Effect of infliximab on small bowel stenoses in patients with Crohn’s disease

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.

Diagnostic Accuracy of Intestinal Ultrasound in the Detection of Intra-Abdominal Complications in Crohn's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Crohn's disease [CD] is frequently associated with the development of strictures and penetrating complications. Intestinal ultrasound [IUS] is a non-invasive imaging modality ideal for point-of-care assessment. In this systematic review and meta-analysis we provide a current overview on the diagnostic accuracy of IUS and its advanced modalities in the detection of intra-abdominal complications in CD compared to endoscopy, cross-sectional imaging, surgery, and pathology.

METHOD

We conducted a literature search for studies describing the diagnostic accuracy of IUS in adult patients with CD-related intra-abdominal complications. Quality of the included studies was assessed with the QUADAS-2 tool. Meta-analysis was performed for both conventional IUS [B-mode] and oral contrast IUS [SICUS].

RESULTS

Of the 1498 studies we identified, 68 were included in this review and 23 studies [3863 patients] were used for the meta-analysis. Pooled sensitivities and specificities for strictures, inflammatory masses, and fistulas by B-mode IUS were 0.81 and 0.90, 0.87 [sensitivities] and 0.95, and 0.67 and 0.97 [specificities], respectively. Pooled overall log diagnostic odds ratios were 3.56, 3.97 and 3.84, respectively. Pooled sensitivity and specificity of SICUS were 0.94 and 0.95, 0.91 and 0.97 [sensitivities], and 0.90 and 0.94 [specificities], respectively. The pooled overall log diagnostic odds ratios of SICUS were 4.51, 5.46, and 4.80, respectively.

CONCLUSION

IUS is accurate for the diagnosis of intra-abdominal complications in CD. As a non-invasive, point-of-care modality, IUS is recommended as the first-line imaging tool if there is a suspicion of CD-related intra-abdominal complications.

Systematic review: Defining, diagnosing and monitoring small bowel strictures in Crohn's disease on intestinal ultrasound

BACKGROUND

Stricturing Crohn's disease (CD) occurs most commonly in the terminal ileum and poses a clinical problem. Cross-sectional imaging modalities such as intestinal ultrasound (IUS), computed tomography enterography (CTE), and magnetic resonance enterography (MRE) allow for assessment of the entire bowel wall and associated peri-enteric findings. Radiologic definitions of strictures have been developed for CTE and MRE; their reliability and responsiveness are being evaluated in index development programs. A comprehensive assessment strategy for strictures using IUS is needed.

AIMS

To provide a detailed summary of definitions, diagnosis and monitoring of strictures on IUS as well as technical aspects of image acquisition.

METHODS

We searched four databases up to 6 January 2024. Two-stage screening was done in duplicate. We assessed risk of bias using QUADAS-2.

RESULTS

There were 56 studies eligible for inclusion. Definitions for strictures on IUS are heterogeneous, but the overall accuracy for diagnosis of strictures is high. The capability of IUS for characterising inflammation versus fibrosis in strictures is not accurate enough to be used in clinical practice or trials. We summarise definitions for improvement of strictures on IUS, and discuss parameters for image acquisition and standardisation.

CONCLUSIONS

This systematic review is the first step for a structured program to develop a stricture IUS index for CD.

Duodenal Crohn's disease: Case report and systematic review

BACKGROUND

Inflammatory bowel disease, including ulcerative colitis, microscopic colitis, and Crohn's disease (CD), has a global impact. This review focuses on duodenal CD (DCD), a rare subtype affecting the duodenum. DCD's rarity and asymptomatic nature create diagnostic challenges, impacting prognosis and patient well-being. Delayed diagnosis can worsen DCD outcomes.

AIM

To report a rare case of DCD and to discuss the diagnostic challenges and its implications on prognosis.

