Familial aggregation in Crohn's disease and ulcerative colitis in a Norwegian population-based cohort followed for ten years

Cryptosporidiosis in individuals with inflammatory bowel disease: a scoping review protocol

INTRODUCTION

Cryptosporidiosis is a leading cause of moderate-to-severe diarrhoea globally, and, while it is often self-limited, in immunocompromised individuals, the infection can be associated with significant morbidity and mortality. Diagnosis might be missed or delayed in patients with inflammatory bowel disease (IBD) due to similar presentation, and these patients may also be on immunosuppressive therapies, increasing their risk of infection. Additionally, gastrointestinal infection and dysbiosis may be a risk factor for IBD. Diagnosis, presentation and treatment of cryptosporidiosis in individuals with IBD, as well as any epidemiologic correlations between the two diseases, will be investigated.

METHODS AND ANALYSIS

MEDLINE, Embase, Cochrane Library, CINAHL, Dissertations and Theses Global and grey literature will be searched. Joanna Briggs Institute (JBI) methodology for scoping reviews was used for the protocol and will be for the review. Two reviewers will independently screen studies and extract data. The evidence and presentation of the results will be analysed with input from the review team. Studies of cryptosporidiosis in patients with IBD will be included. Paediatric, adolescent and adult studies in all patient environments will be included. Cases in which Crohn's disease does not affect the intestine and cases in which cryptosporidial infection is not in the intestine will be excluded.

ETHICS AND DISSEMINATION

Published clinical literature will be systematically reviewed, and this work does not directly involve patients. Consequently, ethical review by an institutional review board is not required. Data will be presented at academic conferences, and a culminating report will be published in a peer-reviewed journal. OPEN SCIENCE FRAMEWORK REGISTRATION: https://osf.io/j47mb.

Concordance of phenotypic characteristics among patients with familial Crohn's disease in China

OBJECTIVES

Familial Crohn's disease (CD) accounts for approximately 1.5%-22.5% of all CD cases worldwide. We aimed to assess the concordance in disease subtype and phenotypic features among patients with CD and their relatives based on data from a large, well-characterized, referral center-based cohort in China.

METHODS

A retrospective study was conducted on patients with familial CD who were admitted to the Sixth Affiliated Hospital of Sun Yat-sen University between January 2012 and June 2022. We analyzed the disease characteristics and performed a concordance analysis within the same family among patients with familial CD.

RESULTS

Among 5150 patients, 70 (1.4%) had a family history of Crohn's disease. The median age of the patients at initial diagnosis did not differ significantly between the probands and successors of family members with CD (p = 0.25). At the initial diagnosis, 54 first-degree relatives showed moderate concordance in age (κ = 0.50) and disease location (κ = 0.44). At the last follow-up visit, all family members and first-degree relatives showed good concordance in upper gastrointestinal involvement (κ = 0.67 and 0.62) and stricturing or penetrating behavior (κ = 0.69 and  0.77), respectively. Patients with familial CD within the same family showed moderate agreement regarding anti-tumor necrosis factor α monoclonal antibody use and treatment efficacy (κ = 0.44 and 0.42) and mild agreement regarding the efficacy and adverse reactions of thiopurine (κ = 0.26 and 0.35).

CONCLUSIONS

The proportion of patients with familial CD in China may be relatively low. The consistency of certain disease features in familial CD may be associated with the degree of kinship and convergence with longer follow-up duration.

How the Western Diet Thwarts the Epigenetic Efforts of Gut Microbes in Ulcerative Colitis and Its Association with Colorectal Cancer

Ulcerative colitis (UC) is an autoimmune disease in which the immune system attacks the colon, leading to ulcer development, loss of colon function, and bloody diarrhea. The human gut ecosystem consists of almost 2000 different species of bacteria, forming a bioreactor fueled by dietary micronutrients to produce bioreactive compounds, which are absorbed by our body and signal to distant organs. Studies have shown that the Western diet, with fewer short-chain fatty acids (SCFAs), can alter the gut microbiome composition and cause the host's epigenetic reprogramming. Additionally, overproduction of H2S from the gut microbiome due to changes in diet patterns can further activate pro-inflammatory signaling pathways in UC. This review discusses how the Western diet affects the microbiome's function and alters the host's physiological homeostasis and susceptibility to UC. This article also covers the epidemiology, prognosis, pathophysiology, and current treatment strategies for UC, and how they are linked to colorectal cancer.

Ulcerative colitis and periodontitis - a cross-sectional pilot study from a Norwegian cohort

BACKGROUND

Inflammatory bowel disease, which includes ulcerative colitis (UC), is an inflammatory disorder with potential impact on periodontal disease, but evidence to date for this association is limited. The primary aim of this study was to investigate the prevalence of periodontitis according to the 2017-classification in a cohort of subjects with UC. The secondary aim was to assess a potential correlation of periodontal status with previous UC disease parameters and to assess oral health-related quality-of-life.

METHOD

A cohort from a community hospital in Norway with confirmed extensive UC was comprehensively examined. Periodontal parameters, OHIP-14 and demographic variables were collected. Previous UC data including colon activity index (CAI), Mayo score and years of UC diagnosis was used to explore a potential correlation with periodontal status.

