The prognostic power of the NOD2 genotype for complicated Crohn's disease: a meta-analysis

Eosinophilic Esophagitis and Inflammatory Bowel Disease: What Are the Differences?

Eosinophilic esophagitis (EoE) and inflammatory bowel disease (IBD) are chronic inflammatory disorders of the gastrointestinal tract, with EoE predominantly provoked by food and aeroallergens, whereas IBD is driven by a broader spectrum of immunopathological and environmental triggers. This review presents a comprehensive comparison of the pathophysiological and therapeutic strategies for EoE and IBD. We examine the current understanding of their underlying mechanisms, particularly the interplay between environmental factors and genetic susceptibility. A crucial element in both diseases is the integrity of the epithelial barrier, whose disruption plays a central role in their pathogenesis. The involvement of eosinophils, mast cells, B cells, T cells, dendritic cells, macrophages, and their associated cytokines is examined, highlighting the importance of targeting cytokine signaling pathways to modulate immune-epithelial interactions. We propose that advances in computation tools will uncover the significance of G-protein coupled receptors (GPCRs) in connecting immune and epithelial cells, leading to novel therapies for EoE and IBD.

Precision Medicine in Inflammatory Bowel Disease: A Spotlight on Emerging Molecular Biomarkers

Inflammatory bowel diseases (IBD) remain challenging in terms of understanding their causes and in terms of diagnosing, treating, and monitoring patients. Modern diagnosis combines biomarkers, imaging, and endoscopic methods. Common biomarkers like CRP and fecal calprotectin, while invaluable tools, have limitations and are not entirely specific to IBD. The limitations of existing markers and the invasiveness of endoscopic procedures highlight the need to discover and implement new markers. With an ideal biomarker, we could predict the risk of disease development, as well as the possibility of response to a particular therapy, which would be significant in elucidating the pathogenesis of the disease. Recent research in the fields of machine learning, proteomics, epigenetics, and gut microbiota provides further insight into the pathogenesis of the disease and is also revealing new biomarkers. New markers, such as BAFF, PGE-MUM, oncostatin M, microRNA panels, αvβ6 antibody, and S100A12 from stool, are increasingly being identified, with αvβ6 antibody and oncostatin M being potentially close to being presented into clinical practice. However, the specificity of certain markers still remains problematic. Furthermore, the use of expensive and less accessible technology for detecting new markers, such as microRNAs, represents a limitation for widespread use in clinical practice. Nevertheless, the need for non-invasive, comprehensive markers is becoming increasingly important regarding the complexity of treatment and overall management of IBD.

Fibrostenosing Crohn's Disease: Pathogenetic Mechanisms and New Therapeutic Horizons

Bowel strictures are well recognized as one of the most severe complications in Crohn's disease, with variable impacts on the prognosis and often needing surgical or endoscopic treatment. Distinguishing inflammatory strictures from fibrotic ones is of primary importance due to the different therapeutic approaches required. Indeed, to better understand the pathogenesis of fibrosis, it is crucial to investigate molecular processes involving genetic factors, cytokines, alteration of the intestinal barrier, and epithelial and endothelial damage, leading to an increase in extracellular matrix synthesis, which ultimately ends in fibrosis. In such a complex mechanism, the gut microbiota also seems to play a role. A better comprehension of molecular processes underlying bowel fibrosis, in addition to radiological and histopathological findings, has led to the identification of high-risk patients for personalized follow-up and testing of new therapies, primarily in preclinical models, targeting specific pathways involving Transforming Growth Factor-β, interleukins, extracellular matrix balance, and gut microbiota. Our review aims to summarize current evidence about molecular factors involved in intestinal fibrosis' pathogenesis, paving the way for potential diagnostic biomarkers or anti-fibrotic treatments for stricturing Crohn's disease.

Genetically transitional disease: conceptual understanding and applicability to rheumatic disease

In genomic medicine, the concept of genetically transitional disease (GTD) refers to cases in which gene mutation is necessary but not sufficient to cause disease. In this Perspective, we apply this novel concept to rheumatic diseases, which have been linked to hundreds of genetic variants via association studies. These variants are in the 'grey zone' between monogenic variants with large effect sizes and common susceptibility alleles with small effect sizes. Among genes associated with rare autoinflammatory diseases, many low-frequency and/or low-penetrance variants are known to increase susceptibility to systemic inflammation. In autoimmune diseases, hundreds of HLA and non-HLA genetic variants have been revealed to be modest- to moderate-risk alleles. These diseases can be reclassified as GTDs. The same concept could apply to many other human diseases. GTD could improve the reporting of genetic testing results, diagnostic yields, genetic counselling and selection of therapy, as well as facilitating research using a novel approach to human genetic diseases.

Prospective Evaluation of the Prediction Score for a Mild Course of Crohn's Disease (PreMiCC) in Newly Diagnosed Patients With Crohn's Disease: The PROGNOS Study

BACKGROUND AND AIMS

The course of Crohn's disease (CD) is highly variable. The Prospektive Evaluation eines Score zur Vorhersage eines milden Verlaufsbei neu diagnostizierten Morbus Crohn-Patienten in gastroenterologischen Fachpraxen (PROGNOS) study aimed to determine the frequency of a mild disease course and validate a proposed prediction score.

METHODS

The PROGNOS study is a prospective study of CD patients who were newly diagnosed and, except for 1 course of 5-aminosalicylic acid or steroids for ≤10 days, therapy-naïve. Among other predefined inclusion criteria, the initial diagnosis had to be made ≤6 weeks before enrollment. All inception cohort patients were diagnosed and screened consecutively in participating gastroenterology practices in Germany specialized in inflammatory bowel disease. All screened CD patients were scored and, if possible, included in the study for up to 5 years (NCT02193048).

RESULTS

A total of 201 CD patients were included in the study (43.3% male; mean age 33 years, mean follow-up 38 months). Altogether, 29.5% of the patients had a mild course at 36 months. Among those with a score ≤2, therapy escalation at 36 months was necessary for only 24.2%, whereas in the group with a score >2, therapy escalation was necessary for 70.2% of patients. In the Kaplan-Meier curve showing time to therapy escalation in the 2 groups, there was a pronounced and statistically significant divergence of the curves starting at 3 months and extending to 48 months (P < .001).

CONCLUSIONS

In this prospective study, about 30% of incident CD patients had a mild disease course. Our suggested PreMiCC (prediction score for a mild course of Crohn's disease) successfully predicted this.

NOD2 and Crohn's Disease Clinical Practice: From Epidemiology to Diagnosis and Therapy, Rewired

Crohn's disease (CD) is a chronic inflammatory bowel disease with a multifactorial pathogenesis involving environmental and genetic factors. Since the late 20th century, the discovery of the first susceptibility gene (NOD2, previously referred to as CARD15) for CD has paved the way for further investigations into the correlations between clinical features and genetics, and its potential impact on clinical practice has fueled the research in the last 2 decades. Recent therapeutic advancements involving novel biologic drugs and small molecules have shifted inflammatory bowel disease management from a disease-centered to a patient-centric approach. To date, the role of NOD2 has not been fully understood yet. Recent data suggest that its clinical impact may be greater than currently recognized. This review overviews the most common NOD2 variants' role in real-life clinical practice. These genetic variants increase the risk of developing the disease and can aid in tailoring diagnosis and treatment. They are associated with the stricturing phenotype and ileal involvement and increase the risk of steroid refractoriness. In the meantime, limited and inconclusive evidence exists regarding their predictive role in response to azathioprine, biologic drugs, and small molecules. Eventually, their role in increasing the risk for surgery is evident, especially in those with the L1007fs variant. If further trials will support the initial evidence reported so far, NOD2 genetic variants will emerge as possible candidates for developing precision medicine in CD.