METHODS

A systematic literature search, following the PRISMA statement, was conducted. Relevant studies were identified and analysed using specific Medical Subject Terms (MeSH) from PubMed/MEDLINE, American Journal of Gastroenterology, and the University of South Wales database. Data collection included information from radiology scans, endoscopy procedures, biopsies, and histopathology results.

RESULTS

The review considered 8 case reports and 1 observational study, involving 44 participants diagnosed with DCD, some of whom developed complications due to delayed diagnosis. Various diagnostic methods were employed, as there is no gold standard workup for DCD. Radiology scans [magnetic resonance imaging (MRI), computed tomography (CT), and upper gastrointestinal X-ray], endoscopy procedures (colonoscopy and esophagogastroduodenoscopy), biopsies, and clinical suspicions were utilized.

CONCLUSION

This review discusses DCD diagnosis challenges and the roles of CT, MRI, and fluoroscopy. It notes their limitations and compares findings with endoscopy and histopathology studies. Further research is needed to improve diagnosis, emphasizing scan interpretation, endoscopy procedures, and biopsies, especially in high-risk patients during routine endoscopy.

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.

Natural compound fraxinellone ameliorates intestinal fibrosis in mice via direct intervention of HSP47-collagen interaction in the epithelium

Intestinal fibrosis is a common complication of inflammatory bowel disease. There is still a lack of effective drugs for the prevention or treatment of intestinal fibrosis. Heat shock protein 47 (HSP47) plays a key role in the development of intestinal fibrosis. In this study we investigated the therapeutic potential and underlying mechanisms of fraxinellone, a degraded limonoid isolated from the root bark of Dictamnus dasycarpus, in the treatment of intestinal fibrosis. Intestinal fibrosis was induced in mice by dextran sodium sulfate (DSS) treatment. DDS-treated mice were administered fraxinellone (7.5, 15, 30 mg·kg-1·d-1, i.g.) for 45 days. We showed that fraxinellone administration dose-dependently alleviated DSS-induced intestinal impairments, and reduced the production of intestinal fibrosis biomarkers such as α-smooth muscle actin (SMA), collagen I, hydroxyproline, fibronectin and laminin, and cytokines such as TGF-β, TNF-α and IL-β. We then established in vitro intestinal fibrosis cell models in SW480 and HT-29 cells, and demonstrated that treatment with fraxinellone (3, 10, 30 μM) significantly relieved TGF-β-induced fibrosis responses by inhibiting the TGF-β/Smad2/3 signaling pathway. Molecular docking suggested that the fraxinellone might disrupt the interaction between HSP47 and collagen, which was confirmed by coimmunoprecipitation experiments. SPR analysis showed that fraxinellone had a high affinity for HSP47 with a Kd value of 3.542 × 10-5 M. This study provides a new example of HSP47-collagen intervention by a natural compound and has important implications for the clinical treatment of inflammation-induced issue fibrosis.

Serial Changes in Intestinal Stenotic Stiffness in Patients with Crohn's Disease Treated with Biologics: A Pilot Study Using Ultrasound Shear Wave Elastography

BACKGROUND/AIMS

Intestinal strictures represent an important serious complication of Crohn's disease. Shear wave elastography is a promising noninvasive ultrasound technique for assessing tissue stiffness. This study aimed to evaluate stiffness in the areas of intestinal stricture in patients with Crohn's disease using shear wave elastography and the changes in stiffness after biologics.

MATERIALS AND METHODS

We enrolled 21 Crohn's disease patients having intestinal stricture. The patients consisted of 3 groups, which were the infliximab naïve (n = 6) group, the ustekinumab naïve (n = 8), and the bio-switch from infliximab to ustekinumab (n = 7) group. Bowell wall thickness was examined by ultrasound sonography, and the stiffness of Crohn's disease stricture lesions was evaluated using Shear wave speed before and 1 year after anti-tumor necrosis factor-alpha antibody infliximab, anti-interleukin 12/23 antibody ustekinumab, and bio-switch from infliximab to ustekinumab.

