Is current smoking still an important environmental factor in inflammatory bowel diseases? Results from a population-based incident cohort

Unraveling the blood microbiome: novel insights into inflammasome responses in Crohn's disease

OBJECTIVE

Crohn's disease (CD), an inflammatory bowel disease with unknown etiology, is influenced by genetic, environmental, and immunological factors. This study aimed to analyze the blood microbiome and inflammasome responses, emphasizing NLRP3 protein expression and IL-1β and IL-18 plasma levels, between Crohn's patients and healthy subjects.

METHODS

A total of 40 volunteers were included in this study. The 16S rRNA technique was used to sequence the V3-V4 regions of the blood sample. NLRP3 protein levels in plasma were ascertained through Western Blot, and IL-1β and IL-18 plasma profiles were examined using ELISA.

RESULTS

Analysis highlighted five unique phyla in patients' plasma, emphasizing the role of the blood microbiome in CD. Compared to controls, Crohn's patients exhibited elevated NLRP3 protein expression. Plasma IL-1β levels were diminished in patients ( P  = 0.0041), whereas IL-18 levels were comparably higher ( P  = 0.8209). In patients with CD, the presence of Staphylococcus sciuri in blood samples highlights its potential role in the disease's onset. The study also underscored the interplay between dietary habits, specifically increased meat consumption, and the progression of CD.

CONCLUSION

Our pioneering research discerns the variations in the blood microbiome and inflammasome responses between Crohn's patients and healthy individuals. Significant microbiome alterations and the detection of the Staphylococcus sciuri pathogen in Crohn's patients were notable. The pronounced NLRP3 protein in patients suggests its potential as a diagnostic biomarker. Future explorations into IL-1β and IL-18 pathways promise to unveil innovative insights into CD.

Research progress of ferroptosis and inflammatory bowel disease

Inflammatory bowel disease (IBD) is a non-specific chronic inflammatory disorder of the gastrointestinal tract, imposing significant burdens on both society and individuals. As a new type of regulated cell death (RCD), ferroptosis is different from classic RCDs such as apoptosis and necrosis in cell morphology, biochemistry and genetics. The main molecular mechanisms of ferroptosis include dysregulation of iron metabolism, impaired antioxidant capacity, mitochondrial dysfunction, accumulation of lipid-associated super-oxides, and membrane disruption. In recent years, increasing evidence has shown that ferroptosis is involved in the pathophysiology of inflammatory bowel disease. However, the exact roles and underlying molecular mechanisms have not been fully elucidated. This article reviews the mechanism of ferroptosis in the occurrence and development of inflammatory bowel disease, in order to provide new ideas for the pathophysiological research of inflammatory bowel disease. Additionally, we discuss potential strategies for the prevention and treatment of inflammatory bowel disease by targeting ferroptosis.

Nicotine improves DSS-induced colitis by inhibiting NLRP3 and altering gut microbiota

Ulcerative colitis (UC) is a chronic recurrent inflammatory disease affecting the rectum and colon. Numerous epidemiological studies have identified smoking as a protective factor for UC. Dysbiosis of intestinal microbiota and release of inflammatory factors are well-established characteristics associated with UC. Therefore, we have observed that nicotine exhibits the potential to ameliorate colitis symptoms in UC mice. Additionally, it exerts a regulatory effect on colonic microbiota dysbiosis by promoting the growth of beneficial bacteria while suppressing harmful bacteria. Combined in vivo and in vitro investigations demonstrate that nicotine primarily impedes the assembly of NLRP3, subsequently inhibiting downstream IL-1β secretion.

Global evolving patterns and cross-country inequalities of inflammatory bowel disease burden from 1990 to 2019: a worldwide report

AIMS

Inflammatory bowel disease (IBD) is a global disease. We aim to summarize the latest epidemiological patterns of IBD at the national, regional and global levels to give well-deserved attention and outline facilitating measures to reduce the disease burden.

METHODS

We collected the incidence, prevalence, mortality and disability-adjusted life years (DALYs) of IBD in 204 countries and territories from 1990 to 2019 using data from the Global Burden of Disease Study 2019. We further calculated the estimated annual percentage change (EAPC) to qualify the temporal trends of IBD burden by sex, age and region over the past 30 years.

RESULTS

Globally, a total of 404.55 thousand incident cases, 4898.56 thousand prevalent cases, 41.00 thousand deaths and 1622.50 thousand DALYs of IBD were estimated in 2019. The age-standardized DALYs decreased from 27.2 in 1990 to 20.15 per 100,000 people in 2019, with an EAPC of -1.04. The high socio-demographic index regions presented pronounced age-standardized rates (ASRs) consistently over the last 30 years. The high-income North America had the highest ASRs in 2019, followed by Western Europe and Australasia. No gender difference was observed after being stratified by sex.

CONCLUSIONS

The accumulated IBD patients are expected to increase in the future due to the increased rate of IBD in developing countries, and social aging in developed countries. Understanding the changes in epidemiological patterns helps to provide evidence to mitigate the rising burden of IBD.

3D Printed Personalized Colon-targeted Tablets: A Novel Approach in Ulcerative Colitis Management

Ulcerative colitis (UC) and Crohn's disease (CD) are two types of idiopathic inflammatory bowel disease (IBD) that are increasing in frequency and incidence worldwide, particularly in highly industrialized countries. Conventional tablets struggle to effectively deliver anti-inflammatory drugs since the inflammation is localized in different areas of the colon in each patient. The goal of 3D printing technology in pharmaceutics is to create personalized drug delivery systems (DDS) that are tailored to each individual's specific needs. This review provides an overview of existing 3D printing processes, with a focus on extrusion-based technologies, which have received the most attention. Personalized pharmaceutical products offer numerous benefits to patients worldwide, and 3D printing technology is becoming more affordable every day. Custom manufacturing of 3D printed tablets provides innovative ideas for developing a tailored colon DDS. In the future, 3D printing could be used to manufacture personalized tablets for UC patients based on the location of inflammation in the colon, resulting in improved therapeutic outcomes and a better quality of life.

Time Trends of Environmental and Socioeconomic Risk Factors in Patients with Inflammatory Bowel Disease over 40 Years: A Population-Based Inception Cohort 1977-2020

BACKGROUND

Data from population-based studies investigating trends in environmental factors associated with inflammatory bowel disease (IBD) is lacking. We aimed to assess long-term time trends of environmental and socioeconomic factors in IBD patients from a well-defined population-based cohort from Veszprem, Hungary.

METHODS

Patients were included between 1 January 1977, and 31 December 2020. Trends of environmental and socioeconomic factors were evaluated in three periods based on the decade of diagnosis, representing different therapeutic eras: cohort-A,1977-1995; cohort-B,1996-2008 (immunomodulator era); and cohort-C, 2009-2020 (biological era).

RESULTS

A total of 2240 incident patients with IBD were included (ulcerative colitis (UC) 61.2%, male 51.2%, median age at diagnosis: 35 years (IQR 29-49)). Rates of active smoking significantly decreased over time in Crohn's disease (CD): 60.2%, 49.9%, and 38.6% in cohorts A/B/C (p < 0.001). In UC, the rates were low and stable: 15.4%, 15.4%, and 14.5% in cohorts A/B/C (p = 0.981). Oral contraceptive use was more common in CD compared to UC (25.0% vs. 11.6%, p < 0.001). In UC, prevalence of appendectomy before diagnosis decreased over time: 6.4%, 5.5%, and 2.3% in cohorts A/B/C (p = 0.013). No significant changes were found in the socio-geographic characteristics of the IBD population (urban living: UC, 59.8%/64.8%/ 62.5% (p = 0.309) and CD, 62.5%/ 62.0%/ 59.0% (p = 0.636), in cohorts A/B/C). A greater percentage of patients had completed secondary school as the highest education level in later cohorts in both UC (42.9%/50.2%/51.6%, p < 0.001) and CD (49.2%/51.7%/59.5%, p = 0.002). A higher percentage of skilled workers (34.4%/36.2%/38.9%, p = 0.027) was found in UC, but not in CD (p = 0.454).

CONCLUSION

The association between trends of known environmental factors and IBD is complex. Smoking has become less prevalent in CD, but no other major changes occurred in socioeconomic factors over the last four decades that could explain the sharp increase in IBD incidence.

Temporal Trends of Inflammatory Bowel Disease Burden in China from 1990 to 2030 with Comparisons to Japan, South Korea, the European Union, the United States of America, and the World

Purpose

To identify and predict the epidemiological burden and trends of inflammatory bowel disease (IBD) in China and compare them globally.

Methods

We collected incidence, prevalence, deaths, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and the age-standardized rates (ASRs) of IBD from 1990 to 2019 in China, four developed countries and the world, from the Global Burden of Disease Study 2019. The average annual percentage change (AAPC) was calculated to evaluate the temporal trends.