Current Approach to Risk Factors and Biomarkers of Intestinal Fibrosis in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), especially Crohn's disease (CD), characterized by a chronic inflammatory process and progressive intestinal tissue damage, leads to the unrestrained proliferation of mesenchymal cells and the development of bowel strictures. Complications induced by fibrosis are related to high rates of morbidity and mortality and lead to a substantial number of hospitalizations and surgical procedures, generating high healthcare costs. The development of easily obtained, reliable fibrogenesis biomarkers is essential to provide an important complementary tool to existing diagnostic and prognostic methods in IBD management, guiding decisions on the intensification of pharmacotherapy, proceeding to surgical methods of treatment and monitoring the efficacy of anti-fibrotic therapy in the future. The most promising potential markers of fibrosis include cartilage oligomeric matrix protein (COMP), hepatocyte growth factor activator (HGFA), and fibronectin isoform- extra domain A (ED-A), as well as antibodies against granulocyte macrophage colony-stimulating factor (GM-CSF Ab), cathelicidin (LL-37), or circulatory miRNAs: miR-19a-3p and miR-19b-3p. This review summarizes the role of genetic predisposition, and risk factors and serological markers potentially contributing to the pathophysiology of fibrotic strictures in the course of IBD.

Comprehensive review and update of stricturing Crohn's disease

Up to 50% of patients with Crohn's disease develop a stricture within 10 years of diagnosis. Crohn's strictures can compose of inflammation, fibrosis or smooth muscle expansion and usually a combination of these. There have been numerous new developments in imaging modalities in determining the composition of Crohn's strictures. Magnetic resonance imaging remains the best upfront imaging modality to characterize Crohn's strictures. Gastrointestinal ultrasound (GIUS) has an increasing role in clinical practice, particularly for monitoring stricture response as a treat-to-target tool. Novel imaging techniques to differentiate between fibrosis and inflammatory strictures have been developed including contrast-enhanced GIUS, strain or shear wave elastography with GIUS and multiple new magnetic resonance imaging (MRI) protocols, including diffusion weighted, delayed contrast enhancement and magnetization transfer MR protocols. However, these techniques require further validation and standardization. Regarding therapeutics, anti-tumor necrosis agents with a treat-to-target strategy have the highest quality evidence in treating strictures and can lead to stricture regression in some cases. Endoscopic balloon dilatation remains a mainstay in the treatment algorithm of treating predominantly fibrostenotic Crohn's strictures, particularly those which are symptomatic, < 5 cm in length and not causing prestenotic dilatation. Endoscopic balloon dilatation has greater effectiveness in anastomotic strictures. Surgery remains an important treatment option in Crohn's strictures, with segmental resection and stricturoplasty having their own advantages and disadvantages. Kono-S anastomosis may be superior to conventional anastomosis for endoscopic recurrence; however, further high-quality studies are required to confirm this. Using risk stratification models such as the BACARDI risk model is important to guide management decisions between a medical and surgical approach. Early post-operative medical prophylaxis with an advanced therapy is an important consideration to prevent disease recurrence. This review expands on the above topics, highlights research gaps and provides a suggested investigation and management pathway in stricturing Crohn's disease.

Stromal Cell Regulation of Intestinal Inflammatory Fibrosis

Intestinal inflammatory fibrosis is a severe consequence of inflammatory bowel diseases (IBDs). There is currently no cure for the treatment of intestinal fibrosis in IBD. Although inflammation is necessary for triggering fibrosis, the anti-inflammatory agents used to treat IBD are ineffective in preventing the progression of intestinal fibrosis and stricture formation once initiated, suggesting that inflammatory signals are not the sole drivers of fibrosis progression once it is established. Among multiple mechanisms involved in the initiation and progression of intestinal fibrosis in IBD, stromal cells play critical roles in mediating the process. In this review, we summarize recent progress on how stromal cells regulate intestinal fibrosis in IBD and how they are regulated by focusing on immune regulation and gut microbiota. We also outline the challenges moving forward in the field.

The Genetics of Inflammatory Bowel Disease

The genetic background of inflammatory bowel disease, both Crohn's disease and ulcerative colitis, has been known for more than 2 decades. In the last 20 years, genome-wide association studies have dramatically increased our knowledge on the genetics of inflammatory bowel disease with more than 200 risk genes having been identified. Paralleling this increasing knowledge, the armamentarium of inflammatory bowel disease medications has been growing constantly. With more available therapeutic options, treatment decisions become more complex, with still many patients experiencing a debilitating disease course and a loss of response to treatment over time. With a better understanding of the disease, more effective personalized treatment strategies are looming on the horizon. Genotyping has long been considered a strategy for treatment decisions, such as the detection of thiopurine S-methyltransferase and nudix hydrolase 15 polymorphisms before the initiation of azathioprine. However, although many risk genes have been identified in inflammatory bowel disease, a substantial impact of genetic risk assessment on therapeutic strategies and disease outcome is still missing. In this review, we discuss the genetic background of inflammatory bowel disease, with a particular focus on the latest advances in the field and their potential impact on management decisions.

Baseline Clinical Factors Are Associated With Risk of Complications in Crohn's Disease: Appraisal of the American Gastroenterological Association Clinical Care Pathway

INTRODUCTION

The American Gastroenterological Association (AGA) has compiled risk factors that may be predictive of disease complications in Crohn's disease (CD) and ulcerative colitis (UC). The aim of this study was to evaluate the performance of the AGA risk factors for risk stratification in UC and CD.

METHODS

We included participants of 2 cohorts: the Ocean State Crohn's and Colitis Area Registry cohort and the Mayo Clinic cohort. Baseline clinical risk factors were extracted according to the AGA pathway. Our primary end point was defined as follows: (i) any inflammatory bowel disease related-hospitalization, (ii) any inflammatory bowel disease-related bowel surgery, or (iii) any progression of disease. We analyzed the association of the number of AGA risk factors with our end point. Statistical multivariable modeling was performed with Cox proportional hazards model.

RESULTS

A total of 412 patients with CD were included. Comparing ≥3 risk factors with 0-1 risk factor, we found a significantly increased risk of complications in both the Ocean State Crohn's and Colitis Area Registry cohort (hazard ratio [HR] 2.75, 95% confidence interval 1.71-4.41) and Mayo Clinic cohort (HR 2.07, 95% confidence interval 1.11-3.84). Diagnosis at younger age (HR 2.07), perianal disease (HR 1.99), and B2/B3 behavior (HR 1.92) were significantly associated with disease complications. We did not observe a consistent association between number of risk factors nor any specific individual risk factors and risk of disease complications in the 265 patients with UC included.

DISCUSSION

We found a significant association between the number of AGA risk factors and the risk of disease complication in CD; this association was not significant in UC. The presence of ≥ 3 risk factors in CD leads to the highest risk of complications. The AGA care pathway is a useful tool to stratify patients who are at higher risk of disease complications in patients with CD.

Identification of Potential Differentially-Methylated/Expressed Genes in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease that causes obstructed airflow from the lungs. DNA methylation can regulate gene expression. Understanding the potential molecular mechanism of COPD is of great importance. The aim of this study was to find differentially methylated/expressed genes in COPD. DNA methylation and gene expression profiles in COPD were downloaded from the dataset, followed by functional analysis of differentially-methylated/expressed genes. The potential diagnostic value of these differentially-methylated/expressed genes was determined by receiver operating characteristic (ROC) analysis. Expression validation of differentially-methylated/expressed genes was performed by in vitro experiment and extra online datasets. Totally, 81 hypermethylated-low expression genes and 121 hypomethylated-high expression genes were found in COPD. Among which, 9 core hypermethylated-low expression genes (CD247, CCR7, CD5, IKZF1, SLAMF1, IL2RB, CD3E, CD7 and IL7R) and 8 core hypomethylated-high expression genes (TREM1, AQP9, CD300LF, CLEC12A, NOD2, IRAK3, NLRP3 and LYZ) were identified in the protein-protein interaction (PPI) network. Moreover, these genes had a potential diagnostic utility for COPD. Some signaling pathways were identified in COPD, including T cell receptor signaling pathway, cytokine-cytokine receptor interaction, hematopoietic cell lineage, HTLV-I infection, endocytosis and Jak-STAT signaling pathway. In conclusion, differentially-methylated/expressed genes and involved signaling pathways are likely to be associated with the process of COPD.