RESULTS

A total of 50 out of 63 invited patients participated. According to the 2017-classification, 74% of the patients presented periodontitis. No correlation was found between periodontitis (stage, grade, bleeding on probing or probing pocket depth ≥6mm) and CAI, Mayo score, or years with UC diagnosis.

CONCLUSIONS

Within the limitations of this study, the prevalence of periodontitis among patients with mild UC for more than 12 years was in line with that reported from a Norwegian general population. No correlation between periodontitis and UC disease indices or years with UC diagnosis was observed. The study suggests that the susceptibility to periodontitis may be limited in patients with well treated or mild UD who regularly attend the dental office, despite a considerable UC disease duration.

Serum Bile Acid Metabolites Predict the Therapeutic Effect of Mesalazine in Patients with Ulcerative Colitis

Ulcerative colitis (UC) is a systematic chronic disease characterized by insufficient intestinal absorption, and mesalazine is a common medical treatment. In the present study, 20 normal healthy controls (NC group), 10 unmedicated UC patients (UC group), and 20 mesalazine-responsive and 20 mesalazine-nonresponsive UC patients were recruited. A total of 42 serum BA metabolites, including 8 primary bile acids and 34 secondary bile acids (SBAs), were quantitatively measured. Compared with the NC group, serum SBAs in the UC patients were significantly lower but increased after mesalazine therapy. Differences in the serum TDCA, DCA, GDCA-3S, 12-keto LCA, and GCDCA-3S metabolites were found between the UC and NC groups, with AUC values of 0.777, 0.800, 0.815, 0.775, and 0.740, respectively. Furthermore, we identified 12-keto LCA as a specific BA marker of UC and BA biomarkers of mesalazine responsiveness. It was concluded that serum SBAs were decreased in UC patients, and TDCA, DCA, GDCA-3S, 12-keto LCA, and GCDCA-3S might aid in the diagnosis of UC. The abundance of SBAs increased after the mesalazine therapy, and serum 12-keto LCA was identified as an alternative invasive biomarker associated with UC diagnosis and therapeutic response, thereby providing a new approach for the prediction of response to mesalazine therapy in UC patients.

Association between IL-10 rs3024505 and susceptibility to inflammatory bowel disease: A systematic review and meta-analysis

Inflammatory bowel disease (IBD) is a chronic inflammatory disease that affects the small intestine, colon, and rectum. We evaluated associations between the interleukin 10 (IL-10) rs3024505 polymorphism and IBD, ulcerative colitis (UC), and Crohn's disease (CD) by meta-analysis. All peer-reviewed manuscripts concerning the relationship between IL-10_rs3024505 and IBD identified by searing the PubMed, Cochrane Library, EMBASE, and Chinese Medical Database were examined. The association between IL-10_rs3024505 and IBD was evaluated in allele (AG), recessive (RG), dominant (DG), homozygous (HMG), and heterozygous (HTG) genetic models. Associations were also conducted on IBD subtypes, CD and UC, and ethnicity (Non-Europeans and Europeans) subgroups. The meta-analysis included 13 studies, 8552 cases (IBD patients), and 12,830 healthy controls. Subgroup analysis of IBD (UC and CD) revealed heterogeneity in AG, DG, and HTG but no heterogeneity in RG or HMG. Moreover, AG, DG, and HTG did not show publication bias in IBD, CD, or UC, but RG and HMG exhibited publication bias. No heterogeneity and no publication bias were found among the five genetic models by a subgroup analysis of Non-Europeans and European ethnicities. The minor allele(T) of rs3024505 was significantly related to IBD: 1.37 (1.30-1.45) for AG, 2.06 (1.74-2.45) for RG, 1.39 (1.27-1.52) for DG, 2.25 (1.89-2.67) for HMG, and 1.32 (1.23-1.40) for HTG (all P < 0.00001). In the subgroup analysis of ethnicity, there was a significant effect of rs3024505 on IBD in Europeans but not non-Europeans: 1.38 (1.31-1.46) for AG, 2.07 (1.73-2.48) for RG, 1.39 (1.31-1.49) for DG, 2.26 (1.89-2.71) for HMG, and 1.33 (1.24-1.42) for HTG in Europeans (all P < 0.00001). Sensitivity analysis showed no dominant study in Europeans, but one study had a dominant impact in Non-Europeans. In conclusion, IL-10_rs3024505 polymorphism confers susceptibility to CD and UC in Europeans, but its impact should have conducted more studies in Non-Europeans.

Incidence and Prevalence of Inflammatory Bowel Disease in Norway and the Impact of Different Case Definitions: A Nationwide Registry Study

Background

Countries have different diagnostic procedures and treatment regimens for inflammatory bowel disease (IBD) patients. In addition to differences in population characteristics, completeness of data and health registries, different follow-up time and case definitions can have a large impact on estimates of the incidence and prevalence of IBD.

Aim

The aim of this study was to use hospital and prescription data to estimate incidence and prevalence of Crohn’s disease (CD) and ulcerative colitis (UC), using different case definitions.