Results

From 1990 to 2019, the numbers of incident and prevalent cases, age-standardized incidence rate (ASIR), and age-standardized prevalence rate (ASPR) of IBD increased in China, regardless of gender and age; decreased YLLs and increased YLDs caused a stable number of DALYs; the age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) decreased. In 2019, the ASIR, ASPR, ASMR, and ASDR were 3.01/100,000 person-years (/100,000) (95% UI: 2.59, 3.50), 47.06/100,000 (95% UI: 40.05, 54.99), 0.30/100,000 (95% UI: 0.24, 0.35), and 13.1/100,000 (95% UI: 10.29, 16.31), respectively; almost all disease burden data were higher in males. In 2017, the ASDR in different socio-demographic index provinces ranged from 24.62/100,000 (95% UI: 16.95, 33.81) to 63.97/100,000 (95% UI: 44.61, 91.48). When compared globally, the ASIR and ASPR in China had opposite trends and the highest AAPCs. In 2019, the ASIR and ASPR in China were in the middle of the world and lower than in some developed countries. The numbers and ASRs of incidence, prevalence, and DALYs were expected to increase by 2030.

Conclusion

The IBD burden in China significantly increased from 1990 to 2019 and was expected to rise further by 2030. China had the world's opposite and most dramatic trends in ASIR and ASPR from 1990 to 2019. Strategies should be adjusted to adapt to the significantly increased disease burden.

Long-term Colectomy rates of Ulcerative Colitis over 40-year of Different Therapeutic eras - Results from Western Hungarian Population-based Inception Cohort between 1977-2020

BACKGROUND AND AIMS

Few population-based studies have investigated the long-term colectomy rates of ulcerative colitis (UC). We aimed to assess the colectomy rates over 40 years of different therapeutic eras in a prospective population-based inception cohort from Veszprem Province, Western Hungary.

METHODS

Patient inclusion lasted between January1,1977, and December31, 2018. Patient follow-up ended December 31,2020. Colectomy rates and disease course were examined in three different eras based on the time of UC diagnosis; cohort-A(1977-1995),cohort-B(1996-2008), and cohort C(2009-2018).

RESULTS

A total of 1,370 incident UC patients were included (male 51.2%,median age at diagnosis:37 years). Median follow-up was 17 years (IQR 9-24); 87 patients(6.4%) underwent colectomy. The cumulative probability of colectomy in the total population was 2.6%(95%CI 2.2-3.0), 4.2%(95%CI 3.6-4.8), 7.0%(95%CI 6.2-7.8), and 10.4%(95%CI 9.1-11.7) after 5, 10, 20, and 30 years, respectively. The proportion of extensive colitis at diagnosis increased over time (24.2%/24.3%/34.9% in cohorts A/B/C,p=0.001). Overall exposure to immunomodulators (11.3%/20.9%/34.4% in cohorts A/B/C,p<0.001), as well as the probability for biological therapy initiation increased over time; 0%/ 3.3%(95%CI 2.6-4.0)/ 13.9%(95%CI 12.1-15.7), p<0.001. There were no statistically significant differences in the cumulative probability of colectomies between cohorts A/B/C; 1.7% (95%CI 1.0-2.4), 2.5%(95%CI 1.9-3.1), and 3.7%(95%CI 2.7-4.7) after 5 years; 3.5%(95%CI 2.5-4.5), 4.2%(95%CI 3.4-5.0), and 4.5%(95%CI 3.3-5.7) after 10 years; and 7.5% (95%CI 6.1-8.9) and 6.3% (95%CI 5.2-7.4) in cohorts A/B after 20 years (Log-rank=0.588). Extensive colitis (HR;2.24:95%CI 1.55-3.23) and continuous active disease activity (HR;6.36:95%CI 3.46-11.67) were independent predictors for colectomy.

CONCLUSION

No differences in colectomy rates have been observed in the incident UC patients over 40 years despite increasing use of immunomodulators and biological therapies.

İnflamatuvar barsak hastalığı olan hastalarda klinik özellikler, tedavi seçenekleri ve komplikasyonların değerlendirilmesi

Introduction: Inflammatory bowel diseases (IBD) form a group of inflammatory diseases occurring in genetically-susceptible people, which are characterized by chronic progression and whose cause is not fully known. The aim of this study is to determine the incidence of IBD in our region and examine the clinical characteristics, sociodemographic features, and treatment results of IBD patients.Methods: Our study retrospectively investigates 211 patients over 18 years of age who were monitored for an IBD diagnosis between January 2, 2013, and December 31, 2019, by the gastroenterology department of Canakkale Onsekiz Mart University’s Faculty of Medicine. The mean age, female-male ratio, smoking habits, disease severity, and localization sites were identified for included patients. Local and systemic complications of administered treatment types and reasons for surgical treatment were also assessed in patients.Results: Of the 211 patients with IBD diagnoses, 158 (74.9%) had Ulcerative Colitis (UC) and 53 (25.1%) had a diagnosis of Crohn’s disease (CD). The mean age at the time of diagnosis was 43.97±16.22 years for UC patients and 42.30±14.73 years for CD cases. The involvement sites for UC were distal colitis for 58.4% of patients, left colon for 24.1% of patients, pancolitis for 16.5% of patients, and backwash ileitis for 7% of patients. According to the treatment results, 152 (72.0%) patients took 5-aminosalicylate (5-ASA) alone, 48 (22.8%) took thiopurine, and 20 (9.5%) took anti-TNF.Conclusion: Knowing the demographic, clinical, and laboratory features of these diseases, which are frequently seen in our region, can support the early identification of probable complications that may occur and the selection of appropriate approaches during diagnosis, treatment, and follow-up monitoring of these diseases.Keywords: Inflammatory Bowel Diseases, Ulcerative Colitis, Crohn’s Disease, Severity of Illness Index, Abdominal Pain, Diarrhea

Lifestyle, behaviour, and environmental modification for the management of patients with inflammatory bowel diseases: an International Organization for Study of Inflammatory Bowel Diseases consensus

Environmental and lifestyle factors play an important role in the natural history of Crohn's disease and ulcerative colitis. A group of international experts from the International Organization for the Study of Inflammatory Bowel Diseases voted on a series of consensus statements to inform the management of inflammatory bowel disease (IBD). The recommendations include avoiding traditional cigarette smoking in patients with Crohn's disease or ulcerative colitis, screening for symptoms of depression, anxiety, and psychosocial stressors at diagnosis and during flares (with referral to mental health professionals when appropriate), and encouraging regular physical activity as tolerated. Patients using dietary approaches for treatment of their IBD should be encouraged to adopt diets that are best supported by evidence and involve monitoring for the objective resolution of inflammation. We recommend formal assessment for obesity and nutritional deficiencies, and patients should be encouraged to maintain a normal body-mass index. A shared decision-making approach to contraception should include the consideration of IBD-related factors, and risk factors for venous thromboembolism. Long-term or frequent use of high-dose non-steroidal anti-inflammatory drugs should be avoided. For primary prevention of disease in the offspring of patients with IBD, we recommend avoiding passive exposure to tobacco, using antibiotics judiciously, and considering breastfeeding when able.

Effect of smoking on the development and outcomes of inflammatory bowel disease in Taiwan: a hospital-based cohort study

Smoking influences the risks of inflammatory bowel disease (IBD). A hospital-based cohort was conducted to evaluate the effect of smoking on the development and outcomes of IBD, with age, sex and comorbidities matched non-IBD controls from the National Health Interview Survey database of Taiwan. 700 IBD patients (360 ulcerative colitis (UC), 340 Crohn’s disease (CD)) were analyzed for outcomes; and 575 patients (297 UC, 278 CD) were analyzed for prevalence. Smoking prevalence was significantly lower in UC patients than controls (20.9% vs. 30.4%, p < 0.01), but no difference between CD patients and controls (19.8% vs. 22.1%, p = 0.60). UC smokers had fewer admissions (1.6 vs. 2.5, p < 0.05) but higher rates of new cancer development (16% vs. 6.7%, p < 0.05) and mortality (16% vs. 4.9%, p < 0.01) than nonsmokers. CD smokers tended to have higher rates of stricturing and penetrating diseases (p < 0.05), and higher surgery risk (60.3% vs. 38.3%, p < 0.01) than nonsmokers. Smoking prevents UC occurrence and is associated with fewer hospitalization but increases risks of cancer and mortality. By contrast, smoking does not affect CD occurrence but is related to more aggressive behavior which results in a higher surgical rate.

A decade of inflammatory bowel disease: a single center experience in Egypt

Background

Inflammatory bowel disease is a chronic inflammatory disorder of the gastrointestinal tract and includes ulcerative colitis and Crohn’s disease. Inflammatory bowel disease has always seemed to be rare in the Middle East and Northern Africa. In this study, we explored the clinical characteristics of inflammatory bowel disease patients in our center.

Methods

This retrospective study was conducted on patients with an established diagnosis of inflammatory bowel disease over 10 years from September 2009 to September 2019 who were referred to our inflammatory bowel disease center. Clinical information was obtained from medical records and patient interviews. We included all patients in whom the diagnosis of ulcerative colitis or Crohn’s disease was confirmed by clinical, laboratory, endoscopic, and histological examination over a 10-year period from 2009 to 2019.