Precision medicine in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an incurable disease characterized by remission-relapse cycles throughout its course. Both Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of IBD, exhibit tendency to develop complications and substantial heterogeneity in terms of frequency and severity of relapse, thus posing great challenges to the clinical management for IBD. Current treatment strategies are effective in different ways in induction and maintenance therapies for IBD. Recent advances in studies of genetics, pharmacogenetics, proteomics and microbiome provide a strong driving force for identifying molecular markers of prognosis and treatment response, which should help clinicians manage IBD patients more effectively, and then, improve clinical outcomes and reduce treatment costs of patients. In this review, we summarize and discuss precision medicine in IBD, focusing on predictive markers of disease course and treatment response, and monitoring indices during therapeutic drug monitoring.

Profiling the inflammatory bowel diseases using genetics, serum biomarkers, and smoking information

Crohn's disease (CD) and ulcerative colitis (UC) are two etiologically related yet distinctive subtypes of the inflammatory bowel diseases (IBD). Differentiating CD from UC can be challenging using conventional clinical approaches in a subset of patients. We designed and evaluated a novel molecular-based prediction model aggregating genetics, serum biomarkers, and tobacco smoking information to assist the diagnosis of CD and UC in over 30,000 samples. A joint model combining genetics, serum biomarkers and smoking explains 46% (42-50%, 95% CI) of phenotypic variation. Despite modest overlaps with serum biomarkers, genetics makes unique contributions to distinguishing IBD subtypes. Smoking status only explains 1% (0-6%, 95% CI) of the phenotypic variance suggesting it may not be an effective biomarker. This study reveals that molecular-based models combining genetics, serum biomarkers, and smoking information could complement current diagnostic strategies and help classify patients based on biologic state rather than imperfect clinical parameters.

Oral Manifestations of Crohn's Disease: A Systematic Review

Crohn's disease (CD) is a chronic inflammatory intestinal condition that can affect the entire gastrointestinal tract. It is characterized by its clinical heterogeneity and irregularities in its course. The etiology and pathogenesis are not well established, so it is difficult to establish an early diagnosis and an effective treatment plan. The objective of this systematic review was to present a qualitative synthesis of the studies referring to the oral manifestations of CD. This systematic review was carried out following the PRISMA guide. Research was conducted in the Pubmed, Web of Science, Scopus, Scielo, and Cocrahne Library databases on 23 February 2023, and updated on 1 September 2023. Articles published between 2012 and 2023 were selected. Articles that analyzed the oral manifestation of CD patients and met the established search terms. In addition, the quality of all the selected studies was analyzed following the CARE guidelines for case reports and the STROBE scale for observational studies. A total of 19 articles were included in this review that met the inclusion criteria. Regarding the oral manifestation of CD, oral ulcers, angular cheilitis, and gingivitis stand out. Periodontitis and vegetative pyostomatitis were the least representative manifestations. The most prevalent locations were lips, mucosa, and gingivae. Ulcers, gingivitis, and angular cheilitis are the most frequent oral manifestations in patients with CD. Their early identification and possible relationship with the disease are important for an early diagnosis and an adequate treatment plan.

Lung Involvement in Inflammatory Bowel Diseases: Shared Pathways and Unwanted Connections

Inflammatory bowel diseases (IBDs) are chronic, relapsing inflammatory disorders of the gastrointestinal tract, frequently associated with extraintestinal manifestations (EIMs) that can severely affect IBD patients' quality of life, sometimes even becoming life-threatening. Respiratory diseases have always been considered a rare and subsequently neglected extraintestinal manifestations of IBD. However, increasing evidence has demonstrated that respiratory involvement is frequent in IBD patients, even in the absence of respiratory symptoms. Airway inflammation is the most common milieu of IBD-related involvement, with bronchiectasis being the most common manifestation. Furthermore, significant differences in prevalence and types of involvement are present between Crohn's disease and ulcerative colitis. The same embryological origin of respiratory and gastrointestinal tissue, in addition to exposure to common antigens and cytokine networks, may all play a potential role in the respiratory involvement. Furthermore, other causes such as drug-related toxicity and infections must always be considered. This article aims at reviewing the current evidence on the association between IBD and respiratory diseases. The purpose is to raise awareness of respiratory manifestation among IBD specialists and emphasize the need for identifying respiratory diseases in early stages to promptly treat these conditions, avoid worsening morbidity, and prevent lung damage.

Creating a Surgical Biobank: The Hershey Medical Center Experience

BACKGROUND

Tissue harvesting at the time of surgery offers surgeons and scientists a unique opportunity to discover and better understand disease pathophysiology. Tissue biobanking presents challenges in patient consents, specimen collection, preparation, and storage, but the potential for scientific discovery justifies the effort. Although the number of tissue biobanks is increasing worldwide, information regarding necessary infrastructure, process flow, and management of expected obstacles is lacking.

OBJECTIVE

To provide a framework and motivation for clinician scientists intending to start an intestinal tissue biobank under their direction.

DATA SOURCES

The Carlino Family Inflammatory Bowel and Colorectal Diseases Biobank is housed at the Milton S. Hershey Medical Center.

STUDY SELECTION

Review.

INTERVENTION

Implementation of a surgical tissue biobank at a large tertiary care institution.

MAIN OUTCOME MEASURES

Assess critical challenges and obstacles over the years as well as keys to the success of the program.

RESULTS

Over 2 decades, the institutional biobank grew from an IBD biobank to one which now incorporates thousands of surgical specimens representing numerous colorectal diseases. This was done through a process of refinement focusing on patient recruitment and an efficient consenting and specimen management process. The biobank's success is further insured by institutional, external, and philanthropic support; scientific collaborations; and sharing of biological specimens with other groups of dedicated researchers.

LIMITATIONS

This is a single-center experience in collecting surgically resected colorectal specimens.

CONCLUSIONS

Surgical specimen biobanks are essential in studying disease cause using genomics, transcriptomics, and proteomic technologies. Therefore, surgeons, clinicians, and scientists should build biobanks at their institutions to promote further scientific discovery and improve specimen diversity.

Predictors and optimal management of tumor necrosis factor antagonist nonresponse in inflammatory bowel disease: A literature review

Tumor necrosis factor-α (TNF-α) antagonists, the first biologics approved for treating patients with inflammatory bowel disease (IBD), are effective for the induction and maintenance of remission and significantly improving prognosis. However, up to one-third of treated patients show primary nonresponse (PNR) to anti-TNF-α therapies, and 23%-50% of IBD patients experience loss of response (LOR) to these biologics during subsequent treatment. There is still no recognized predictor for evaluating the efficacy of anti-TNF drugs. This review summarizes the existing predictors of PNR and LOR to anti-TNF in IBD patients. Most predictors remain controversial, and only previous surgical history, disease manifestations, drug concentrations, antidrug antibodies, serum albumin, some biologic markers, and some genetic markers may be potentially predictive. In addition, we also discuss the next steps of treatment for patients with PNR or LOR to TNF antagonists. Therapeutic drug monitoring plays an important role in treatment selection. Dose escalation, combination therapy, switching to a different anti-TNF drug, or switching to a biologic with a different mechanism of action can be selected based on the concentration of the drug and/or antidrug antibodies.

How to Evaluate Fibrosis in IBD?

