of NFKB1 -94ins/delATTG had a tendency toward a reduced risk of PC (incidence rate ratio (IRR), 0.73; 95% confidence interval (CI) 0.52-1.04). A lowered risk for PC was also found for carriers of variant allele NFKB1 -94ins/delATTG among non-users of NSAIDs (IRR 0.68; 95% CI 0.47-0.99), for non-aggressive disease (IRR 0.64; 95% CI 0.42-0.99), and among men with a body mass index above 30 kg/m(2) (IRR 0.56; 95% CI 0.27-1.16), although the latter estimate was based on small numbers. A similar pattern was seen for the variant C allele of the COX-2 +8473T→C polymorphism. No apparent association with PC was observed for the other studied polymorphisms. Our study did not indicate that chronic inflammation is a major risk factor for aggressive PC.

Associations between genetic polymorphisms in IL-33, IL1R1 and risk for inflammatory bowel disease

BACKGROUND

Recent evidence suggests that the IL-33/IL1RL1 axis plays a critical role in several autoimmune and inflammatory disorders; however, its mechanistic role in inflammatory bowel disease (IBD) has not been clearly defined. We investigated the contribution of IL-33 and IL1RL1 polymorphisms to IBD risk, and possible correlations with phenotype in an Italian cohort of adult and pediatric patients.

METHODS

We evaluated the association of six SNPs in IL-33 and IL1RL1 genes, in 805 Crohn's disease (CD), 816 ulcerative colitis (UC), and 752 controls, using Taqman. IL-33 and IL1RL1 mRNA expression was also analyzed.

RESULTS

Significant allele and genotype associations with IL-33 rs3939286 were found in CD (P = 0.004; P = 0.035) and UC patients (P = 0.002; P = 0.038). After stratifying the cohort for age at diagnosis, the differences remained significant only in the IBD adult-onset. Significant associations were also obtained in CD patients with two IL1RL1 polymorphisms (rs13015714 and rs2058660, P<0.015). By combining homo- and heterozygous carriers of the rs13015714 risk allele, differences were still significant for both CD adult- and pediatric-onset. Upon genotype-phenotype evaluation, an increased frequency of extensive colitis in adult UC (P = 0.019) and in steroid-responsive pediatric patients (P = 0.024) carrying the IL-33 rs3939286 risk genotype, was observed. mRNA expression of IL-33 and IL1RL1 in inflamed IBD biopsy samples was significantly increased.

CONCLUSIONS

Common IL-33 and IL1RL1 polymorphisms contribute to the risk of IBD in an Italian cohort of adult and pediatric patients, with some influence on sub-phenotypes.

Role of interleukin polymorphisms in gastric cancer: "Pros and cons"

Helicobacter pylori (H. pylori) infection is the leading cause of gastric cancer worldwide. Infection with this bacterium causes a chronic active immune response that persists for the life of the host. The combination of bacterial factors, environmental insults, and the host immune response drives the initiation and progression of mucosal atrophy, metaplasia, and dysplasia toward GC. Among the host factors, IL-1 gene cluster polymorphisms (IL-1B encoding IL-1β and IL-1RN encoding IL-1ra, its naturally occurring receptor antagonist) play a decisive role in modulating the risk of developing hypochlorhydria, gastric atrophy and GC in the presence of H. pylori infection. In particular, one single nucleotide polymorphism in the IL-1B promoter (IL-1B-511C⁄T), and the short allele of a 86-bp variable number of tandem repeats polymorphism in the IL-1RN second intron (IL-1RN*2) are associated with an increased risk for GC. However this hypothesis is still to be fully confirmed. This review focuses on the divergent results obtained by several epidemiological and functional in vitro and in vivo studies and show that IL-1 genotyping has still no role in the clinical management of patients with H. pylori infection.

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.

Influence of inflammatory cytokine polymorphisms on eradication rates of Helicobacter pylori

Pro-inflammatory cytokines and anti-inflammatory cytokines are produced in gastric mucosa from inflammatory cells activated by Helicobacter pylori (H. pylori) infection. Of the inflammatory cytokines, interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha have a potent inhibitive effect on gastric acid production. Polymorphisms in these genes are associated with individual differences in cytokine messenger RNA levels, which result in different gastric mucosal inflammation, different acid inhibition and different gastroduodenal disease risks in response to H. pylori infection. The sustained higher intragastric pH during an eradication therapy is known to be one of the therapeutic determinants of the H. pylori eradication as well as antibiotics resistance and poor compliance. The IL-1B-511 polymorphism is related to eradication rate, and, in combined analysis of previous reports, the eradication rate in patients with the IL-1B-511 C/C genotype (77.4%, 209/270), low IL-1beta producer genotype, is lower than that of the IL-1B-511 C/T and T/T genotypes (87.2%, 631/724) (Odds ratio for eradication failure: 1.98, 95% confidence interval: 1.38-2.84, P = 0.0002). Moreover, the odds ratio of combined CYP2C19 rapid metabolizer-IL-1B-511 C/C type for eradication failure is 11.15 (5.23-23.78) times that of the CYP2C19 poor metabolizer-IL-1B-511 non-C/C type. However, there is no positive data indicating the role of other inflammatory cytokine polymorphisms (e.g. IL-1RN, TNF-A or IL-10) in eradication therapy. Nevertheless, the studies show that inflammatory cytokine polymorphisms, especially the IL-1B-511 T/T genotype, are the determinants of eradication by affecting gastric acid secretion and mucosal inflammation. Therefore, the tailored eradication therapy, considering inflammatory cytokine polymorphisms, may be effective for the higher eradication rates.