Results

Our study had one hundred and sixty-nine inflammatory bowel disease patients; one hundred and thirty-six ulcerative colitis patients and the remaining thirty-three patients had Crohn’s disease. The main presenting symptom was bloody diarrhea (78 patients) representing 46.2% of the patients in our study. The majority of ulcerative colitis patients (55.9%) had moderate disease (Truelove & Witts score), while the majority of Crohn’s disease patients (66.7%) had moderate to severe disease (Crohn’s Disease Activity Index).

Conclusions

The prevalence of inflammatory bowel disease is still low in Egypt despite the rising curve of newly diagnosed cases.

(RS)-bambuterol and its enantiomers: Potential improvement of (R)-bambuterol in mice with colitis

Bambuterol (BMB) has been used clinically to treat asthma due to its bronchodilation activity. However, the effect of BMB on ulcerative colitis (UC) has not been examined. The present work focused on the effects of enantiomeric BMB on UC. Acute UC was induced in mice by 3% dextran sulfate sodium (DSS), and (R)-, (S) and (RS)-BMB were orally administered. Body weight loss and the disease activity index (DAI) were measured once a day. Inflammatory factors were detected by ELISA and qRT-PCR. Histological evaluations of colon samples were performed. IL-6, STAT3, and RORγt pathway-related proteins were analyzed by western blotting. The results verified that colitis severity was dramatically ameliorated by (R)-BMB, which was significantlybetter than the effect of (RS)-BMB or (S)-BMB, as evidenced by body weight loss, DAI, colon length, spleen/body weight ratio and histopathological manifestations. Furthermore, (R)-BMB treatment significantly diminished the levels of inflammatory cytokines and macrophages infiltration in mice with colitis. Besides, treated with (R)-BMB obviously elevated the level of β2AR. In addition, (R)-BMB decreased the expression of IL-6, IL-17, retinoic acid receptor-related orphan receptor-gamma t (RORt), and phosphorylated STAT3 (p-STAT3) in a dose-dependent manner in the colon tissues. The efficacy of (R)-BMB was more notable than aminosalicylic acid (5-ASA). (R)-BMB is either butyrilcholinesterase inhibitor or β2AR agonist which offers new treatment of colitis.

Smoking Behaviour Changes After Diagnosis of Inflammatory Bowel Disease and Risk of All-cause Mortality

BACKGROUND AND AIMS

We examined smoking behaviour changes after diagnoses of Crohn's disease [CD] and ulcerative colitis [UC] and evaluated their impact on mortality.

METHODS

Study population included incident CD or UC cases from three cohorts of the Nurses' Health Study [NHS], NHSII, and Health Professionals Follow-up Study. Smoking and other risk factors were prospectively assessed. Smoking behaviour changes were categorised as never, former [i.e., quit smoking before diagnosis], quitters [i.e., quit smoking after diagnosis], and current [i.e., continue smoking after diagnosis]. Follow-up for date and cause of death was completed through linkage to the National Death Index. Cox proportional hazard regression was used to estimate hazard ratios [HRs] and 95% confidence intervals [CIs].

RESULTS

Among 909 eligible CD and UC cases, 45% were never smokers, 38% were past smokers, and 16% were active smokers at the time of diagnosis. Among active smokers, 70% of patients with CD and 44% of patients with UC continued to smoke after diagnosis. In patients with CD, compared with current smokers, the multivariable-adjusted HRs [95% CI] of death were 0.19 [0.10 to 0.38] for never smokers, 0.31 [0.16 to 0.57] for former smokers, and 0.41 [0.18 to 0.93] for quitters. Similarly for UC, compared with current smokers, we observed a reduced risk of mortality for never smokers [HR = 0.23, 95% CI 0.10 to 0.51], former smokers [HR = 0.23, 95% CI 0.11 to 0.48], and quitters [HR = 0.28, 95% CI 0.11 to 0.72].

CONCLUSIONS

In three cohorts of health professionals, a substantial proportion of patients with new diagnosis of CD and UC and history of smoking continued to smoke after diagnosis. Smoking cessation around the time of diagnosis was associated with a significant reduction in mortality.

Associations Between Smoking and Primary Sjögren Syndrome Classification Using the Sjögren's International Collaborative Clinical Alliance Cohort

OBJECTIVE

The objective of this study was to examine the association of smoking with Primary Sjögren syndrome (pSS) classification and pSS diagnostic test results. We hypothesized that past and current smokers would have lower odds of being classified as having Sjögren syndrome (SS) and lower odds of having abnormal individual SS diagnostic test results compared with nonsmokers.

METHODS

Participants with suspected or established pSS were enrolled into the Sjögren's International Collaborative Clinical Alliance (SICCA) registry and had oral, ocular, and rheumatologic examinations performed; blood and saliva samples collected; and labial salivary gland biopsy examinations performed; they also completed questionnaires at baseline. Logistic regression was used to determine whether smoking status was associated with pSS classification and individual pSS diagnostic test results.

RESULTS

A total of 3514 participants were enrolled in SICCA. A total of 1541 (52.9%) met classification criteria for pSS. Compared with never smokers, current smokers had reduced odds of being classified as having pSS, reduced odds of having a focus score ≥ 1 and serologic positivity for anti-SSA/anti-SSB antibodies, and lower odds of having abnormal signs or test results of dry eye disease. Compared with never smokers, past smokers did not have a statistically significant reduction in odds of being classified as having pSS and of having abnormal individual pSS diagnostic test results.

CONCLUSION

Compared with never smokers, current smokers in the SICCA cohort had lower odds of being classified as having pSS, lower odds of exhibiting abnormal signs and test results for dry eye disease, and lower odds of having a labial salivary gland biopsy supportive of pSS classification. Such negative associations, however, do not suggest that current smoking is of any benefit with respect to pSS.

Ethnic Differences in the Smoking-related Risk of Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

The association between smoking and inflammatory bowel disease [IBD] relies on old meta-analyses including exclusively non-Jewish White populations. Uncertainty persists regarding the role of smoking in other ethnicities.

METHODS

We systematically searched Medline/PubMed, Embase, and Scopus for studies examining tobacco smoking and the risk of developing IBD, ie, Crohn's disease [CD] or ulcerative colitis [UC]. Two authors independently extracted study data and assessed each study's risk of bias. We examined heterogeneity and small-study effect, and calculated summary estimates using random-effects models. Stratified analyses and meta-regression were employed to study the association between study-level characteristics and effect estimates. The strength of epidemiological evidence was assessed through prespecified criteria.

RESULTS

We synthesised 57 studies examining the smoking-related risk of developing CD and UC. Non-Jewish White smokers were at increased risk of CD (29 studies; relative risk [RR]: 1.95, 95% confidence interval [CI]: 1.69‒2.24; moderate evidence). No association was observed in Asian, Jewish. and Latin-American populations [11 studies; RR: 0.97; 95% CI: 0.83-1.13], with no evidence of heterogeneity across these ethnicities. Smokers were at reduced risk of UC [51 studies; RR: 0.55, 95% CI: 0.48-0.64; weak evidence] irrespectively of ethnicity; however, cohort studies, large studies, and those recently published showed attenuated associations.

CONCLUSIONS

This meta-analysis did not identify any increased risk of CD in smokers in ethnicities other than non-Jewish Whites, and confirmed the protective effect of smoking on UC occurrence. Future research should characterise the genetic background of CD patients across different ethnicities to improve our understanding of the role of smoking in CD pathogenesis.

ECCO Topical Review: Refractory Inflammatory Bowel Disease

Inflammatory bowel disease is a chronic disease with variable degrees of extent, severity, and activity. A proportion of patients will have disease that is refractory to licensed therapies, resulting in significant impairment in quality of life. The treatment of these patients involves a systematic approach by the entire multidisciplinary team, with particular consideration given to medical options including unlicensed therapies, surgical interventions, and dietetic and psychological support. The purpose of this review is to guide clinicians through this process and provide an accurate summary of the available evidence for different strategies.

Three-dimensional culture method enhances the therapeutic efficacies of tonsil-derived mesenchymal stem cells in murine chronic colitis model

Tonsil-derived mesenchymal stem cells (TMSCs) showed therapeutic effects on acute and chronic murine colitis models, owing to their immunomodulatory properties; therefore, we evaluated enhanced therapeutic effects of TMSCs on a murine colitis model using three-dimensional (3D) culture method. The expression of angiogenic factors, VEGF, and anti-inflammatory cytokines, IL-10, TSG-6, TGF-β, and IDO-1, was significantly higher in the 3D-TMSC-treated group than in the 2D-TMSC-treated group (P < 0.05). At days 18 and 30 after inducing chronic colitis, disease activity index scores were estimated to be significantly lower in the 3D-TMSC-treated group than in the colitis control (P < 0.001 and P < 0.001, respectively) and 2D-TMSC-treated groups (P = 0.022 and P = 0.004, respectively). Body weight loss was significantly lower in the 3D-TMSC-treated group than in the colitis control (P < 0.001) and 2D-TMSC-treated groups (P = 0.005). Colon length shortening was significantly recovered in the 3D-TMSC-treated group compared to that in the 2D-TMSC-treated group (P = 0.001). Histological scoring index was significantly lower in the 3D-TMSC-treated group than in the 2D-TMSC-treated group (P = 0.002). These results indicate that 3D-cultured TMSCs showed considerably higher therapeutic effects in a chronic murine colitis model than those of 2D-cultured TMSCs via increased anti-inflammatory cytokine expression.

