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

Association of serum interleukin-6 and soluble interleukin-2-receptor levels with disease activity status in patients with inflammatory bowel disease: A prospective observational study

Crohn’s disease (CD) and ulcerative colitis (UC) are characterized by overexpression of proinflammatory cytokines. We determined the association of serum levels of interleukin (IL)-6, soluble-IL-2-receptor (sIL-2R) and CRP as well as of faecal calprotectin (FC) values with disease activity in CD and UC patients. This prospective study included 145 CD and 84 UC patients. Serum proinflammatory biomarkers and FC levels were measured and demographic, clinical and endoscopic characteristics were collected. Uni- and multivariate statistical analyses were performed. Serum IL-6 and CRP levels as well as FC values of CD patients were associated with clinical and endoscopic remission. In multivariate analysis serum IL-6 levels remained significantly associated with clinical and endoscopic remission. FC levels were also associated with endoscopic remission in CD patients. CD patients under the threshold levels of 8.5 pg/mL and 5.5 pg/mL for serum IL-6 were in 70% and 66% in clinical and endoscopic remission, respectively. Serum sIL-2R, CRP levels and FC values of UC patients were associated in univariate analysis with clinical and endoscopic remission. In multivariate analysis CRP and FC values were associated with clinical remission and serum sIL-2R as well as FC levels with endoscopic remission. UC patients under the threshold levels of 759 IU/mL and 646 IU/mL for serum sIL-2R were in 76% and 76% in clinical and endoscopic remission, respectively. Beside CRP and FC, serum IL-6 levels in CD patients and sIL-2R levels in UC patients can be a further useful non-invasive biomarker to identify the disease activity status.

Genetic and environmental factors significant for the presentation and development of inflammatory bowel disease

OBJECTIVES

The aim of the study was to evaluate associations between inflammatory bowel disease (IBD) presentation and variants in NOD2, TLR4, TNF-α, IL-6, IL-1β, and IL-RN genes in order to identify possible environmental factors that may affect IBD occurrence, investigate potential predictors for surgical treatment of IBD, and correlate the presence of granulomas in biopsy specimens with clinical characteristics of Crohn's disease (CD) patients.

PATIENTS AND METHODS

We genotyped 167 IBD patients using PCR-based methodology and tested for disease genotype-phenotype associations.

RESULTS

In CD patients ileal localization of disease was more frequent in NOD2 variant carriers. Ileal CD was associated with IL-6 GC+CC genotypes, identifying C allele as a possible marker of increased risk for ileal CD. In CD patients a positive family history for IBD was related to earlier onset of disease, higher risk for CD-related surgery, and appendectomy. CD patients who are TLR4 299Gly carriers are at higher risk for surgery at onset of the disease compared with TLR4 299Asp variant carriers. The presence of granuloma in biopsy specimens was more frequent in patients in whom a diagnosis of CD was made during emergency surgery. Multivariate analysis showed that CD carriers of the 299Gly allele had a 4.6-fold higher risk for emergency surgery before CD diagnosis is established compared with noncarriers, suggesting an aggressive disease course. Granuloma in endoscopic biopsies is detected 5.4-fold more frequently in patients treated surgically at the time of diagnosis.

CONCLUSION

Genetic variants together with epidemiological and clinical data of IBD patients could potentially be used as predictors of the disease course.

Effect of Cyperus Rotundus on Cytokine Gene Expression in Experimental Inflammatory Bowel Disease

BACKGROUND

The protective effect of the chloroform extract of Cyperus rotundus (CHCR) is attributed to its anti-inflammatory and antioxidant activities. Cytokines, important regulators of inflammation and repair, play a key role in the pathogenesis of inflammatory bowel disease (IBD). Targeting these cytokines can effectively ameliorate the symptoms of IBD. The aim of the present study was to unravel the molecular mechanism through cytokine regulation in rats in experimental IBD.