Relevance of IL-1 and TNF gene polymorphisms on interleukin-1beta and tumor necrosis factor-alpha gastric mucosal production

We aimed to evaluate the influence of Helicobacter pylori infection and IL-1/TNF gene polymorphisms on interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha gastric mucosal production. IL-1beta and TNF-alpha levels in homogenized biopsy specimens taken from the antrum and corpus of 81 patients were measured by enzyme-linked immunosorbent assay. Genomic DNA was typed for the IL1B-511, IL1B+3954, variable number of tandem repeat (VNTR) IL1RN, TNFA-308, TNFA-238, LTA NcoI, and LTA Bsi gene polymorphisms by polymerase chain reaction, restriction fragment length polymorphism, and TaqMan assays. H. pylori infection and CagA/VacA antibody status were determined by Western blot. IL-1beta and TNF-alpha protein levels were significantly higher in the gastric antrum of patients infected with H. pylori compared with uninfected patients [9.54 (5.07-16.28) vs. 4.55 (3.69-8.28) pg IL-1beta/mg protein, p = 0.004, and 1.5 (0.7-2.71) vs. 0.63 (0.3-1.26) pg TNF-alpha/mg protein, p = 0.001]. Among H. pylori-infected individuals, carriers of the IL1RN*2 allele had significantly higher antrum mucosal IL-1beta levels than noncarriers [15.97 (9.59-26.6) vs. 10.08 (7.72-13.33), p = 0.008]. No association between gastric mucosal TNF-alpha levels and genotypes of the TNFA and LTA gene polymorphisms was reported. Our results indicate that the VNTR polymorphism of the IL1RN gene influences IL-1beta gastric mucosal production in patients infected with H. pylori.

Immune response and gene polymorphism profiles in Crohn's disease and ulcerative colitis

BACKGROUND

Polymorphisms in genes linked to the innate and adaptive immune response may be involved in inflammatory bowel disease pathogenesis. Our aim was to investigate associations among IL1B-511, IL1B-31, IL1RN, TNFA-307, TLR-2, TLR-4, IL2-330, NOD2 G908R, NOD2 L1007fsinsC polymorphisms and both Crohn's disease (CD) and ulcerative colitis (UC) in a Brazilian population.

METHODS

We studied 43 patients with CD, 42 with UC, and 541 blood donors. Polymorphisms were evaluated by PCR, PCR-CTPP, or PCR-RFLP. Data were analyzed in multivariate models adjusting for confounding factors.

RESULTS

IL1RN VNTR (P = 0.00, odds ratio [OR] = 2.43, 95% confidence interval [CI] = 1.50-3.90), as well as TNFA-307 polymorphic allele (P = 0.05, OR = 1.70, 95% CI = 1.00-2.94) were associated with UC. Both NOD2 mutations (G908R, P = 0.02, OR = 6.83, 95% CI = 1.62-25.45, and L1007fsinsC, P = 0.00, OR = 20.00, 95% CI = 3.21-124.69) were associated with CD.

CONCLUSIONS

Our analyses showed positive associations between proinflammatory polymorphisms at IL1RN and TNFA-307 loci and UC, as well as polymorphisms in the NOD2 gene and CD. These results highlight the importance of different genetic profiles associated with CD and UC.

From model cell line to in vivo gene expression: disease-related intestinal gene expression in IBD

Crohn's disease (CD) and ulcerative colitis (UC) are subforms of inflammatory bowel diseases (IBD). Genetic and environmental factors influencing the onset and course of the diseases have been recently identified. This study uses a two-step approach to detect genes involved in the pathogenesis of IBD by microarray analysis and real-time PCR (RT-PCR). In a first step, microarray expression screening was used to obtain tumour necrosis factor-alpha (TNF-alpha) induction profiles of two human cell lines to represent the tissue cell types involved in IBD. In a second step, a subset of differentially expressed genes was examined by real-time PCR in intestinal biopsy samples of normal controls (NC) compared with UC and CD patients, as well as to a cohort of patients suffering from intestinal diseases other than IBD. Data were obtained from 88 CD, 88 UC, 53 non-IBD patients (inflammatory control), DC and 45 NC individuals. The experimental design enabled the identification of disease-specific expressed genes. DnaJ (Hsp40) homologue, subfamily B, member 5 (DNAJB5) was downregulated in intestinal biopsy samples of the UC cohort compared with NC. A difference in JUNB expression levels was observed by comparing biopsy samples from inflamed and non-inflamed areas of UC patients. Transcript expression differences between IBD and control cohorts were found by examining histamine N-methyltransferase (HNMT), interleukin-1A (IL-1A) and proplatelet basic protein (PPBP) expression. The experimental procedure represents an approach to identify disease-relevant genes, which is applicable to any disease where appropriate model systems are available.

Genetic epidemiology of primary sclerosing cholangitis

The aetiology of primary sclerosing cholangitis (PSC) is not known. A more than 80-fold increased risk of PSC among first-degree relatives emphasizes the importance of genetic factors. Genetic associations within the human leukocyte antigen (HLA) complex on chromosome 6p21 were detected in PSC 25 years ago. Subsequent studies have substantiated beyond doubt that one or more genetic variants located within this genetic region are important. The true identities of these variants, however, remain to be identified. Several candidate genes at other chromosomal loci have also been investigated. However, according to strict criteria for what may be denominated a susceptibility gene in complex diseases, no such gene exists for PSC today. This review summarises present knowledge on the genetic susceptibility to PSC, as well as genetic associations with disease progression and clinical subsets of particular interest (inflammatory bowel disease and cholangiocarcinoma).

The bisphosphonate alendronate improves the damage associated with trinitrobenzenesulfonic acid-induced colitis in rats

BACKGROUND AND PURPOSE

The nitrogen-containing bisphosphonates are drugs used successfully in the treatment of osteoporosis. They act inhibiting farnesyl diphosphate synthase. This mechanism may also produce anti-inflammatory effects. The therapeutic activity of alendronate was tested in vivo using a model of inflammatory bowel disease.

EXPERIMENTAL APPROACH

The trinitrobenzenesulfonic acid model of colitis in the rat was used. Rats were treated orally with alendronate and its efficacy compared with that of oral sulphasalazine or vehicle, starting 2 h after colitis induction. The status of the animals was assessed 5 days later.

KEY RESULTS

Alendronate treatment (25 or 75 mg kg(-1) day(-1)) resulted in a decrease in the colonic damage score and loss of body weight (at 25 mg kg(-1) day(-1) only). This was associated to a dramatic reduction in the mRNA levels of interleukin 1 beta (IL-1 beta), monocyte chemoattractant protein 1 (MCP-1) and interleukin 1 receptor antagonist (IL-1 ra). The magnitude of the beneficial effect was comparable to that of sulphasalazine (at a 6-20 fold higher dose). Thus sulphasalazine post-treatment reduced the mRNA levels of IL-1 beta/IL-1 ra and MCP-1 to the same extent as alendronate and additionally lowered colonic alkaline phosphatase activity, but failed to affect body weight loss or colonic damage score. Alendronate failed to exert beneficial effects when administered intraperitoneally.