Crohn's disease-related single nucleotide polymorphisms are associated with ileal pouch afferent limb stenosis

BACKGROUND

Ileal pouch-anal anastomosis (IPAA) is a common surgical treatment for ulcerative colitis. Afferent limb stenosis is an infrequent complication following IPAA, suggesting underlying Crohn's disease (CD). We hypothesized that CD-related single nucleotide polymorphisms (SNPs) are associated with afferent limb stenosis.

METHODS

Afferent limb stenosis and CD control group patients were recruited from a prospective institutional inflammatory bowel disease database and associated biobank. Patient demographics, Montreal classification, and medication use were recorded. Ten SNPs associated with stricturing Crohn's disease were examined in genomic DNA and compared among afferent limb stenosis, stricturing CD, and non-stricturing CD controls.

RESULTS

Twenty-seven afferent limb stenosis and 162 CD control group patients (108 stricturing, 54 non-stricturing) were identified. Patients were gender and race matched. Afferent limb stenosis and stricturing CD controls were younger at diagnosis (Montreal A1/A2 vs. A3) compared to non-stricturing CD controls (both p < 0.05). The majority of afferent limb stenosis patients were non-smokers compared to CD controls (74% vs. 36%, p < 0.01) and did not use biologic therapies (4% vs. 37%, p < 0.001). The FUT2 G allele was more frequent in afferent limb stenosis and stricturing CD controls compared to non-stricturing CD controls (both p < 0.05). The NOD2 T allele was more frequent in stricturing CD controls compared to afferent limb stenosis and non-stricturing CD controls (both p < 0.05).

CONCLUSION

Afferent limb stenosis patients are phenotypically similar to stricturing CD controls, but differ with lower smoking rates and lower NOD2 allele frequency. Such differences could contribute to the presentation delay with a stricturing phenotype. Selective SNP assessment may help categorize patients likely to develop afferent limb stenosis.

Inflammatory bowel disease and psoriasis: modernizing the multidisciplinary approach

Psoriasis and inflammatory bowel disease (IBD) are immune-mediated diseases occurring in barrier organs whose main task is to protect the organism from attack. These disorders are highly prevalent especially in northern Europe where psoriasis has a prevalence of around 3-4% and IBD around 0.3%. The prevalence of IBD in North America has been estimated at around 0.4%. The total incidence rates in northern Europe have been estimated at around 6 for Crohn's disease and 11 for ulcerative colitis per 100 000 person-years, compared with an incidence rate of around 280 per 100 000 person-years for psoriasis. Both diseases are less common in countries with a lower index of development. The rise in IBD appears to occur as populations adopt a westernized lifestyle, whereas psoriasis seems more stable and prevalence differences may derive more from variation in genetic susceptibility. The gut microbiota is clearly an important driver of IBD pathogenesis; in psoriasis, changes in gut and skin microbiota have been reported, but it is less clear whether and how these changes contribute to the pathogenesis. Large studies show that most identified genes are involved in the immune system. However, psoriasis and IBD are highly heterogeneous diseases and there is a need for more precise and deeper phenotyping to identify specific subgroups and their genetic, epigenetic and molecular signatures. Epigenetic modifications of DNA such as histone modifications, noncoding RNA effects on transcription and translation and DNA methylation are increasingly recognized as the mechanism underpinning much of the gene-environment interaction in the pathogenesis of both IBD and psoriasis. Our understanding of underlying pathogenetic mechanisms has deepened fundamentally over the past decades developing hand in hand with novel therapies targeting pathways and proinflammatory cytokines incriminated in disease. There is not only substantial overlap between psoriasis and IBD, but also there are differences with implication for therapy. In psoriasis, drugs targeting interleukin-23 and interleukin-17 have shown superior efficacy compared with anti-TNFs, whilst in IBD, drugs targeting interleukin-17 may be less beneficial. The therapeutic toolbox for psoriasis is impressive and is enlarging also for IBD. Still, there are unmet needs reflecting the heterogeneity of both diseases and there is a need for closer molecular diagnostics to allow for the development of precise therapeutics.

Surgical options for perianal fistula in patients with Crohn's disease: A comparison of seton placement, fistulotomy, and stem cell therapy

OBJECTIVE

This study was designed to assess the demographic characteristics of patients with Crohn's perianal fistula (CPF) who were treated at a tertiary referral institution. Surgical outcomes were compared in groups of patients who underwent seton placement, fistulotomy, and stem cell therapy.

METHODS

Patients who underwent surgery for CPF between 2015 and 2017 at Asan Medical Center, Seoul, Korea, were retrospectively evaluated. Patients were divided into groups who underwent seton placement, fistulotomy, and stem cell therapy. Their clinical variables and closure rates were compared.

RESULTS

This study included 156 patients who underwent a total of 209 operations. More than half of the operations consisted of seton placement (67%), followed by stem cell therapy (18%) and fistulotomy (15%) patients. Of the 209 fistulas, 153 (73%) were complex, with an overall closure rate of 38% during a median follow-up of 29 months. Closure rates following fistulotomy, stem cell therapy, and seton placement were 90%, 70%, and 18%. Seton placement was more significantly frequently used than the other procedures in patients with complex fistula and those with abscesses. Of the 79 fistulas that achieved complete closure, 11 (14%) recurred. The recurrence rates did not differ among the various techniques.

CONCLUSION

Surgical treatment of CPF is dependent on lesion type. Seton placement was the primary draining procedure for complex fistulas and abscesses, resulting in low closure rates. Fistulotomy was the definite procedure for low type and simple fistula. Stem cell therapy showed high closure rates as definitive treatment, even for complex fistulas.

Long-Term Follow-Up, Association between CARD15/NOD2 Polymorphisms, and Clinical Disease Behavior in Crohn's Disease Surgical Patients

Background

CARD15/NOD2 is the most significant genetic susceptibility in Crohn's disease (CD) even though a relationship between the different polymorphisms and clinical phenotype has not been described yet. The study is aimed at analyzing, in a group of CD patients undergoing surgery, the relationship between CARD15/NOD2 polymorphisms and the clinical CD behavior after a long-term follow-up, in order to identify potential clinical biomarkers of prognosis.

Methods

191 surgical CD patients were prospectively characterized both for the main single nucleotide polymorphisms of CARD15/NOD2 and for many other environmental risk factors connected with the severe disease form. After a mean follow-up of 7.3 years, the correlations between clinical features and CD natural history were analyzed.

Results

CARD15/NOD2 polymorphisms were significantly associated with younger age at diagnosis compared to wild type cases (p < 0.05). Moreover, patients carrying a 3020insC polymorphism presented a larger Δ between diagnosis and surgery (p = 0.0344). Patients carrying an hz881 and a 3020insC exhibited, respectively, a lower rate of responsiveness to azathioprine (p = 0.012), but no difference was found in biologic therapy. Finally, the risk of surgical recurrence was significantly associated, respectively, to age at diagnosis, to familial CD history, to diagnostic delay, to arthritis, and to the presence of perioperative complications.

Conclusions

3020insC CARD15 polymorphism is associated with an earlier CD onset, and age at CD diagnosis < 27 years was confirmed to have a detrimental effect on its clinical course. In addition, the familiarity seems to be connected with a more aggressive postoperative course. Finally, for the first time, we have observed a lower rate of responsiveness to azathioprine in patients carrying an hz881 and a 3020insC.

Divergent Effect of Cigarette Smoke on Innate Immunity in Inflammatory Bowel Disease: A Nicotine-Infection Interaction

Cigarette smoke (CS) has adverse effects in patients with Crohn’s disease (CD), an inflammatory bowel disease (IBD) that has been associated with microbial infection, immuno-dysregulation, and mucosal dysfunction. However, CS seems to provide relief and protection to patients with another IBD known as ulcerative colitis (UC). These two subsets are featured as M1- and M2-mediated responses, respectively. Nicotine is the most active, addictive, and studied ingredient in CS. The mechanism of how nicotine and/or other CS ingredients induce pro-inflammatory or anti-inflammatory phenotypes in IBD patients remains under investigation. Our most recent in vitro nicotine study provided significant insights toward understanding the contradictory effects of nicotine on IBD patients, and it elucidated the mechanistic role of α7nAChR in modulation of macrophages in tobacco smokers. Shifting the beneficial effect of nicotine to a harmful outcome in CD patients was linked to a nicotine-microbe interaction that supports a microbial etiology in CD pathogenesis. Among the most debated pathogens in CD etiology is Mycobacterium avium subspecies paratuberculosis (MAP). Other studies associated nicotine with upregulation of miR-124 expression in macrophages, which led to anti-inflammatory response. This review discusses published work on the role of nicotine in modulation of the innate immune response and subsequent signaling in macrophages in IBD subsets.

