Smoking in inflammatory bowel disease: impact on disease course and insights into the aetiology of its effect

The Effects of Combustible Cigarettes and Electronic Nicotine Delivery Systems on Immune Cell-Driven Inflammation and Mucosal Healing in Ulcerative Colitis

INTRODUCTION

The effects of combustible cigarettes (CCs) and electronic nicotine delivery systems (ENDS) on immune cell-driven colon inflammation and intestinal healing of patients with ulcerative colitis (UC) are still unknown and, therefore, were examined in this study.

AIMS AND METHODS

Intracellular staining and flow cytometry analysis of immune cells isolated from UC patients who used ENDS (UCENDS), CCs (UCCC) and who were nonsmokers (UCAIR) were performed to elucidate cellular mechanisms which were responsible for CCs and ENDS-dependent modulation of immune response during UC progression. Additionally, dextran sulfate sodium (DSS)-colitis was induced in ENDS/CC/air-exposed mice (DSSENDS/ DSSCC/DSSAIR groups) to support clinical findings.

RESULTS

Significantly increased number of immunosuppressive, IL-10, TGF-β, and IL-35-producing, FoxP3-expressing CD3 + CD4 + T regulatory cells (Tregs) was observed in the blood of UCENDS patients while the reduced presence of inflammatory, TNF-α and IFN-γ-producing, Tbx21-expressing CD3 + CD4 + Th1, IL-4-producing Gata3-expresing Th2 and IL-17, IL-22-producing, RORγT, IL-23R-expressing Th17 cells were noticed in the blood of UCCC patients. Exposure to either CCs or ENDS was associated with enhanced mucosal healing, ameliorated spontaneous recovery, and improved survival of DSS-treated mice. An expansion of immunosuppressive cells (IL-10-producing tolerogenic CD11c + dendritic cells, alternatively activated CD206, Arginase 1-expressing, IL-10-producing F4/80 + macrophages, IL-10-producing FoxP3-expressing Tregs) was noticed in the colons of DSSENDS-treated mice, while reduced number of inflammatory, IL-17- and IL-4-producing T lymphocytes was observed in the colons of DSSCC-compared to DSSAIR-treated mice.

CONCLUSIONS

Despite different mechanisms of action, both ENDS and CCs attenuated ongoing colon inflammation, enhanced healing, and ameliorated recovery of injured intestines of DSS-treated mice and UC patients.

IMPLICATIONS

This is the first study that compared the effects of CCs and ENDS on immune cells of patients suffering from UC, providing new information about molecular and cellular mechanisms which were responsible for ENDS and CCs-dependent modulation of immune cell-driven colon injury and inflammation. Obtained results showed that both ENDS and CCs had the capacity to attenuate detrimental immune response, enhance healing, and ameliorate recovery of injured intestines.

Severe obesity, a susceptibility factor for developing inflammatory bowel disease: results of a population-based study

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) develops in genetically susceptible individuals exposed to certain environmental factors, of which only a few have been established. We aimed to assess whether bariatric surgery (BS) and severe obesity are associated with an increased risk of developing IBD.

METHODS

Adults diagnosed with obesity or severe obesity between 2005 and 2020 were identified from the Catalan Health Surveillance System; those diagnosed with IBD prior to the diagnosis of obesity or severe obesity were excluded. Individuals who had undergone BS and those with a new diagnosis of IBD were identified and their likelihood of developing IBD was analyzed.

RESULTS

A total of 93 473 individuals with severe obesity, 1 009 256 with obesity and 14 698 who underwent BS were identified. The incidence rates of IBD among individuals who had undergone BS prior to IBD diagnosis was 0.84 cases per 1000 person-years, 0.90 cases per 1000 person-years among individuals with severe obesity without BS and 0.60 cases per 1000 person-years in individuals with obesity. In the multivariable regression analysis, severe obesity (hazard ratio [HR] 1.46; 95% confidence interval [95%CI] 1.31-1.62), BS (HR 1.57; 95%CI 1.25-1.97), and smoking habit (HR 1.57; 95%CI 1.46-1.69) were risk factors for developing IBD (as well as for Crohn's disease and ulcerative colitis).

CONCLUSIONS

Severe obesity and BS were independent risk factors for the development of IBD. noninvasive screening for IBD seems to be warranted in this population.

The Role of Environmental Factors Prior to Diagnosis on the Activity and Severity of Inflammatory Bowel Diseases-Results From the Prospective Population-Based Copenhagen Inflammatory Bowel Disease Inception Cohort

BACKGROUND

The influence of environmental factors on the severity of early inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is unclear. Herein, we aimed to investigate the role of environmental factors in the initial phenotype, activity, and severity of IBD.

METHODS

Copenhagen IBD Inception Cohort is a prospective population-based cohort of patients with newly diagnosed IBD between May 2021 and May 2023. Data on environmental factors were captured at IBD diagnosis using International Organisation of IBD (IOIBD) and HeartDiet questionnaires. Environmental factors' influence on outcome was analyzed and odds ratios (aOR) were adjusted for age, gender, and disease characteristics (adjusted OR, aOR [95% confidence interval]).

RESULTS

In total, 208 and 128 patients with incident UC and CD, respectively, were included. Active smoking was associated with increased risk of CD-related hospitalization (aOR = 2.84 [1.03; 7.88]) and stricturing phenotype (aOR = 5.28 [1.76; 15.85]) but lower risk of severe UC course (aOR = 0.28 [0.08; 0.95]). Further, previous smoking was not associated with negative effects in patients with CD in terms of early need for biologics, surgery, or hospitalization. In terms of diets, daily consumption of fruits (aOR = 0.27 [0.07; 0.99]) or vegetables (aOR = 0.27 [0.09; 0.80]) was inversely associated with stricturing CD, whereas whole meal bread was associated with reduced risk of severe CD activity (aOR = 0.40 [0.16; 0.98]).

CONCLUSIONS

This prospective population-based study highlighted several environmental factors associated with the initial severity and activity of IBD, emphasizing their pivotal role in the initial disease burden and giving guidance to personalized patient counseling.

Risk factors for inflammatory bowel disease: an umbrella review

Introduction

Inflammatory bowel disease (IBD) represents a cluster of chronic idiopathic inflammatory disorders situated at the nexus of intricate interplays. The primary aim of the present investigation is to perform an umbrella review of metaanalyses, systematically offering a comprehensive overview of the evidence concerning risk factors for IBD.

Methods

To achieve this, we searched reputable databases, including PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews, from inception through April 2023. Two authors independently assessed the methodological quality of each metaanalysis using the AMSTAR tool and adhered to evidence classification criteria.

Results

In total, we extracted 191 unique risk factors in meta-analyses, including 92 significantly associated risk factors. The top ten risk factors were human cytomegalovirus (HCMV) infection, IBD family history, periodontal disease, poliomyelitis, campylobacter species infection, hidradenitis suppurativa, psoriasis, use of proton pump inhibitors, chronic obstructive pulmonary disease, and western dietary pattern.

Discussion

In conclusion, this umbrella review extracted 62 risk factors and 30 protective factors, most of which were related to underlying diseases, personal lifestyle and environmental factors. The findings in this paper help to develop better prevention and treatment measures to reduce the incidence of IBD, delay its progression, and reduce the burden of IBD-related disease worldwide.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023417175.

Chronic Poor Sleep is Associated with Increased Disease Activity in Patients with Ulcerative Colitis: Prospective Observational Study in Japan

BACKGROUND AND AIM

Although sleep disorders are associated with the pathogenesis of inflammatory bowel disease, the causal relationship is unclear. Therefore, in this study we aimed to clarify the causal relationship between them.

METHODS

We administered the Pittsburgh Sleep Questionnaire to participants during regular visits to evaluate their sleep condition, and prospectively observed the participants. Participants were divided into poor sleep and non-poor sleep groups according to their first and second questionnaire scores. We compared inflammatory bowel disease relapse rates between the two groups.

RESULTS

The study population included 139 patients with inflammatory bowel disease, including 60 with chronic poor sleep. Disease relapse rate was significantly higher in the poor sleep group than in the non-poor sleep group [28.3% vs 8.9%; p = 0.0033]. Ulcerative colitis relapse rate was significantly higher in the poor sleep group than in the non-poor sleep group [34.5% vs 10.3%, p = 0.031]. Multivariate analysis identified chronic poor sleep as a clinical factor that affected inflammatory bowel disease relapse (odds ratio [OR] = 6.69, 95% confidence interval [CI]: 2.23-20.0, p = 0.0007] and ulcerative colitis relapse [OR = 8.89, 95% CI: 1.57-50.2, p = 0.014]. The Kaplan - Meier curve showed significantly lower cumulative treatment retention rates in the poor sleep group than in the non-poor sleep group [all patients, p = 0.0061; ulcerative colitis, p = 0.025].