RESULTS

Bowell wall thickness was significantly improved after infliximab, ustekinumab, and the bio-switch. However, shear wave speed indices only in the ustekinumab group significantly decreased after treatment (P = .028), but not in the other group.

CONCLUSIONS

Shear wave elastography might be a useful method to evaluate stiffness in the areas of intestinal stricture in patients with Crohn's disease treated with biologics. However, a prospective randomized study evaluating the development of obstruction after biological treatment is needed to validate the study findings.

Fibro-Stenosing Crohn's Disease: What Is New and What Is Next?

Fibro-stenosing Crohn's disease (CD) is a common disease presentation that leads to impaired quality of life and often requires endoscopic treatments or surgery. From a pathobiology perspective, the conventional view that intestinal fibro-stenosis is an irreversible condition has been disproved. Currently, there are no existing imaging techniques that can accurately quantify the amount of fibrosis within a stricture, and managing patients is challenging, requiring a multidisciplinary team. Novel therapies targeting different molecular components of the fibrotic pathways are increasing regarding other diseases outside the gut. However, a large gap between clinical need and the lack of anti-fibrotic agents in CD remains. This paper reviews the current state of pathobiology behind fibro-stenosing CD, provides an updated diagnostic and therapeutic approach, and finally, focuses on clinical trial endpoints and possible targets of anti-fibrotic therapies.

hucMSC-Ex Alleviates IBD-Associated Intestinal Fibrosis by Inhibiting ERK Phosphorylation in Intestinal Fibroblasts

Background

Intestinal fibrosis, one of the complications of inflammatory bowel disease (IBD), is associated with fistula and intestinal stricture formation. There are currently no treatments for fibrosis. Mesenchymal stem cell-derived exosomes have been proven to exert inhibitory and reversal effects in IBD and other organ fibrosis. In this study, we explored the role of human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-Ex) in IBD-related fibrosis and its associated mechanism to provide new ideas for the prevention and treatment of IBD-related intestinal fibrosis.

Methods

We established a DSS-induced mouse IBD-related intestinal fibrosis model and observed the effect of hucMSC-Ex on the mouse model. We also used the TGF-induced human intestinal fibroblast CCD-18Co to observe the role of hucMSC-Ex in the proliferation, migration, and activation of intestinal fibroblasts. Having observed that the extracellular-signal-regulated kinase (ERK) pathway in intestinal fibrosis can be inhibited by hucMSC-Ex, we treated intestinal fibroblasts with an ERK inhibitor to emphasize the potential target of ERK phosphorylation in the treatment of IBD-associated intestinal fibrosis.

Results

In the animal model of IBD-related fibrosis, hucMSC-Ex alleviated inflammation-related fibrosis as evident in the thinning of the mice's intestinal wall and decreased expression of related molecules. Moreover, hucMSC-Ex inhibited TGF-β-induced proliferation, migration, and activation of human intestinal fibroblasts, and ERK phosphorylation played a key role in IBD-associated fibrosis. The inhibition of ERK decreased the expression of fibrosis-related indicators such as α-SMA, fibronectin, and collagen I.

Conclusion

hucMSC-Ex alleviates DSS-induced IBD-related intestinal fibrosis by inhibiting profibrotic molecules and intestinal fibroblast proliferation and migration by decreasing ERK phosphorylation.

IL-10 is not anti-fibrotic but pro-fibrotic in endometriosis: IL-10 treatment of endometriotic stromal cells in vitro promotes myofibroblast proliferation and collagen type I protein expression

STUDY QUESTION

Is interleukin-10 (IL-10) anti-fibrotic in endometriosis?

SUMMARY ANSWER

IL-10 is not anti-fibrotic but pro-fibrotic in endometriosis, because IL-10 treatment of endometriotic stromal cells in vitro promotes myofibroblast proliferation and collagen type I protein expression.

