Inflammatory Bowel Disease and Cardiovascular Diseases.

BACKGROUND: Emerging data showed patients with chronic inflammatory disorders, including inflammatory bowel disease, are more likely to develop atherosclerotic cardiovascular diseases, heart failure, and atrial fibrillation. This article aims to review the evidence of those associations. METHODS: PubMed was searched from inception to January 2022 using the keywords, including inflammatory bowel diseases, Crohn disease, ulcerative colitis, atherosclerotic cardiovascular disease, coronary artery disease, cardiovascular disease, atrial fibrillation, heart failure, and premature coronary artery disease. Relevant literature, including retrospective/prospective cohort studies, clinical trials, meta-analyses, and guidelines, were reviewed and summarized. RESULTS: Both ulcerative colitis and Crohn disease are associated with an increased risk of atherosclerotic cardiovascular diseases, cerebrovascular accidents, premature coronary artery disease, and atrial fibrillation. Ulcerative colitis is associated with an increased risk of heart failure. The increased atrial fibrillation occurred during inflammatory bowel disease flares and persistent activity but not during periods of remission. Hypotheses for the mechanism underlying the association of inflammatory bowel disease and atherosclerotic cardiovascular diseases include shared risk factors (ie, obesity, diabetes, smoking, diet) and pathophysiology (gut microbiome dysfunction) or adverse effects from inflammatory bowel disease itself or its treatment (ie, chronic inflammation, dyslipidemia, thrombocytosis, steroids). CONCLUSION: Inflammatory bowel disease is associated with an increased risk of atherosclerotic cardiovascular diseases, heart failure, and atrial fibrillation. A multidisciplinary team with gastroenterologists and cardiologists is needed to optimize the care for patients with inflammatory bowel disease and associated cardiac diseases.

Single-Cell Analysis Reveals Unexpected Cellular Changes and Transposon Expression Signatures in the Colonic Epithelium of Treatment-Naïve Adult Crohn's Disease Patients.

BACKGROUND & AIMS: The intestinal barrier comprises a monolayer of specialized intestinal epithelial cells (IECs) that are critical in maintaining mucosal homeostasis. Dysfunction within various IEC fractions can alter intestinal permeability in a genetically susceptible host, resulting in a chronic and debilitating condition known as Crohn's disease (CD). Defining the molecular changes in each IEC type in CD will contribute to an improved understanding of the pathogenic processes and the identification of cell type-specific therapeutic targets. We performed, at single-cell resolution, a direct comparison of the colonic epithelial cellular and molecular landscape between treatment-naïve adult CD and non-inflammatory bowel disease control patients. METHODS: Colonic epithelial-enriched, single-cell sequencing from treatment-naïve adult CD and non-inflammatory bowel disease patients was investigated to identify disease-induced differences in IEC types. RESULTS: Our analysis showed that in CD patients there is a significant skew in the colonic epithelial cellular distribution away from canonical LGR5+ stem cells, located at the crypt bottom, and toward one specific subtype of mature colonocytes, located at the crypt top. Further analysis showed unique changes to gene expression programs in every major cell type, including a previously undescribed suppression in CD of most enteroendocrine driver genes as well as L-cell markers including GCG. We also dissect an incompletely understood SPIB+ cell cluster, revealing at least 4 subclusters that likely represent different stages of a maturational trajectory. One of these SPIB+ subclusters expresses crypt-top colonocyte markers and is up-regulated significantly in CD, whereas another subcluster strongly expresses and stains positive for lysozyme (albeit no other canonical Paneth cell marker), which surprisingly is greatly reduced in expression in CD. In addition, we also discovered transposable element markers of colonic epithelial cell types as well as transposable element families that are altered significantly in CD in a cell type-specific manner. Finally, through integration with data from genome-wide association studies, we show that genes implicated in CD risk show heretofore unknown cell type-specific patterns of aberrant expression in CD, providing unprecedented insight into the potential biological functions of these genes. CONCLUSIONS: Single-cell analysis shows a number of unexpected cellular and molecular features, including transposable element expression signatures, in the colonic epithelium of treatment-naïve adult CD.