CONCLUSIONS

Concomitant chronic poor sleep may have a negative influence on the disease activity in patients with inflammatory bowel disease, particularly in those with ulcerative colitis.

Estimating Causal Effects on a Disease Progression Trait Using Bivariate Mendelian Randomisation

Genome-wide association studies (GWAS) have provided large numbers of genetic markers that can be used as instrumental variables in a Mendelian Randomisation (MR) analysis to assess the causal effect of a risk factor on an outcome. An extension of MR analysis, multivariable MR, has been proposed to handle multiple risk factors. However, adjusting or stratifying the outcome on a variable that is associated with it may induce collider bias. For an outcome that represents progression of a disease, conditioning by selecting only the cases may cause a biased MR estimation of the causal effect of the risk factor of interest on the progression outcome. Recently, we developed instrument effect regression and corrected weighted least squares (CWLS) to adjust for collider bias in observational associations. In this paper, we highlight the importance of adjusting for collider bias in MR with a risk factor of interest and disease progression as the outcome. A generalised version of the instrument effect regression and CWLS adjustment is proposed based on a multivariable MR model. We highlight the assumptions required for this approach and demonstrate its utility for bias reduction. We give an illustrative application to the effect of smoking initiation and smoking cessation on Crohn's disease prognosis, finding no evidence to support a causal effect.

Effects of smoking on clinical treatment outcomes amongst patients with chronic inflammatory diseases initiating biologics: secondary analyses of the prospective BELIEVE cohort study

The prevalence and disease burden of chronic inflammatory diseases (CIDs) are predicted to rise. Patients are commonly treated with biological agents, but the individual treatment responses vary, warranting further research into optimizing treatment strategies. This study aimed to compare the clinical treatment responses in patients with CIDs initiating biologic therapy based on smoking status, a notorious risk factor in CIDs. In this multicentre cohort study including 233 patients with a diagnosis of Crohn's disease, ulcerative colitis, rheumatoid arthritis, axial spondyloarthritis, psoriatic arthritis or psoriasis initiating biologic therapy, we compared treatment response rates after 14 to 16 weeks and secondary outcomes between smokers and non-smokers. We evaluated the contrast between groups using logistic regression models: (i) a "crude" model, only adjusted for the CID type, and (ii) an adjusted model (including sex and age). Among the 205 patients eligible for this study, 53 (26%) were smokers. The treatment response rate among smokers (n = 23 [43%]) was lower compared to the non-smoking CID population (n = 92 [61%]), corresponding to a "crude" OR of 0.51 (95% CI: [0.26;1.01]) while adjusting for sex and age resulted in consistent findings: 0.51 [0.26;1.02]. The contrast was apparently most prominent among the 38 RA patients, with significantly lower treatment response rates for smokers in both the "crude" and adjusted models (adjusted OR 0.13, [0.02;0.81]). Despite a significant risk of residual confounding, patients with CIDs (rheumatoid arthritis in particular) should be informed that smoking probably lowers the odds of responding sufficiently to biological therapy. Registration: Clinical.Trials.gov NCT03173144.

Whole Blood DNA Methylation Changes Are Associated with Anti-TNF Drug Concentration in Patients with Crohn's Disease

BACKGROUND AND AIMS

Anti-tumour necrosis factor [TNF] treatment failure in patients with inflammatory bowel disease [IBD] is common and frequently related to low drug concentrations. In order to identify patients who may benefit from dose optimisation at the outset of anti-TNF therapy, we sought to define epigenetic biomarkers in whole blood at baseline associated with anti-TNF drug concentrations at week 14.

METHODS

DNA methylation from 1104 whole blood samples from 385 patients in the Personalised Anti-TNF Therapy in Crohn's disease [PANTS] study were assessed using the Illumina EPIC Beadchip [v1.0] at baseline and weeks 14, 30, and 54. We compared DNA methylation profiles in anti-TNF-treated patients who experienced primary non-response at week 14 if they were assessed at subsequent time points and were not in remission at week 30 or 54 [infliximab n = 99, adalimumab n = 94], with patients who responded at week 14 and when assessed at subsequent time points were in remission at week 30 or 54 [infliximab n = 99, adalimumab n = 93].

RESULTS

Overall, between baseline and week 14, we observed 4999 differentially methylated positions [DMPs] annotated to 2376 genes following anti-TNF treatment. Pathway analysis identified 108 significant gene ontology terms enriched in biological processes related to immune system processes and responses. Epigenome-wide association [EWAS] analysis identified 323 DMPs annotated to 210 genes at baseline associated with higher anti-TNF drug concentrations at Week 14. Of these, 125 DMPs demonstrated shared associations with other common traits [proportion of shared CpGs compared with DMPs] including body mass index [23.2%], followed by C-reactive protein [CRP] [11.5%], smoking [7.4%], alcohol consumption per day [7.1%], and IBD type [6.8%]. EWAS of primary non-response to anti-TNF identified 20 DMPs that were associated with both anti-TNF drug concentration and primary non-response to anti-TNF with a strong correlation of the coefficients [Spearman's rho = -0.94, p <0.001].

CONCLUSION

Baseline DNA methylation profiles may be used as a predictor for anti-TNF drug concentration at week 14 to identify patients who may benefit from dose optimisation at the outset of anti-TNF therapy.

Differential Impact of Smoking on Methylome and Transcriptome in Crohn's Disease and Ulcerative Colitis

BACKGROUND

Smoking is an environmental factor that differentially impacts Crohn's disease (CD) and ulcerative colitis (UC). The mechanism of impact of smoking on disease risk and clinical outcomes remains to be established.

METHODS

This study used a prospective cohort of patients with CD or UC. Self-reported smoking status was validated using serum cotinine measurement. We profiled methylation changes in peripheral blood using the Illumina Methylation BeadChip. Transcriptomic profiling was performed on ileal and colonic tissue using an Illumina TruSeq platform. We compared the methylation and transcriptional changes in current, former, and never smokers stratified by disease type.

RESULTS

Our cohort included 200 patients with CD or UC with methylation profiles and 160 with transcriptomic data. The mean serum cotinine level was higher in current compared with former or never smokers. Epigenetic changes common to both CD and UC included hypomethylation at AHRR. Smoking-associated MGAT3 hypomethylation was associated with severe disease course only in UC, while IER3 hypomethylation was associated with worse course only in CD. Smoking downregulated several inflammatory pathways in UC. Current smoking in CD but not in UC was associated with upregulation of several genes mediating Paneth cell function. Genes with opposite direction of effects in CD and UC include HSD3B2 and GSTA1.

CONCLUSIONS

Our findings suggest both common and differential effects of cigarette smoking on CD and UC. Paneth cell dysfunction may mediate adverse impact of smoking on CD. Bile acid and oxidative stress pathways may be relevant for the differential effect of smoking on CD and UC.

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.

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.

Gut microbiota composition in patients with Crohn's disease in Saudi Arabia

Crohn's disease (CD) entails intricate interactions with gut microbiome diversity, richness, and composition. The relationship between CD and gut microbiome is not clearly understood and has not been previously characterized in Saudi Arabia. We performed statistical analysis about various factors influencing CD activity and microbiota dysbiosis, including diagnosis, treatment, and its impact on their quality of life as well as high-throughput metagenomic V3-V4 16S rRNA encoding gene hypervariable region of a total of eighty patients with CD, both in its active and inactive state with healthy controls. The results were correlated with the demographic and lifestyle information, which the participants provided via a questionnaire. α-diversity measures indicated lower bacterial diversity and richness in the active and inactive CD groups compared to the control group. Greater dysbiosis was observed in the active CD patients compared to the inactive form of the disease, showed by a reduction in microbial diversity. Specific pathogenic bacteria such as Filifactor, Peptoniphilus, and Sellimonas were identified as characteristic of CD groups. In contrast, anti-inflammatory bacteria like Defluviitalea, Papillibacter, and Petroclostridium were associated with the control group. Among the various factors influencing disease activity and microbiota dysbiosis, smoking emerged as the most significant, with reduced α-diversity and richness for the smokers in all groups, and proinflammatory Fusobacteria was more present (p<0.05). Opposite to the control group, microbial diversity and richness were lower in CD participants of older age compared to younger ones, and male CD participants showed less diversity compared to women participants from the same groups. Our results describe the first report on the relationship between microbiota and Crohn's disease progress in Saudi Arabia, which may provide a theoretical basis for the application of therapeutic methods to regulate gut microbes in CD.