Methods

This study used nationwide data from the Norwegian Patient Registry (2008 to 2017) and the Norwegian Prescription Database (2004 to April 2018). Incidence and prevalence were estimated using different case definitions of an IBD patient, varying the number of IBD-related hospital visits and IBD prescriptions required. The base case definition included patients with at least one IBD hospital visit and two IBD prescriptions or two IBD hospital visits.

Results

From 2010 to 2017, 16,758 incident IBD patients fulfilled our base case definition, with 6045 diagnosed with CD (36.1%) and 10,713 (63.9%) with UC. For CD, 47.2% of the patients were male while 53.8% of UC patients were male. The base case incidence varied between 14.1 and 16.0 per 100,000 person-years for CD and 24.7 and 28.4/100,000 person-years for UC patients in the years 2010–2017. When we required at least two IBD hospital visits, not utilizing the prescription data, the CD incidence was 22.3 per 100,000 person-years in 2010 and 13.9 per 100,000 person-years in 2017. For UC, the incidence was 47.4 and 20.6 per 100,000 person-years in 2010 and 2017. In 2017, the prevalence of CD was 0.27% (95% CI: 0.26–0.27) and 0.50% (95% CI: 0.490–0.502) for UC.

Conclusion

According to our base case definition, the incidence of IBD in Norway was stable from 2010 to 2017. Both the incidence and prevalence of IBD in Norway is among the highest in the world. Moreover, the study also highlights the consequences of different case definitions.

Assessment of Causal Direction Between Gut Microbiota and Inflammatory Bowel Disease: A Mendelian Randomization Analysis

Background

Recent studies have shown that the gut microbiota is closely related to the pathogenesis of Inflammatory Bowel Disease (IBD), but the causal nature is largely unknown. The purpose of this study was to assess the causal relationship between intestinal bacteria and IBD and to identify specific pathogenic bacterial taxa via the Mendelian randomization (MR) analysis.

Materials and Methods

MR analysis was performed on genome-wide association study (GWAS) summary statistics of gut microbiota and IBD. Specifically, the TwinsUK microbiota GWAS (N = 1,126 twin pairs) was used as exposure. The UK inflammatory bowel disease (UKIBD) and the Understanding Social Program (USP) study GWAS (N = 48,328) was used as discovery outcome, and the British IBD study (N = 35,289) was used as replication outcome. SNPs associated with bacteria abundance at the suggestive significance level (α = 1.0 × 10^-5) were used as instrumental variables. Bacteria were grouped into families and genera.

Results

In the discovery sample, a total of 30 features were available for analysis, including 15 families and 15 genera. Three features were nominally significant, including one family (Verrucomicrobiaceae, 2 IVs, beta = -0.04, p = 0.05) and two genera (Akkermansia, 2 IVs, beta = 0.04, p = 0.05; Dorea, 2 IVs, beta = -0.07, p = 0.04). All of them were successfully replicated in the replication sample (Verrucomicrobiaceae and Akkermansia P _replication = 0.02, Dorea P _replication = 0.01) with consistent effect direction.

Conclusion

We identified specific pathogenic bacteria features that were causally associated with the risk of IBD, thus offering new insights into the prevention and diagnosis of IBD.

Atherosclerosis and Inflammatory Bowel Disease-Shared Pathogenesis and Implications for Treatment

Atherosclerosis and inflammatory bowel disease (IBD) are often regarded as 2 distinct entities. The commonest manifestation of atherosclerosis is ischemic heart disease (IHD), and an association between IHD and IBD has been reported. Atherosclerosis and IBD share common pathophysiological mechanisms in terms of their genetics, immunology, and contributing environmental factors. Factors associated with atherosclerosis are implicated in the development of IBD and vice versa. Therefore, treatments targeting the common pathophysiology pathways may be effective in both conditions. The current review considers the pathophysiological pathways that are shared between the 2 conditions and discusses the implications for treatment and research.

Chinese research into ulcerative colitis from 1978 to 2017: A bibliometric analysis

BACKGROUND

Over the last 40 years, with accumulating evidence demonstrating a significant increase in the incidence of ulcerative colitis (UC) in China, the number of studies on UC has been rapidly increasing. But it still lacks a comprehensive meta-analysis of publications regarding UC for the last four decades in China. Thus, a bibliometric analysis of UC is warranted to investigate the trend and distribution of the publications on UC in China in recent years. And it is supposed that the number of the papers related to UC increased by year.

AIM

To investigate the current status of research output from Chinese studies related to UC during the period of 1978 to 2017, with special attention paid to the distribution of publication dates, journals, regions, and research organizations.

METHODS

Publications on UC were searched in the Chinese periodical database SinoMed from January 1978 to December 2017. The search term used for retrieval was “ulcerative colitis”. The language of the publications was restricted to English or Chinese. The studies have to be performed in China. Then, a bibliometric analysis was performed on the distribution of publication dates, journals, regions, and research organizations with EndNote, Excel, MySQL, and GraphPad Prism.

RESULTS

A total of 16257 papers matched the search criteria, which included 7561 papers published in core journals, 4641 evidence-based articles, and 4177 publications of randomized controlled trials. These papers were mainly published in Chinese Journal of Coloproctology, World Chinese Journal of Digestology, Chinese Journal of Digestion, Chinese Journal of Integrated Traditional and Western Medicine on Digestion, and Modern Journal of Integrated Traditional Chinese and Western Medicine. In particular, the majority of these organizations were located in Jiangsu, Henan, Shandong, and Guangdong Provinces which are rich areas or have the largest population per province. Most of these studies were conducted by academic institutions.