METHODS

Sprague Dawley rats were randomly allocated to 5 groups (n=6). Group I served as the normal control. Group II served as the vehicle control and received 50% ethanol intracolonically on day 11 of the study. Group III served as the model control. Group IV and Group V were given standard drug 5-aminosalicylic acid (100 mg/kg) and CHCR (800 mg/kg), respectively, for 18 days once a day orally. Colitis was induced with dinitrobenzene sulfonic acid (180 mg/kg in 50% ethanol) intracolonically in groups III-V on day 11 of the study. On day 18, the rats were euthanized and colon tissues were removed for IL-4, IL-6, IL-12, and IFN-gamma gene expression studies using quantitative RT-PCR.

RESULTS

The expression levels of proinflammatory cytokines IL-4, IL-6, IL-12, and IFN-gamma were upregulated in the model control rats. Pretreatment with 5-aminosalicylic acid (100 mg/kg) and CHCR (800 mg/kg) significantly decreased the fold of the expression of the above cytokines.

CONCLUSION

CHCR acts as a molecular brake and downregulates the expression of proinflammatory cytokine genes; this is beneficial for reducing the severity of the experimental IBD. Thus, Cyperus rotundus is a safe, economical, and effective alternative for the treatment of patients with IBD.

Sex- and corticotropin-releasing factor receptor 2- dependent actions of urocortin 1 during inflammation

We investigated whether corticotropin-releasing factor receptor 2 (CRF2) and its high-affinity agonist urocortin 1 (Ucn1) mediate sex-specific signaling and immune responses. Intrarectal trinitrobenzene sulfonic acid was used to induce experimental colitis in wild-type, CRF2 knockout (CRF2KO), and heterozygous (CRF2Ht) mice of both sexes. Changes in plasma extravasation, organ weight, survival, immune cell numbers, inflammatory cytokines, and the MAPK signaling pathway were assessed. Stored intestinal biopsies from patients with Crohn's disease (CD) and age- and sex-matched individuals without inflammatory bowel disease (IBD) were examined by immunofluorescence and confocal microscopy to characterize Ucn1 and CRF receptor expression. CRF2Ht mice of both sexes showed decreased survival during colitis compared with other genotypes. Ucn1 improved survival in male mice alone. Ucn1 restored colon length and spleen and adrenal weight and decreased colonic TNF-α, IL-6, and IL-1β levels in male CRF2Ht mice alone. CRF2Ht mice of both sexes showed decreased phosphorylation of MAPK p38 and heat shock protein 27 (Hsp27) levels. Ucn1 restored p-Hsp27 levels in male CRF2Ht mice alone. Expression of the chaperone protein Hsp90 decreased during colitis, except in male CRF2Ht mice. Taken together, our data indicate that sex shows significant interaction with genotype and Ucn1 during colitis. Human duodenal and colonic biopsies revealed that sex-specific differences exist in levels of CRF receptors and Ucn1 expression in patients with CD compared with the matched non-IBD subjects. To conclude, Ucn1 mediates sex-specific immune and cellular signaling responses via CRF2, emphasizing the need for inclusion of females in preclinical studies.

Interleukin 6 Increases Production of Cytokines by Colonic Innate Lymphoid Cells in Mice and Patients With Chronic Intestinal Inflammation

BACKGROUND & AIMS

Innate lymphoid cells (ILCs) are a heterogeneous group of mucosal inflammatory cells that participate in chronic intestinal inflammation. We investigated the role of interleukin 6 (IL6) in inducing activation of ILCs in mice and in human beings with chronic intestinal inflammation.

METHODS

ILCs were isolated from colons of Tbx21(-/-) × Rag2(-/-) mice (TRUC), which develop colitis; patients with inflammatory bowel disease (IBD); and patients without colon inflammation (controls). ILCs were characterized by flow cytometry; cytokine production was measured by enzyme-linked immunosorbent assay and cytokine bead arrays. Mice were given intraperitoneal injections of depleting (CD4, CD90), neutralizing (IL6), or control antibodies. Isolated colon tissues were analyzed by histology, explant organ culture, and cell culture. Bacterial DNA was extracted from mouse fecal samples to assess the intestinal microbiota.