Increased colonic expression of ACE2 associates with poor prognosis in Crohn's disease.

The host receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), is highly expressed in small intestine. Our aim was to study colonic ACE2 expression in Crohn's disease (CD) and non-inflammatory bowel disease (non-IBD) controls. We hypothesized that the colonic expression levels of ACE2 impacts CD course. We examined the expression of colonic ACE2 in 67 adult CD and 14 NIBD control patients using RNA-seq and quantitative (q) RT-PCR. We validated ACE2 protein expression and localization in formalin-fixed, paraffin-embedded matched colon and ileal tissues using immunohistochemistry. The impact of increased ACE2 expression in CD for the risk of surgery was evaluated by a multivariate regression analysis and a Kaplan-Meier estimator. To provide critical support for the generality of our findings, we analyzed previously published RNA-seq data from two large independent cohorts of CD patients. Colonic ACE2 expression was significantly higher in a subset of adult CD patients which was defined as the ACE2-high CD subset. IHC in a sampling of ACE2-high CD patients confirmed high ACE2 protein expression in the colon and ileum compared to ACE2-low CD and NIBD patients. Notably, we found that ACE2-high CD patients are significantly more likely to undergo surgery within 5 years of CD diagnosis, and a Cox regression analysis found that high ACE2 levels is an independent risk factor for surgery (OR 2.17; 95% CI, 1.10-4.26; p = 0.025). Increased intestinal expression of ACE2 is associated with deteriorated clinical outcomes in CD patients. These data point to the need for molecular stratification that can impact CD disease-related outcomes.

Whole-genome sequencing of African Americans implicates differential genetic architecture in inflammatory bowel disease.

Whether or not populations diverge with respect to the genetic contribution to risk of specific complex diseases is relevant to understanding the evolution of susceptibility and origins of health disparities. Here, we describe a large-scale whole-genome sequencing study of inflammatory bowel disease encompassing 1,774 affected individuals and 1,644 healthy control Americans with African ancestry (African Americans). Although no new loci for inflammatory bowel disease are discovered at genome-wide significance levels, we identify numerous instances of differential effect sizes in combination with divergent allele frequencies. For example, the major effect at PTGER4 fine maps to a single credible interval of 22 SNPs corresponding to one of four independent associations at the locus in European ancestry individuals but with an elevated odds ratio for Crohn disease in African Americans. A rare variant aggregate analysis implicates Ca2+-binding neuro-immunomodulator CALB2 in ulcerative colitis. Highly significant overall overlap of common variant risk for inflammatory bowel disease susceptibility between individuals with African and European ancestries was observed, with 41 of 241 previously known lead variants replicated and overall correlations in effect sizes of 0.68 for combined inflammatory bowel disease. Nevertheless, subtle differences influence the performance of polygenic risk scores, and we show that ancestry-appropriate weights significantly improve polygenic prediction in the highest percentiles of risk. The median amount of variance explained per locus remains the same in African and European cohorts, providing evidence for compensation of effect sizes as allele frequencies diverge, as expected under a highly polygenic model of disease.

Increased Colonic Expression of ACE2 Associates with Poor Prognosis in Crohn's disease.