CONCLUSIONS AND IMPLICATIONS

Oral but not intraperitoneal alendronate significantly protected the colon in experimental rat colitis. Inflammatory bowel disease patients might benefit from exposure to oral alendronate.

Polymorphisms in exons 1B and 1C of the type I interleukin-1 receptor gene in patients with endometriosis

To study possible correlation between the prevalence of polymorphisms in the type I interleukin-1 receptor gene and pelvic endometriosis. Genotypes of 223 women were analyzed: 109 women with surgically and histologically confirmed endometriosis and 114 healthy women. Distributions of two single-base polymorphisms of the human interleukin-1 receptor type I (IL-1RI) gene were evaluated: PstI, due to a C-->T transition in exon 1B and BsrBI a C-->A transition at position 52 in exon 1C. Polymorphisms were detected by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism analysis (RFLP) resolved on 3% agarose gels stained with ethidium bromide. Genotypes for PstI polymorphisms did not differ significantly among control and endometriosis (P = 0.058). However, in relation to BsrBI polymorphism, protective risk was observed for the development of endometriosis [OR 0.39-IC 95% (0.2-0.9)]. BsrBI heterozygote genotype (C/A) showed protective effect against endometriosis development.

Interaction between IL1B gene promoter polymorphisms in determining susceptibility to Helicobacter pylori associated duodenal ulcer

It has been speculated that IL-1 genes play a crucial role in the genetic predisposition to duodenal ulcer upon H. pylori infection by modulating the host immune response. In the present study, 310 individuals from Eastern India were subjected to a case-control study to determine the IL1B and IL1RN risk genotypes to H. pylori mediated duodenal ulcer. An analysis of genotype frequency revealed a significantly higher frequency of IL1B -511TT (NT_022135.14:g.2302610C>T), OR=4.22 (95% CI=1.8-9.4) and -31CC (NT_022135.14:g.2302130C>T), OR=2.16 (95% CI 1.12-4.15) genotypes in H. pylori-infected individuals with duodenal ulcer compared to infected individuals with normal mucosa. Moreover, the T/C haplotype of IL1B -511 and IL1B -31 loci was present in a significantly higher frequency in H. pylori-infected duodenal ulcer patients than in infected controls (OR=2.47, CI=1.27-4.8). Quantitative analysis of the mucosal IL1B mRNA revealed that among H. pylori-infected individuals, carriers of the -31CC genotype had significantly lower IL1B transcript levels than carriers of the CT (P<0.001) and TT (P<0.001) genotypes, independently of disease status. An IL1B promoter activity assay showed that the promoter with -31T had a 10-fold increase in activity compared to the one with -31C. The IL1B promoter bearing the different combinations of both polymorphic loci showed an interaction between the -511 and -31 loci. Our results show that H. pylori-infected individuals with the -31CC genotype secrete less IL1B and are susceptible to duodenal ulcers. They also suggest that the allelic interaction between the -511 and -31 polymorphic sites determines the overall strength of the IL1B promoter.

-137 (G/C) IL-18 promoter polymorphism in patients with inflammatory bowel disease

OBJECTIVE

There is strong evidence that genetic factors contribute to the susceptibility for inflammatory bowel diseases (IBD). Recently, IL-18 promoter polymorphisms were characterized as risk factors for inflammatory diseases such as sepsis, asthma and adult-onset Still's disease. The aim of this study was to determine whether the -137 (G/C) IL-18 promoter polymorphism was associated with IBD susceptibility.

MATERIAL AND METHODS

For association analysis, 470 patients with Crohn's disease (CD), 235 unrelated patients with ulcerative colitis (UC) and 347 controls were enrolled. Furthermore, 233 UC and 470 CD trios were included for segregation analysis. Genotyping was performed by application of the TaqMan MGB biallelic discrimination system.

RESULTS

When comparing genotype frequencies of CD and UC patients versus controls, no significant difference was found (p=0.089 and p=0.078, respectively). However, the Cochran-Armitage trend test revealed a rising probability for CD and UC with increasing number of G alleles (p=0.030 and 0.028, respectively) for the case-control analysis. On the contrary, the family-based transmission disequilibrium test (TDT) did not show an association of the G allele with CD or UC in 470 CD and 233 UC trios (p=0.53 and p=0.79, respectively).

CONCLUSION

The -137 (G/C) IL-18 promoter polymorphism is not a susceptibility factor for IBD in a German cohort.

Association of cytokine and DNA repair gene polymorphisms with hepatitis B-related hepatocellular carcinoma

BACKGROUND

Hepatitis B virus (HBV) induces hepatocellular carcinoma (HCC) mainly by causing chronic necroinflammatory hepatic disease. We investigated the mechanisms underlying the inflammatory hepatocarcinogenesis by examining whether genetic variations in cytokines, antioxidant enzymes, and DNA repair genes affect the HCC risk.

METHODS

We analyzed 10 polymorphisms in the genes for interleukin-1beta (IL-1B), interleukin-1-receptor antagonist (IL-1RN), tumor necrosis factor-alpha (TNF-A), glutathione S-transferase, XRCC1, hMLH1, and XPD in 577 HBV carriers with HCC and 389 HBV carrier controls.

RESULTS

Overall, only the hMLH1-93*A allele significantly increased HCC risk. We identified polymorphism combinations associated with HCC. In the presence of the IL-1RN*2 allele, adjusted odds ratios (ORs) for HCC associated with C/C, T/C, and T/T genotypes of the IL-1B-31 polymorphism were 1.00, 2.93 [95% confidence interval (95% CI) 1.07-8.07], and 5.76 (95% CI 1.79-18.53), respectively. There was a dose-dependent association between the number of putative high-risk genotypes in the IL-1B, TNF-A, hMLH1, and XRCC1 genes and HCC. The adjusted OR for HBV carriers with > or = 3 putative high-risk genotypes was 9.29 (95% CI 2.90-29.75) compared with those with none or only one of the high-risk genotypes. These associations were not observed among HBV carriers without the IL-1RN*2 allele. Smoking modified the combined effect of multiple loci in the IL-1RN, IL-1B, TNF-A, hMLH1, and XRCC1 genes; a high-risk multilocus genotype only significantly increased the risk in smokers (adjusted OR 4.84; 95% CI 1.69-13.92).