RESULTS

IL17A- and IL22-producing, natural cytotoxicity receptor-negative, ILC3 were the major subset of ILCs detected in colons of TRUC mice. Combinations of IL23 and IL1α induced production of cytokines by these cells, which increased further after administration of IL6. Antibodies against IL6 reduced colitis in TRUC mice without significantly affecting the structure of their intestinal microbiota. Addition of IL6 increased production of IL17A, IL22, and interferon-γ by human intestinal CD3-negative, IL7-receptor-positive cells, in a dose-dependent manner.

CONCLUSIONS

IL6 contributes to activation of colonic natural cytotoxicity receptor-negative, CD4-negative, ILC3s in mice with chronic intestinal inflammation (TRUC mice) by increasing IL23- and IL1α-induced production of IL17A and IL22. This pathway might be targeted to treat patients with IBD because IL6, which is highly produced in colonic tissue by some IBD patients, also increased the production of IL17A, IL22, and interferon-γ by cultured human colon CD3-negative, IL7-receptor-positive cells.

Pro- and anti-inflammatory cytokine gene single-nucleotide polymorphisms in inflammatory bowel disease

Anti-inflammatory cytokines have an important role in disease, tumour and transplant processes. Alterations in the regulation of several cytokines have been implicated in a variety of inflammatory disorders, including IBD (inflammatory bowel disease) [Crohn's disease (CD) and ulcerative colitis (UC)]. Cytokine polymorphisms are also known to affect the level of gene expression. Thus, the aim of this study was to determine the relationship between cytokine polymorphisms and the IBD pathologies in a Spanish population. Polymorphisms analysis was performed using PCR-SSOP using a microbeads luminex assay. The following polymorphisms were determined: TNFα [-238G/A (rs361525) and -308G/A (rs1800629)], IFNγ [+874A/T (rs62559044)], TGFβ [+869C/T (rs1982073) and +915G/C (rs1800471)], IL10 [-1082A/A (rs1800896), -592A/C (rs1800872), -819C/T (rs1800871)], IL6 [-174C/G (rs1800795)], IL12p40 [3'UTR -1188A/C (rs3212227)], IL1α [-889C/T (rs1800587)], IL1β [-511C/T (rs1143634) and +3962C/T (rs1143633)], IL1R [Pst-1 1970C/T] and IL1RA [Mspa-1 11100C/T]. No statistical differences in TNFα, IFNγ, TGFβ, IL10, IL6, IL1α, IL1β, IL1R and IL1Ra genotypes and allele distributions between the IBD groups and healthy controls were found. However, we observed significant differences in the 3'UTR -1188A/C polymorphism of IL12p40. So -1188A allele was increased in patients with UC and the -1188C allele (high IL12p40 production) was increased in patients with CD with respect to controls. These data are in concordance with the fact that CD has been shown to be associated with a Th1 T-cell-mediated inflammation model and high IL12/IFNγ production at histological affected sites. These data suggest that cytokine polymorphisms in TNFα, IFNγ, TGFβ, IL10, IL6 and IL1α, IL1β, IL1R and IL1Ra cytokine gene do not seem to be relevant in IBD susceptibility and IL12p40 3'UTR -1188A/C polymorphism seems to be associated with a differential IBD development.

Translational research and efficacy of biologics in Crohn's disease: a cautionary tale

In the last several years many biologic agents for Crohn's disease have been developed. Due to their unique molecular specificity biologics are de facto indicators of the ultimate significance of the molecule targeted by the biologic itself. Here, we have reviewed many clinical studies that have used biologics for Crohn's disease. Their results show that despite potentially sound theoretical mechanisms of action and some initially promising data, most biologics - with few notable exceptions - have failed. Pharmacologic, study design or patient-related issues might explain these findings in some studies. However in many cases clinical failure of biologics might highlight the complexity of in vivo events and the potential deficiencies of current experimental settings. Hence, these observations call for new and efficient ways of predicting drug efficacy in clinical trials based on bench research. Conceivably, computer-based pathogenetic models could be used to simulate and predict clinical studies results in vivo.