CONCLUSION

Over the past four decades, the output of research into UC in China has increased significantly, with academic institutions playing a central role in the academic field, but the number and quality of these researches vary substantially among different regions.

Prevalence of Anal Fistulas in Europe: Systematic Literature Reviews and Population-Based Database Analysis

Introduction

Despite the fact that perianal fistulas are associated with significant morbidity and impaired quality of life, their prevalence in Europe is unknown. The aim of this study was to estimate the prevalence of perianal fistulas in Europe, overall and according to etiology.

Methods

Two independent literature reviews were performed using different search strategies to maximize the identification of potentially relevant studies. Data from relevant articles were used to estimate the prevalence of perianal fistulas in Europe. The robustness of the estimate was evaluated using data from a large population-based database from the UK.

Results

A total of 26 studies provided epidemiological data on perianal fistulas, of which 16 provided suitable data to estimate the prevalence. Estimations using these data yielded a total prevalence of 1.69 per 10,000 population. Cryptoglandular infection and Crohn’s disease (CD) were the predominant etiologies, with prevalence rates at 0.86 and 0.76 per 10,000 population, respectively. Comparison of prevalence data from the UK population-based database with the European population resulted in a standardized prevalence estimate of all perianal fistulas of 1.83 per 10,000 population, confirming the robustness of the literature-based estimate.

Conclusion

Although in terms of incidence cryptoglandular fistulas were clearly predominant, the prevalence of fistulas in CD and cryptoglandular infection appeared more balanced. This is due to the longer duration and higher frequency of relapses of fistulas in CD. The estimated prevalence implies that perianal fistulas meet the criteria to be considered as a rare condition in Europe (prevalence less than 5 per 10,000 population).

Funding

This study was funded by Takeda Pharmaceutical U.S.A., Inc. and TiGenix SAU.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-019-01117-y) contains supplementary material, which is available to authorized users.

Incidence and prevalence of inflammatory bowel disease in Mexico from a nationwide cohort study in a period of 15 years (2000-2017)

Despite the worldwide increasing incidence and prevalence of Inflammatory Bowel Disease (IBD), our knowledge about it in Mexico is still limited. The aim of this study is to describe the incidence and prevalence of IBD as well as its clinical and socio-demographical characteristics in Mexico from a nation-wide perspective.Multicenter nation-wide cohort study that included 42 IBD clinics from all over the country that participated with electronically register of the new cases over 17 years as well as all known existing cases together with their clinical and socio-demographical characteristics from patients with IBD (ulcerative colitis [UC], Crohn disease [CD], and inflammatory bowel disease unclassified [IBDU]). The data collection was conducted between January and October 2017. Incidence, prevalence, and mean incidence over 2 decades were then calculated. Data base was analyzed using SPSS v24 program SPSS (version 24, IBM Corp., Armonk, NY, USA).A total of 2645 patients with IBD were registered. The crude incidence rates of IBD, UC, and CD, respectively, were 0.21, 0.16, and 0.04 cases per 100,000-person year. The highest incidence was registered in the year 2015, compared with to the previous years. The mean incidence of IBD has increased steadily from 0.05 to 0.21 per 100,000 person-years over the past 15 years (P = .06). The incidence of IBD new cases have increased significantly throughout the last 16 years, 5.9-fold for IBD, 5.3-fold for UC, and 9.5-fold for CD. The prevalence rates of IBD, UC, and CD, respectively, were 1.83, 1.45, and 0.34 cases per 100,000-person-year.This is the first study from a nation-wide perspective that demonstrated a significant increase of prevalence and incidence of IBD in Mexico in the last 15 years.

Increased Risk of Inflammatory Bowel Disease in Families with Tonsillectomy: A Danish National Cohort Study

BACKGROUND

The possible etiologic link between tonsillectomy and inflammatory bowel diseases remains unclear. To investigate the hereditary component, we assessed the risk of inflammatory bowel disease after own tonsillectomy as well as after tonsillectomy among family members.

METHODS

A nationwide Danish cohort of 7,045,288 individuals was established and linked to comprehensive national registers with data on kinship, tonsillectomy surgery, and diagnosis of inflammatory bowel disease from all health sectors. We used Poisson regression models to estimate hospital contact rate ratios (RR) for Crohn's disease and ulcerative colitis, with 95% confidence intervals (CI), between individuals with or without tonsillectomy, as well as between individuals with or without tonsillectomized relatives.

RESULTS

During 189 million person-years of follow-up between 1977 and 2014, 276,673 individuals were tonsillectomized, 22,015 developed Crohn's disease, and 49,550 developed ulcerative colitis. Rates of inflammatory bowel disease were elevated up to 20 years after own tonsillectomy (Crohn's disease: RR 1.52 [95% CI = 1.43, 1.61]; ulcerative colitis: RR 1.24 [95% CI = 1.18, 1.29]). RRs for Crohn's disease was 1.22 (95% CI = 1.17, 1.27) after first-degree relatives' tonsillectomy, 1.14 (95% CI = 1.08, 1.19) after second-degree relatives' tonsillectomy, and 1.08 (95% CI = 1.01, 1.15) after third-degree relatives' tonsillectomy. Corresponding RRs for ulcerative colitis were 1.10 (95% CI = 1.07, 1.13), 1.05 (95% CI = 1.01, 1.08), and 1.03 (95% CI = 0.98, 1.09).