CONCLUSIONS

Genetic variations in cytokine and DNA repair genes contribute to susceptibility to HBV-related HCC. Smoking increased such genetic susceptibility.

Influence of IL-1 gene cluster polymorphisms on the development of H. pylori associated gastric ulcer

BACKGROUND AND AIMS

Chronic H. pylori infection is the main cause of ulcer disease which depicts a major burden of our healthy care systems. The individual host immune response plays a pivotal role in the outcome of the infection but genetic susceptibility to develop gastric ulcer is unknown. IL-1beta and its natural receptor antagonist IL-1ra are involved in the inflammatory response to H. pylori infection. Thus, we investigated the influence of functional genetic variants in the IL-1 gene cluster on the development of gastric ulcer disease.

PATIENTS AND METHODS

390 H. pylori infected patients were genotyped for IL-1B -31 and +3954 by TaqMan technology. Alleles of IL-1RN 86VNTR were determined by gel electrophoresis after amplification. Three hundred and sixty healthy blood donors were included as healthy controls.

RESULTS

Carriage of the IL-1B -31 C allele conferred a increased but not significant risk for H. pylori infection (OR: 1.3, Wald 95% CI: 0.8<OR<2.1). Patients carrying short allele 2 of IL-1RN had a 1.6-fold significantly increased risk for the development of gastric ulcer (Pearson's=4.0, p=0.044, OR: 1.6, Wald 95% CI: 1.0<OR<2.4).

CONCLUSION

Our results underline the crucial role of the host immune response to H. pylori infection and confirm the importance of polymorphisms in the IL-1 cluster as a factor to give rise to different clinical outcomes. Further studies are needed to fully understand the pathophysiological effect of polymorphisms in the IL-1 cluster in H. pylori associated ulcer disease and susceptibility to infection itself.

Prediction of malignant potential in reflux disease: are cytokine polymorphisms important?

OBJECTIVES

Esophageal reflux is common in the Western world and can lead to a number of diseases, such as esophagitis, Barrett's esophagus, and adenocarcinoma. Barrett's predisposes to adenocarcinoma and endoscopic surveillance may lead to earlier detection of adenocarcinoma. However, clinical methods only identify one patient in 15 with Barrett's esophagus. The aim of this study was to find factors that may help identify patients with Barrett's earlier.

METHODS

Blood samples and detailed histories were taken from 456 patients with gastroesophageal reflux who were recruited into three study groups: esophagitis, Barrett's esophagus without dysplasia, and Barrett's with dysplasia or adenocarcinoma. PCR was used to determine the frequency of five functional cytokine polymorphisms: interleukin-1 receptor antagonist position +2018 (IL-1 Ra +2018), interleukin-1 beta position -511 (IL-1 beta-511), tumor necrosis factor-alpha position -238 (TNF-alpha-238), interleukin-10 position +1082 (IL-10 +1082), and interleukin-4 receptor position -1902 (IL-4R -1902).

RESULTS

IL-1 Ra +2018 genotype 2/2 was associated with Barrett's more commonly than esophagitis (OR-3.7, p= 0.0345). The IL-10 +1082 genotype 2/2 was more strongly associated with Barrett's and adenocarcinoma than esophagitis (OR-1.76, p= 0.056 and OR 1.96, p= 0.025, respectively). There were no differences for the IL-1 beta-511, IL-4R -1902, and TNF-alpha-238 polymorphisms.

CONCLUSIONS

Cytokine polymorphisms are more commonly found in patients with Barrett's or adenocarcinoma than those with esophagitis. Together with demographic data, this may help identify those patients with Barrett's who would benefit from surveillance.

Gastric mucosal cytokine levels in relation to host interleukin-1 polymorphisms and Helicobacter pyloricagA genotype

OBJECTIVE

The outcome of a Helicobacter pylori infection is related in part to interrelationships among H. pylori virulence factors and the H. pylori-induced mucosal response. The host inflammatory response is partly governed by polymorphisms in pro-inflammatory genes.

MATERIAL AND METHODS

Cytokine levels (interleukin (IL)-1beta, IL-6 and IL-8) were examined in H. pylori-infected and uninfected normal-appearing mucosa from patients with non-ulcer dyspepsia (NUD), margins of gastric ulcers and cancer tissues. Cytokine levels were compared with cagA genotypes and host interleukin (IL)-1 polymorphisms.

RESULTS

The study comprised 168 Thai patients. All infected patients possessed anti-CagA antibody. Gastric mucosal IL-8 levels were significantly higher in H.pylori-positive cases than in -negative cases in all three tissue types (e.g. 1115 versus 217 pg/mg protein for NUD) (p<0.001). Normal-appearing but H. pylori-infected antral mucosa of patients with cagA type 1a strains had higher IL-8 levels than those with type 2a strains (2632 versus 1036 pg/mg protein) (p<0.005). IL-1B-511T/T carriers had higher antral mucosal IL-1ss levels versus non-carriers (pg/mg protein) (T/T=221, T/C=178, C/C=70) (p=0.005). IL-1B-511T/T carriers also had higher IL-1beta levels versus non-carriers in H. pylori-negative patients.

CONCLUSIONS

It was found that both the host factors (IL-1 polymorphisms) and bacterial factors (cagA type 1a versus type 2a) influenced gastric mucosal cytokine levels. Future studies should concentrate on interactions among host factors (e.g. genetics and tissue responses) and bacterial and environmental factors.

INTERLEUKIN-1 GENE CLUSTER POLYMORPHISMS AND ALCOHOLISM IN SPANISH MEN

AIMS

In an attempt to explain differences in susceptibility to alcoholism and alcohol liver disease (ALD), different genes have been analysed, among them those encoding inflammatory cytokines. Thus, it has been reported recently that both the interleukin 1 receptor antagonist (IL1RN) and the IL1beta (IL1B) genes may influence the risk of ALD in Japanese alcoholics. We analysed the distribution of single nucleotide polymorphisms (SNPs) located in the IL1A, IL1B, IL1R1 and IL1RN genes in alcoholic and non-alcoholic Spanish subjects.