Factors associated with surgical resection in patients with Crohn's disease: long-term evaluation

PURPOSE

To evaluate patient characteristics and factors associated with surgical resection in patients with Crohn's disease (CD).

METHODS

An analysis was performed on data from 295 patients with CD in follow-up from 2001 to 2018. Medical record data comprised age, gender, location, behavior and duration of the CD, smoking, and extraintestinal manifestation. Patients were divided into two groups according to the presence or absence of surgical resection.

RESULTS

Out of the 295 patients with CD, 155 underwent surgical resection (53.2% male, mean age: 43.88 ± 14.35 years). The main indications for surgery were stenosis (44.5%), clinical intractability (15.5%), and intra-abdominal fistulas (15.5%). Smoking (p < 0.001), longer CD duration (p < 0.0001), ileo-colonic location (p = 0.003), stenosing behavior (p < 0.0001), and fistulizing behavior (p < 0.0001) were significantly associated with surgical resection. Initial use of biological was significantly more frequent in the group of patients without surgical resection (p < 0.001).

CONCLUSIONS

Patients with CD still frequently need surgical treatment. Smoking (current or past), longer disease time, stenosing and fistulizing behavior, and ileo-colonic localization in CD patients were associated with a higher risk of surgery. Awareness about factors associated with unfavorable outcome allows such patients to be treated more appropriately.

Cigarette smoking and risk of adult-onset Still disease: a propensity score matching analysis

BACKGROUND

Environmental factors play an important role in the pathogenesis of rheumatic diseases. Smoking is thought to be a risk factor for autoimmune rheumatic diseases.

AIMS

The purpose of the present study was to assess the association between smoking and adult-onset Still disease (AOSD) and the effect of smoking on outcomes of this disease.

METHODS

In this case-control study, patients with AOSD who met the Yamaguchi criteria, were older than 16 years at the disease onset and were in follow-up for at least 12 months were consecutively enrolled in the study. The outcome of AOSD was assessed by acquiring remission on treatment, remission off treatment, time to remission and rate of flare. The smoking status of participants was defined by direct or phone interviews. Individuals who had smoked daily for at least 6 months were defined as a smoker. We performed propensity score matching analyses by using four parameters, including age, sex, educational status and marital status.

RESULTS

Propensity score matching resulted in 72 patients with AOSD and 216 matched controls. The number of ever smokers in the AOSD and control groups were 11 (15.3%) and 25 (11.6%) respectively. There was no significant increase in the risk of AOSD in multivariate analysis after adjustment for age, sex, marital status and educational level. There were no significant differences in the outcomes of AOSD between ever and never smokers.

CONCLUSIONS

Smoking probably is not a risk factor for AOSD and did not affect the response to treatment.

Altered DNA methylation within DNMT3A, AHRR, LTA/TNF loci mediates the effect of smoking on inflammatory bowel disease

This work aims to investigate how smoking exerts effect on the development of inflammatory bowel disease (IBD). A prospective cohort study and a Mendelian randomization study are first conducted to evaluate the association between smoking behaviors, smoking-related DNA methylation and the risks of Crohn's disease (CD) and ulcerative colitis (UC). We then perform both genome-wide methylation analysis and co-localization analysis to validate the observed associations. Compared to never smoking, current and previous smoking habits are associated with increased CD (P = 7.09 × 10-10) and UC (P < 2 × 10-16) risk, respectively. DNA methylation alteration at cg17742416 [DNMT3A] is linked to both CD (P = 7.30 × 10-8) and UC (P = 1.04 × 10-4) risk, while cg03599224 [LTA/TNF] is associated with CD risk (P = 1.91 × 10-6), and cg14647125 [AHRR] and cg23916896 [AHRR] are linked to UC risk (P = 0.001 and 0.002, respectively). Our study identifies biological mechanisms and pathways involved in the effects of smoking on the pathogenesis of IBD.

Association between dietary inflammatory index and anemia in US adults

Background and aims

Anemia is a widespread global health concern, and recent research has unveiled a link between anemia and inflammation. The Dietary Inflammation Index (DII) is a novel tool used to assess the overall inflammatory potential of an individual's diet. However, until now, there have been no studies demonstrating a connection between DII and anemia. This study aimed to explore the relationship between DII and the risk of anemia among Americans, as well as to examine the influence of other risk factors on this association.

Methods

Data from 32,244 patients were collected from the National Health and Nutrition Examination Survey (NHANES) database spanning from 1999 to 2018. Using multivariable logistic regression, we examined the correlation between DII and anemia. Subgroup analyses and smoothed curve analyses were conducted to further investigate the association between DII and anemia.

Results

The analysis revealed a significant positive association between higher DII scores and increased anemia risk in the American population (Odds Ratio [OR] = 1.06, 95% Confidence Interval [CI] = 1.03 to 1.09, p < 0.0001). This association remained consistent in subgroup analyses, encompassing various age groups, distinct Body Mass Index (BMI) categories, varying diabetes mellitus statuses, histories of hypertension, females, individuals with a RIP <3.5, and Non-Hispanic Black individuals. Notably, the association was particularly significant among non-smokers. Smoothed curve fitting analysis demonstrated a linear relationship between DII and the prevalence of anemia.

Conclusion

Our findings underscore a positive correlation between the inflammatory potential of one's diet and the risk of anemia, especially when coupled with other risk factors. Consequently, reducing the consumption of pro-inflammatory foods may serve as one of the effective measures against the development of anemia. Given the variations in gender, age, BMI, and chronic diseases observed in our study, tailored policies could better cater to the specific needs of diverse populations.

NLRP6 controls pulmonary inflammation from cigarette smoke in a gut microbiota-dependent manner

Chronic obstructive pulmonary disease (COPD) is a major health issue primarily caused by cigarette smoke (CS) and characterized by breathlessness and repeated airway inflammation. NLRP6 is a cytosolic innate receptor controlling intestinal inflammation and orchestrating the colonic host-microbial interface. However, its roles in the lungs remain largely unexplored. Using CS exposure models, our data show that airway inflammation is strongly impaired in Nlrp6-deficient mice with drastically fewer recruited neutrophils, a key cell subset in inflammation and COPD. We found that NLRP6 expression in lung epithelial cells is important to control airway and lung tissue inflammation in an inflammasome-dependent manner. Since gut-derived metabolites regulate NLRP6 inflammasome activation in intestinal epithelial cells, we investigated the link between NLRP6, CS-driven lung inflammation, and gut microbiota composition. We report that acute CS exposure alters gut microbiota in both wild-type (WT) and Nlrp6-deficient mice and that antibiotic treatment decreases CS-induced lung inflammation. In addition, gut microbiota transfer from dysbiotic Nlrp6-deficient mice to WT mice decreased airway lung inflammation in WT mice, highlighting an NLRP6-dependent gut-to-lung axis controlling pulmonary inflammation.

Inflammatory bowel disease and bladder cancer risk: based on a Mendelian randomization study

BACKGROUND

Prior epidemiological observational studies have duly documented a correlative link between inflammatory bowel disease (IBD) and bladder cancer (BC); however, the establishment of a definitive causal relationship has remained elusive. The principal objective of this meticulous investigation was to rigorously evaluate the causal nexus between IBD and BC, employing the robust methodology of Mendelian randomization (MR) analysis.

METHODS

We meticulously performed both univariate and multivariate Mendelian randomization (MVMR) analyses employing publicly accessible genome-wide association study (GWAS) data. The central approach employed for our investigations was inverse variance weighting (IVW) method, while diligently scrutinizing potential sources of heterogeneity and horizontal pleiotropy via the rigorous utilization of Cochran's Q test, the MR-PRESSO method, and MR-Egger.

RESULTS

In the univariate MR analysis, no causal link was observed between genetic prediction of IBD and BC. Furthermore, both Crohn's disease (CD) and ulcerative colitis (UC) showed no causal association with BC. The consistent association between CD and UC in the MVMR analysis supports this finding.

CONCLUSION

This study found no genetic basis for the causative association of IBD and BC. It is crucial to emphasize that further comprehensive investigations are warranted to delve into the intricate underlying mechanisms that may contribute to these associations.