WHAT IS KNOWN ALREADY

We previously showed that persistent activation of signal transducer and activator of transcription 3 (STAT3) via IL-6 trans-signaling promotes fibrosis of endometriosis. Studies showed marked anti-fibrotic effects of IL-10 via the STAT3 signaling pathway, which is generally considered to be anti-inflammatory, in various organs.

STUDY DESIGN, SIZE, DURATION

Endometrial and/or endometriotic samples of 54 patients who had histological evidence of deep endometriosis, and endometrial samples from 30 healthy fertile women were analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The effects of IL-10/STAT3 signaling as well as inhibition of STAT3 activation by knockdown of STAT3 gene on the pro-fibrotic phenotype in endometrial and endometriotic stromal cells in vitro were investigated. Then, the effects of various time points of IL-10 treatment in combination with transforming growth factor (TGF)-β1 and/or IL-6/soluble IL-6 receptor (sIL-6R) on the profibrotic phenotype of endometrial and endometriotic stromal cells were investigated.

MAIN RESULTS AND THE ROLE OF CHANCE

IL-10 induced pro-fibrotic phenotype (cell proliferation, collagen type I synthesis, α-smooth muscle actin positive stress fibers and collagen gel contraction) of endometriotic stromal cells. Knockdown of STAT3 gene decreased the IL-10 induced pro-fibrotic phenotype of endometriotic stromal cells. In contrast, IL-10 had no significant effects on pro-fibrotic phenotype of endometrial stromal cells of healthy women. Sequential IL-10 treatment with or without TGF-β1 and/or IL-6/sIL-6R induced persistent activation of STAT3 and significantly increased proliferation of myofibroblasts (cells with α-smooth muscle actin positive stress fibers) and protein expression of collagen type I in endometriotic stromal cells. TGF-β1 and/or IL-6/sIL6RIL-6/sIL6R treatment significantly increased tissue inhibitor of metalloproteinase 1 (TIMP1) protein expression, whereas IL-10 had no significant effects. Knockdown of STAT3 gene significantly decreased the TGF-β1 and/or IL-6/sIL6R induced TIMP1 protein expression. In contrast, pre-treatment with IL-10 before TGF-β1 and/or IL-6/sIL-6R treatment and sequential IL-10 treatment with or without TGF-β1 and/or IL-6/sIL-6R significantly decreased proliferation of fibroblasts (cells without α-smooth muscle actin positive stress fibers) and collagen type I protein expression in endometrial stromal cells of healthy women.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Given the large number of complex interactions and signaling pathways of pro- and anti-inflammatory mediators that are involved in the pathophysiology of endometriosis, the present study investigated only a very small portion of the whole. Further in vivo studies are required to validate the present findings.

WIDER IMPLICATIONS OF THE FINDINGS

Inflammatory mediators in the pathophysiology of endometriosis have been extensively investigated as potential therapeutic targets. However, the present study showed that anti-inflammatory signals of IL-10 and IL-6 through persistent STAT3 activation may promote endometriosis fibrosis. Therapeutic strategies, such as suppression of 'inflammation', might dysregulate the cross-regulation of 'pro- and anti-inflammatory mediators', leading to detrimental effects in patients with endometriosis, such as fibrosis. To develop new, but not deleterious, therapeutic strategies, studies are required to investigate whether, how and what 'anti-inflammatory mediators' along with pro-inflammatory mediators are involved in individual patients with endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported in part by KARL STORZ SE & Co. KG (Tuttlingen, Germany). The authors have no conflict of interest to disclose.

Monotherapy with thiopurines in stricturing Crohn's disease: A real-life experience from low- and middle-income countries

BACKGROUND

Stricturing Crohn's disease (CD) is difficult to manage medically with limited treatment options, anti-tumor necrosis factor (TNF) therapy being the first-line therapy. Although thiopurines are also recommended first-line treatment option for maintenance of remission in steroid-dependent CD, evidence on their use in stricturing CD is lacking. We evaluated the efficacy of azathioprine (AZA) in patients with stricturing CD.