CONCLUSIONS

Even individuals with tonsillectomized family members were at increased risk of inflammatory bowel disease. These findings call into question a direct influence of tonsillectomy on gastrointestinal inflammation and point instead toward shared hereditary or environmental factors. See video abstract at, http://links.lww.com/EDE/B464.

Epidemiologic features of ınflammatory bowel disease in Western Blacksea region of Turkey for the last 10 years: retrospective cohort study

BACKGROUND/AIMS

There are only a few epidemiological study about inflammatory bowel disease in the last 10 years in Turkey, especially in Western Blacksea region. In our study, we aimed to identify the changes in the incidence and the prevalence of inflammatory bowel disease in Western Blacksea region at the last 10 years.

METHODS

Totally 223 patients with inf lammatory bowel disease (160 ulcerative colitis, 63 Crohn's disease) were enrolled in the study followed up between 2004 to 2013 years. The epidemiological characteristics of patients were recorded.

RESULTS

The prevalences were 12.53/105 and 31.83/105 for Crohn's disease and ulcerative colitis respectively. Mean annual incidences increased from 0.99/105 and 0.45/105 for ulcerative colitis and Crohn's disease (2004 to 2005 years) to 4.87/105 and 2.09/105 for ulcerative colitis and Crohn's disease respectively (2011 to 2013 years). While the prevalence was higher in urban areas in Crohn's disease (12.60/105 ), it was higher in rural areas in ulcerative colitis (36.17/105 ). In ulcerative colitis, mean annual incidences were 2.91/105 and 2.86/105 for urban and rural areas respectively. In Crohn's disease, they were 1.37/105 and 1.08/105 for urban and rural areas respectively.

CONCLUSION

The incidence of inflammatory bowel disease seems to increase in Western Blacksea region at the last 10 years. This increment is more prevalent in rural areas.

The Impact of Inflammatory Bowel Disease in Canada 2018: IBD Research Landscape in Canada

Background

Health research in Canada is funded by government, health charities, foundations and industry. We investigated levels of IBD research funding and the scientific impact of this research in Canada between 2013 and 2017.

Methods

An analysis of global and Canadian funding in IBD research was conducted using the Canadian Institutes of Health Research (CIHR) Funded Research Database and UberResearch’s Dimensions platform. Examples of priority-driven and investigator-initiated IBD research in Canada are provided. Bibliometric analysis was used to assess the quality of IBD research output in Canada.

Results

Total funding for IBD research Canada between 2013 and 2017 was over $119 million Canadian dollars (CAD), with CIHR, the largest funder, contributing almost $66 million CAD, and Crohn’s and Colitis Canada, investing more than $32 million CAD. This ranks Canada fourth internationally. A comparative analysis indicates that publications by Canadian IBD researchers have a greater impact than other Canadian and international comparators. When productivity and impact in IBD research are combined, Canada is among the top three in the world.

Conclusions

Investment in IBD research in Canada has resulted in the development of a strong collaborative group of researchers producing impactful, world-class research. On all measures of academic productivity and influence, Canada ranks in the top two or three internationally. The challenges ahead are to continue to fund innovative IBD research and grow the next generation of IBD researchers while moving research findings into changes in health policy and practice in order to benefit affected patients and their families—and ultimately, to find the cause(s) and identify the cure(s).

Current, experimental, and future treatments in inflammatory bowel disease: a clinical review

Inflammatory bowel diseases (IBDs) may result from dysregulated mucosal immune responses directed toward the resident intestinal microbiota. This review describes the hallmark immunobiology of Crohn's disease and ulcerative colitis as well as therapeutic targets and mechanisms of action for current, experimental, and future treatments in IBD. Conventional therapies include 5-aminosalicylic acid, glucocorticosteroids, thiopurines, and methotrexate. Since 1997, monoclonal antibodies have gained widespread use. These consist of antibodies directed against pro-inflammatory cytokines such as tumor necrosis factor α, interleukin (IL)-12, and IL-23, or anti-homing antibodies directed against α4β7 integrin. Emerging oral therapies include modulators of intracellular signal transduction such as Janus kinase inhibitors. Vitamin D may help to regulate innate and adaptive immune responses. Modulation of the intestinal microbiota, using live microorganisms (probiotics), substrates for the colonic microbiota (prebiotics), or fecal microbiota transplantation (FMT), is in development. Dietary supplements are in widespread use, but providing evidence for their benefit is challenging. Stem cell treatment and nervous stimulation are promising future treatments.