Extracolonic Cancer Risk After Total Colectomy for Inflammatory Bowel Disease: A Population-based Cohort Study

BACKGROUND

Patients with inflammatory bowel disease are at increased risk of extracolonic cancers. Little is known regarding this risk following total colectomy [TC].

METHODS

Patients who underwent TC for inflammatory bowel disease in Denmark during 1977-2013 were identified from the Danish National Patient Registry. Incidence rates of extracolonic cancers were determined through record linkage to the Danish Cancer Registry and compared with expected incidence rates in the general population. Standardized incidence ratios [SIRs] were calculated as the observed vs expected cancer incidence.

RESULTS

In total, 4430 patients (3441 with ulcerative colitis [UC]; 989 with Crohn's disease [CD]) were followed for 54,183 person-years after TC. Following their surgery, 372 patients were diagnosed with extracolonic cancer compared to 331 expected [SIR = 1.1 (95% confidence interval {CI}: 1.0-1.2)]. The risk of extracolonic cancer overall was increased among patients with CD and TC (SIR = 1.5 [95% CI: 1.2-1.8]), but not among patients with UC and TC (SIR = 1.0 [95% CI: 0.9-1.2]). Patients with UC and TC had a higher risk of intestinal extracolonic cancer (SIR = 2.0 [95% CI: 1.4-2.7]). Patients with CD and TC had a higher risk of smoking-related cancers (SIR = 1.9 [95% CI: 1.2-2.9]), intestinal extracolonic cancer (SIR = 3.1 [95% CI: 1.6-5.5]) and immune-mediated cancers (SIR = 1.5 [95% CI: 1.0-2.1]).

CONCLUSION

Patients with CD and TC had a higher risk of extracolonic cancer overall compared to the general population, while patients with UC and TC did not. Site-specific cancer risk varied according to inflammatory bowel disease type.

Impact of smoking cigarette on the mRNA expression of cytokines in mucosa of inflammatory bowel disease

It is well known that smoking is the risk factor in the development and clinical course of Crohn s disease (CD), but on the other hand, smoking is a protective factor against ulcerative colitis (UC). The pathways that are influenced by smoking in CD and UC are poorly understood. The aim of our study was to analyse the influence of smoking on the mRNA expression of cytokines in mucosa in patients with CD and UC. We performed a cross-sectional study. The cohort consisted of 86 IBD patients (48 CD patients and 38 UC patients) and took place at the IBD Centre at the University Hospital Bratislava-Ružinov. We took the demographic and clinical data of each patient, including information about their smoking habits. We performed a colonoscopy on each patient and took biopsies from both inflamed and non-inflamed sigma (CD, UC) and terminal ileum (CD). mRNA was extracted from mucosal biopsy samples for each cytokine and was normalized to a housekeeping gene (GAPDH). Finally, we compared the mRNA expression of target cytokines in the mucosa of smokers and non-smokers in IBD patients. Smokers with Crohn s disease have a significantly higher mRNA expression of pro-inflammatory cytokine TNF ? (p=0.003) in inflamed mucosa in sigma compared with non-smokers. In smokers with ulcerative colitis, we observed significantly higher mRNA expression of anti-inflammatory cytokine IL 10 (p=0.022) in non-inflamed mucosa of sigma. Similarly, smokers with UC have a significantly decreased mRNA expression of cytokine TLR 2 (p=0.024) and CCR1 (p=0.049) in non-inflamed mucosa of sigma. Based on our results, smoking has a positive influence on cessation and the clinical course of UC due to the stimulation of anti-inflammatory cytokine IL 10 in mucosa. On the other hand, smokers with CD have a higher expression of pro-inflammatory cytokine TNF ?, which could be associated with a worsening of the disease and response to therapy.

Crohn's disease

Crohn's disease is an inflammatory bowel disease that is characterized by chronic inflammation of any part of the gastrointestinal tract, has a progressive and destructive course and is increasing in incidence worldwide. Several factors have been implicated in the cause of Crohn's disease, including a dysregulated immune system, an altered microbiota, genetic susceptibility and environmental factors, but the cause of the disease remains unknown. The onset of the disease at a young age in most cases necessitates prompt but long-term treatment to prevent disease flares and disease progression with intestinal complications. Thus, earlier, more aggressive treatment with biologic therapies or novel small molecules could profoundly change the natural history of the disease and decrease complications and the need for hospitalization and surgery. Although less invasive biomarkers are in development, diagnosis still relies on endoscopy and histological assessment of biopsy specimens. Crohn's disease is a complex disease, and treatment should be personalized to address the underlying pathogenetic mechanism. In the future, disease management might rely on severity scores that incorporate prognostic factors, bowel damage assessment and non-invasive close monitoring of disease activity to reduce the severity of complications.

The epidemiology of inflammatory bowel disease: East meets west

The incidence of inflammatory bowel diseases (IBD) in East has risen over the past decade to become a global disease. The increasing number of studies on the incidence and course of IBD in East has enabled us to explore East versus West differences in the epidemiology of IBD which could enhance our understanding of the heterogeneity of the disease and eventually assist in the discovery of novel therapeutic targets and design of preventive strategies. Comparison of population-based data in East and West reveals that the incidence of IBD has risen rapidly in East while plateauing in West. Furthermore, the clinical presentation and course of IBD differs between East and West with more patients in East presenting with complicated disease. Considering the scarcity of population-based data from East and the lack of studies with long durations of follow-up, it remains to be clarified whether these differences reflect true differences in disease presentation. The effects of genetic and environmental risk factors contributing to IBD also differ between Eastern and Western populations. Considering the differential effects of genetic and environmental risk factors in East and West, future studies should seek to discover novel genetic and environmental risk factors which might specifically apply to eastern populations. In this narrative review, we compare the epidemiology of IBD between eastern and western countries by summarizing evidence from population-based cohort studies in the last ten years. Furthermore, we look at differences in genetic susceptibility and environmental triggers of IBD between East and West.

Role of environmental factors in the pathogenesis of Crohn's disease: a critical review

PURPOSE

To review role of environmental factors in the pathogenesis of Crohn's disease.

METHODS

We systematically reviewed trials and systematic reviews using PubMed and Web of science databases. Here, we review the current information on the causative factors and mechanisms of CD, including smoking, exercise, diet, animal protein, breastfeeding, history of childhood infection and vaccination, oral contraceptives, and antibiotics of CD. We also highlight important knowledge gaps that need to be filled in order to advance the field of CD research.

RESULTS

Epidemiological studies have indicated the significance of environmental factors in the disease behavior and outcome of Crohn's disease (CD). There are a few recognized environmental factors, such as cigarette smoking, exercise, dietary habits, and breastfeeding, which are associated with the pathogenesis of CD. These factors are hypothesized to change the epithelial barrier function, which disturbs both the innate and adaptive immune systems and the intestinal flora. However, the effect of several risk factors, such as appendectomy and pharmaceutical use, differs across several studies, indicating the need for more rigorous research. Furthermore, few studies have examined effective interventions based on environmental factors that can improve disease outcomes. Recent studies have indicated that the pathogenesis of CD is related to environmental and genetic factors.

CONCLUSION

We review the current information on the causative factors and mechanisms of CD, including smoking, exercise, diet, animal protein, breastfeeding, history of childhood infection and vaccination, oral contraceptives, and antibiotics of CD. However, further studies are needed to understand knowledge gaps in the field of CD.

Efficacy of Endoscopic Dilation of Gastroduodenal Crohn's Disease Strictures: A Systematic Review and Meta-Analysis of Individual Patient Data

BACKGROUND & AIMS

Little is known about the effects of endoscopic balloon dilation (EBD) for strictures of the upper gastrointestinal (UGI) tract in patients with Crohn's disease (CD). We performed a pooled analysis of the efficacy and safety of EBD for UGI CD-associated strictures.

METHODS

We searched Embase, Medline, and the Cochrane library, as well as bibliographies of relevant articles, for cohort studies of adults with CD and strictures of the stomach or duodenum (up to the ligament of Treitz) who underwent EBD through December 2016. We obtained data from 7 international referral centers on 94 patients who underwent 141 EBDs. We performed a patient-level meta-analysis of data from published and unpublished cohort studies to determine mechanical and clinical success. We performed a time-to-event analysis to assess symptom recurrence and need for redilation or surgery. The patients analyzed had strictures of the duodenum (n = 107), stomach (n = 30), or spanning both (n = 4).