BACKGROUND AND AIMS: The host receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), is highly expressed in small intestine. Our aim was to study colonic ACE2 expression in Crohn's disease (CD) and non-inflammatory bowel disease (non-IBD) controls. We hypothesized that the colonic expression levels of ACE2 impacts CD course. METHODS: We examined the expression of colon ACE2 using RNA-seq and quantitative (q) RT-PCR from 69 adult CD and 14 NIBD control patients. In a subset of this cohort we validated ACE2 protein expression and localization in formalin-fixed, paraffin-embedded matched colon and ileal tissues using immunohistochemistry. The impact of increased ACE2 expression in CD for the risk of surgery was evaluated by a multivariate regression analysis and a Kaplan-Meier estimator. To provide critical support for the generality of our findings, we analyzed previously published RNA-seq data from two large independent cohorts of CD patients. RESULTS: Colonic ACE2 expression was significantly higher in a subset of adult CD patients (ACE2-high CD). IHC in a sampling of ACE2-high CD patients confirmed high ACE2 protein expression in the colon and ileum compared to ACE2-low CD and NIBD patients. Notably, we found that ACE2-high CD patients are significantly more likely to undergo surgery within 5 years of diagnosis, with a Cox regression analysis finding that high ACE2 levels is an independent risk factor (OR 2.18; 95%CI, 1.05-4.55; p=0.037). CONCLUSION: Increased intestinal expression of ACE2 is associated with deteriorated clinical outcomes in CD patients. These data point to the need for molecular stratification that may impact CD disease-related outcomes.

Decreased Colonic Activin Receptor-Like Kinase 1 Disrupts Epithelial Barrier Integrity in Patients With Crohn's Disease.

BACKGROUND & AIMS: Intestinal epithelial cell (IEC) barrier dysfunction is critical to the development of Crohn's disease (CD). However, the mechanism is understudied. We recently reported increased microRNA-31-5p (miR-31-5p) expression in colonic IECs of CD patients, but downstream targets and functional consequences are unknown. METHODS: microRNA-31-5p target genes were identified by integrative analysis of RNA- and small RNA-sequencing data from colonic mucosa and confirmed by quantitative polymerase chain reaction in colonic IECs. Functional characterization of activin receptor-like kinase 1 (ACVRL1 or ALK1) in IECs was performed ex vivo using 2-dimensional cultured human primary colonic IECs. The impact of altered colonic ALK1 signaling in CD for the risk of surgery and endoscopic relapse was evaluated by a multivariate regression analysis and a Kaplan-Meier estimator. RESULTS: ALK1 was identified as a target of miR-31-5p in colonic IECs of CD patients and confirmed using a 3'-untranslated region reporter assay. Activation of ALK1 restricted the proliferation of colonic IECs in a 5-ethynyl-2-deoxyuridine proliferation assay and down-regulated the expression of stemness-related genes. Activated ALK1 signaling increased colonic IEC differentiation toward colonocytes. Down-regulated ALK1 signaling was associated with increased stemness and decreased colonocyte-specific marker expression in colonic IECs of CD patients compared with healthy controls. Activation of ALK1 enhanced epithelial barrier integrity in a transepithelial electrical resistance permeability assay. Lower colonic ALK1 expression was identified as an independent risk factor for surgery and was associated with a higher risk of endoscopic relapse in CD patients. CONCLUSIONS: Decreased colonic ALK1 disrupted colonic IEC barrier integrity and was associated with poor clinical outcomes in CD patients.

Chronic Antibiotic Dependent Pouchitis Is Associated With Older Age at the Time of Ileal Pouch Anal Anastomosis (J-pouch) Surgery.

BACKGROUND: Risk factors for the development of chronic antibiotic dependent pouchitis (CADP) are not well understood. METHODS: Using multivariable logistic regression, we compared clinical factors between 194 patients with acute antibiotic responsive pouchitis or CADP. RESULTS: Individuals with CADP were significantly older (40.9 vs 30.8 years, P < 0.001) and demonstrated a longer disease duration before IPAA (10.3 vs 7.0 years, P = 0.004). Age ≥55 years at the time of IPAA was significantly associated with CADP (adjusted odds ratio = 4.35, 95% confidence interval = 1.01-18.7). CONCLUSIONS: Although older age should not represent a barrier to IPAA, further studies evaluating etiologies of this association are warranted.

Combined Endoscopic and Oral Fecal Microbiota Transplantation in Patients with Antibiotic-Dependent Pouchitis: Low Clinical Efficacy due to Low Donor Microbial Engraftment.