The Role of the Microbiome in the Pathogenesis and Treatment of Ulcerative Colitis-A Literature Review

Ulcerative colitis (UC) is a chronic inflammatory bowel disease affecting the colon and rectum. UC's pathogenesis involves colonic epithelial cell abnormalities and mucosal barrier dysfunction, leading to recurrent mucosal inflammation. The purpose of the article is to show the complex interplay between ulcerative colitis and the microbiome. The literature search was conducted using the PubMed database. After a screening process of studies published before October 2023, a total of 136 articles were selected. It has been discovered that there is a fundamental correlation of a robust intestinal microbiota and the preservation of gastrointestinal health. Dysbiosis poses a grave risk to the host organism. It renders the host susceptible to infections and has been linked to the pathogenesis of chronic diseases, with particular relevance to conditions such as ulcerative colitis. Current therapeutic strategies for UC involve medications such as aminosalicylic acids, glucocorticoids, and immunosuppressive agents, although recent breakthroughs in monoclonal antibody therapies have significantly improved UC treatment. Furthermore, modulating the gut microbiome with specific compounds and probiotics holds potential for inflammation reduction, while fecal microbiota transplantation shows promise for alleviating UC symptoms. This review provides an overview of the gut microbiome's role in UC pathogenesis and treatment, emphasizing areas for further research.

Risk-stratified monitoring for thiopurine toxicity in immune-mediated inflammatory diseases: prognostic model development, validation, and, health economic evaluation

Background

Patients established on thiopurines (e.g., azathioprine) are recommended to undergo three-monthly blood tests for the early detection of blood, liver, or kidney toxicity. These side-effects are uncommon during long-term treatment. We developed a prognostic model that could be used to inform risk-stratified decisions on frequency of monitoring blood-tests during long-term thiopurine treatment, and, performed health-economic evaluation of alternate monitoring intervals.

Methods

This was a retrospective cohort study set in the UK primary-care. Data from the Clinical Practice Research Datalink Aurum and Gold formed development and validation cohorts, respectively. People age ≥18 years, diagnosed with an immune mediated inflammatory disease, prescribed thiopurine by their general practitioner for at-least six-months between January 1, 2007 and December 31, 2019 were eligible. The outcome was thiopurine discontinuation with abnormal blood-test results. Patients were followed up from six-months after first primary-care thiopurine prescription to up to five-years. Penalised Cox regression developed the risk equation. Multiple imputation handled missing predictor data. Calibration and discrimination assessed model performance. A mathematical model evaluated costs and quality-adjusted life years associated with lengthening the interval between blood-tests.

Findings

Data from 5982 (405 events over 16,117 person-years) and 3573 (269 events over 9075 person-years) participants were included in the development and validation cohorts, respectively. Fourteen candidate predictors (21 parameters) were included. The optimism adjusted R2 and Royston D statistic in development data were 0.11 and 0.76, respectively. The calibration slope and Royston D statistic (95% Confidence Interval) in the validation data were 1.10 (0.84-1.36) and 0.72 (0.52-0.92), respectively. A 2-year period between monitoring blood-test was most cost-effective in all deciles of predicted risk but the gain between monitoring annually or biennially reduced in higher risk deciles.

Interpretation

This prognostic model requires information that is readily available during routine clinical care and may be used to risk-stratify blood-test monitoring for thiopurine toxicity. These findings should be considered by specialist societies when recommending blood monitoring during thiopurine prescription to bring about sustainable and equitable change in clinical practice.

Funding

National Institute for Health and Care Research.

Tobacco use in Crohn's disease patients and association with disease outcomes in the United States Medicaid population, 2010-2019

Background and Aim

To identify demographic factors associated with tobacco use in Crohn's disease (CD) patients in the US Medicaid population and examine how tobacco use affects disease outcomes.

Methods

We included Medicaid-eligible patients who had ≥1 ICD code for CD, and 1 year of eligibility before and after the initial encounter. We used ICD codes to identify tobacco use with respect to the time of diagnosis and used logistic regression to identify the association between age, sex, and race with tobacco use at any point before diagnosis and after diagnosis, and determine the association of tobacco use before and after diagnosis on disease outcomes.

Results

We identified 98 176 eligible patients; 74.5% had no documented use of tobacco and 25.5% used tobacco at some point; 21.1% had used tobacco before their CD diagnosis and 11.8% had used tobacco after diagnosis. The population that used tobacco had a higher proportion of women, those who were White, non-Hispanic, and those in their middle ages (21-60) than the group that did not use tobacco. Tobacco use before diagnosis resulted in higher risk of hospitalization and surgery (OR: 1.85 and 1.36, respectively).

Conclusion

Within the CD Medicaid population, tobacco use is more common in women than men, which differs from the general population, which is possibly a result of using diagnostic codes rather than survey data. Smoking cessation efforts should especially be directed at younger people who are at risk for CD, due to increased risk for more adverse outcomes among those who use tobacco before diagnosis.

The Relationship Between Smoking Status, Carbon Monoxide Levels, Quality of Life, and Disease Features in Inflammatory Bowel Diseases

Objective: The aim of the study was to analyze the relationship between smoking status and exhaled carbon monoxide (E-CO) levels, quality of life, and disease characteristics in patients with inflammatory bowel disease. Methods: The demographic and disease characteristics and smoking status of 121 patients with inflammatory bowel disease who presented our hospital between 01.12.2020 and 01.03.2021 were investigated. After the first follow-up, the E-CO levels of these participants were measured every four consecutive weeks. The mean of these E-CO readings was accepted as the main E-CO value. After one month after their first application SF-36 Quality of Life Scale was applied. The relationship between these variables was investigated. Results: The mean age of the participants was 42.06±14.9 years, and 36.3% were active smokers. While patients with Crohn’s disease (CD) exhibited a higher smoking rate, smokers with ulcerative colitis (UC) registered significantly higher mean CO ppm readings (p

Pilot study of an elimination diet in adults with mild to moderate Crohn's disease

BACKGROUND

There remains limited data supporting the efficacy of dietary therapy in adults with Crohn's disease (CD). This was a pilot study of the McMaster Elimination diet for CD (MED-CD), which excludes several potentially detrimental ingredients commonly found in the Western diet.

METHODS

Prospective study in adults with mild-moderately active CD [Harvey-Bradshaw Index (HBI) scores 5-16] and endoscopic disease activity of >7 (or ≥4 for isolated ileal disease) as measured by the Simple Endoscopic Score for Crohn's disease (SES-CD). Patients were treated for 2 weeks using oral enteral nutrition (EN). Those with symptomatic improvement (HBI score reduction ≥2) were transitioned to the MED-CD for 12 weeks. Outcomes of interest included satisfactory adherence (≥20 on the modified medical adherence report scale-5 questionnaire), clinical remission (CR) (HBI ≤4), clinical response (HBI reduction ≥3), endoscopic response (SES-CD reduction ≥50%), and endoscopic remission (ER) (SES-CD <3).

RESULTS

A total of 17 patients were treated with 2 weeks of EN. Of these, 13 were deemed responders and treated with 12 weeks of MED-CD. Satisfactory adherence was reported among 11/13 (84.6%) at week 6 and 8/12 (67%) at week 14. Of the 13 patients who responded to EN by week 2, 5 (38.5%) had attained CR at week 2 and maintained CR until week 14 using MED-CD. Endoscopic response was observed in 6 (46.2%) participants and ER was seen in 2 (15.4%).

CONCLUSIONS

Two weeks of oral EN followed by 12 weeks of the MED-CD was acceptable by most adult patients who enroled in this study.

Environmental risk factors for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, progressive immune-mediated inflammatory condition of the gastrointestinal tract. Environmental risk factors play a role in developing either type of IBD, Crohn's disease and ulcerative colitis; although the exact mechanism is still unknown. Herein, we review environmental risks from early life exposures, lifestyle and hygiene, vaccinations, surgeries, exposure to drugs and gastrointestinal pathogens that may increase the risk of developing IBD.

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.

Can smoking have a positive effect on the course of certain diseases? A systematic review

Background: Smoking cigarettes is a process during which many harmful substances are introduced into the lungs and the influence of these substances on the human body is not completely known. There are many diseases caused by smoking. Interestingly, there are also reports of positive consequences of smoking on some disorders. Aim of the study: The purpose of this article is to review the literature in regards to the diseases in which cigarettes might have a paradoxically beneficial effect — both on the onset and their course. We also want to focus on the mechanisms responsible for this impact. Material and Methods: Electronic searching of PubMed was performed. We analyzed articles published in the last 10 years with a particular emphasis on the most recent publications. Combinations of the following words were used: “smoking”, “nicotine”, and “autoimmune”. Publications were selected for reliability and non-bias. Results: A total of 69 articles out of 2979 qualified for the review. Only studies involving humans were included. The positive effect of smoking cigarettes is observed especially in immunological diseases. It is possible that it is mediated by both stimulating and suppressing the immune system. It is assumed that cigarettes can reduce the risk of developing certain diseases. Smoking might also have an impact on the course of different comorbidities in the same patient. Conclusions: There are many different mechanisms through which cigarette smoke and nicotine affect the human body. The harmful impact of these substances on one’s health has been demonstrated and their addictive component disqualifies them as remedies. Analysis of the mechanisms responsible for the beneficial effects of nicotine can lead to the search for new forms of therapy and prevention.