Gender differences in paediatric patients of the swiss inflammatory bowel disease cohort study

PURPOSE

Gender differences in paediatric patients with inflammatory bowel disease (IBD) are frequently reported as a secondary outcome and the results are divergent. To assess gender differences by analysing data collected within the Swiss IBD cohort study database since 2008, related to children with IBD, using the Montreal classification for a systematic approach.

METHODS

Data on gender, age, anthropometrics, disease location at diagnosis, disease behaviour, and therapy of 196 patients, 105 with Crohn's disease (CD) and 91 with ulcerative or indeterminate colitis (UC/IC) were retrieved and analysed.

RESULTS

THE CRUDE GENDER RATIO (MALE : female) of patients with CD diagnosed at <10 years of age was 2.57, the adjusted ratio was 2.42, and in patients with UC/IC it was 0.68 and 0.64 respectively. The non-adjusted gender ratio of patients diagnosed at ≥10 years was 1.58 for CD and 0.88 for UC/IC. Boys with UC/IC diagnosed <10 years of age had a longer diagnostic delay, and in girls diagnosed with UC/IC >10 years a more important use of azathioprine was observed. No other gender difference was found after analysis of age, disease location and behaviour at diagnosis, duration of disease, familial occurrence of IBD, prevalence of extra-intestinal manifestations, complications, and requirement for surgery.

CONCLUSION

CD in children <10 years affects predominantly boys with a sex ratio of 2.57; the impact of sex-hormones on the development of CD in pre-pubertal male patients should be investigated.

Inflammatory bowel disease in pediatric and adolescent patients: A biomolecular and histopathological review

Crohn’s disease (CD) and ulcerative colitis (UC) are the two main forms of inflammatory bowel disease (IBD) with both overlapping and distinct clinical, pathological and biomolecular features. It has been suggested that pediatric IBD is a distinct disease entity, with probably different disease subtypes.The aim of this study is to review and summarize the evolution of the current concept of pediatric IBD. The results of this review reinforce the idea that pediatric CD and UC may be further classified in various clinicopathologic entities. For clinicians and pathologists convenience, practical algorithms for the distinction of the various subphenotypes of pediatric IBD are also provided.

Novel concepts in inflammatory bowel disease

INTRODUCTION

Clinical management in inflammatory bowel disease (IBD) is constantly changing. Although improvement in symptoms is of paramount importance, using this as the only surrogate marker of disease activity might underestimate disease burden.

SOURCES OF DATA

New data from randomized clinical trials are now available. Treatment paradigms are constantly changing leading to an evolution in the therapeutic approach in routine IBD practice.

AREAS OF AGREEMENT

Patients with an aggressive disease phenotype should be identified at the onset and treated more intensely in order to achieve long-lasting mucosal remission.

AREAS OF CONTROVERSY

Patients who have mild and indolent disease need to be identified and not over treated.

GROWING POINTS

The primary endpoint in IBD management should ideally be mucosal healing. Ample data are now available that correlates mucosal healing with surgical-free outcomes with minimal intestinal damage and patient disability. However, the exact degree of mucosal healing that will lead to improved long-term remission, decreased hospital and surgical rates remains unknown.

AREAS TIMELY FOR DEVELOPING RESEARCH

Clinical translational work is needed to identify novel pathways in IBD pathogenesis that sub-select patients who would benefit by specific-cytokine pathway modulation.

The value of experimental models of colitis in predicting efficacy of biological therapies for inflammatory bowel diseases

During the last decade, biological therapies have an increasing share in the modern therapeutics of various diseases including inflammatory bowel diseases (IBD). Animal models of IBD have often been used to identify the targets of biological therapies, to test their relevance to disease pathogenesis, to assess their therapeutic efficacy in vivo, and to check for drug toxicity. In the field of inflammatory diseases the majority of biologics under development have failed to reach the clinic. This review examines the ability of preclinical data from animal models of IBD to predict success or failure of biologics in human IBD. Specifically, it describes the murine models of IBD, the mechanism of disease induction, the phenotype of the disease, its relevance to human IBD, and the specific immunological features of disease pathogenesis in each model and mainly compares the results of the phase II and III trials of biologics in IBD with preclinical data obtained from studies in animal models. Finally, it examines the possible reasons for low success in translation from bench to bedside and offers some suggestions to improve translation rates.