BACKGROUND AND OBJECTIVE: A significant number of pouch patients develop antibiotic-dependent pouchitis (ADP). Microbial dysbiosis is thought to be a major driver of clinical symptoms in ADP. The objective of this proof of concept study was to evaluate safety, efficacy, and donor microbial engraftment of an intensified fecal microbiota transplant (FMT) consisting of a single endoscopic FMT followed by daily oral FMT for 2 weeks in patients with ADP. METHODS: We performed a prospective placebo-controlled double-blind FMT trial in patents with established ADP and planned to enroll 20 patients in this proof of concept study. In case of non-response, patients were offered an optional open label active FMT treatment. The endpoints were safety, clinical remission without need for antibiotics during 16 weeks of follow-up, quantitative changes of fecal calprotectin (FCP), and engraftment of donor FMT as determined by metagenomic sequencing of the V4 region of the 16S rRNA gene. RESULTS: Due to a lower than expected clinical remission rate and low FMT engraftment, enrollment in the study was stopped prematurely after 6 patients were included. All 6 patients enrolled in the placebo-controlled portion failed to respond and needed antibiotic rescue therapy shortly after FMT. FCP increased in the majority of patients in the setting of relapse after FMT. In the active open label FMT extension study 1 out of 5 patients achieved antibiotic-free clinical remission. FMT engraftment after active FMT was observed only in this single patient, whereas engraftment of donor FMT occurred in none of the other patients receiving active FMT, paralleling the lack of clinical response. CONCLUSIONS: Low donor FMT engraftment resulted in low clinical efficacy of FMT in patients with ADP. Before embarking on larger clinical trials with FMT in patients with ADP or other forms of pouchitis, it is mandatory to explore approaches for superior FMT engraftment.

Bariatric Surgery Is a Safe and Effective Option for Patients with Inflammatory Bowel Diseases: A Case Series and Systematic Review of the Literature.

BACKGROUND: Questions remain regarding both the safety and efficacy of bariatric surgery in patients with inflammatory bowel diseases (IBD), including the effects of bariatric surgery on the course of disease. We report a case series from a tertiary care IBD referral center and review the existing literature regarding the safety and efficacy of bariatric surgery in IBD patients. OBJECTIVES: Examine the safety and efficacy of bariatric surgery in IBD patients. Explore possible effects of weight loss on postoperative IBD course. METHOD: We performed a retrospective review of patients at our center undergoing bariatric surgery with a concurrent IBD diagnosis, collecting baseline characteristics, surgery type, and postoperative course (including IBD outcomes and weight loss). Data from these patients were combined with available data from the existing literature to calculate standardized means with standard error, variance, and confidence intervals (CI). RESULTS: Data from 13 patients who had undergone bariatric surgery at our facility were combined with data from 8 other studies to create a study population of 101 patients. Of these, 61 had Crohn's disease, 37 ulcerative colitis, and 3 IBD-unspecified, with a mean preoperative BMI of 44.2 (95% CI 42.9-45.7). Following surgery, a mean excess weight loss of 68.4% was demonstrated (95% CI, 65.7-71.2). Of the 101 patients, 22 experienced early and 20 experienced late postoperative complications. Postoperatively, 10 patients experienced a flare of IBD, 20 remained in remission, and 7 patients were able to discontinue immunosuppressive therapy. CONCLUSIONS: Based on available studies, bariatric surgery appears to be both an effective and safe option for weight loss in patients with IBD.

Ustekinumab Is Effective for the Treatment of Crohn's Disease of the Pouch in a Multicenter Cohort.