Novel Models of Crohn's Disease Pathogenesis Associated with the Occurrence of Mitochondrial Dysfunction in Intestinal Cells

Crohn’s disease remains one of the challenging problems of modern medicine, and the development of new and effective and safer treatments against it is a dynamic field of research. To make such developments possible, it is important to understand the pathologic processes underlying the onset and progression of Crohn’s disease at the molecular and cellular levels. During the recent years, the involvement of mitochondrial dysfunction and associated chronic inflammation in these processes became evident. In this review, we discuss the published works on pathogenetic models of Crohn’s disease. These models make studying the role of mitochondrial dysfunction in the disease pathogenesis possible and advances the development of novel therapies.

Meta-Analysis of IBD Gut Samples Gene Expression Identifies Specific Markers of Ileal and Colonic Diseases

BACKGROUND

Inflammatory bowel diseases (IBDs) are characterized by chronic inflammation and tissue damages in limited segments of the digestive tract. Pathogenesis in the tissue and mucosal inflammation probably differs according to disease location. Our aim was to further analyze transcriptomic profiles in different locations of IBD, differentiating ulcerative colitis (UC), colonic Crohn's disease (CD), ileal CD, and pouchitis, with respect to normal colonic and ileal mucosa. We thus performed a meta-analysis focusing on specific transcriptomic signatures of ileal and colonic diseases.

METHODS

We identified 5 cohorts with available transcriptomic data in ileal or colonic samples from active IBD and non-IBD control samples. The meta-analysis was performed on 1047 samples. In each cohort separately, we compared gene expression in CD ileitis and normal ileum; in CD colitis, UC, and normal colon; and finally in pouchitis and normal ileum.

RESULTS

We identified specific markers of ileal (FOLH1, CA2) and colonic (REG3A) inflammation and showed that, with disease, some cells from the ileum start to express colonic markers. We confirmed by immunohistochemistry that these markers were specifically present in ileal or colonic diseases. We highlighted that, overall, colonic CD resembles UC and is distinct from ileal CD, which is in turn closer to pouchitis.

CONCLUSIONS

We demonstrated that ileal and colonic diseases exhibit specific signatures, independent of their initial clinical classification. This supports molecular, rather than clinical, disease stratification, and may be used to design drugs specifically targeting ileal or colonic diseases.

Smoking associated with reduced odds of Sjögren's syndrome among rheumatoid arthritis patients

OBJECTIVE

The objective of this medical record review study is to define the association between smoking and Sjӧgren's syndrome (SS) in a large rheumatoid arthritis (RA) cohort.

METHODS

Electronic health records from a population-based cohort were screened for RA eligibility between 2005 and 2018. Inclusion criteria were age ≥ 18 years, two or more RA diagnoses, including two diagnoses by a rheumatologist, or positive rheumatoid factor or anti-cyclic citrullinated peptide (anti-CCP) antibody. The independent variable, smoking status, was defined as never, current, or past. The outcome, SS, was defined by two or more ICD-9 codes. Multivariable logistic regression was performed to determine odds ratios (ORs) of SS adjusted for age, sex, and race.

RESULTS

Among 1861 patients with RA identified for cohort inclusion, 1296 had a reported smoking status. Current smokers were younger and less likely to be female than never smokers. The adjusted OR of current compared to never smokers was negatively associated with SS [OR 0.20, 95% confidence interval (CI) 0.06-0.65]. Female sex and age were associated with SS (OR 2.70, 95% CI 1.18-6.14; OR 3.75, 95% CI 1.23-11.4).

CONCLUSION

We report that RA patients who currently smoke had 80% lower odds of SS. Age had a 3.7-fold association and female sex a 2.7-fold association with SS among RA patients. Our data suggest a negative correlation between current smoking and prevalent SS among RA patients. Prospective studies examining pack-year relationships or smoking cessation could further examine risk reduction and causality to follow-up our cross-sectional observational study.

Nicotine Oral Administration Attenuates DSS-Induced Colitis Through Upregulation of Indole in the Distal Colon and Rectum in Mice

Nicotine affects the gastrointestinal environment and modulates ulcerative colitis (UC). However, the associations among nicotine, gut metabolites, and UC are still largely unknown. We investigated whether orally administered nicotine affected gut metabolites and dextran sodium sulfate (DSS)-induced colitis. C57BL/6 male mice were orally administered nicotine solution in drinking water prior to inducing DSS-induced colitis. Short-chain fatty acids (SCFAs) and indole in gut contents and fecal samples were measured by GC-MS and hydroxylamine-based indole assays, respectively. Oral administration of nicotine increased indole concentration in feces, but, in contrast, SCFA values did not differ with nicotine administration. Indole levels were increased in the distal colon and rectum but not in the cecum and proximal colon. DSS-induced colitis was less severe clinically and histological changes were minimal in the rectum of orally nicotine-administered mice compared to mice drinking only water. 16S rRNA microbiome on the feces revealed an increasing in Clostridium and Porphyromonas in nicotine-administered mice. In conclusion, nicotine administration was associated with increased indole levels in the distal colon and rectum and attenuated DSS-induced colitis. Oral administration of nicotine may play a potential role in indole upregulation and prevention of UC.

Microbial pathogenesis in inflammatory bowel diseases

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal system. Previously, it is considered the disease of the western world but now the incidence and prevalence of IBD are increasing globally with urbanization and modernization. Additionally, the major problem is the highest incidence of IBD among children and adolescents. The precise etiology of IBD is unknown and there is no cure for IBD, which is also the reason for increasing the number of cases worldwide. The IBD is a complex interplay of environment, immune system, and microbiota in a genetically susceptible host. Among these factors, the alteration in intestinal microbiota has been detected in IBD patients. The bacterial species associated with IBD include Mycobacterium paratuberculosis, adherent-invasive E. coli (AIEC), Helicobacter pylori, and Campylobacter concisus. Moreover, the efficacy of antibiotics and probiotics further suggests the role of microbes in IBD. However, no study confirmed the bacterial species as a cause of IBD as per Koch's postulates. Thus, still controversies exist regarding the role of microbes in IBD. Therefore, this paper aims to review the current literature to evaluate the role of microbes in IBD that would be a useful inventory of researchers working in this area.

Histopathological Features in Colonic Biopsies at Diagnosis Predict Long-term Disease Course in Patients with Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease [CD] is characterised by a heterogeneous disease course. Patient stratification at diagnosis using clinical, serological, or genetic markers does not predict disease course sufficiently to facilitate clinical decision making. The current study aimed to investigate the additive predictive value of histopathological features to discriminate between a long-term mild and severe disease course.

METHODS

Diagnostic biopsies from treatment-naïve CD patients with mild or severe disease courses in the first 10 years after diagnosis were reviewed by two gastrointestinal pathologists after developing a standardised form comprising 15 histopathological features. Multivariable logistic regression models were built to identify predictive features and compute receiver operating characteristic [ROC] curves. Models were internally validated using bootstrapping to obtain optimism-corrected performance estimates.

RESULTS

In total, 817 biopsies from 137 patients [64 mild, 73 severe cases] were included. Using clinical baseline characteristics, disease course could only moderately be predicted (area under receiver operating characteristic curve [AUROC]: 0.738 [optimism 0.018], 95% confidence interval [CI] 0.65-0.83, sensitivity 83.6%, specificity 53.1%). When adding histopathological features, in colonic biopsies a combination of [1] basal plasmacytosis, [2] severe lymphocyte infiltration in lamina propria, [3] Paneth cell metaplasia, and [4] absence of ulcers were identified and resulted in significantly better prediction of a severe course (AUROC: 0.883 [optimism 0.033], 95% CI 0.82-0.94, sensitivity 80.4%, specificity 84.2%).

CONCLUSIONS

In this first study investigating the additive predictive value of histopathological features in biopsies at CD diagnosis, we found that certain features of chronic inflammation in colonic biopsies contributed to prediction of a severe disease course, thereby presenting a novel approach to improving stratification and facilitating clinical decision making.