In this review, we will describe the importance of fibrosis in inflammatory bowel disease (IBD) by discussing its distinct impact on Crohn's disease (CD) and ulcerative colitis (UC) through their translation to histopathology. We will address the existing knowledge on the correlation between inflammation and fibrosis and the still not fully explained inflammation-independent fibrogenesis. Finally, we will compile and discuss the recent advances in the noninvasive assessment of intestinal fibrosis, including imaging and biomarkers. Based on the available data, none of the available cross-sectional imaging (CSI) techniques has proved to be capable of measuring CD fibrosis accurately, with MRE showing the most promising performance along with elastography. Very recent research with radiomics showed encouraging results, but further validation with reliable radiomic biomarkers is warranted. Despite the interesting results with micro-RNAs, further advances on the topic of fibrosis biomarkers depend on the development of robust clinical trials based on solid and validated endpoints. We conclude that it seems very likely that radiomics and AI will participate in the future non-invasive fibrosis assessment by CSI techniques in IBD. However, as of today, surgical pathology remains the gold standard for the diagnosis and quantification of intestinal fibrosis in IBD.

Harnessing the Power of Precision Medicine and Novel Biomarkers to Treat Crohn’s Disease

Crohn’s disease (CD) is a chronic inflammatory condition that affects the gastrointestinal tract. It is part of a spectrum of inflammatory Bowel Diseases (IBD). The disease is complex, characterized by significant inter and intra-individual heterogeneity, which contributes to a diverse and multifaceted portrayal of the disease. Consequently, applying specific and accurate treatment is challenging, and therapeutic success rates remain disappointing and insufficient. In recent years, significant advances in the therapeutic potential of CD have been made. Hope has been provided by these developments in the form of an expanding treatment toolkit. However, even with these beneficial adjustments, patients are frequently treated using an ineffective “one size fits all” treatment protocol, ultimately leading to a plateau in drug effectiveness and a decline in overall treatment success rates. Furthermore, with the advancement in the genome-wide association study, in combination with significant bioinformatic developments, the world of medicine has moved in the direction of personalized, tailored-treatment medicine, and this trend has not escaped the world of IBDs. Prediction models, novel biomarkers, and complex algorithms are emerging and inspiring optimism that CD patients will be treated with “precision medicine” in the near future, meaning that their treatments will be selected based on the patient’s various unique features. In this review, we will outline the current diagnostic and therapeutic limitations that lead to a glass ceiling effect and thus send us in pursuit of discovering novel biomarkers. We will illustrate the challenges and difficulties in discovering relevant and innovative biomarkers and implementing them into everyday clinical practice. We will also heighten the progress made in practicing personalized medicine for CD patients and shed light on future directions and horizons.

A Method Using Longitudinal Laboratory Data to Predict Future Intestinal Complication in Patients with Crohn's Disease

BACKGROUND

Stenosis, fistulization, and perforation of the bowel are severe outcomes which can occur in patients with Crohn's disease. Accurate prediction of these events may enable clinicians to alter treatment strategies and avoid these outcomes.

AIMS

To study the correlation between longitudinal laboratory testing and subsequent intestinal complications in patients with Crohn's disease.

METHODS

An observational cohort of patients with Crohn's disease at a single center were analyzed between 01/01/1994 and 06/30/2016. A complication was defined as the development of an intestinal fistula, stenosis, or perforation. Exploratory analysis using Cox regression was performed to select the best statistical method to represent longitudinal laboratory data. Cox regression was used to identify laboratory variables independently associated with the development of a subsequent complication. A clinical scoring tool was designed.

RESULTS

In 246 patients observed over a median of 5.72 years, 134 complications occurred. Minimum or maximum value in a preceding window period of one year was most strongly associated with subsequent complication. A Longitudinal Laboratory score of ≥ 2 (maximum albumin level < 39 g/L = 1, maximum mean cell volume < 88 fL = 1, minimum platelet count > 355 × 10⁹/L = 1, minimum C reactive protein > 5 mg/L = 1) was 62% sensitive and 91% specific in identifying patients who develop a subsequent complication.

CONCLUSION

A consistent reduction in serum albumin and mean cell volume, and a consistent increase in platelet count and C reactive protein were associated with a subsequent complication in patients with Crohn's disease. Longitudinal laboratory tests may be used as described in this paper to provide a rational for earlier escalation of therapy.

Precision medicine and drug optimization in adult inflammatory bowel disease patients

Inflammatory bowel diseases (IBD) encompass two main entities including ulcerative colitis and Crohn's disease. Although having a common global pathophysiological mechanism, IBD patients are characterized by a significant interindividual heterogeneity and may differ by their disease type, disease locations, disease behaviours, disease manifestations, disease course as well as treatment needs. Indeed, although the therapeutic armamentarium for these diseases has expanded rapidly in recent years, a proportion of patients remains with a suboptimal response to medical treatment due to primary non-response, secondary loss of response or intolerance to currently available drugs. Identifying, prior to treatment initiation, which patients are likely to respond to a specific drug would improve the disease management, avoid unnecessary side effects and reduce the healthcare expenses. Precision medicine classifies individuals into subpopulations according to clinical and molecular characteristics with the objective to tailor preventative and therapeutic interventions to the characteristics of each patient. Interventions would thus be performed only on those who will benefit, sparing side effects and expense for those who will not. This review aims to summarize clinical factors, biomarkers (genetic, transcriptomic, proteomic, metabolic, radiomic or from the microbiota) and tools that could predict disease progression to guide towards a step-up or top-down strategy. Predictive factors of response or non-response to treatment will then be reviewed, followed by a discussion about the optimal dose of drug required for patients. The time at which these treatments should be administered (or rather can be stopped in case of a deep remission or in the aftermath of a surgery) will also be addressed. IBD remain biologically complex, with multifactorial etiopathology, clinical heterogeneity as well as temporal and therapeutic variabilities, which makes precision medicine especially challenging in this area. Although applied for many years in oncology, it remains an unmet medical need in IBD.

How autophagy, a potential therapeutic target, regulates intestinal inflammation

Inflammatory bowel disease (IBD) is a group of disorders that cause chronic inflammation in the intestines, with the primary types including ulcerative colitis and Crohn's disease. The link between autophagy, a catabolic mechanism in which cells clear protein aggregates and damaged organelles, and intestinal health has been widely studied. Experimental animal studies and human clinical studies have revealed that autophagy is pivotal for intestinal homeostasis maintenance, gut ecology regulation and other aspects. However, few articles have summarized and discussed the pathways by which autophagy improves or exacerbates IBD. Here, we review how autophagy alleviates IBD through the specific genes (e.g., ATG16L1, IRGM, NOD2 and LRRK2), crosstalk of multiple phenotypes with autophagy (e.g., Interaction of autophagy with endoplasmic reticulum stress, intestinal antimicrobial defense and apoptosis) and autophagy-associated signaling pathways. Moreover, we briefly discuss the role of autophagy in colorectal cancer and current status of autophagy-based drug research for IBD. It should be emphasized that autophagy has cell-specific and environment-specific effects on the gut. One of the problems of IBD research is to understand how autophagy plays a role in intestinal tract under specific environmental factors. A better understanding of the mechanism of autophagy in the occurrence and progression of IBD will provide references for the development of therapeutic drugs and disease management for IBD in the future.