RESULTS

The rate of technical success for EBD was 100%, with 87% short-term clinical efficacy; major complications arose from 2.9% of all procedures. During a median follow-up period of 23.1 months, 70.5% of patients had a recurrence of symptoms, 59.6% required redilation, and 30.8% required surgical intervention. Patients whose disease was located in the small bowel had a higher risk for symptom recurrence (hazard ratio [HR], 2.1; P = .003). Asian race (HR, 2.8; P < .001) and location of disease in the small bowel (HR, 1.9; P = .004) increased the need for redilation. Prestenotic dilation was a risk factor for needing surgery earlier (HR, 1.9; P = .001).

CONCLUSIONS

In a meta-analysis, we found EBD for CD-associated strictures of the UGI to be an effective alternative to surgery, with a high rate of short-term technical and clinical success, moderate long-term efficacy, and an acceptable rate of complications.

Dose-response relationship between cigarette smoking and risk of ulcerative colitis: a nationwide population-based study

BACKGROUND

Former cigarette smokers are at risk of developing ulcerative colitis (UC). However, the impact of smoking behavior on the occurrence of UC according to the amount smoked remains elusive. We aimed to determine the relationship between smoking behavior and the risk of UC development.

METHODS

We conducted a retrospective population-based cohort study using the National Health Insurance Service database in South Korea. From January 2009 to December 2012, 23,235,771 individuals over 18 years of age who underwent a national health examination were enrolled and followed until 2016. All study participants were divided into the following 3 groups: nonsmokers, former smokers, and current smokers. The primary endpoint was newly developed UC.

RESULTS

Compared with nonsmokers, the risk of UC development was significantly higher in former smokers [adjusted hazard ratio (aHR) 1.83; 95% confidence interval (CI) 1.73-1.95] but significantly lower in current smokers (aHR 0.92; 95% CI 0.87-0.98). Among current smokers, individuals who stopped smoking after the baseline evaluation had a significantly higher risk of UC development than those who continued to smoke (aHR 2.42; 95% CI 2.10-2.80). The risk of UC development among former smokers was significantly associated with smoking amount and duration. Among current smokers, however, the risk of UC development was not correlated with the cumulative lifetime smoking exposure. The preventive effect of current smoking on UC development was observed only in men (aHR 0.90; 95% CI 0.84-0.96).

CONCLUSIONS

Compared with nonsmokers, former smokers have a significantly higher risk of UC development that may be proportional to the cumulative smoking exposure.

Global smoking trends in inflammatory bowel disease: A systematic review of inception cohorts

Background and aims

The effect of smoking on the risk of developing inflammatory bowel diseases (IBD) may be heterogeneous across ethnicity and geography. Although trends in smoking for the general population are well described, it is unknown whether these can be extrapolated to the IBD cohort. Smoking prevalence trends specific to the global IBD cohort over time have not been previously reported. This is a systematic review of smoking prevalence specific to the IBD cohort across geography.

Methods

A systematic literature search was conducted on Medline and Embase from January 1^st 1946 to April 5^th 2018 to identify population-based studies assessing the prevalence of smoking at diagnosis in inception cohorts of Crohn’s disease(CD) or ulcerative colitis(UC). Studies that did not report smoking data from time of diagnosis or the year of IBD diagnosis were excluded. Prevalence of smoking in IBD was stratified by geography and across time.

Results

We identified 56 studies that were eligible for inclusion. Smoking prevalence data at diagnosis of CD and UC was collected from twenty and twenty-five countries respectively. Never-smokers in the newly diagnosed CD population in the West has increased over the last two decades, especially in the United Kingdom and Sweden; +26.6% and +11.2% respectively. Never-smokers at CD diagnosis in newly industrialised nations have decreased over the 1990s and 2000s; China (-19.36%). Never-smokers at UC diagnosis also decreased in China; -15.4%. The former-smoker population at UC diagnosis in China is expanding; 11%(1990–2006) to 34%(2011–2013).

Conclusion

There has been a reduction in the prevalence of smoking in the IBD cohort in the West. This is not consistent globally. Although, smoking prevalence has decreased in the general population of newly industrialised nations, this remains an important risk factor with longer term outcomes awaiting translation in both UC and CD.

The impact of smoking and smoking cessation on disease outcomes in ulcerative colitis: a nationwide population-based study

BACKGROUND

Smokers are less likely to develop ulcerative colitis (UC) but the impact of smoking and subsequent cessation on clinical outcomes in UC is unclear.

AIM

To evaluate the effect of smoking status and smoking cessation on disease outcomes.

METHODS

Using a nationally representative clinical research database, we identified incident cases of UC during 2005-2016. Patients were grouped as never-smokers, ex-smokers and smokers based on smoking status recorded in the 2 years preceding UC diagnosis. We defined subgroups of persistent smokers and smokers who quit within 2 years after diagnosis. We compared the rates of overall corticosteroid use, corticosteroid-requiring flares, corticosteroid dependency, thiopurine use, hospitalisation and colectomy between these groups.

RESULTS

We identified 6754 patients with a new diagnosis of UC over the study period with data on smoking status, of whom 878 were smokers at diagnosis. Smokers had a similar risk of corticosteroid-requiring flares (OR 1.16, 95% CI 0.92-1.25), thiopurine use (HR 0.84, 95% CI 0.62-1.14), corticosteroid dependency (HR 0.85, 95% CI 0.60-1.11), hospitalisation (HR 0.92, 95% CI 0.72-1.18) and colectomy (HR 0.78, 95% CI 0.50-1.21) in comparison with never-smokers. Rates of flares, thiopurine use, corticosteroid dependency, hospitalisation and colectomy were not significantly different between persistent smokers and those who quit smoking after a diagnosis of UC.

CONCLUSIONS

Smokers and never-smokers with UC have similar outcomes with respect to flares, thiopurine use, corticosteroid dependency, hospitalisation and colectomy. Smoking cessation was not associated with worse disease course. The risks associated with smoking outweigh any benefits. UC patients should be counselled against smoking.

Impact of Genes and the Environment on the Pathogenesis and Disease Course of Inflammatory Bowel Disease

Crohn's disease and ulcerative colitis constitute two major subgroups of inflammatory bowel diseases (IBD), a group of complex polygenic diseases characterized by chronic and progressive inflammation in the gastrointestinal tract. In recent years, methodological advances in genetic analysis have greatly expanded our understanding of the genetic background of IBD. So far, more than 240 genetic risk loci have been identified for IBD. However, these risk alleles explain less than 30% of the susceptibility to disease development, suggesting that environmental factors contribute considerably. The increasing occurrence of IBD in Eastern countries following their 'westernization', as well as the increased risk of disease among those who migrate to high-incidence regions, also suggest that the environment is key in the pathogenesis of IBD. In this review, we summarize the current evidence on the role of genetic and environmental factors in the susceptibility to, and disease course of, IBD, and we suggest how these findings might be applied to clinical practice.

Risk factors and timing for colectomy in chronically active refractory ulcerative colitis: A systematic review

BACKGROUND

In patients with chronic refractory ulcerative colitis (UC) the precise timing for indication to colectomy is unclear.

AIMS

We performed a systematic review of the literature on the risk factors for colectomy in patients with chronic refractory UC in the biologic era.

METHODS

PubMed Central/Medline and Embase were systemically searched for records published between January 2000 and December 2017. Current evidence was summarized and filtered by expert opinion.

RESULTS

70 studies were included in the qualitative synthesis. Several factors were found to be associated with a higher or reduced risk for colectomy, including variables at baseline - such as progression from proctitis/left-sided to extensive colitis, extensive colitis at diagnosis, high baseline C Reactive Protein or erythrocyte sedimentation rate, male gender, and younger age at diagnosis - previous medical history, and factors arising during therapy with biologics, including the absence of clinical response after induction with infliximab or adalimumab, and the lack of mucosal healing during therapy with anti-TNFs.

CONCLUSIONS

Two main points may help physicians to decide when the surgical option may be considered in patients with chronic refractory UC: (1) a first risk stratification can be obtained by analyzing factors at baseline and medical history, including the previous exposure to anti-TNFs; (2) during therapy with biologics, the early assessment (after 12-16 weeks of treatment) of clinical and endoscopic response is a strong predictor of the subsequent risk of colectomy.

The Multifactorial Etiopathogeneses Interplay of Inflammatory Bowel Disease: An Overview

The gastrointestinal system where inflammatory bowel disease occurs is central to the immune system where the innate and the adaptive/acquired immune systems are balanced in interactions with gut microbes under homeostasis conditions. This article overviews the high-throughput research screening on multifactorial interplay between genetic risk factors, the intestinal microbiota, urbanization, modernization, Westernization, the environmental influences and immune responses in the etiopathogenesis of inflammatory bowel disease in humans. Inflammatory bowel disease is an expensive multifactorial debilitating disease that affects thousands new people annually worldwide with no known etiology or cure. The conservative therapeutics focus on the established pathology where the immune dysfunction and gut injury have already happened but do not preclude or delay the progression. Inflammatory bowel disease is evolving globally and has become a global emergence disease. It is largely known to be a disease in industrial-urbanized societies attributed to modernization and Westernized lifestyle associated with environmental factors to genetically susceptible individuals with determined failure to process certain commensal antigens. In the developing nations, increasing incidence and prevalence of inflammatory bowel disease (IBD) has been associated with rapid urbanization, modernization and Westernization of the population. In summary, there are identified multiple associations to host exposures potentiating the landscape risk hazards of inflammatory bowel disease trigger, that include: Western life-style and diet, host genetics, altered innate and/or acquired/adaptive host immune responses, early-life microbiota exposure, change in microbiome symbiotic relationship (dysbiosis/dysbacteriosis), pollution, changing hygiene status, socioeconomic status and several other environmental factors have long-standing effects/influence tolerance. The ongoing multipronged robotic studies on gut microbiota composition disparate patterns between the rural vs. urban locations may help elucidate and better understand the contribution of microbiome disciplines/ecology and evolutionary biology in potentially protecting against the development of inflammatory bowel disease.