Ulcerative colitis

Ulcerative colitis is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide. The pathogenesis is multifactorial, involving genetic predisposition, epithelial barrier defects, dysregulated immune responses, and environmental factors. Patients with ulcerative colitis have mucosal inflammation starting in the rectum that can extend continuously to proximal segments of the colon. Ulcerative colitis usually presents with bloody diarrhoea and is diagnosed by colonoscopy and histological findings. The aim of management is to induce and then maintain remission, defined as resolution of symptoms and endoscopic healing. Treatments for ulcerative colitis include 5-aminosalicylic acid drugs, steroids, and immunosuppressants. Some patients can require colectomy for medically refractory disease or to treat colonic neoplasia. The therapeutic armamentarium for ulcerative colitis is expanding, and the number of drugs with new targets will rapidly increase in coming years.

Variation at 2q35 (PNKD and TMBIM1) influences colorectal cancer risk and identifies a pleiotropic effect with inflammatory bowel disease

To identify new risk loci for colorectal cancer (CRC), we conducted a meta-analysis of seven genome-wide association studies (GWAS) with independent replication, totalling 13 656 CRC cases and 21 667 controls of European ancestry. The combined analysis identified a new risk association for CRC at 2q35 marked by rs992157 (P = 3.15 × 10-8, odds ratio = 1.10, 95% confidence interval = 1.06-1.13), which is intronic to PNKD (paroxysmal non-kinesigenic dyskinesia) and TMBIM1 (transmembrane BAX inhibitor motif containing 1). Intriguingly this susceptibility single-nucleotide polymorphism (SNP) is in strong linkage disequilibrium (r2 = 0.90, D' = 0.96) with the previously discovered GWAS SNP rs2382817 for inflammatory bowel disease (IBD). Following on from this observation we examined for pleiotropy, or shared genetic susceptibility, between CRC and the 200 established IBD risk loci, identifying an additional 11 significant associations (false discovery rate [FDR]) < 0.05). Our findings provide further insight into the biological basis of inherited genetic susceptibility to CRC, and identify risk factors that may influence the development of both CRC and IBD.

Animal models to study acute and chronic intestinal inflammation in mammals

Acute and chronic inflammatory diseases of the intestine impart a significant and negative impact on the health and well-being of human and non-human mammalian animals. Understanding the underlying mechanisms of inflammatory disease is mandatory to develop effective treatment and prevention strategies. As inflammatory disease etiologies are multifactorial, the use of appropriate animal models and associated metrics of disease are essential. In this regard, animal models used alone or in combination to study acute and chronic inflammatory disease of the mammalian intestine paired with commonly used inflammation-inducing agents are reviewed. This includes both chemical and biological incitants of inflammation, and both non-mammalian (i.e. nematodes, insects, and fish) and mammalian (i.e. rodents, rabbits, pigs, ruminants, dogs, and non-human primates) models of intestinal inflammation including germ-free, gnotobiotic, as well as surgical, and genetically modified animals. Importantly, chemical and biological incitants induce inflammation via a multitude of mechanisms, and intestinal inflammation and injury can vary greatly according to the incitant and animal model used, allowing studies to ascertain both long-term and short-term effects of inflammation. Thus, researchers and clinicians should be aware of the relative strengths and limitations of the various animal models used to study acute and chronic inflammatory diseases of the mammalian intestine, and the scope and relevance of outcomes achievable based on this knowledge. The ability to induce inflammation to mimic common human diseases is an important factor of a successful animal model, however other mechanisms of disease such as the amount of infective agent to induce disease, invasion mechanisms, and the effect various physiologic changes can have on inducing damage are also important features. In many cases, the use of multiple animal models in combination with both chemical and biological incitants is necessary to answer the specific question being addressed regarding intestinal disease. Some incitants can induce acute responses in certain animal models while others can be used to induce chronic responses; this review aims to illustrate the strengths and weaknesses in each animal model and to guide the choice of an appropriate acute or chronic incitant to facilitate intestinal disease.

Inflammatory bowel disease

Scandinavian researchers have contributed to the present understanding of inflammatory bowel disease (IBD). Important epidemiological data and family risk factors have been reported from all the Nordic countries, original twin studies mainly from Denmark and Sweden, and relationships to cancer and surgery mostly from Sweden. In collaboration with the industry, development of medical compounds was for a long time in the front line of international research, and the Scandinavian countries participated in the clinical breakthrough of biologic treatment. At present, many Nordic centers are working in the forefront of IBD research. An increasing number of young investigators have entered the scene along with the extended distribution of University clinics and research laboratories in these countries. This presentation of IBD gives a brief overview in the fields of clinical epidemiology and molecular biology. Many areas are covered by International collaborations with partners from Nordic centers. IBD was a topic focused by the founders of Scandinavian Journal of Gastroenterology. After 50 years one may state that the journal's history reflects important pieces of scientific knowledge within these diseases. The early scope of Johannes Myren for IBD was shown through his work in the original World Association of Gastroenterology (OMG), and after 50 years we can clearly support the view that global perspectives in IBD are increasingly important.

Temporal trends in non-stricturing and non-penetrating behaviour at diagnosis of Crohn's disease in Örebro, Sweden: a population-based retrospective study

BACKGROUND AND AIM

The incidence of Crohn's disease (CD) is continuing to rise in several countries and in others it appears to have already levelled off after a period of increase. We updated our previous population-based study, by re-extraction of all information on patients diagnosed with CD between 1963 and 2010. Our aim was to assess temporal trends in incidence, prevalence and disease phenotype at diagnosis.