Effectiveness of a Telephone-Based Motivational Intervention for Smoking Cessation in Patients With Crohn Disease: A Randomized, Open-Label, Controlled Clinical Trial

A randomized, open-label, controlled clinical trial was designed to assess the effectiveness of a motivational intervention based on the 5 R's model (relevance, risks, rewards, roadblocks, and repetition) delivered by specialized inflammatory bowel disease nurses every 3 months over a 1-year period as compared with patients who were followed regularly. Patients diagnosed with Crohn disease, aged 18 years or older, who reported being active smokers with Internet access at home and an e-mail address were eligible. A total of 144 patients (72 per group) were included (50% women, median age 40 years). They smoked a median of 10 cigarettes per day (range = 1-40) and had been smoking for a median of 22 years (range = 1-51). Motivation to quit (Richmond test) was low in 73 patients, moderate in 39 patients, and high in 32 patients. Statistically significant differences between the study groups in the predisposition to change, motivation to quit, and tobacco withdrawal were not found. However, 14 patients (20.9%) in the intervention group and 9 patients (13.2%) among controls stopped smoking at the end of the study. These findings support a higher trend toward smoking cessation associated with the motivational intervention 5 R's. This behavioral strategy can aid patients with Crohn disease to quit smoking.

Perianal disease onset age is associated with distinct disease features and need for intestinal resection in perianal Crohn's disease: a ten-year hospital-based observational study in China

BACKGROUND AND AIMS

The significance of different ages of perianal disease (PD) onset in patients with perianal Crohn's disease (PCD) remains unknown. We aimed to investigate the impact of paediatric-onset PD (POP) and adult-onset PD (AOP) on the Crohn's disease (CD) course in a Chinese cohort.

METHODS

The medical records of diagnosed PCD patients from 2008 to 2018 were reviewed retrospectively. The cumulative incidence and predictors of intestinal resection were calculated using the Kaplan-Meier and logistic regression analysis.

RESULTS

Complex perianal fistulas (71.7% vs 50.0%, p = 0.011) and infliximab (IFX) treatment (33.3% vs 22.0%, p = 0.044) were more common among the POP patients (age < 18 years old, n = 84). A younger PD onset age (15.1 ± 2.9 vs 30.2 ± 10.5 years, p < 0.001) and shorter PCD diagnostic delay (12 vs 24 months, p = 0.033) was found in the POP cohort. AOP patients (age ≥ 18 years old, n = 209) had a higher rate of current smoking (12.9% vs 4.8%, p = 0.040), stricturing behaviour (42.1% vs 27.4%, p = 0.024) and intestinal resection (21.1% vs 4.8%, p = 0.001). The cumulative probability of intestinal resection in AOP patients was higher than that in POP patients (p = 0.007). In multivariable analysis, AOP (OR: 4.939, 95% CI 1.538-15.855, p = 0.007), stricturing behaviour (OR: 1.810, 95% CI 1.008-3.251, p = 0.047) and rectal inflammation (OR: 3.166, 95% CI 1.119-8.959, p = 0.030) were predictive factors for CD-related intestinal resection in all PCD patients. AOP patients with complex perianal fistula (OR: 2.257, 95% CI 1.041-4.891, p = 0.039) and POP patients with rectal inflammation (OR: 3.166, 95% CI 1.119-8.959, p = 0.030) were more likely to suffer intestinal resection. The IFX administration significantly decreased the rate of intestinal resection in AOP patients (r = - 0.900, p = 0.037).

CONCLUSIONS

The AOP patients have more complicated luminal disease and higher rate of intestinal resection than COP patients. The perianal diseases onset-age can provide clinical treatment guidance for individual management of CD patients.

Results of the Seventh Scientific Workshop of ECCO: Precision Medicine in IBD-What, Why, and How

Many diseases that affect modern humans fall in the category of complex diseases, thus called because they result from a combination of multiple aetiological and pathogenic factors. Regardless of the organ or system affected, complex diseases present major challenges in diagnosis, classification, and management. Current forms of therapy are usually applied in an indiscriminate fashion based on clinical information, but even the most advanced drugs only benefit a limited number of patients and to a variable and unpredictable degree. This 'one measure does not fit all' situation has spurred the notion that therapy for complex disease should be tailored to individual patients or groups of patients, giving rise to the notion of 'precision medicine' [PM]. Inflammatory bowel disease [IBD] is a prototypical complex disease where the need for PM has become increasingly clear. This prompted the European Crohn's and Colitis Organisation to focus the Seventh Scientific Workshop on this emerging theme. The articles in this special issue of the Journal address the various complementary aspects of PM in IBD, including what PM is; why it is needed and how it can be used; how PM can contribute to prediction and prevention of IBD; how IBD PM can aid in prognosis and improve response to therapy; and the challenges and future directions of PM in IBD. This first article of this series is structured on three simple concepts [what, why, and how] and addresses the definition of PM, discusses the rationale for the need of PM in IBD, and outlines the methodology required to implement PM in IBD in a correct and clinically meaningful way.

Sustained Crohn’s Disease Remission with an Exclusive Elemental and Exclusion Diet: A Case Report

The incidence of inflammatory bowel diseases, such as Crohn’s disease (CD), is increasing worldwide. Despite several new therapeutics to treat CD, many patients fail to respond to their medications and inevitably face surgical resection. While genetics plays a role in CD, environmental factors are potential triggers. Recent research from the past few years suggest that pro-inflammatory foods are associated with an increased risk of CD. Some studies have shown the benefit of including exclusion diets, such as the specific carbohydrate diet (SCD) and exclusive elemental diets, to induce CD remission, but published data is limited. This case study explores how an exclusive elemental and exclusion diet helped induce clinical and biochemical remission and radiologic healing in a young adult male who had failed to achieve remission using standard medical treatment. C-reactive protein (CRP), fecal calprotectin, and magnetic resonance enterography (MRE) served as objective markers of inflammation in this study.

Periodontal and dental health in inflammatory bowel diseases: a systematic review

Introduction: An increased risk of dental caries and periodontal diseases has been reported for inflammatory bowel disease (IBD) patients and are challenging conditions to manage.Areas covered: The authors searched international databases to find all studies assessing dental/periodontal outcomes in patients with IBD and other immune-mediated inflammatory disease (IMID), as well as the association between IMID medications and dental/periodontal status.Expert opinion: IBD are associated with a higher risk of both periodontitis and caries. Some evidence from rheumatoid arthritis suggests that periodontitis may be associated with a lower response to anti-TNF. There is no reliable evidence that IBD patients may be at greater risk of complications during routine dental care. On the basis of current data, guidelines can be proposed for the dental management focusing on the detection and eradication of infectious foci prior to the implementation of immunosuppressants/biologics and modified dental treatment protocol for invasive dental procedures that includes antibiotic prophylaxis.

Identification of Risk Factors for Coexisting Sinusitis and Inflammatory Bowel Disease

Background

This study aimed to analyze the association of coexisting sinusitis and inflammatory bowel disease (IBD), establish significant factors involved in their development, and enable further biological correlation between these 2 diseases.

Methods

The IBD and Sinusitis Study at UChicago Medicine (TISSUe) is a retrospective, single-center study. We reviewed patients to confirm IBD and chronic sinusitis diagnoses. Case-control propensity score matching was performed using matched controls with IBD only or sinusitis only. Statistical methods included chi-squared test and Wilcoxon rank sum test. Logistic regression analysis was performed, and factors were considered significant if P &lt; .05.

Results

Stratifying 214 patients with coexisting IBD and sinusitis, 176 patients had IBD first and 38 patients had sinusitis first. Multivariable analysis of factors associated with subsequent disease with matched controls determined that duration of disease, UC, steroid exposure ever, and younger age of IBD diagnosis were associated with subsequent sinusitis in patients with IBD; steroid exposure ever and duration of sinusitis were significantly associated with subsequent IBD in patients with sinusitis.

Conclusion

This study suggests that IBD maintenance therapies are not associated with increased risk of sinusitis, as proposed by adverse events in clinical trial data; rather, UC diagnosis and duration of disease may be more influential in sinusitis development. While further studies are necessary, this study also demonstrates that sinusitis precedes IBD in some patients, probing its biological association with IBD and possible classification as an extraintestinal manifestation.