Association of a functional variant in the Wnt co-receptor LRP6 with early onset ileal Crohn's disease

Ileal Crohn's Disease (CD), a chronic small intestinal inflammatory disorder, is characterized by reduced levels of the antimicrobial peptides DEFA5 (HD-5) and DEFA6 (HD-6). Both of these α-defensins are exclusively produced in Paneth cells (PCs) at small intestinal crypt bases. Different ileal CD-associated genes including NOD2, ATG16L1, and recently the β-catenin-dependant Wnt transcription factor TCF7L2 have been linked to impaired PC antimicrobial function. The Wnt pathway influences gut mucosal homeostasis and PC maturation, besides directly controlling HD-5/6 gene expression. The herein reported candidate gene study focuses on another crucial Wnt factor, the co-receptor low density lipoprotein receptor-related protein 6 (LRP6). We analysed exonic single nucleotide polymorphisms (SNPs) in a large cohort (Oxford: n = 1,893) and prospectively tested 2 additional European sample sets (Leuven: n = 688, Vienna: n = 1,628). We revealed an association of a non-synonymous SNP (rs2302685; Ile1062Val) with early onset ileal CD (OR 1.8; p = 0.00034; for homozygous carriers: OR 4.1; p = 0.00004) and additionally with penetrating ileal CD behaviour (OR 1.3; p = 0.00917). In contrast, it was not linked to adult onset ileal CD, colonic CD, or ulcerative colitis. Since the rare variant is known to impair LRP6 activity, we investigated its role in patient mucosa. Overall, LRP6 mRNA was diminished in patients independently from the genotype. Analysing the mRNA levels of PC product in biopsies from genotyped individuals (15 controls, 32 ileal, and 12 exclusively colonic CD), we found particularly low defensin levels in ileal CD patients who were carrying the variant. In addition, we confirmed a direct relationship between LRP6 activity and the transcriptional expression of HD-5 using transient transfection. Taken together, we identified LRP6 as a new candidate gene in ileal CD. Impairments in Wnt signalling and Paneth cell biology seem to represent pathophysiological hallmarks in small intestinal inflammation and should therefore be considered as interesting targets for new therapeutic approaches.

Transmission distortion in Crohn's disease risk gene ATG16L1 leads to sex difference in disease association

BACKGROUND

Crohn's disease (CD), an inflammatory disease of the bowel, affects millions of people around the world. Evidence suggests that disease onset and pathogenesis differ between males and females. Yet no comprehensive efforts exist to assess the sex-specific genetic architecture of CD.

METHODS

We used genotyping data from a cohort of 1748 CD cases and 2938 controls to investigate 71 meta-analysis-confirmed CD risk loci for sex differences in disease risk. We further validated the significant results in separate cohorts of 968 CD cases and 2809 controls, and performed a meta-analysis across datasets.

RESULTS

The single nucleotide polymorphism (SNP) rs3792106 (C/T) in ATG16L1 showed a significant sex effect with P-value 6.9 × 10(-13) and allelic odds ratio 1.48 in females, and P-value 0.013 and odds ratio 1.22 in males (odds ratio heterogeneity P-value 0.037). Surprisingly, the difference was found to arise from a discrepancy in allele frequencies between male and female controls (P-value 0.0045) rather than cases. We found similar results for this SNP in the separate validation datasets. Using 155 HapMap 3 trios, we detected significant maternal overtransmission of the T allele at rs3792106 (P-value 0.027).

CONCLUSIONS

Our results indicate that different transmission patterns between sexes may sustain the disparate allele frequencies at rs3792106 in healthy populations, and furthermore that a virus-risk variant mechanism implicated in CD alters the distribution in diseased patients. To our knowledge, this is the first report of sex-specific CD association in ATG16L1. The possible implications in CD and basic human biology present interesting areas for future investigation.