METHODS

Patients of all ages with a potential diagnosis of CD were identified retrospectively by evaluation of medical notes of all current and previous patients at the colitis clinic, Örebro University Hospital amended by computerised search in the inpatient, outpatient, primary care and histopathological records. Diagnosis was confirmed by subsequent evaluation of medical notes. Disease phenotype was defined according to the Montreal classification.

RESULTS

The incidence increased over time, especially among Crohn's disease, A1 and A3. SaTScan model revealed a statistically significant high incidence during 1991-2010 (p=0.0001). The median age at diagnosis increased from 28 (3-79) years to 37 (5-87) years (p=0.0002). The point prevalence increased from 21/10(5) (14-32) in 1965 to 267/10(5) (244-291) in 2010. Non-stricturing and non-penetrating disease at diagnosis increased from 12.5% in 1963-1965 to 82.3% in 2006-2010 (p<0.0001).

CONCLUSION

The incidence of CD increased over time, although it seemed to be plateauing during the most recent decades. A striking increase in non-stricturing, non-penetrating disease at diagnosis was observed, suggesting earlier diagnosis or phenotypic change. The observed point prevalence in 2010 is among the highest reported.

An analysis of genetic factors related to risk of inflammatory bowel disease and colon cancer

BACKGROUND AND AIMS

Patients with inflammatory bowel disease (IBD) have a higher risk of developing colorectal cancer than the general population. Genome-wide association studies have identified and replicated several loci associated with risk of IBD; however, it is currently unknown whether these loci are also associated with colon cancer risk.

METHODS

We selected 15 validated SNPs associated with risk of either Crohn's disease, ulcerative colitis, or both in previous GWAS and tested whether these loci were also associated with colon cancer risk in a two-stage study design.

RESULTS

We found that rs744166 in STAT3 was associated with colon cancer risk in two studies; however, the direction of the observation was reversed in TP53 mutant tumors possibly due to a nullification of the effect by mutant p53. The SNP, which lies within intron 1 of the STAT3 gene, was associated with lower expression of STAT3 mRNA in TP53 wild-type, but not mutant, tumors.

CONCLUSIONS

These data suggest that the STAT3 locus is associated with both IBD and cancer. Further understanding the function of this variant in relation to TP53 could possibly explain the role of this gene in autoimmunity and cancer. Furthermore, an analysis of this locus, specifically in a population with IBD, could help to resolve the relationship between this SNP and cancer.

Inhibitors of apoptosis (IAPs) regulate intestinal immunity and inflammatory bowel disease (IBD) inflammation

The inhibitor of apoptosis (IAP) family members, notably cIAP1, cIAP2, and XIAP, are critical and universal regulators of tumor necrosis factor (TNF) mediated survival, inflammatory, and death signaling pathways. Furthermore, IAPs mediate the signaling of nucleotide-binding oligomerization domain (NOD)1/NOD2 and other intracellular NOD-like receptors in response to bacterial pathogens. These pathways are important to the pathogenesis and treatment of inflammatory bowel disease (IBD). Inactivating mutations in the X-chromosome-linked IAP (XIAP) gene causes an immunodeficiency syndrome, X-linked lymphoproliferative disease type 2 (XLP2), in which 20% of patients develop severe intestinal inflammation. In addition, 4% of males with early-onset IBD also have inactivating mutations in XIAP. Therefore, the IAPs play a greater role in gut homeostasis, immunity and IBD development than previously suspected, and may have therapeutic potential.

High and increasing prevalence of inflammatory bowel disease in Finland with a clear North-South difference

BACKGROUND AND AIM

Inflammatory bowel disease (IBD) prevalence has increased and a North-South gradient has been reported. We estimated the nationwide prevalence of IBD, ulcerative colitis (UC) and Crohn's disease (CD) in 1993, and prevalence of IBD in 2008, and assessed the geographical distribution of IBD in Finland. In addition, we investigated the vitamin D levels in a study population from a large, nationally representative health examination survey, the Health 2000 Survey.

METHODS

The register study for prevalences included all patients who had special reimbursement of medications for IBD in the years 1993 (n=10,958) and 2008 (31,703). The study for D-vitamin measurement consisted of 6134 persons who had participated in the Health 2000 Survey.

RESULTS

The nationwide point prevalence of IBD in 1993 was 216 per 100,000 inhabitants, and 595 in 2008. In 1993, the prevalence of UC (177) was fourfold higher than the prevalence of CD (38). The prevalence of IBD and UC in Finland increased from South to North. For CD, no geographical variation could be demonstrated. In the Health 2000 survey, vitamin D levels were lower in Northern than in Southern Finland.

CONCLUSIONS

Finland belongs to high prevalence area of IBD and this prevalence has increased nearly threefold during the past 15 years. A clear North-South gradient has been shown for IBD and UC, but not for CD. Slightly lower vitamin D levels in Northern Finland may be associated with the observed higher prevalence of IBD there.

Next generation exome sequencing of paediatric inflammatory bowel disease patients identifies rare and novel variants in candidate genes

BACKGROUND

Multiple genes have been implicated by association studies in altering inflammatory bowel disease (IBD) predisposition. Paediatric patients often manifest more extensive disease and a particularly severe disease course. It is likely that genetic predisposition plays a more substantial role in this group.