Prevalence of inflammatory bowel disease in the Australian general practice population: A cross-sectional study

The burden of inflammatory bowel disease (IBD) in Australia is increasing but national data about the current prevalence are limited. We aimed to estimate the prevalence of IBD (including Crohn’s disease, ulcerative colitis and unspecified IBD) as well as Crohn’s disease and ulcerative colitis separately in a general practice population in Australia. We also assessed risk factors associated with Crohn’s disease and ulcerative colitis. We conducted a cross-sectional study using data from MedicineInsight, a national database of general practice electronic health records, from 1 July 2017 to 30 June 2019. The prevalence of IBD was calculated and stratified by sociodemographic characteristics. Logistic regression analysis was conducted to assess risk factors associated with Crohn’s disease and ulcerative colitis. The study comprised 2,428,461 regular patients from 481 practices. The estimated crude prevalence of IBD was 653 per 100,000 patients; Crohn’s disease was 306 per 100,000 and ulcerative colitis was 334 per 100,000. Males were independently associated with a lower risk of Crohn’s disease (OR: 0.86; 95% CI: 0.81, 0.90) but a greater risk of ulcerative colitis (OR: 1.12; 95% CI: 1.06, 1.17) than females. Compared to non-smokers, patients who were current smokers were associated with a greater risk of Crohn’s disease (OR: 1.13; 95% CI: 1.04, 1.23) but a lower risk of ulcerative colitis (OR: 0.52; 95% CI: 0.47, 0.57). Other factors positively associated with both Crohn’s disease and ulcerative colitis were age (≥ 25 years), non-Indigenous status and socioeconomic advantage. Our findings provide a current estimate of the prevalence of IBD, Crohn’s disease and ulcerative colitis in a large national general practice population in Australia and an assessment of the factors associated with Crohn’s disease and ulcerative colitis. These data can assist in estimating the health burden and costs, and planning for health services.

Risk of Urinary Bladder Cancer in Patients With Inflammatory Bowel Diseases: A Meta-Analysis

A systematic search of the PubMed, Cochrane, Embase, and Web of Science databases was conducted to investigate the risk of urinary bladder cancer (BC) in patients with inflammatory bowel disease (IBD). We identified 168 articles, of which 11 met the inclusion and exclusion criteria. Our analysis included 165,176 patients with IBD, 491 of whom had BC. Overall, the pooled standardized incidence ratio (SIR) was 0.99 (95% CI: 0.87–1.12; I² = 0%). Further subgroup analysis showed that BC risk was neither statistically higher for Crohn's disease (CD) (SIR: 1.19; 95% CI: 0.94–1.44; I² = 0%) nor for patients with ulcerative colitis (UC) (SIR: 0.92; 95% CI: 0.77–1.06; I² = 0%). In the analysis of two case-control studies providing data on BC in UC and CD combined, IBD patients seemed to have a higher risk of BC than non-IBD patients (relative risk: 1.25; 95% CI: 0.77–2.03; I² = 37.5%). Although the overall risk of BC was not significantly increased among patients with IBD, there was a weak trend for the risk to be elevated in CD patients, indicating marginal significance. These findings may primarily be explained by the opposite effects of smoking on CD and UC as well as the immunosuppressive drugs these patients often take.

Rates of inflammatory bowel disease in Hispanics comparable to non-Hispanic Whites: results of a cohort study

PURPOSE

Previous studies have suggested that inflammatory bowel disease (IBD) occurs at higher rates among non-Hispanic Whites (NHWs) compared to other ethnicities; however, Hispanics as the largest minority in the United States remain underrepresented in IBD research and we hypothesize that they have similar rates of IBD. We examined the epidemiology, demographics, clinical presentation, and treatment of IBD in a predominantly Hispanic cohort in Los Angeles (LA) County.

METHODS

This was a retrospective cohort study based at Olive View-UCLA Medical Center, one of the three major safety-net hospitals in LA County. Electronic medical records from 2015 to 2018 were queried, and biopsy-proven cases of IBD (n = 170) were identified. Outcomes included the incidence and prevalence of IBD, disease distribution, treatment, and IBD-related surgery.

RESULTS

The incidence of IBD among Hispanics was 175 (95% confidence interval [CI] 127-240) and 113 (95% CI 62-200) for NHWs per 100,000 person-years. Prevalence of IBD per 100,000 people was 418 (95% CI 341-512) for Hispanics and 557 (95% CI 431-739) for NHWs. Notably, the proportion of Hispanic IBD patients with a history of smoking was 21.5% vs 50.8% in NHWs (p = 0.011). There were no significant differences between the two groups with regard to Montreal classification, pharmacotherapy, or IBD-related surgery.

CONCLUSIONS

In one of the largest US studies of Hispanics with IBD, and the only one to have both clinical and histopathologic confirmation as inclusion criteria, we found the incidence and prevalence of IBD among Hispanics to be higher than previously recognized and comparable to NHWs. Additionally, Hispanic IBD patients had lower rates of smoking compared to NHWs.

Characteristics of the intestinal microbiome in ankylosing spondylitis

The importance of intestinal microbiota in the development of various systemic diseases has been highlighted over time. Ankylosing spondylitis (AS) is a systemic disease with a complex pathogenesis involving a particular genetic marker and distinctive environmental triggers such as a specific gut dysbiosis. We conducted a prospective case-control study which included 60 subjects from Iasi Rehabilitation Hospital: 28 AS cases and 32 healthy controls. Intestinal microbiota analysis was performed by real-time polymerase chain reaction (qPCR) in stool samples. We performed the quantitative analysis of gut microbiome, focusing both on anti-inflammatory (Bifidobacterium, Lactobacillus, Faecalibacterium prausnitzii) and pro-inflammatory (Bacteroides, Escherichia coli) species. Overall, intestinal bacterial diversity in the AS group was decreased compared to that noted in the control. A significantly decreased level of Clostridium leptum was observed, associated with an increased level of Escherichia coli. We showed correlations between laboratory tests (liver and kidney functional tests, inflammatory syndrome), the presence of HLA-B27, smoker status, the forms of AS with peripheral arthritis vs. pure axial forms and bacterial structures. No significant correlations were shown for disease activity scores, radiological stage of sacroiliitis or for body mass index. Our findings support that the intestinal microbiome in AS patients has a special signature characterized by an inflammatory status. Numerous environmental, genetical, clinical and paraclinical factors can lead to changes in gut bacterial diversity in these cases.

The clinical practice of ulcerative colitis in elderly patients: An investigation using a nationwide database in Japan

Background and Aim

The number of elderly patients with ulcerative colitis (UC) is increasing worldwide. The clinical practice of associated treatment is still unclear. Therefore, we aimed to analyze clinical treatment realities and mortality in elderly and non‐elderly patients with UC.

Methods

We collected UC patients' data using the diagnosis procedure combination (DPC) database system and divided eligible patients into elderly (≥65 years) and non‐elderly (≤64 years) groups. We investigated and compared their therapeutic histories (medical treatments vs. surgery). Logistic regression analysis was conducted to identify clinical factors affecting surgery and in‐hospital death in each group.

Results

The rates of systemic steroid injection, molecular targeting drug usage, and surgery were not different between the two age groups. Meanwhile, the rate of in‐hospital death in elderly patients was higher than that in non‐elderly patients (2.7% vs. 0.19%, P < 0.0001). Multivariate analysis revealed that lower body mass index, treatment at an academic hospital, smoking history, molecular targeting drug use, and treatment with systemic steroid injection affected the rate of surgery in the elderly group. Multivariate analysis also revealed that male and older age affected the rate of in‐hospital death in the elderly group. Similar tendencies were also recognized in the non‐elderly group.

Conclusions

The clinical practice of treating elderly patients with UC is overall not different from treating non‐elderly patients with UC. Although the form of medical treatment and surgery rate for elderly patients with UC may not be significantly different from non‐elderly patients, the rate of in‐hospital death for elderly patients is higher.

A watchful waiting approach for newly diagnosed Crohn's disease patients with an inflammatory phenotype

BACKGROUND

An early treat-to-target approach in Crohn's disease (CD) patients is recommended to avoid complications. However, CD may not always progress despite lack of treatment, thus exposing some patients to unnecessary side effects. We aimed to examine whether newly diagnosed CD patients with an inflammatory phenotype can benefit from a watchful waiting approach.

METHODS

This retrospective cohort study followed CD patients with an inflammatory phenotype who were diagnosed between 2010 and 2015 and followed for at least 1 year. A watchful waiting approach was defined as maintenance therapy with 5-ASA medication only or no treatment during the first year of diagnosis or longer. Disease complications were defined as need for surgery or change in disease phenotype.