Smoking Status at Diagnosis and Subsequent Smoking Cessation: Associations With Corticosteroid Use and Intestinal Resection in Crohn's Disease

BACKGROUND

The impact of smoking at diagnosis and subsequent smoking cessation on clinical outcomes in Crohn's disease (CD) has not been evaluated in a population-based cohort.

METHODS

Using a nationally representative clinical research database, we identified incident cases of CD between 2005 and 2014. We compared the following outcomes: overall corticosteroid (CS) use; flares requiring CS; CS dependency and intestinal surgery between smokers and non-smokers at time of CD diagnosis. Differences in these outcomes were also compared between persistent smokers and smokers who quit within 2 years of diagnosis.

RESULTS

We identified 3553 patients with a new CD diagnosis over the study period of whom 1121 (32%) were smokers. Smokers at CD diagnosis had significantly higher CS-use (56 versus 47%, p < 0.0001), proportionally more CS flares (>1 CS flare/year: 9 versus 6%, p < 0.0001), and higher CS dependency (27 versus 21%, p < 0.0001) than non-smokers. Regression analysis identified smoking at diagnosis to be associated with a higher risk of intestinal surgery (HR 1.64, 95% CI 1.16-2.52). There was a significantly higher proportion of 'quitters' who remained steroid-free through follow-up in comparison to 'persistent smokers' (45.4 versus 37.5%, respectively, p = 0.02). 'Quitters' also had lower rates of CS dependency compared to 'persistent smokers' (24 versus 33%, p = 0.008).

CONCLUSIONS

Smokers at CD diagnosis have higher CS-use, CS dependency and higher risk of intestinal surgery. Quitting smoking appears to have beneficial effects on disease related outcomes, including reducing CS dependency highlighting the importance of offering early smoking cessation support.

Determinants of IBD Heritability: Genes, Bugs, and More

Defining the etiology of inflammatory bowel disease (IBD) continues to elude researchers, in part due to the possibility that there may be different triggers for a spectrum of disease phenotypes that are currently classified as either Crohn's disease (CD) or ulcerative colitis (UC). What is clear is that genetic susceptibility plays an important role in the development of IBD, and large genome-wide association studies using case-control approaches have identified more than 230 risk alleles. Many of these identified risk alleles are located in a variety of genes important in host-microbiome interactions. In spite of these major advances, the mechanisms behind the genetic influence on disease development remain unknown. In addition, the identified genetic risks have thus far failed to fully define the hereditability of IBD. Host genetics influence host interactions with the gut microbiota in maintaining health through a balance of regulated immune responses and coordinated microbial composition and function. What remains to be defined is how alterations in these interactions can lead to disease. The nature and cause of changes in the microbiota in patients with IBD are poorly understood. In spite of the large catalog of alterations in the microbiota of IBD patients, inflammation itself can alter the microbiota, leaving open the question of which is cause or effect. The composition and function of the gut microbiota are influenced by many factors, including environmental factors, dietary factors, and, as recent studies have shown, host genetic makeup. More than 200 loci have shown potential to influence the microbiota, but replication and larger studies are still required to validate these findings. It would seem reasonable to consider the combination of both host genetic makeup and the inheritance of the microbiota as interdependent heritable forces that could explain the nature of an individual's susceptibility to IBD or indeed the actual cause of IBD. In this review, we will consider the contribution of the host genetics, the microbiome, and the influence of host genetics on the microbiota to the heritability of IBD.

Clinical characteristics and long-term prognosis of elderly-onset Crohn's disease

OBJECTIVES

This study aimed to evaluate the clinical characteristics and clinical course of Asian elderly-onset Crohn's disease (EOCD) patients in a large well-defined cohort of South Korean IBD patients.

MATERIALS AND METHODS

From the Asan inflammatory bowel disease registry, we identified 29 EOCD patients (diagnosed with CD in age of 60 years or over) out of 2989 CD patients (1.0%). After excluding two patients with unclear data, 27 EOCD were matched with 108 young-onset CD (YOCD) and 108 middle age-onset CD (MOCD) for the interval from symptom onset to diagnosis (±3 years) and follow-up duration (±3 years).

RESULTS

Females were predominant in the EOCD group (59.3%) compared to MOCD (31.5%) and YOCD (29.6%) groups (p = .012). In EOCD group, terminal ileal location was the most common (63.0%) at diagnosis, whereas ileocolonic location in other groups (57.4% in MOCD and 78.7% in YOCD, respectively) (p < .001). Patients with perianal fistula at CD diagnosis were less common (14.8% in EOCD vs. 28.7% in MOCD vs. 49.1% in YOCD, p < .001). During follow-up, thiopurines were used less frequently in the EOCD group (48.1% in EOCD vs. 87.0% in MOCD vs. 89.8% in YOCD, p < .001), but the risk for intestinal resection was comparable among three groups (p = .583).

CONCLUSIONS

EOCD may have a better clinical course than MOCD and YOCD, as demonstrated by the similar risk for intestinal resection despite the less frequent use of thiopurines.

Assessment of factors associated with smoking cessation at diagnosis or during follow-up of Crohn's disease

BACKGROUND AND AIM

Smoking cessation is known to improve the course of Crohn's disease (CD). However, the factors associated with smoking cessation after CD diagnosis have not been well established.

METHODS

Clinical characteristics and change in smoking status were evaluated in 445 current smokers at the time of CD diagnosis. Patients were classified into three subgroups based on their final smoking status and time of smoking cessation: non-quitters, quitters at diagnosis, and quitters during follow-up.

RESULTS

The overall smoking cessation rate was 55.7% (248 of 445 patients). The diagnosis of CD was the main reason for quitting (41.5%, 103 of 248 patients). Smoking cessation at the time of CD diagnosis was associated with intestinal resection within 3 months from CD diagnosis (odds ratio [OR] 2.355, 95% confidence interval [CI] 1.348-4.116, P = 0.003), light smoking (OR 2.041, 95% CI 1.157-3.602, P = 0.014), and initiation of smoking before 18 years of age (OR 0.570, 95% CI 0.327-0.994, P = 0.047). Light smoking (OR 1.762, 95% CI 1.019-3.144, P = 0.043) and initiation of smoking before 18 years (OR 0.588, 95% CI 0.381-0.908, P = 0.017) were also associated with overall smoking cessation.

CONCLUSION

Quitters after CD diagnosis, including quitters at diagnosis and quitters during follow-up, had features distinct from those of non-quitters. Given the motivation at CD diagnosis, a detailed history of smoking habits should be taken and all current smokers should be encouraged to quit smoking at the time of CD diagnosis.

Albumin as a prognostic marker for ulcerative colitis

AIM

To evaluate the role of albumin at the time of ulcerative colitis (UC) diagnosis in predicting the clinical course of disease.

METHODS

Nationwide cohort of patients with newly diagnosed UC in the Veterans Affairs health care system was identified and divided into two categories: hypoalbuminemia (i.e., ≤ 3.5 gm/dL) or normal albumin levels (i.e., > 3.5 gm/dL) at the time of UC diagnosis. The exposure of interest was presence of hypoalbuminemia defined as albumin level ≤ 3.5 g/dL at the time of UC diagnosis. Patients were then followed over time to identify the use of ≥ 2 courses of corticosteroids (CS), thiopurines, anti-TNF medications and requirement of colectomy for UC management.

RESULTS

The eligible study cohort included 802 patients, but 92 (11.4%) patients did not have their albumin levels checked at the time of UC diagnosis, and they were excluded. A total of 710 patients, who had albumin levels checked at time of UC diagnosis, were included in our study. Amongst them, 536 patients had a normal albumin level and 174 patients had hypoalbuminemia. Patients with hypoalbuminemia at diagnosis had a higher likelihood of ≥ 2 courses of CS use (adjusted HR = 1.7, 95%CI: 1.3-2.3), higher likelihood of thiopurine or anti- TNF use (adjusted HR = 1.72, 95%CI: 1.23-2.40) than patients with normal albumin level at diagnosis. There was a trend of higher likelihood of colectomy in hypoalbuminemic patients, but it was not statistically significant (Adjusted HR = 1.7, 95%CI: 0.90-3.25).