METHODS

In this retrospective cohort study (January 2005 to July 2020), patients with stricturing CD who were managed with AZA as a primary therapy for at least 6 months, and had a follow-up of at least 6 months after AZA initiation were included. Disease characteristics, complications, long-term response, and adverse events were noted.

RESULTS

One hundred and fifteen patients were included (mean age 33.8±14 years, 67.8% males, median disease duration 98 months [IQR: 60-158], median follow-up duration 60 months [IQR: 50-96]). 46.1% (n=53) patients had significant anemia at presentation, and 73% (n=84) had isolated small bowel involvement. Median dose of AZA was 100 mg (equivalent to 1.5 mg/kg). Median therapy and follow-up duration (after AZA initiation) was 17 (IQR: 9-42) and 33 months (IQR 18-60), respectively. The cumulative probability of maintaining response without treatment failure at 1, 2, and 5 years was 73.1%, 40.7%, and 18.5%, respectively. Among patients with AZA failure, 15.6% received methotrexate, 13% received anti-TNFs, and 9.5% underwent surgery. Significant anemia (&lt;10 g/dL) at presentation and steroid dependence predicted AZA failure. 31.3% patients experienced adverse events, commonest being leukopenia (n=29, 25.2%).

CONCLUSION

Azathioprine demonstrated good short-term and modest long-term response rates in patients with stricturing CD.

BMI is important in predicting the loss of response in inflammatory bowel disease patients on tumour necrosis factor-α inhibitors

INTRODUCTION

Obesity is an emerging phenomenon among patients with inflammatory bowel disease (IBD). This study aims to evaluate whether the response to tumour necrosis factor-α (TNF-α) inhibitors (infliximab and adalimumab) could be influenced by BMI in IBD.

METHODS

We identified a cohort of 181 IBD patients attending a single-tertiary centre, naive to biologic therapy and stratified them according to their BMI. The primary outcome is the first occurrence of loss of response (LOR).

RESULTS

The median BMI was 26 kg/m2 (15-63 kg/m2). Approximately 68% of patients had LOR on both adalimumab (ADA) (n = 52) and infliximab (IFX) (n = 71). However, 83% on ADA with BMI ≥30 kg/m2 had LOR compared to 61% on IFX with BMI ≥30 kg/m2. For patients on ADA, Cox regression analysis revealed that after accounting for age, sex, disease type, duration of disease, fistulising disease, smoking status, haemoglobin, C-reactive protein, albumin and platelet levels, there were statistically significant associations between BMI (≥30 kg/m2 vs. <30 kg/m2) and LOR [P = 0.010; hazard ratio (HR) 3.2; confidence interval (CI), 1.3-7.6]. However, for patients on IFX, after accounting for the same factors, the only significant factor was the association of lower rate of LOR with higher albumin levels (P = 0.024; HR 0.95; CI, 0.91-0.99). There was an increased accelerated time to LOR for patients on ADA with BMI ≥30 kg/m2 compared to BMI <30 kg/m2 (P = 0.026). However, there was no difference in time to LOR for patients on IFX (P = 0.177).

CONCLUSION

BMI is important in predicting the LOR among IBD patients on TNF-α inhibitors, especially among patients receiving ADA.

Medical, Endoscopic and Surgical Management of Stricturing Crohn's Disease: Current Clinical Practice

The development of fibrostenotic intestinal disease occurs in approximately one-third of patients with Crohn's disease and is associated with increased morbidity. Despite introducing new biologic agents, stricturing Crohn's disease remains a significant clinical challenge. Medical treatment is considered the first-line treatment for inflammatory strictures, and anti-TNF agents appear to provide the most considerable benefit among the available medical treatments. However, medical therapy is ineffective on strictures with a mainly fibrotic component, and a high proportion of patients under anti-TNF will require surgery. In fibrotic strictures or cases refractory to medical treatment, an endoscopic or surgical approach should be considered depending on the location, length, and severity of the stricture. Both endoscopic balloon dilatation and endoscopic stricturoplasty are minimally invasive and safe, associated with a small risk of complications. On the other hand, the surgical approach is indicated in patients not suitable for endoscopic therapy. This review aimed to present and analyze the currently available medical, endoscopic, and surgical management of stricturing Crohn's disease.