BACKGROUND: Crohn's disease (CD) of the pouch and chronic pouchitis occur in approximately 10% of patients after ileal pouch-anal anastomosis (IPAA) for refractory ulcerative colitis (UC) or UC-related dysplasia. The efficacy of anti-tumor necrosis factor (anti-TNF) agents and vedolizumab have been reported for the treatment of CD of the pouch and chronic pouchitis, but little is known regarding the use of ustekinumab in these settings. Our primary aim was to evaluate the efficacy of ustekinumab for these conditions. METHODS: This is a retrospective, multicenter cohort study evaluating the efficacy of ustekinumab in patients with CD of the pouch and chronic pouchitis. Clinical response or remission was judged by the treating physician's assessment at 6 months. RESULTS: Fifty-six patients (47 with CD of the pouch and 9 with chronic pouchitis) were included the study. Of these, 73% had previously been treated with either anti-TNF therapy, vedolizumab, or both after IPAA. Among patients with CD of the pouch and chronic pouchitis, 83% demonstrated clinical response 6 months after induction with ustekinumab. Responders demonstrated significantly less pouch inflammation on endoscopy when compared with nonresponders (29% vs 100%; P = 0.023). Higher mean body mass index at induction (26.3 vs 23.7; P = 0.033) and male sex (83% vs 30%; P = 0.014) were significant predictors of nonresponse to ustekinumab in those with CD of the pouch. CONCLUSION: In this refractory patient population, ustekinumab appears to be a safe and effective treatment for chronic pouchitis and CD of the pouch in biologic-naïve patients and those with prior anti-TNF or vedolizumab therapy failure. 10.1093/ibd/izx005_video1 izy302.video1 5844889626001.

Methotrexate Is Not Superior to Placebo in Maintaining Steroid-Free Response or Remission in Ulcerative Colitis.

BACKGROUND & AIMS: Parenteral methotrexate induces clinical remission but not endoscopic improvement of mucosal inflammation in patients with ulcerative colitis (UC). We performed a randomized, placebo-controlled trial to assess the efficacy of parenteral methotrexate in maintaining steroid-free response or remission in patients with UC after induction therapy with methotrexate and steroids. METHODS: We performed a 48-week trial, from February 2012 through May 2016, of 179 patients with active UC (Mayo score of 6-12 with endoscopy subscore ≥ 2) despite previous conventional or biological therapy. The study comprised a 16-week open label methotrexate induction period followed by a 32-week double-blind, placebo-controlled maintenance period. Patients were given subcutaneous methotrexate (25 mg/wk) and a 12-week steroid taper. At week 16, steroid-free responders were randomly assigned to groups that either continued methotrexate (25 mg/wk, n = 44) or were given placebo (n = 40) until week 48. We compared the efficacy of treatment by analyzing the proportion of patients who remained relapse free and were in remission at week 48 without use of steroids or other medications to control disease activity. RESULTS: Ninety-one patients (51%) achieved response at week 16, and 84 patients were included in the maintenance period study. During this period, 60% of patients in the placebo group (24/40) and 66% in the methotrexate group (29/44) had a relapse of UC (P = .75). At week 48, 30% of patients in the placebo group (12/40) and 27% of patients in the methotrexate group (12/44) were in steroid-free clinical remission without need for additional therapies (P = .86). No new safety signals for methotrexate were detected. CONCLUSIONS: Parenteral methotrexate (25 mg/wk) was not superior to placebo in preventing relapses of UC in patients who achieved steroid-free response during induction therapy. ClinicalTrials.gov, Number: NCT01393405.

Correction: ACG Clinical Guideline: Management of Crohn's Disease in Adults.

Since the publication of these Guidelines, the authors have noticed an error in the text on page 15. The incorrect statement is.

ACG Clinical Guideline: Management of Crohn's Disease in Adults.

Crohn's disease is an idiopathic inflammatory disorder of unknown etiology with genetic, immunologic, and environmental influences. The incidence of Crohn's disease has steadily increased over the past several decades. The diagnosis and treatment of patients with Crohn's disease has evolved since the last practice guideline was published. These guidelines represent the official practice recommendations of the American College of Gastroenterology and were developed under the auspices of the Practice Parameters Committee for the management of adult patients with Crohn's disease. These guidelines are established for clinical practice with the intent of suggesting preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When exercising clinical judgment, health-care providers should incorporate this guideline along with patient's needs, desires, and their values in order to fully and appropriately care for patients with Crohn's disease. This guideline is intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. To evaluate the level of evidence and strength of recommendations, we used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.