CONCLUSION

Hypoalbuminemia at disease diagnosis can serve as a prognostic marker to predict the clinical course of UC at the time of diagnosis.

Underestimation of Smoking Rates in an East Asian Population with Crohn's Disease

Background/Aims

The reported rates of current smoking at the time of Crohn’s disease (CD) diagnosis tend to be low in East Asian studies. However, we hypothesized that East Asian patients may be reluctant to disclose their smoking history, likely because of the influence of the Confucian culture.

Methods

We prospectively re-evaluated the smoking status at diagnosis in 1,437 Korean CD patients whose smoking status had been reported in our previous study.

Results

After re-evaluation, the current smokers at diagnosis increased from 388 patients (27.0%) to 445 patients (31.0%), indicating that 12.8% (57 of 445 patients) of the current smokers at diagnosis did not disclose their smoking status at their initial evaluation. The proportion of current smokers at diagnosis who had initially concealed their smoking status was significantly higher among the female patients (29.7%, 11/37) compared with the male patients (11.3%, 46/408) (p<0.005) and among the patients who were ≤18 years old at diagnosis (56.4%, 22/39) compared with the patients >18 years old at diagnosis (8.6%, 35/406) (p<0.001).

Conclusions

Subgroups of Korean CD patients, particularly young patients and female patients, are reluctant to disclose their smoking history. Therefore, the suggestion that smoking is not a risk factor for the development of CD in East Asians should be made with caution.

Healthcare maintenance in elderly patients with inflammatory bowel disease

The increasing number of older patients (age ≥60 years) with inflammatory bowel disease (IBD) highlights the importance of healthcare maintenance in this vulnerable population. Older IBD patients are more susceptible and have higher rates of many disease- and treatment-related adverse effects. Compared to younger IBD patients, older patients are at increased risk for infection, malignancy, bone disease, eye disease, malnutrition and thrombotic complications. Preventive strategies in the elderly differ from those in younger adults and are imperative. Changes to the immune system with aging can decrease the efficacy of vaccinations. Cancer screening guidelines in older IBD patients have to account for unique considerations, such as life expectancy, functional performance status, multimorbidity, financial status, and patient desires. Additionally, providers need to be vigilant in screening for osteoporosis, ocular disease, depression, and adverse events arising from polypharmacy.

Modifiable Environmental Factors in Inflammatory Bowel Disease

PURPOSE OF REVIEW

Environmental factors may influence predisposition to develop inflammatory bowel diseases (Crohn's disease, ulcerative colitis) or alter its natural history by modification of both the host immune response and intestinal microbial composition. The purpose of this review is to translate such evidence into clinical practice by a focus on interventional studies that have modified such environmental influences to improve disease outcomes.

RECENT FINDINGS

Several environmental influences have been identified in the recent literature including tobacco use, diet, antibiotics, vitamin D deficiency, stress, appendectomy, and oral contraceptive use. Some risk factors have similar influences on both Crohn's disease and ulcerative colitis while others are disease-specific or have divergent effects. Emerging epidemiologic evidence has confirmed the association of many of these factors with incident disease using prospective data. In addition, laboratory data has supported their mechanistic plausibility and relevance to intestinal inflammation.

Determinants of Healthcare Utilization Among Veterans with Inflammatory Bowel Disease

BACKGROUND

Identifying patient-level and disease-specific predictors of healthcare utilization in inflammatory bowel disease (IBD) may allow targeted interventions to reduce costs and improve outcomes.

AIM

To identify demographic and clinical predictors of healthcare utilization among veterans with IBD.

METHODS

We conducted a single-center cross-sectional study of veterans with IBD from 1998 to 2010. Demographics and disease characteristics were abstracted by manual chart review. Annual number of IBD-related visits was estimated by dividing total number of IBD-related inpatient and outpatient encounters by duration of IBD care. Associations between predictors of utilization were determined using stepwise multivariable linear regression.

RESULTS

Overall, 676 patients (56% ulcerative colitis (UC), 42% Crohn's disease (CD), and 2% IBD unclassified (IBDU)) had mean 3.08 IBD-related encounters annually. CD patients had 3.59 encounters compared to 2.73 in UC (p < 0.01). In the multivariable model, Hispanics had less visits compared to Caucasians and African-Americans (2.09 vs. 3.09 vs. 3.42), current smokers had more visits than never smokers (3.54 vs. 2.43, p = 0.05), and first IBD visit at age <40 had more visits than age >65 (3.84 vs. 1.75, p = 0.04). UC pancolitis was associated with more visits than proctitis (3.47 vs. 2.15, p = 0.04). CD penetrating phenotype was associated with more encounters than inflammatory type (4.68 vs. 4.15, p = 0.04).

CONCLUSIONS

We found that current tobacco use, age <40 at first IBD visit, UC pancolitis, and CD fistuilizing phenotype in addition to Caucasian and African-American race were independent predictors of increased healthcare utilization. Interventions should be targeted at these groups to decrease healthcare utilization and costs.

ACG Clinical Guideline: Preventive Care in Inflammatory Bowel Disease

Recent data suggest that inflammatory bowel disease (IBD) patients do not receive preventive services at the same rate as general medical patients. Patients with IBD often consider their gastroenterologist to be the primary provider of care. To improve the care delivered to IBD patients, health maintenance issues need to be co-managed by both the gastroenterologist and primary care team. Gastroenterologists need to explicitly inform the primary care provider of the unique needs of the IBD patient, especially those on immunomodulators and biologics or being considered for such therapy. In particular, documentation of up to date vaccinations are crucial as IBD patients are often treated with long-term immune-suppressive therapies and may be at increased risk for infections, many of which are preventable with vaccinations. Health maintenance issues addressed in this guideline include identification, safety and appropriate timing of vaccinations, screening for osteoporosis, cervical cancer, melanoma and non-melanoma skin cancer as well as identification of depression and anxiety and smoking cessation. To accomplish these health maintenance goals, coordination between the primary care provider, gastroenterology team and other specialists is necessary.

Predicting Outcomes to Optimize Disease Management in Inflammatory Bowel Diseases

BACKGROUND AND AIMS

Efforts to slow or prevent the progressive course of inflammatory bowel diseases [IBD] include early and intensive monitoring and treatment of patients at higher risk for complications. It is therefore essential to identify high-risk patients - both at diagnosis and throughout disease course.

METHODS

As a part of an IBD Ahead initiative, we conducted a comprehensive literature review to identify predictors of long-term IBD prognosis and generate draft expert summary statements. Statements were refined at national meetings of IBD experts in 32 countries and were finalized at an international meeting in November 2014.

RESULTS

Patients with Crohn's disease presenting at a young age or with extensive anatomical involvement, deep ulcerations, ileal/ileocolonic involvement, perianal and/or severe rectal disease or penetrating/stenosing behaviour should be regarded as high risk for complications. Patients with ulcerative colitis presenting at young age, with extensive colitis and frequent flare-ups needing steroids or hospitalization present increased risk for colectomy or future hospitalization. Smoking status, concurrent primary sclerosing cholangitis and concurrent infections may impact the course of disease. Current genetic and serological markers lack accuracy for clinical use.

CONCLUSIONS

Simple demographic and clinical features can guide the clinician in identifying patients at higher risk for disease complications at diagnosis and throughout disease course. However, many of these risk factors have been identified retrospectively and lack validation. Appropriately powered prospective studies are required to inform algorithms that can truly predict the risk for disease progression in the individual patient.

The Same Intestinal Inflammatory Disease despite Different Genetic Risk Factors in the East and West?

Background

Inflammatory bowel disease (IBD) is a chronic inflammatory disease with unknown etiology. It is likely caused by a complex interplay between genetic, immunologic and environmental factors. Although IBD is still relatively uncommon in Asia, a multitude of studies have shown that it is an emerging disease around the world. Recent insights have highlighted both the similarities and differences amongst Asian and Western IBD patients.

Summary

The annual incidence of IBD in the East is still low compared with the West, but there are differences between different regions of Asia. Time trend studies have shown that the incidence of IBD is on the rise. Some notable differences in the clinical manifestations of IBD between the East and West have also been noted. 'Westernization' of lifestyle may encompass various social and environmental changes that account for the emergence of IBD in our population, although genetics also plays a role in disease pathogenesis. Diagnosis and treatment challenges include limited access to medical care in certain areas, limited availability and high cost of medications, lack of insurance reimbursement, paucity of multidisciplinary teams for the management of complicated IBD cases, and a high prevalence of endemic infections. Currently, the risk of colorectal cancer is lower in the East than in the West, but cancer rates will likely approach that of the West in the future as the prevalence of IBD continues to rise.

Key Messages

Measures to improve access to diagnostic tools, increase the availability of medication, and provide adequate multidisciplinary care for IBD patients will become increasingly important in Asia. Differences between the East and West will provide a unique opportunity for global collaboration in basic and clinical research to further our understanding of the disease entity and also provide more locoregional data to healthcare providers and policymakers to make informed decisions and policy changes when tackling the rising burden of IBD in Asia.