METHODS

DNA samples were obtained from 139 male alcoholics, 78 of whom were diagnosed as alcohol dependent (32 patients with liver cirrhosis and 46 without ALD) and 61 as alcohol abusers (25 with liver cirrhosis and 36 without ALD). As a control, we studied 81 age- and sex-matched healthy volunteers.

RESULTS

Alleles -511 IL1B*1 and IL1RN*1 were represented more in alcoholic patients than in the control group. We did not find any association of alcoholism or ALD with polymorphisms in the IL1A and IL1R1 genes.

CONCLUSIONS

We conclude that the proteins encoded by the IL1RN and IL1B genes may be involved in susceptibility to alcoholism in Spanish men, probably through a different pathway from that involved in the regulation of the inflammatory response.

Interleukin-1B (IL-1B) polymorphisms and gastric mucosal levels of IL-1beta cytokine in Korean patients with gastric cancer

Interleukin-1B and IL-1 receptor antagonist gene polymorphisms are associated with an increased risk of gastric cancer (GC) in Caucasian populations. However, recent studies could not find any association between IL-1B-511T polymorphism and the risk of GC in Asians. We tested for an association between IL-1 loci polymorphisms with increased gastric mucosal levels of IL-1beta and an increased risk of developing GC in a Korean population. Polymorphisms of IL-1A-889, IL-1B-31, IL-1B-511 and IL-1RN were genotyped in 434 controls and 234 patients with GC. Mucosal IL-1beta cytokine was measured using an ELISA. The frequencies of IL-1A, IL-1B-511, IL-1B-31 and IL-1RN were not statistically different between controls and all patients with GC. After subclassification of GC, only patients with intestinal-type GC showed a higher frequency of IL-1B-31T homozygotes (OR = 2.2; 95% CI = 1.1-4.3) compared with controls. Risk was also significantly increased in these patients for IL-1B-31T homozygotes compared with patients with diffuse-type GC (OR = 3.4; 95% CI = 1.5-7.7). As in Caucasian populations, linkage disequilibrium between IL-1B-31 and IL-1B-511 was nearly complete, but the pattern of haplotype related to the risk of GC (IL-1B-31T/IL-1B-511C) was opposite (IL-1B-511T/IL-1B-31C). Mucosal IL-1beta levels in H. pylori-infected GC patients were higher in patients homozygous for IL-1B-31T compared with IL-1B-31C/T and IL-1B-31C/C. Thus, the combined effects of H. pylori infection and IL-1B-31T/IL-1B-511C polymorphisms with enhanced mucosal IL-1beta production contributed to the development of intestinal-type GC in this Korean population.

Specific interleukin-1 gene polymorphisms in Turkish patients with Behcet's disease

Genetic factors that predispose individuals to Behçet's disease (BD) are considered to play important roles in the development of the disease. The pro-inflammatory cytokine interleukin-1 (IL-1) has been implicated in the pathogenesis of BD. Our aim was to determine a possible association of specific polymorphisms of IL-1alpha, IL-1beta, and IL-1 receptor antagonist genes with susceptibility for BD. We genotyped 72 patients with BD and 163 healthy controls for IL-1alpha-889, IL-1beta-511, and +3953 (nt5887) single-nucleotide polymorphisms besides IL-1 receptor antagonist variable number of tandem repeat polymorphism (for five different alleles). Comparison of the IL-1beta+3953 T allele and TT genotype frequencies showed a significant difference between patients with BD and controls (54.2 vs. 40.5%, OR = 1.74, P = 0.024, and 40.3 vs. 19.6%, OR = 2.76, P = 0.009, respectively). However, no difference was observed in the genotype or allele frequencies of IL-1alpha-889, IL-1beta-511, and IL-1 receptor antagonist between the patients with BD and the controls. Our results indicate that susceptibility to BD is increased in individuals carrying the IL-1beta+3953 T allele and TT genotype.

Functional correlates of the interleukin-1 receptor antagonist gene polymorphism in the colonic mucosa in ulcerative colitis

Association studies have identified the interleukin-1 receptor antagonist gene allele 2(IL-1RN*2) as a marker of susceptibility in ulcerative colitis (UC). This study investigated the significance of the IL-1RN genotype with respect to protein and mRNA expression in the colonic mucosa. Homogenates of rectal biopsies from 99 UC and 54 controls were assayed for cytokines IL-1ra, IL-1a and IL-1b using ELISA. IL1RN, IL1A and IL1B genotypes were determined using restriction-enzyme analysis. The ability of the two IL1RN alleles to generate steady-state mRNA accumulation was assessed in the colonic mucosa of seven heterozygous patients. Stepwise linear regression demonstrated that IL-1RN genotype (P=0.001), diagnosis (P<0.0001) and treatment (P<0.03) were independent factors associated with the IL-1ra protein level whilst IL1RN genotype (P=0.005) and macroscopic inflammatory grade (P<0.0001) were associated with the IL-1ra/ total IL-1 ratio. The IL1RN*2 correlated with reduced IL-1ra and IL-1ra/IL-1 ratio with a gene dosage effect. In heterozygous UC patients the ratio of allele 1 mRNA / allele 2 steady state mRNA was always greater than 1 (range: 1.2-3.1) (P=0.018). The IL-1RN*2 is associated with reduced levels of IL-1ra protein and IL-1RN mRNA in the colonic mucosa, providing a biologically plausible explanation for the observed association of the allele with the disease.

Association between the interleukin-1 receptor antagonist polymorphism and ulcerative colitis with younger age at diagnosis

The VNTR polymorphism in intron 2 of the interleukin-1 receptor antagonist (IL-1RA) gene has been shown associated with ulcerative colitis (UC) in some populations. This study aimed to assess the relationship between the IL-1RA polymorphism and UC in a Japanese population. Genotyping was carried out with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for 468 DNA specimens from 239 healthy volunteers and 229 patients with UC. Genotype distribution was compared between cases and controls, and association of patients' genotype with clinical parameters was evaluated. No significant difference of genotype distribution was found between UC patients and healthy controls. However, when the relation of the carriage rate of allele 2 with clinical parameters was evaluated by Fisher's exact test, it was found that the allele 2 carriage rate was higher in patients with lower ages at diagnosis (< 30) than those with higher ages (> or =30) (odds ratio (OR), 5.049; 95% confidence interval (CI), 1.667-15.288; P= 0.0020). In addition, it tended to be higher in patients with pancolitis type than those with other types restricted to the distal or left-sided colon (OR, 3.005; 95% CI, 1.186-7.616; P=0.0256). These data suggest that the IL-1RA polymorphism is associated with UC with younger age at diagnosis.