Newly Diagnosed Crohn's Disease Patients in India and Israel Display Distinct Presentations and Serological Markers: Insights from Prospective Cohorts

Background: Crohn’s disease (CD) incidence is rising in India. However, features of newly diagnosed patients with CD in this population are largely unknown. The Indo-Israeli IBD GastroEnterology paRtnership (TiiiGER) aimed to investigate differences in presentation among patients with newly diagnosed CD in India and Israel, and to explore phenotype−serotype correlations. Methods: A prospective observational cohort study of consecutive adults (>18 years) conducted in two large referral centers in India and Israel (2014−2018). Clinical data, an antiglycan serological panel, and 20 CD-associated genetic variants were analyzed. Outcomes: complicated phenotype at diagnosis and early complicated course (hospitalizations/surgeries) within 2 years of diagnosis. Results: We included 260 patients (104, Indian (65.4%, male; age, 37.8); 156 Israeli (49.4%, male; 31.8, age)). Median lag time from symptoms onset to diagnosis was 10.5 (IQR 3−38) vs. 3 (IQR 1−8) months in Indian vs. Israeli patients (p < 0.001). Complicated phenotype at diagnosis was observed in 48% of Indian and 30% of Israeli patients (p = 0.003). Complicated phenotype was associated with higher anti-Saccharomyces cerevisiae antibody (ASCA) seropositivity rate among Israeli patients (p < 0.001), but not among Indian patients. Antiglycan serology did not correlate with the tested genetic variants. Early complicated course occurred in 28 (18%) Israeli and 13 (12.5%) Indian patients. The time from diagnosis to complication was comparable (log rank p = 0.152). Antiglycan serology did not correlate with a complicated early course in either cohort. Conclusions: There are significant differences in patients presenting with newly diagnosed CD in India and Israel, including phenotype and distinct biomarkers at diagnosis. These differences suggest different genetic and environmental disease modifiers.

Macrophages-microenvironment crosstalk in fibrostenotic inflammatory bowel disease: from basic mechanisms to clinical applications

INTRODUCTION

Intestinal fibrosis is a common complication of Inflammatory Bowel Disease (IBD) with no available drugs. The current therapeutic principle is surgical intervention as the core. Intestinal macrophages contribute to both the progression of inflammation and fibrosis. Understanding the role of macrophages in the intestinal microenvironment could bring new hope for fibrosis prevention or even reversal.

AREAS COVERED

This article reviewed the most relevant reports on macrophage in the field of intestinal fibrosis. The authors discussed current opinions about how intestinal macrophages function and interact with surrounding mediators during inflammation resolution and fibrostenotic IBD. Based on biological mechanisms findings, authors summarized related clinical trial outcomes.

EXPERT OPINION

The plasticity of intestinal macrophages allows them to undergo dramatic alterations in their phenotypes or functions when exposed to gastrointestinal environmental stimuli. They exhibit distinct metabolic characteristics, secrete various cytokines, express unique surface markers, and transmit different signals. Nevertheless, the specific mechanism through which the intestinal macrophages contribute to intestinal fibrosis remains unclear. It should further elucidate a novel therapeutic approach by targeting macrophages, especially distinct mechanisms in specific subgroups of macrophages involved in the progression of fibrogenesis in IBD.

Prognostication in inflammatory bowel disease

Personalized care in inflammatory bowel diseases (IBD) hinges on parsing the heterogeneity of IBD patients through prognostication of their disease course and therapeutic response to allow for tailor-made treatment and monitoring strategies to optimize care. Herein we review the currently available predictors of outcomes in IBD and those on the both near and far horizons. We additionally discuss the importance of worldwide collaborative efforts and tools to support clinical use of these prognostication tools.

Principles, Preparation, Indications, Precaution, and Damage Control of Endoscopic Therapy in Inflammatory Bowel Disease

Interventional inflammatory bowel disease (IBD) or endoscopic therapy for IBD or IBD surgery-associated complications has emerged as a main treatment modality bridging medical and surgical treatment. It delivers therapy more definitive than medical therapy and less invasive than surgical treatment. The main applications of interventional IBD are strictures, fistulas, abscesses, bleeding, foreign bodies, postoperative complications, and colitis-associated neoplasia. The major endoscopic treatment modalities are balloon dilation, stricturotomy, strictureplasty, fistulotomy, sinusotomy, septectomy, banding ligation, incision and drainage, polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection.

NOD1/CARD4(G796A) and NOD2/CARD15(R702W, G908R and L1007fsinC) polymorphisms associated with Crohn's disease in Iraqi patients

Inflammatory bowel disease (IBD) applies to two main forms of chronic relapsing inflammatory intestinal disorders: Crohn's disease (CD), Ulcerative colitis (UC). CD requires an irregular immune reaction that induces intense inflammation. The cause of CD disease is not yet fully known; previous research, however, indicated inflammation of the intestines elevated or continues due to inappropriate immune responses due to associations between genetic factors, intestinal microbiota, and environmental factors contributing to the production of IBD. This study aimed to investigate predisposing genes, single nucleotide Polymorphisms (SNPs) NOD1/CARD4 and NOD2/CARD15) with CD in Iraqi patients. The common NOD1 (G796A) SNP and NOD2 SNPs R702W, G908R and L1007fsinC for NOD2 SNPs were selected. Thirty Iraqi citizens with a recognized diagnosis of CD and twenty apparently healthy controls were included in the study from November 2019 to December 2020; the common NOD1 and NOD2 polymorphisms have been screened by the polymerase chain reaction/restriction analysis length polymorphism (PCR/RFLP). The results of the current investigation for NOD1 polymorphism in studied patients and controls, the allelic and genotypic data show a highly significant association of G796A SNPs in the NOD1 with Crohn's disease, GA percentage was 56.67% in patients as compared to controls genotype was (0.00%). Furthermore, the G allele was more common in Crohn's patients than the A allele 0.72 vs. 0.28. Also, the allelic and genotypic frequency distribution of the studied NOD2 SNPs in the current study were (R702W, G908R, and L1007fs) in Iraqi patients, and controls revealed a highly significant connection between the G908R SNP with Crohn's disease susceptibility. The proportion of the genotype GC was 30% in patients while 0% in the control group, the frequency of the G allele was 0.85 vs 0.15 respectively, which was more than the frequency of the A allele. There were no significant changes in genotypic and allelic frequencies of the R702W and L1007fs SNPs in Iraqi Crohn's disease patients. The present study concluded that the NOD1 SNP of allelic and genotypic data show a highly significant association of G796A with a predisposition to Crohn's disease in Iraqi patients. And the NOD2 SNPs of G908R were also revealed to be highly effective. While the other studied SNPs were R702W and L1007fsinsC of NOD2, which showed no significant changes in the allelic and genotypic frequencies of the SNPs with Crohn's disease Iraqi patients. Keywords: Inflammatory bowel disease, Crohn's disease, NOD1/CARD4, NOD2/CARD15, polymorphisms.

NOD2 in Crohn's disease- unfinished business

Studies of Crohn's disease consistently implicate NOD2 as the most important gene in disease pathogenesis since first being identified in 2001. Since this point, genome-wide association, next-generation sequencing, and functional analyses have all confirmed a key role for NOD2, but despite this, NOD2 also has significant unresolved complexity. More recent studies have reinvigorated an early hypothesis that NOD2 may be a single-gene cause of disease, and the distinct ileal stricturing phenotype seen with NOD2-related disease presents an opportunity for personalised diagnosis, disease prediction and targeted therapy. The genomics of NOD2 has much that remains unknown, including the role of rare variation, phasing of variants across the haplotype block and the role of variation in the NOD2-regulatory regions. Here, we discuss the evidence and the unmet needs of NOD2-research, based on recently published evidence, and suggest methods that may meet these requirements.

The Future of Precision Medicine to Predict Outcomes and Control Tissue Remodeling in Inflammatory Bowel Disease

Inflammatory bowel disease is characterized by significant interindividual heterogeneity. With a wider selection of pharmacologic and nonpharmacologic interventions available and in advanced developmental stages, a priority for the coming decade is to determine accurate methods of predicting treatment response and disease course. Precision medicine strategies will allow tailoring of preventative and therapeutic decisions to individual patient needs. In this review, we consider the future of precision medicine in inflammatory bowel disease. We discuss the critical need to extend from research focused on short-term symptomatic response to integrative multi-omic systems biology strategies to identify and validate biomarkers that underpin precision approaches. Crucially, the international community has collective responsibility to provide well-phenotyped and -curated longitudinal datasets for scientific discovery and validation. Research must also study broader aspects of the immune response, including components of the extracellular matrix, to better understand biological pathways initiating and perpetuating tissue fibrosis and longer-term disease complications.