OBJECTIVE

To identify the spectrum of rare and novel variation in known IBD susceptibility genes using exome sequencing analysis in eight individual cases of childhood onset severe disease.

DESIGN

DNA samples from the eight patients underwent targeted exome capture and sequencing. Data were processed through an analytical pipeline to align sequence reads, conduct quality checks, and identify and annotate variants where patient sequence differed from the reference sequence. For each patient, the entire complement of rare variation within strongly associated candidate genes was catalogued.

RESULTS

Across the panel of 169 known IBD susceptibility genes, approximately 300 variants in 104 genes were found. Excluding splicing and HLA-class variants, 58 variants across 39 of these genes were classified as rare, with an alternative allele frequency of <5%, of which 17 were novel. Only two patients with early onset Crohn's disease exhibited rare deleterious variations within NOD2: the previously described R702W variant was the sole NOD2 variant in one patient, while the second patient also carried the L1007 frameshift insertion. Both patients harboured other potentially damaging mutations in the GSDMB, ERAP2 and SEC16A genes. The two patients severely affected with ulcerative colitis exhibited a distinct profile: both carried potentially detrimental variation in the BACH2 and IL10 genes not seen in other patients.

CONCLUSION

For each of the eight individuals studied, all non-synonymous, truncating and frameshift mutations across all known IBD genes were identified. A unique profile of rare and potentially damaging variants was evident for each patient with this complex disease.

Crohn's disease

Crohn's disease is a relapsing systemic inflammatory disease, mainly affecting the gastrointestinal tract with extraintestinal manifestations and associated immune disorders. Genome wide association studies identified susceptibility loci that--triggered by environmental factors--result in a disturbed innate (ie, disturbed intestinal barrier, Paneth cell dysfunction, endoplasmic reticulum stress, defective unfolded protein response and autophagy, impaired recognition of microbes by pattern recognition receptors, such as nucleotide binding domain and Toll like receptors on dendritic cells and macrophages) and adaptive (ie, imbalance of effector and regulatory T cells and cytokines, migration and retention of leukocytes) immune response towards a diminished diversity of commensal microbiota. We discuss the epidemiology, immunobiology, amd natural history of Crohn's disease; describe new treatment goals and risk stratification of patients; and provide an evidence based rational approach to diagnosis (ie, work-up algorithm, new imaging methods [ie, enhanced endoscopy, ultrasound, MRI and CT] and biomarkers), management, evolving therapeutic targets (ie, integrins, chemokine receptors, cell-based and stem-cell-based therapies), prevention, and surveillance.

Deep resequencing of GWAS loci identifies independent rare variants associated with inflammatory bowel disease

More than 1,000 susceptibility loci have been identified through genome-wide association studies (GWAS) of common variants; however, the specific genes and full allelic spectrum of causal variants underlying these findings have not yet been defined. Here we used pooled next-generation sequencing to study 56 genes from regions associated with Crohn's disease in 350 cases and 350 controls. Through follow-up genotyping of 70 rare and low-frequency protein-altering variants in nine independent case-control series (16,054 Crohn's disease cases, 12,153 ulcerative colitis cases and 17,575 healthy controls), we identified four additional independent risk factors in NOD2, two additional protective variants in IL23R, a highly significant association with a protective splice variant in CARD9 (P < 1 × 10(-16), odds ratio ≈ 0.29) and additional associations with coding variants in IL18RAP, CUL2, C1orf106, PTPN22 and MUC19. We extend the results of successful GWAS by identifying new, rare and probably functional variants that could aid functional experiments and predictive models.

Relationships between inflammatory bowel disease and perinatal factors: both maternal and paternal disease are related to preterm birth of offspring

BACKGROUND

The aims of this study were to explore the influences of familial, maternal, and paternal inflammatory disease (IBD) on perinatal outcomes in the offspring and the risk for development of IBD related to perinatal factors.

METHODS

Eighty-five patients with Crohn's disease (CD) and 86 with ulcerative colitis (UC) were included from a population-based incidence study enrolled 1990-1994. Family and birth records of these patients, as well as of their 207 infants, were drawn from the Norwegian Medical Birth Registry, established in 1967, and compared with the national birth cohort from the same period.

RESULTS

Maternal (odds ratio [OR] = 2.15, 95% confidence interval [CI]: 1.36, 3.39) and paternal IBD (OR = 3.02, 95% CI: 1.82, 5.01) influenced the risk of preterm birth (<37 weeks), which further increased if the affected parents had a first-degree relative with IBD (OR = 4.29, 95% CI: 1.59, 11.63). Maternal CD was associated with lower birth weight in the offspring (crude difference: 271.79 g, 95% CI: 87.83, 455.77, versus controls). Maternal UC increased the risk of perinatal bacterial infection in the offspring (OR = 6.03, 95% CI: 2.03, 17.91). IBD patients (2.3%) were less likely to be delivered by cesarean section than controls (8.1%) (OR = 0.27, CI: 95%: 0.10, 0.73).

CONCLUSIONS

Familial, maternal, and paternal IBD were linked to preterm birth, which might be explained by genetic mechanisms. The present protective effect of cesarean sections needs further clarification in future studies.