Human colon carcinomas constitutively express and shed type II IL-1 receptor, an IL-1 antagonist

We reported earlier that rat intestinal epithelial cells respond to helminth infection, to NSAID injury, and to detachment in vitro with expression of the IL-1RII. Now we have sought to determine whether human colon carcinoma cell lines express, or may be induced to express, this potent IL-1 antagonist. Using RT-PCR, the T84 and HT-29 cell lines constitutively expressed mRNA for the membrane-bound, but not the secreted variant of the receptor. The protein was detectable by immunohistochemistry and was estimated to be 70 kDa by western blotting. TNF treatment of T84 cells led to slightly increased levels of IL-1RII mRNA and to significant increases in soluble protein detected in culture supernatants. Treating T84 cells with inhibitory anti-IL-1RII antibodies led to heightened responsiveness to IL-1, measured as IL-8 production. Expression of the IL-1RII by human epithelial cells has implications in terms of the IL-1 agonist versus antagonist balance in the diseased intestines.

Gastric marginal zone lymphoma is associated with polymorphisms in genes involved in inflammatory response and antioxidative capacity

Gastric marginal zone lymphoma (GMZL) is strongly associated with Helicobacter pylori infection, which induces a chronic inflammatory response. Inflammation can result in DNA damage related to its severity, the cellular antioxidant capacity, and the integrity of DNA repair mechanisms. Interleukin-1 (IL-1) polymorphisms have been shown to be important mediators of inflammation, while glutathione S-transferase GST T1 and GST M1 polymorphisms are believed to affect cellular antioxidant capacity. We aimed to determine whether polymorphisms at the IL-1 and GST T1 and GST M1 loci modulate the risk of developing GMZL. Blood and biopsy samples were obtained for a historical series of 66 GMZL cases, whereas blood samples were available from 163 healthy controls. Genotypes were obtained for GST T1, GST M1, IL-1 RN, and IL-1B-31 using PCR-based techniques. H pylori infection was found in 86.0% of cases, whereas in the control population only 37.4% tested positive. The IL-1 RN 2/2 genotype was significantly associated with risk of GMZL (odds ratio [OR], 5.51; 95% confidence interval [CI] 2.16-14.07), but not the IL-1B-31 genotype. Likewise, the GST T1 null genotype was strongly associated with risk of GMZL (OR, 9.51; 95% CI 4.57-19.81), but not the GST M1 genotype. Evidence was found of effect modification between the IL-1 RN and GST T1 genotypes (P =.02). The combination of the IL-1 RN 2/2 and GST T1 null genotype was most strongly associated with risk of GMZL (OR, 32.29; 95% CI 6.92-150-63). These results support the hypothesis that the risk of developing GMZL is influenced by inter-individual variation in the cellular inflammatory immune responses to H pylori infection, and to antioxidative capacity.

Effect of interleukin 1 polymorphisms on gastric mucosal interleukin 1beta production in Helicobacter pylori infection

BACKGROUND & AIMS

Although epidemiological studies suggest that interleukin (IL)-1 genetic polymorphisms are involved in Helicobacter pylori-related gastric carcinogenesis, the data are conflicting regarding the effects of these polymorphisms on IL-1beta production.

METHODS

IL-1B-511 polymorphism was genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism, and IL-1RN variable number of tandem repeats was determined by PCR. Mucosal IL-1beta levels were measured by enzyme-linked immunosorbent assay. To determine which factors influence mucosal IL-1beta levels, gastric inflammation, and atrophy, multiple regression analyses were performed.

RESULTS

We studied 117 H. pylori-infected Japanese patients. Carriers of the IL-1B-511T/T genotype or IL-1RN*2 allele had higher mucosal IL-1beta levels than noncarriers (partial regression coefficient [PRC] +/- SE), TT versus CC: 37.6 +/- 6 [antrum] and 32.1 +/- 6 [corpus] pg/mg protein (P < 0.001 for each), *1/*2 versus *1/*1: 24 +/- 8 [antrum] (P <0.01) and 36.5 +/- 7 [corpus] (P <0.001). Simultaneous carriers of IL-1B-511T/T genotype and IL-1RN*2 allele had the highest IL-1beta levels (82.9 +/- 12 [antrum] and 87.2 +/- 11 [corpus]) and showed a synergistic effect between 2 loci. The *1/*2 carriers were closely related to atrophy (PRC +/- SE; 0.87 +/- 0.4 [antrum] and 0.93 +/- 0.4 [corpus], P < 0.05), whereas being a carrier of the -511T/T genotype was related to severe gastric inflammation.

CONCLUSIONS

IL-1 genetic polymorphisms influenced H. pylori-related gastric mucosal IL-1beta levels and were related to gastric inflammation and atrophy, factors thought to be important in gastric carcinogenesis.

Polymorphisms of the IL-1beta and IL-1beta-inducible genes in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic disorder of undetermined etiology, but a genetic predisposition to UC is well recognized. Among cytokines induced in UC, interleukin 1 (IL-1) appears to have a central role because of its immunological upregulatory and proinflammatory activities. The aim of this study was to assess whether UC is associated with polymorphisms of the IL-1beta gene and three additional genes inducible with IL-1beta in Japanese subjects.

METHODS

A total of 96 patients with UC and 106 ethnically matched controls were genotyped at polymorphic sites in IL-1beta, matrix metalloproteinase 1 (MMP-1), matrix metalloproteinase 3 (MMP-3), and inducible nitric oxide synthase (iNOS) genes, using polymerase chain reaction (PCR)-based methods.

RESULTS

There was no significant difference in genotype distributions of IL-1beta, MMP-1, MMP-3, and iNOS genes between controls and UC patients in a Japanese population. Also, no significant association of those polymorphisms with various clinical parameters of the patients was found. However, concerning association of age at onset with clinical factors in UC, the frequency of pancolitis was significantly higher in UC patients with age at onset being less than 30 years than in those more than 30 years of age (P = 0.049).