Position Statement. Recommendations of the Spanish Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on the treatment of strictures in Crohn's disease

Despite pharmacological advances, strictures in Crohn's disease (CD) continues to be an important problem that leads in a high percentage of patients to undergo endoscopic and/or surgical treatments. There are currently no clinical scores or diagnostic tools that allow predicting which patients will develop this complication, and when a stricture is diagnosed, it is usually already well established and clinically relevant. The current role of pharmacological treatment is limited to treat inflammation and once there is significant fibrosis, the only therapeutic options are endoscopic and/or surgical. To establish a correct therapeutic algorithm and based on the current scientific evidence available, the Spanish Group Working on Crohn's Disease and Ulcerative Colitis (GETECCU) has decided to conduct this position statement on the treatment of strictures in CD. This document embraces the three mentioned therapeutic approaches, medical, endoscopic and surgical. Recommendations and therapeutic algorithms are established to help us to choose the most appropriate option based on the characteristics of the stricture and the patient.

Current and Emerging Approaches to the Diagnosis and Treatment of Crohn's Disease Strictures

The management and understanding of Crohn's disease (CD) continues to evolve quickly. Intestinal strictures were previously thought to be an inevitable result of irreversible fibrosis caused by chronic inflammation. However, increased understanding of the dynamic nature of strictures and of the pathophysiology of this condition has highlighted emerging targets for potential treatment. In the diagnosis of strictures, a distinction must be made between inflammatory and fibrotic types, as the former may respond to medical therapy. Emerging technologies, such as dual-energy computed tomography enterography and iodine density, have allowed more accurate characterization of strictures. Surgical and endoscopic treatment remains the mainstay for fibrotic strictures, but developments in systemic and intralesional biologic therapy have shown efficacy. This article reviews the pathophysiology of this debilitating complication of CD as well as current and emerging diagnostics and treatments.

Intestinal Fibrosis in Inflammatory Bowel Disease and the Prospects of Mesenchymal Stem Cell Therapy

Intestinal fibrosis is an important complication of inflammatory bowel disease (IBD). In the course of the development of fibrosis, certain parts of the intestine become narrowed, significantly destroying the structure and function of the intestine and affecting the quality of life of patients. Chronic inflammation is an important initiating factor of fibrosis. Unfortunately, the existing anti-inflammatory drugs cannot effectively prevent and alleviate fibrosis, and there is no effective anti-fibrotic drug, which makes surgical treatment the mainstream treatment for intestinal fibrosis and stenosis. Mesenchymal stem cells (MSCs) are capable of tissue regeneration and repair through their self-differentiation, secretion of cytokines, and secretion of extracellular vesicles. MSCs have been shown to play an important therapeutic role in the fibrosis of many organs. However, the role of MSC in intestinal fibrosis largely remained unexplored. This review summarizes the mechanism of intestinal fibrosis, including the role of immune cells, TGF-β, and the gut microbiome and metabolites. Available treatment options for fibrosis, particularly, MSCs are also discussed.

Choosing the right biologic for complications of inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic, inflammatory condition that involves the intestinal tract, and can also present with extra-intestinal manifestations (EIM). Choosing the right treatment for IBD is often nuanced and decisions can become even more complicated when a patient presents with or develops a complication of the disease.

AREAS COVERED

We aimed to provide an overview of the most common complications of IBD, specifically intestinal and EIM, and summarize the data regarding biologic therapy for treatment of these conditions. A comprehensive literature review was performed using PubMed and Medline databases to identify studies published in the English language relevant to the broad scope of this review.