To grow up with Crohn’s disease

Objective: To assess the characteristics and course of childhood-onset Crohn’s disease among Hungarian patients. Methods: Records of 81 patients admitted between 1984 and 2006 and treated at least for one year until the 18th year of age were reviewed. Results: There was a 62% male dominance and a rate of 12.5% of familial cases. The diagnostic lag was 11.36 (1–96) months. The mean age was 13.6 years (4–17), the activity index was 37.88 (5–80) at diagnosis and the initial frequencies were as follows: ileal affection 87%, stricturing and penetrating forms 27%, perianal manifestation 26%, giant cells or granuloma formation 47%, malnutrition 23,5%, growth failure 11%. Steroid therapy and azathioprin treatment were given in 84% and 62% of the patients, respectively. Biologic treatment was not possible during the study period. 31% of the patients underwent surgery (abdominal surgery 20%, perianal surgery 11%). When patients reached the 18th year of age the mean activity index decreased to 6.63 (0–35), the rate of malnutrition to 9.9% and that of growth failure to 2.5%. All these changes were statistically significant. Conclusions: Characteristics of childhood-onset Crohn’s disease in Hungary are similar to those obtained in other European countries. The prolonged diagnostic lag, the high initial activity index, the granuloma formation and the stricturing/penetrating behavior may predict subsequent complications and need for surgery, and, therefore, justify intense initial therapy. The early introduction of immunomodulatory therapy affects favorably the course of illness. Orv. Hetil., 2011, 152, 546–554.

Genetics of childhood-onset inflammatory bowel disease

Nearly a third of inflammatory bowel disease (IBD) patients present in childhood or adolescence, with epidemiological and natural history studies clearly demonstrating a rising incidence in this population. Although early-onset disease has a distinct phenotype, such as more extensive disease at onset and rapid progression, two recent genome-wide association studies (GWAS) carried out exclusively in this age group have demonstrated marked genetic similarities to adult disease. Although these parallels exist, this review will focus on the novel regions associated with early-onset IBD susceptibility identified by these early-onset GWAS. These new loci reaffirm the dysregulated pathways previously implicated in adult IBD pathogenesis and provide further insight into the pathophysiology of intestinal inflammation. The newly identified loci and expression data suggest mutations in genes encoding IL-27, which is involved in Th17 effector cell physiology; MTMR3, which we demonstrate is an essential component of autophagy; and CAPN10, which is necessary in regulating endoplasmic reticulum stress. In addition, the roles of PSMG1, TNFRSF6B, ZMIZ1 and SMAD3 are also discussed in relation to abnormal protein degradation and the secondary immune response. It is clear that with increasing technology our understanding of IBD pathogenesis is deepening at the genomic level and that the use of early patient selection coupled with ongoing work on therapeutic targets will lead to improved disease-modifying treatments in the near future.

Pediatric inflammatory bowel diseases: coming of age

PURPOSE OF REVIEW

Inflammatory bowel diseases (IBD) comprise a heterogeneous group of distinct intestinal disorders. Here, we discuss the concept of childhood-onset IBD as separate disease forms within a larger multifactorial disease category.

RECENT FINDINGS

There are excellent epidemiological data indicating that the incidence of pediatric IBD, mainly Crohn's disease, is still increasing over the last decades, with indicators of more extensive and more severe disease presentations in children compared to adults, also reflected by higher levels of humoral immune responses. Recent genetic scans allowed to identify particular susceptibility genes for pediatric IBD forms, such as IL27 or probably DcR3. Early postnatal onset forms of IBD might reflect monogenetic causes, as suggested with the finding of IL10 signaling defects that may define a new form of IBD.

SUMMARY

There are good epidemiological, genetic and clinical data to distinguish different forms of IBD, particularly forms starting early in life. Profound insights in the molecular basis of immune dysregulation in IBD have been gained over the last few years. These recent discoveries will nourish and substantially stimulate the future search for precise cause(s) responsible for life-long intestinal inflammation and it will help to explain the still ongoing rise in incidence in childhood IBD.