CONCLUSIONS

No association of the IL-1beta and three IL-1beta-inducible gene polymorphisms with UC was observed in a Japanese population.

Production of IL-1beta and IL-1Ra as risk factors for susceptibility and progression of relapse-onset multiple sclerosis

Interleukin-1beta (IL-1beta) is present in multiple sclerosis (MS) lesions. Interleukin-1 receptor antagonist (IL-1Ra) moderates the induction of experimental autoimmune encephalomyelitis (EAE). Here, we show that families that are characterized by high IL-1beta over IL-1Ra production ratio are at 2.2-fold (95% CI, 1.0-4.8; p=0.05) increased risk to have a patient relative with relapse-onset MS than families with a low ratio. It is also related to the reduction of volumetric magnetization transfer ratio (MTR) histogram height, a measure of parenchymal integrity (p=0.04). Those families who combine a high IL-1beta over IL-1Ra ratio with a high tumor necrosis factor (TNF) over IL-10 production ratio have a 6.2-fold (95% CI, 1.8-21; p=0.002) increased risk. Innate production of IL-1beta and IL-1Ra is not related to the outcome of primary progressive MS. Taq1 polymorphism in the IL-1beta gene and the variable number of tandem repeats (VNTR) polymorphism of 86-base pairs within the IL-1Ra gene cannot explain these findings.

Relationship of polymorphisms of the Interleukin-1 gene cluster to occurrence and severity of rheumatoid arthritis

Interleukin-1 (IL-1) has been implicated in the pathogenesis of rheumatoid arthritis (RA). We investigated whether IotaL-1 gene locus polymorphisms are associated with susceptibility to or severity of RA. Genotyping for IL-1alpha, IL-1beta and IL-1Ra single nucleotide polymorphisms (SNPs) performed in a cross-sectional group of 312 consecutive RA patients (RA-group 1) and a cohort of 94 incident female RA patients (RA-group 2) revealed that the rare IL-1RN + 2017 C allele was significantly increased in RA compared to controls (n = 245). A retrospective analysis in RA-group 1 showed no significant associations between IL-1 genotypes and disease severity. A prospective study in RA-group 2 demonstrated that the extent of joint destruction over 12 years was higher in patients genotyped heterozygous for the IL-1 A + 4845, IL-1B + 3953 and IL-1RN + 5111 SNPs compared to homozygous wildtype patients, although differences did not reach statistical significance. These data indicate that the IL-1RN + 2017 polymorphism is associated with susceptibility to RA.

The interleukin 1 receptor antagonist gene allele 2 as a predictor of pouchitis following colectomy and IPAA in ulcerative colitis

BACKGROUND & AIMS

The interleukin 1 receptor antagonist gene allele 2 has been suggested as a determinant of both disease susceptibility and extent in ulcerative colitis. The aim of this study was to assess the allele as a predictor of both the indication for colectomy and the occurrence of pouchitis after ileal pouch-anal anastomosis formation.

METHODS

Genotyping for the +2018 single nucleotide polymorphism in the interleukin 1 receptor antagonist gene was performed in 109 patients who had undergone colectomy, including 82 patients who had been followed prospectively after ileal pouch-anal anastomosis formation.

RESULTS

Patients with pouchitis had a higher allele 2 carriage rate compared with those without pouchitis (72% vs. 45%) and Kaplan-Meier survival analysis showed that allele 2 carriers had a significantly increased incidence of pouchitis compared with noncarriers (log-rank test, 6.5). After adjustment for confounding covariates in a Cox proportional hazards model, the relative hazard was 3.1 (95% confidence interval [CI], 1.2-7.8; P = 0.02). Although there was a higher allele 2 carriage rate in patients with chronic refractory compared with acute severe ulcerative colitis (63% vs. 48%), this difference was not significant (odds ratio, 1.9; 95% CI, 0.9-4.1; P = 0.1).

CONCLUSIONS

The interleukin 1 receptor antagonist gene allele 2 predicts pouchitis after ileal pouch-anal anastomosis in ulcerative colitis.

Association analysis of IL1A and IL1B variants in alopecia areata

Alopecia areata is an inflammatory hair loss disease with a major genetic component. The disease is characterized by focal inflammatory lesions with perifollicular T-cell infiltrates, reflecting the role of local cytokine production in the development of patchy hair loss. IL-1 alpha and IL-1 beta are important inhibitors of hair growth in vitro. Their effect is opposed by the interleukin-1 receptor antagonist, IL-1ra. Genes of the IL-1 cluster are candidate genes in the pathogenesis of alopecia areata. To investigate the role of the IL-1 system in alopecia areata we examined three biallelic polymorphisms within the IL-1 gene cluster (IL1A+4845, IL1B+3954 and IL1B-511) in 165 patients and a large number of matched controls (n=1150). There was no significant association of IL1B-511 or IL1B+3954 genotypes with the overall dataset, or with disease severity or age at onset, in contrast with a previous report. The results suggested the possibility of an association with IL1A+4845 in the overall dataset [OR 1.39 (95% CI 1.00, 1.93)] although this was not statistically significant. This was due mainly to the contribution from mild cases of alopecia areata [OR 1.48 (0.96, 2.29)], suggesting that IL-1 alpha may have a particular role in the pathogenesis of this subgroup.