Prediction of Inflammatory Bowel Disease Course Based on Fecal Scent

The early prediction of changes in disease state allows timely treatment of patients with inflammatory bowel disease (IBD) to be performed, which improves disease outcome. The aim of this pilot study is to explore the potential of fecal volatile organic compound (VOC) profiles to predict disease course. In this prospective cohort, IBD patients were asked to collect two fecal samples and fill in a questionnaire at set intervals. Biochemically, active disease was defined by FCP ≥ 250 mg/g and remission was defined by FCP < 100 mg/g. Clinically, active disease was defined by a Harvey Bradshaw Index (HBI) ≥ 5 for Crohn’s disease or by a Simple Clinical Colitis Activity Index (SCCAI) ≥ 3 for ulcerative colitis. Clinical remission was defined by an HBI < 4 or SCCAI ≤ 2. Fecal VOC profiles were measured using gas chromatography-ion mobility spectrometry (GC-IMS). The fecal samples collected first were included for VOC analysis to predict disease state at the following collection. A total of 182 subsequently collected samples met the disease-state criteria. The fecal VOC profiles of samples displaying low FCP levels at the first measurements differed between patients preceding exacerbation versus those who remained in remission (AUC 0.75; p < 0.01). Samples with FCP levels at the first time point displayed different VOC profiles in patients preceding remission compared with those whose disease remained active (AUC 0.86; p < 0.01). Based on disease activity scores, there were no significant differences in any of the comparisons. Alterations in fecal VOC profiles preceding changes in FCP levels may be useful to detect disease-course alterations at an early stage. This could lead to earlier treatment, decreased numbers of complications, surgery and hospital admission.

Contribution of the Gut Microbiota to Intestinal Fibrosis in Crohn's Disease

In Crohn's disease (CD), intestinal fibrosis is a critical determinant of a patient's prognosis. Although inflammation may be a prerequisite for the initiation of intestinal fibrosis, research shows that the progression or continuation of intestinal fibrosis can occur independently of inflammation. Thus, once initiated, intestinal fibrosis may persist even if medical treatment controls inflammation. Clearly, an understanding of the pathophysiological mechanisms of intestinal fibrosis is required to diminish its occurrence. Accumulating evidence suggests that the gut microbiota contributes to the pathogenesis of intestinal fibrosis. For example, the presence of antibodies against gut microbes can predict which CD patients will have intestinal complications. In addition, microbial ligands can activate intestinal fibroblasts, thereby inducing the production of extracellular matrix. Moreover, in various animal models, bacterial infection can lead to the development of intestinal fibrosis. In this review, we summarize the current knowledge of the link between intestinal fibrosis in CD and the gut microbiota. We highlight basic science and clinical evidence that the gut microbiota can be causative for intestinal fibrosis in CD and provide valuable information about the animal models used to investigate intestinal fibrosis.

Precision Medicine in Pediatric Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) describes a heterogenous group of diseases characterized by chronic inflammation of the intestinal tract. The IBD subtypes, Crohn's disease, ulcerative colitis, and IBD-Unspecified, each have characteristic features, but heterogeneity remains even among the subtypes. There has been an explosion of new knowledge on the possible pathogenesis of IBD over the last 2 decades mirroring innovation and refinement in technology, particularly the generation of large scale - "-omic" data. This knowledge has fostered a veritable renaissance of novel diagnostics, prognostics, and therapeutics, with patients with IBD seeing hope bloom in the increasingly large armamentarium of IBD therapies. However, while there are increased numbers of therapies and more pathways being targeted, the number of medications for IBD is still finite and the efficacy has reached a plateau. Precision medicine (PM) is much needed to rationally select and optimize IBD therapies in the new reality of wider but still limited choice with a concurrent, increasingly fine resolution on the significance and utility of clinical, genetic, microbial, and proteomic characteristics that define individual patients. PM is a rapidly changing art, but this review will strive to detail the current state and future directions of PM in pediatric IBD.

Novel Genetic Variant Predicts Surgical Recurrence Risk in Crohn's Disease Patients

BACKGROUND

We aimed to identify a model of clinical and genetic risk factors through hypothesis-free search across genome that can predict the surgical recurrence risk after the first abdominal surgery in CD patients.

MATERIALS AND METHODS

Two independent inflammatory bowel disease (IBD) cohort studies were used to derive and validate the genetic risk profile. The study subjects were genotyped using Illumina Immunochip custom genotyping array. Surgical recurrence was defined as having the second or more abdominal bowel resections after the first abdominal surgery at the time of study enrollment; nonsurgical recurrence was defined as having no further abdominal resection after the first abdominal surgery.

RESULTS

Among 372 CD patients who had at least 1 abdominal surgery at the study enrollment, 132 (35.5%) had subsequent surgical recurrence after their first abdominal surgery, and 240 (64.5%) required no subsequent abdominal surgery at the end of follow up. Among clinical factors, multivariable analysis showed that history of immunomodulatory use (odds ratio [OR], 3.96; P = 0.002) and early era of CD first surgery (OR, 1.12; P = 1.01E-04) remained significant. Genotypic association tests identified a genome-wide significant locus rs2060886 in TCF4 at chr18q21.2 associated with surgical recurrence risk (OR, dom, 4.10 [2.37-7.11]; P = 4.58E-08).

CONCLUSIONS

Novel genetic locus rs2060886 in TCF4 was associated with surgical recurrence risk at genome-wide significance level among CD patients after their first abdominal surgery. Early era of CD first intestinal surgery predicts higher surgical recurrence risk. These results suggest that genetic variants may help guide the CD management strategy in patients at the highest risk of repeated abdominal surgeries.

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.

Genetic Variants of DMBT1 and SFTPD and Disease Severity in Paediatric Inflammatory Bowel Disease—A Polish Population-Based Study

Deleted in malignant brain tumours 1 protein (DMBT1) and surfactant protein D (SFTPD) are antimicrobial peptides previously linked to inflammatory bowel disease (IBD) susceptibility. This study attempts to link the most potential IBD-associated polymorphisms in DMBT1 and SFTPD with the disease severity in children. A total of 406 IBD patients (Crohn’s disease (CD) n = 214 and ulcerative colitis (UC) n = 192) were genotyped using hydrolysis probe assay. Clinical expression was described by disease activity scales, albumin and C-reactive protein levels, localisation and behaviour (Paris classification), systemic steroid, immunosuppressive, biological, and surgical treatment, number of exacerbation-caused hospitalisations, relapses and nutritional status. IBD patients with the risk genotype (AA) in DMBT1 rs2981804 had more frequent biological treatment (AA: vs. AG/GG; p = 0.012), concomitant diseases (AA vs. AG vs. GG; p = 0.015) and cutaneous manifestations (AA vs. AG/GG, p = 0.008). In UC, rs2981804 genotypes might be linked with albumin concentrations at diagnosis (AA vs. AG vs. GG; p = 0.009). In CD, DMBT1 rs2981745 was significantly associated with the number of severe relapses per year of disease (p = 0.020) and time-to-immunosuppression (p = 0.045). SFTPD was seemingly found to be associated with age at first immunosuppression in IBD (CC vs. CT vs. TT; p = 0.048). In conclusion, selected polymorphisms of DMBT1 and SFTPD might be associated with some disease severity measures in children with IBD. However, the magnitude of associations and their clinical relevance might be minor.

ECCO Topical Review: Refractory Inflammatory Bowel Disease

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

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.

Clinical and Genetic Factors Impact Time to Surgical Recurrence After Ileocolectomy for Crohn's Disease

OBJECTIVE

The aim of this study was to evaluate factors associated with time to surgical recurrence after Crohn's ileocolectomy.