RESULTS

Eighty-six patients were included and followed-up for 57.0 ± 29.0 months. Thirty-seven patients were managed with a watchful waiting approach and 49 with an early therapeutic intervention. The majority of patients (83.8%) in the watchful waiting group did not develop disease complications. In this group, there was no difference in clinical disease severity (stools per day, 2.7 ± 1.7 vs 3.3 ± 1.0, P = 0.39; abdominal pain, 74.2 vs 50.0%, P = 0.24) between those who did not develop complications and those who did. Smoking was associated with a complicated course (multivariate analysis: OR = 1.98, 95% CI 1.06-3.71, P = 0.03).

CONCLUSIONS

A watchful waiting approach of newly diagnosed CD patients with an inflammatory phenotype may be a feasible option, with low long-term complication rate specifically in nonsmoking patients.

The Association between Periodontitis and Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND

It has been reported that patients with inflammatory bowel disease (IBD) are more susceptible to periodontitis. However, data regarding the risk of periodontitis in IBD patients are scarce, and results from individual studies remain controversial. The aim of this study is to investigate the risk of periodontitis in IBD patients.

METHODS

Web of Science, PubMed, and Embase were searched for studies investigating the risk of periodontitis in the IBD patient population from Jan. 2000 to Nov. 2020. Articles were included if they contained the number of people with IBD diagnosed with periodontitis (or periodontal disease parameters) compared with a control group. Case reports, reviews, animal studies, and articles without available abstracts were excluded. A pooled odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the association between periodontitis and IBD.

RESULTS

Six studies were included in the meta-analysis. The overall risk of periodontitis was significantly higher in IBD patients than controls (OR: 2.10, 95% CI: 1.60-2.74; I 2 = 27%). In particular, Crohn's disease (CD) and ulcerative colitis (UC) were both linked to an increased risk of periodontitis (OR: 1.72, 95% CI: 1.36-2.19; I 2 = 0% for CD vs. OR:2.39, 95% CI: 1.19-4.80; I 2 = 85% for UC).

CONCLUSIONS

IBD patients are at higher risk of periodontitis than controls. After subgroup analysis, the elevated risk remained significant when analyzing CD or UC alone. UC patients were at higher risk of developing periodontitis than CD patients.

Estimating the Odds of Ulcerative Colitis-Associated Pyoderma Gangrenosum: A Population-Based Case-Control Study

BACKGROUND

Ulcerative colitis (UC) is a well-known underlying comorbidity of pyoderma gangrenosum (PG). However, the risk conferred by UC for the subsequent development of PG is yet to be elucidated. We aimed to estimate the magnitude of the association between UC and the subsequent occurrence of PG, which would enable us to assess the odds of PG developing in individuals with a history of UC.

METHODS

A population-based case-control study was conducted to compare PG patients (n = 302) and age-, sex- and ethnicity-matched control subjects (n = 1,497) regarding the presence of UC. Logistic regression models were utilized for univariate and multivariate analyses.

RESULTS

The prevalence of preexisting UC was greater in patients with PG than in controls (7.3 vs. 0.5%; p < 0.001). A 15-fold increase in the odds of PG in individuals with preexisting UC was observed (OR 14.62, 95% CI 6.45-33.18). The greatest risk of developing PG occurred in the first years following the diagnosis of UC (OR 35.50, 95% CI 4.35-289.60), and decreased thereafter to 10.03 (95% CI 1.83-55.03), 6.69 (95% CI 1.49-30.02), and 10.03 (95% CI 1.83-55.03) at 1-5, 5-10, and 10-15 years after the diagnosis of UC, respectively. This association retained its statistical significance following the adjustment for confounding factors (adjusted OR 10.78, 95% CI 4.55-25.52). Patients with both PG and UC were younger and had a lower prevalence of smoking than the remaining patients with PG.

CONCLUSIONS

UC increases the odds of developing PG by 15-fold, with the highest probability of developing PG occurring within the first year after the diagnosis of UC. Patients with UC may be advised to avoid additional precipitating factors for the development of PG.

Passive Smoking Increases the Risk for Intestinal Surgeries in Patients With Crohn's Disease

BACKGROUND

Despite substantial evidence on the negative effect of active smoking, the impact of passive smoking on the course of Crohn's disease (CD) remains largely unclear. Our aim was to assess passive smoking as a risk factor for intestinal surgeries in CD.

METHODS

The study was conducted in a university-based, monocentric cohort of 563 patients with CD. Patients underwent a structured interview on exposure to passive and active smoking. For clinical data, chart review was performed. Response rate was 84%, leaving 471 cases available for analysis. For evaluation of the primary objective, which was the impact of exposure to passive smoking on the risk for intestinal surgery, only never actively smoking patients were included.

RESULTS

Of 169 patients who never smoked actively, 91 patients (54%) were exposed to passive smoking. Exposed patients were more likely to undergo intestinal surgery than nonexposed patients (67% vs 30%; P < 0.001). Multivariate Cox regression analysis revealed that passive smoking was an independent risk factor for intestinal surgeries (hazard ratio, 1.7; 95% CI, 1.04-2.9; P = 0.034) after adjustment for ileal disease at diagnosis (hazard ratio, 2.9; 95% CI, 1.9-4.5; P < 0.001) and stricturing or penetrating behavior at diagnosis (hazard ratio, 1.9; 95% CI, 1.2-3.1; P = 0.01). Passive smoking during childhood was a risk factor for becoming an active smoker in later life (odds ratio, 2.2; 95% CI, 1.5-3.2; P < 0.001).

CONCLUSION

Passive smoking increases the risk for intestinal surgeries in patients with CD.

Cigarette Smoking, Coffee Consumption, Alcohol Intake, and Risk of Crohn's Disease and Ulcerative Colitis: A Mendelian Randomization Study

BACKGROUND

Crohn's disease (CD) and ulcerative colitis (UC) are widely associated with smoking in epidemiological studies, whereas there are conflicting results for the association between CD and UC for both coffee and alcohol consumption. Herein, we aimed to investigate whether cigarette smoking and alcohol and coffee consumption are causally associated with either CD or UC.

METHODS

We utilized 540 genome-wide significant single-nucleotide polymorphisms for 3 potentially addictive substances-nicotine, alcohol, and caffeine-to assess the association of smoking, coffee, and alcohol consumption with CD and UC (12,194 CD cases, 12,366 UC cases, and 25,042 controls of European ancestry), using Mendelian randomization analysis. Mendelian randomization estimates were used to evaluate the effect of the exposure factors on CD and UC risk. Sensitivity analysis was employed to test for any directional pleiotropy.

RESULTS

We found evidence for a positive causal association between the age of smoking initiation and UC risk and between alcohol consumption and CD risk, which disappeared after sensitivity analysis for both associations (P > 0.05). No evidence for a causal association between cigarettes per day, smoking initiation, smoking cessation, and coffee consumption variables and UC or CD was found.

CONCLUSIONS

We found no clear evidence that either genetically predicted smoking, coffee consumption, or alcohol consumption are causally associated with the risk for CD or UC, although our findings indicate a potential positive association between the age of smoking and UC and between alcohol consumption and CD.

Does the location of inflammatory lesions in the gastrointestinal tract determine the clinical course of Crohn’s disease?

Introduction

Crohn’s disease (CD) is a chronic, inflammatory bowel disease that can affect any part of the digestive system. The ileocecal region is most commonly involved. Recently, there have been reports about Crohn’s disease isolated to the colon, which may be associated with different clinical behaviour and the need for various treatment options.

Materials/Methods

The study included 305 patients with CD, 171 women (56%) and 134 men (44%), hospitalized at the Department of Gastroenterology, University Hospital in Lodz. Among them, a group of 101 patients was identified with a lesion location only in the colon (L2) and 204 in the small intestine and colon (L1 and L3). An attempt was made to analyze patients with CD in terms of demographic data, clinical behavior of the disease and location of inflammatory lesions.

Results

Among the features distinguishing the location of inflammatory lesions isolated to the colon (L2), statistically significantly less frequent occurrence of stenoses (21% at L2 location to 79% at L3, p <0.01) was observed compared to other locations. Moreover, patients with location of L2 lesions required surgery less frequently (27% with L2 vs. 73% L1 with L3, p <0.05). It was also demonstrated that among all the subjects, 42 patients underwent appendectomy before the diagnosis of CD, which constituted 19% of the L2 group patients to 81% of the L1 and L3 group (p <0.05).

Conclusions

In CD there is a great diversity in the clinical behavior of the disease, which is undoubtedly related to its location. The obtained results indicate that in the group of patients with the location isolated to the colon, stenoses are less common and patients require surgery less frequently.