IL-1B and IL-1Ra gene polymorphisms and disease severity in rheumatoid arthritis: interaction with their plasma levels

The balance between interleukin-1 (IL-1) and its competitive antagonist IL-1 receptor antagonist (IL-1Ra) may contribute to the pathogenesis of rheumatoid arthritis (RA). We analysed the frequency of different alleles in the IL-1B gene (at -511 and at +3954) as well as in the IL-1Ra gene (at +2018) in an association study involving 297 RA patients and 112 healthy controls from the same geographic area. We tested associations with RA susceptibility or severity, and with circulating levels of IL-1Ra and IL-1beta. Carriage of the rare IL-1B (+3954) allele 2 was increased in destructive arthritis (DRA) as compared to non-destructive arthritis (NDRA) (OR 1.7, 95% CI 1.1-2.8, 49.0% vs 35.9%) and controls (OR 1.7, 95% CI 1.1-2.8, 35.8%). Patients carrying this allele had a more destructive (Larsen wrist radiological index: mean +/- s.e.m., 2.1 +/- 0.2 vs 1.6 +/- 0.1, P = 0.005; Steinbrocker functional index: 2.4 +/- 0.1 vs 1.9 +/- 0.1, P = 0.002) and active disease (Ritchie articular index: 8.1 +/- 0.8 vs 5.3 +/- 0.6, P = 0.002; erythrocyte sedimentation rate (ESR): 36.6 +/- 2.9 mm/h vs 25.3 +/- 1.8 mm/h, P = 0.002). This contribution was independent from that of HLA DR4/DR1 to severity. IL-1Ra plasma levels adjusted to ESR values were significantly lower in IL-1B2 (+3954) positive than negative RA patients (1.0 +/- 0.1 vs 1.2 +/- 0.1 ng/ml, P = 0.01). This IL-1B (+3954) gene polymorphism may be an important marker for the severity of joint destruction in RA and is associated with an imbalance in IL-1Ra production. As this genetic association was independent and additive to the risk of HLA DR4/DR1 status, it could be a useful addition to HLA-DR4/1 as a genetic prognostic marker early in the course of the disease.

Single nucleotide polymorphisms in intron 2 of the human interleukin-1 receptor antagonist (IL-1Ra) gene: further definition of the IL-1 beta and IL-1Ra polymorphisms in North American Caucasians and Taiwanese Chinese

Previous studies have suggested that a variable number tandem repeat (VNTR) polymorphism in the second intron of the interleukin-1 receptor antagonist (IL-1Ra) gene and the single nucleotide polymorphisms at positions -511 and +3954 of the IL-1beta gene might be associated with increased risks of chronic inflammatory diseases, autoimmune diseases and gastric cancer. In the present study, IL-1beta and IL-1Ra genotypes were analyzed among Asians in Taiwan and Caucasians in North America. We identified a novel polymorphism with 3 nucleotide substitutions in the IL-1Ra VNTR 2-repeat allele. One of the substitutions corresponds with the fourth 3' end nucleotide of the reverse primer that is often used for analysis of the IL-1Ra-associated VNTR locus. Mismatching between this primer and the 2-repeat allele can cause misleading amplification results when stringent conditions are used for annealing. The estimated haplotype frequencies of the variant IL-1 genes were significantly different between Taiwanese and Caucasians. The frequency of the pro-inflammatory IL-1Ra 2-repeat allele was significantly lower in Taiwanese than in Caucasians. In contrast, the frequencies of the pro-inflammatory IL-1beta -511T allele and +3954C allele were significantly higher among Taiwanese compared with Caucasians.

Association of the interleukin 1 receptor antagonist gene with ulcerative colitis in Northern European Caucasians

BACKGROUND AND AIMS

An association between the allele 2 of the interleukin 1 receptor antagonist gene variable number tandem repeats polymorphism in intron 2 and ulcerative colitis was first reported in 1994. Subsequent studies in Caucasian Northern European patients have not confirmed this, although trends towards an association were observed. The lack of statistical significance could reflect inadequate power. In this study the association was reassessed in a large independent set of well characterised Caucasian patients and a meta-analysis of reported patient series was performed.

PATIENTS AND METHODS

A total of 320 patients with endoscopically and histologically confirmed ulcerative colitis (124 pancolitis, 196 left sided and distal disease) and 827 ethnically matched controls were genotyped at polymorphic sites in the interleukin 1 receptor antagonist gene. Carriage rates were compared using chi(2) statistics. A meta-analysis of this and seven previous studies in North European Caucasian patients was performed using the Mantel-Haenszel chi(2) test.

RESULTS

Patients had a significantly increased carriage rate of allele 2 compared with controls (52% v 45%; odds ratio 1.3 (95% confidence interval (CI) 1.01-1.7); p=0.04). The allele 2 carriage rate was highest in extensive colitis (carriage rate 56%; odds ratio 1.5 (95% CI 1.1-2.3) p=0.02) and in individuals who had undergone colectomy (carriage rate 55%; odds ratio 1.5 (95% CI 0.95-2.4); p=0.08). Meta-analysis of all eight studies showed a significant association between carriage of allele 2 and ulcerative colitis (odds ratio 1.23 (95% CI 1.04-1.45); p=0.01).

CONCLUSIONS

The association of the interleukin 1 receptor antagonist gene polymorphism with ulcerative colitis is confirmed. The association is minor and confers only a small risk to an individual but will contribute a high attributable risk in a population due to the high allelic frequency. Accurate phenotypic characterisation defines more homogeneous subsets of patients, such as those with extensive disease, in whom the association is greater.

Genetic factors determine extent of bone loss in inflammatory bowel disease

BACKGROUND & AIMS

Although bone loss and osteoporosis are well-known long-term sequelae of inflammatory bowel disease (IBD), the risk factors for increased bone loss have not been identified. Balances of pro- and anti-inflammatory cytokines influence mechanisms of both chronic inflammation and bone resorption. The aim of this study was to identify genetic risk factors for rapid bone loss in IBD patients as a model of disease- and inflammation-associated bone loss.

METHODS

Multiple clinical parameters, biochemical markers of bone metabolism (vitamin D, parathyroid hormone, N-terminal telopeptide of type-I collagen, desoxypyridinoline, bone alkaline phosphatase), and bone mineral density were prospectively assessed in 83 IBD patients over 1.6+/-0.3 years. Eighty-six healthy bone marrow donors served as controls for allelotyping. The allele status of the interleukin 1 receptor antagonist (IL-1ra), IL-6, heat shock protein 70-2 (hsp 70-2), and heat shock protein 70-hom (hsp hom) genes was typed and correlated with clinical course of IBD and extent of bone loss.

RESULTS

The extent of bone loss was not correlated to clinical severity of disease or application of corticosteroids. Noncarriage of the 240-base pair allele of the IL-1ra gene and carriage of the 130-base pair allele of IL-6 were independently associated with increased bone loss. Genetic variations of the hsp genes were not associated with degree of bone loss. The combined presence of the named risk factors was significantly associated with increasing bone loss.

CONCLUSIONS

Genetic variations in the IL-6 and IL-1ra gene identify IBD patients at risk for increased bone loss.