SUMMARY BACKGROUND DATA

The most common surgery performed for Crohn's disease is ileocolectomy. Identifying patients at high risk for surgical recurrence may assist with medical and surgical decision-making.

METHODS

Data were obtained from 409 patients with Crohn's disease (CD) who had undergone ≥1 ileocolectomies at Penn State Hershey Medical Center. Six single-nucleotide polymorphisms (SNPs) associated with CD were evaluated in these patients: rs2076756, rs2066844, and rs2066845 in NOD2, rs4958847 and rs13361189 in IRGM, and rs2241880 in ATG16L1. Genotype and clinical factors were analyzed to determine associations with time to recurrent ileocolectomy. A subgroup analysis was performed on 241 patients naïve to biologics before initial ileocolectomy to assess the effect of biologic therapy on time to recurrent surgery.

RESULTS

There were 286 patients who underwent a single ileocolectomy, whereas 123 required multiple ileocolectomies. Ileocolonic involvement [hazard ratio (HR) 1.90, 95% confidence interval (CI) 1.21-3.00, P = 0.006] and rs2066844 in NOD2 (HR 1.8, 95% CI 1.17-2.77, P = 0.007) were associated with decreased time to surgical recurrence by multivariate analysis. In patients naïve to preoperative biologics, the initiation of postoperative biologics was associated with a 40% decreased incidence of surgical recurrence (HR 0.60, CI 0.39-0.93, P = 0.02) over time.

CONCLUSIONS

Ileocolonic distribution of disease and the rs2066844 SNP in NOD2 are associated with shorter time to recurrent ileocolectomy. The initiation of postoperative biologics in naïve patients was associated with a reduced incidence of recurrence over time.

Early Indolent Course of Crohn's Disease in Newly Diagnosed Patients Is Not Rare and Possibly Predictable

BACKGROUND & AIMS

The early stages of Crohn's disease (CD) course are heterogeneous, and it is a challenge to predict the course of disease in patients with new diagnosis.

METHODS

We performed an observational longitudinal study of 156 adults (79 male; median age, 27.7 years; 57 treatment naïve) with newly diagnosed CD (within 6 months of enrollment), referred from medical centers and community clinics in Israel from 2013 through 2017. Study participants each received semi-annual scheduled evaluations. Indolent disease was defined as a disease course without need for strict interventions to control complicated course of CD (hospitalization or surgery, or decision to start steroid, immunomodulator, or biologic therapy). Cox regression and receiver operating characteristic analyses were used to identify factors associated with early indolent or complicated course of CD. We validated our findings in an independent cohort of patients with CD from a separate medical center in Israel in 2018.

RESULTS

Over a median follow-up period of 17.2 months (interquartile range, 8.8-23.8 months), 52 patients (33.3%) had an indolent course of CD, 29 (18.5%) required hospitalizations, and 75 (48%) were recommended to start steroid, immunomodulator, or biologic therapies. The median time to first intervention was 3.4 months (95% CI, 2.4-4.4). We developed a model based on clinical factors that identified 4 factors associated with complicated course in treatment-naïve patients: body mass index <25 kg/m² (hazard ratio [HR], 2.45; 95% CI, 1.07-5.43; P = .033), serum level of vitamin B12 <350 pg/mL (HR, 2.78; 95% CI, 1.21-6.41; P = .016), white blood cells ≥7 × 10³/μL (HR, 2.419; 95% CI, 1.026-5.703; P = .044), and serum level of ALT ≥25 IU/L (HR, 2.680; 95% CI, 1.186-6.058; P = .018). This model discriminated between patients with vs without a complicated course of disease with 90% and 89% accuracy at 6 and 12 months after diagnosis, respectively. A validation cohort demonstrated a discriminatory ability of 79% at 3 months after diagnosis, and a nomogram was constructed.

CONCLUSIONS

In an observational longitudinal study of 156 patients with newly diagnosed CD, we found that one third have an early indolent course of disease. We identified factors that can be measured at diagnosis to identify patients at risk for an early complicated course-these might be used in patient management and selection of treatment.

Prognostic biomarkers to identify patients likely to develop severe Crohn's disease: a systematic review

BACKGROUND

Identification of biomarkers that predict severe Crohn's disease is an urgent unmet research need, but existing research is piecemeal and haphazard.

OBJECTIVE

To identify biomarkers that are potentially able to predict the development of subsequent severe Crohn's disease.

DESIGN

This was a prognostic systematic review with meta-analysis reserved for those potential predictors with sufficient existing research (defined as five or more primary studies).

DATA SOURCES

PubMed and EMBASE searched from inception to 1 January 2016, updated to 1 January 2018.

REVIEW METHODS

Eligible studies were studies that compared biomarkers in patients who did or did not subsequently develop severe Crohn's disease. We excluded biomarkers that had insufficient research evidence. A clinician and two statisticians independently extracted data relating to predictors, severe disease definitions, event numbers and outcomes, including odds/hazard ratios. We assessed risk of bias. We searched for associations with subsequent severe disease rather than precise estimates of strength. A random-effects meta-analysis was performed separately for odds ratios.

RESULTS

In total, 29,950 abstracts yielded just 71 individual studies, reporting 56 non-overlapping cohorts. Five clinical biomarkers (Montreal behaviour, age, disease duration, disease location and smoking), two serological biomarkers (anti-Saccharomyces cerevisiae antibodies and anti-flagellin antibodies) and one genetic biomarker (nucleotide-binding oligomerisation domain-containing protein 2) displayed statistically significant prognostic potential. Overall, the strongest association with subsequent severe disease was identified for Montreal B2 and B3 categories (odds ratio 4.09 and 6.25, respectively).

LIMITATIONS

Definitions of severe disease varied widely, and some studies confounded diagnosis and prognosis. Risk of bias was rated as 'high' in 92% of studies overall. Some biomarkers that are used regularly in daily practice, for example C-reactive protein, were studied too infrequently for meta-analysis.

CONCLUSIONS

Research for individual biomarkers to predict severe Crohn's disease is scant, heterogeneous and at a high risk of bias. Despite a large amount of potential research, we encountered relatively few biomarkers with data sufficient for meta-analysis, identifying only eight biomarkers with potential predictive capability.

FUTURE WORK

We will use existing data sets to develop and then validate a predictive model based on the potential predictors identified by this systematic review. Contingent on the outcome of that research, a prospective external validation may prove clinically desirable.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016029363.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 45. See the NIHR Journals Library website for further project information.

Apolipoprotein E variants correlate with the clinical presentation of paediatric inflammatory bowel disease: A cross-sectional study

BACKGROUND

It has been suggested that apolipoprotein E (APOE) polymorphisms are associated with the risk of developing inflammatory bowel disease (IBD) and the early age of disease onset. However, there are no reports regarding the relationship with clinical characteristics and disease severity.

AIM

To summarise that APOE polymorphisms are associated with the risk of developing IBD and the early age of disease onset.

METHODS

In total, 406 patients aged 3-18 with IBD (192 had ulcerative colitis and 214 had Crohn’s disease) were genotyped using the TaqMan hydrolysis probe assay. Clinical expression was described at diagnosis and the worst flare by disease activity scales, albumin and C-reactive protein levels, localisation and behaviour (Paris classification). Systemic steroid intake with the total number of courses, immunosuppressive, biological, and surgical treatment with the time and age of the first intervention were determined. The total number of exacerbation-caused hospitalisations, the number of days spent in hospital due to exacerbation, the number of relapses, and severe relapses were also estimated.

RESULTS

Ulcerative colitis patients with the APOEε4 allele had lower C-reactive protein values at diagnosis (P = 0.0435) and the worst flare (P = 0.0013) compared to patients with the APOEε2 allele and genotype APOEε3/ε3. Crohn’s disease patients with the APOEε2 allele scored lower on the Pediatric Crohn’s Disease Activity Index at diagnosis (P = 0.0204). IBD patients with APOEε2 allele spent fewer days in the hospital due to relapse (P = 0.0440).

CONCLUSION

APOE polymorphisms are associated with the risk of developing IBD and the clinical expression of IBD. However, the clinical relevance of the differences identified is rather modest.

The Genetics of Postoperative Recurrence in Crohn Disease: A Systematic Review, Meta-analysis, and Framework for Future Work

Background

Recurrence following abdominal surgery in Crohn disease is over 50%. The impact of genetics on postoperative recurrence is not well defined.

Methods

A literature search was conducted where inclusion required an assessment, by genotype, of postoperative recurrence. The primary endpoint was odds of surgical recurrence.

Results

Twenty-eight studies identified a total of 6715 patients. Thirteen loci were identified as modifying the risk of recurrence. NOD2 was identified as a risk factor for recurrence by multiple works (cumulative odds ratio: 1.64, P = 0.003).

Conclusions

A NOD2 risk allele is associated with recurrence following surgery in Crohn disease. Progress in this area will require standardized reporting in future works.

Fibrotic Strictures in Crohn's Disease: Mechanisms and Predictive Factors

Fibrotic strictures are one of the most severe complications of Crohn's Disease (CD). They occur in about 50% of patients at five years and in 70% at ten years of the diagnosis. The only treatment available for symptomatic fibrotic strictures is surgical resection and endoscopic dilation. Both strategies are associated with a high rate of recurrence, and with multiple surgical resections, which pose the threat of surgical morbidity and short bowel syndrome. Therefore, it is crucial to identify, early, the patients more prone to develop intestinal fibrosis to intensify follow-ups, switch to more aggressive treatments, and suggest lifestyle modifications. Scarce data are available concerning biomarkers and genetic determinants to predict which patient will develop intestinal fibrosis. Biologic or clinical markers would be useful to determine this subgroup of CD patients and to predict the onset of intestinal fibrosis and, ideally, its severity. Furthermore, the identification of environmental risk factors may suggest lifestyle changes aimed at modifying the natural course, thus decreasing the risk of complicated CD. In this review, we will critically revise clinical, environmental, genetic, and serologic factors that have been associated with a complicated CD course with a particular focus on the fibrostenosing phenotype and their possible implications as predictive factors of intestinal fibrosis.

NOD2 deficiency increases retrograde transport of secretory IgA complexes in Crohn's disease

Intestinal microfold cells are the primary pathway for translocation of secretory IgA (SIgA)-pathogen complexes to gut-associated lymphoid tissue. Uptake of SIgA/commensals complexes is important for priming adaptive immunity in the mucosa. This study aims to explore the effect of SIgA retrograde transport of immune complexes in Crohn's disease (CD). Here we report a significant increase of SIgA transport in CD patients with NOD2-mutation compared to CD patients without NOD2 mutation and/or healthy individuals. NOD2 has an effect in the IgA transport through human and mouse M cells by downregulating Dectin-1 and Siglec-5 expression, two receptors involved in retrograde transport. These findings define a mechanism of NOD2-mediated regulation of mucosal responses to intestinal microbiota, which is involved in CD intestinal inflammation and dysbiosis.

The Role of Organoids as a Novel Platform for Modeling of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting immune-mediated disorder affecting the gut. It is common in Westernized regions and is increasing in incidence in developing countries. At a molecular level, intrinsic deficiencies in epithelial integrity, mucosal barrier function, and mechanisms of immune response and resolution contribute to the development of IBD. Traditionally two platforms have been utilized for disease modeling of IBD; in-vitro monolayer cell culture and in-vivo animal models. Both models have limitations, including cost, lack of representative cell types, lack of complexity of cellular interactions in a living organism, and xenogeneity. Organoids, three-dimensional cellular structures which recapitulate the basic architecture and functional processes of the organ of origin, hold potential as a third platform with which to investigate the pathogenesis and molecular defects which give rise to IBD. Organoids retain the genetic and transcriptomic profile of the tissue of origin over time and unlike monolayer cell culture can be induced to differentiate into most adult intestinal cell types. They may be used to model intestinal host-microbe interactions occurring at the mucosal barrier, are amenable to genetic manipulation and can be co-cultured with other cell lines of interest. Bioengineering approaches may be applied to render a more faithful representation of the intestinal epithelial niche. In this review, we outline the concept of intestinal organoids, discuss the advantages and disadvantages of the platform comparative to alternative models, and describe the translational applications of organoids in IBD.

Strictures in Crohn's Disease: From Pathophysiology to Treatment

Despite recent advances aimed to treat transmural inflammation in Crohn's disease (CD) patients, the progression to a structuring behavior still represents an issue for clinicians. As inflammation becomes chronic and severe, the attempt to repair damaged tissue can result in an excessive production of extracellular matrix components and deposition of connective tissue, thus favoring the formation of strictures. No specific and accurate clinical predictors or diagnostic tools for intestinal fibrosis exist, and to date, no genetic or serological marker is in routine clinical use. Therefore, intestinal fibrosis is usually diagnosed when it becomes clinically evident and strictures have already occurred. Anti-fibrotic agents such as tranilast, peroxisome proliferator-activated receptor gamma agonists, rho kinase inhibitors, and especially mesenchymal stem cell therapy have provided interesting results, but most of the evidence has been derived from studies performed in vitro. Therefore, current therapy of fibrotic strictures relies mainly on endoscopic and surgical procedures. Although its long-term outcomes may be debated, endoscopic balloon dilation appears to be the safest and most effective approach to treat appropriately selected strictures. The use of endoscopic stricturotomy is currently limited by the expertise needed to perform it and by the few data available in the literature. Some good results have been achieved by the positioning of self-expandable metal stents (SEMS). However, there is no concordance regarding the type of stent to use and for how long it should be left in place. The development of new specific SEMS may lead to better outcomes and to an increased use of this alternative in CD-related strictures.

Serum biomarkers of fibrostenotic Crohn's disease: Where are we now?

Intestinal fibrosis and subsequent stricture formation are major clinical challenges in inflammatory bowel disease, resulting in an increased rate of operation and poor prognosis compared with those without. With the changing perception that intestinal fibrosis is irreversible to the point of view that it is reversible in recent years, various candidate serum biomarkers have been studied over the past decades, which may stratify patients based on their risks of developing stenosis and enable the detection of early stages of fibrosis. However, reliable and accurate biomarkers are still unavailable due to conflicting results and the lack of high-quality evidence. In this review we summarized the serum biomarkers that have been proposed for intestinal fibrosis in recent years, which includes gene polymorphisms or variants, epigenetic markers, extracellular matrix components, growth factors, and antibodies, aiming to provide clues for future research.

Identifying Patients With Inflammatory Bowel Diseases at High vs Low Risk of Complications

People with Crohn's disease and ulcerative colitis have varying presentations and clinical consequences of their disease. Patients commonly ask about their prognosis, and what this diagnosis means for them. They are asking their clinicians to predict the future. The importance of predicting the course of any disease is to guide patient expectations and to guide treatment decisions. In the past decade the strategy of inflammatory bowel disease (IBD) treatment has shifted to treat patients earlier in the course of their disease, before irreversible damage occurs. Treatment approaches for disease categorized as mild, moderate or severe has most often been based on a current assessment of symptoms or disease activity without including a longitudinal assessment of a patient's disease course including past disease complications and surgeries. While a patient's current disease activity most typically drives these treatment decisions, optimally, treatment decisions would be made accounting for past disease activity and complications and the predicted future disease course. When developing a treatment plan for an individual patient, the immediate goal is to treat the current disease activity for relief of symptoms, and the long-term goal is to prevent progression of their disease due to complications. Since not all patients will progress to a complicated disease course, it is important to be able to select the right patients for the right therapy. Therefore, developing methods of stratifying patients into low-risk versus high-risk of complications will be an important aspect of treating IBD now and in the future.