EXPERT OPINION

There are still significant gaps in our understanding of the pathophysiology of IBD and its treatment, especially in regards to complications of the disease. As novel therapies continue to emerge for treatment of IBD, we feel concurrent examination of their impact on intestinal complications and EIM of IBD is important and should be a priority of future research.

Revisiting fibrosis in inflammatory bowel disease: the gut thickens

Intestinal fibrosis, which is usually the consequence of chronic inflammation, is a common complication of inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis. In the past few years, substantial advances have been made in the areas of pathogenesis, diagnosis and management of intestinal fibrosis. Of particular interest have been inflammation-independent mechanisms behind the gut fibrotic process, genetic and environmental risk factors (such as the role of the microbiota), and the generation of new in vitro and in vivo systems to study fibrogenesis in the gut. A huge amount of work has also been done in the area of biomarkers to predict or detect intestinal fibrosis, including novel cross-sectional imaging techniques. In parallel, researchers are embarking on developing and validating clinical trial end points and protocols to test novel antifibrotic agents, although no antifibrotic therapies are currently available. This Review presents the state of the art on the most recently identified pathogenic mechanisms of this serious IBD-related complication, focusing on possible targets of antifibrotic therapies, management strategies, and factors that might predict fibrosis progression or response to treatment.

Management of Crohn's stricture: medical, endoscopic and surgical therapies

Patients with Crohn's disease are at high risk of presenting with or developing a bowel stricture during the course of their disease. The available therapeutic options to manage a symptomatic Crohn's stricture include medical therapy (mainly biologics), surgical resection and endoscopic interventions. The choice of therapeutic modality depends on the clinical presentation of the stricture, the nature of the stricture (inflammatory vs fibrotic, primary vs anastomotic) and its anatomical characteristics on endoscopy and imaging (length, number, location of strictures and severity of obstruction). The aim herein is to provide an overview of the comprehensive assessment of a Crohn's stricture and to review the indications of the different therapeutic modalities, their success rates and their limitations to help clinicians properly evaluate and manage Crohn's strictures.

Predictors of necessity for endoscopic balloon dilatation in patients with Crohn's disease-related small bowel stenosis

BACKGROUND AND AIM

In patients with Crohn's disease (CD) and small bowel stenosis, endoscopic balloon dilation (EBD) is considered to be useful in improving stenotic symptoms and avoiding surgery. However, it carries risks such as bleeding and perforation. The aim of this study was to identify the indications for endoscopic intervention in patients with CD and small bowel stenosis.

METHODS

From November 2007 to March 2020, 143 CD patients with small bowel stenosis were enrolled in this study. We identified the factors associated with not requiring endoscopic intervention during long-term follow-up of these patients.

RESULTS

Forty of the 143 patients had abdominal symptoms of stenosis and had undergone EBD, whereas the remaining 103 were asymptomatic and had not undergone endoscopic intervention. During long-term follow-up, 95 of those 103 patients never required endoscopic or surgical intervention. Multivariate logistic regression analysis revealed that not consuming an elemental diet (OR 3.18, 95% CI 1.48-6.82; p < .01) and ileocecal valve (ICV) stenosis (OR 0.30, 95% CI 0.11-0.83; p = .02) were independently associated with not requiring EBD. The cumulative emergency hospitalisation-free rate also tended to be higher in patients not consuming an elemental diet or with ICV stenosis.

CONCLUSIONS

Two factors, namely not consuming an elemental diet and ICV stenosis, predict a long-term intervention-free prognosis in CD patients with small bowel stenosis.Key messagesWhen an endoscopically impassable small bowel stenosis is found in a CD patient, long-term follow-up without endoscopic intervention may be possible if the patient is asymptomatic, is not using an elemental diet, and the stenosis is ICV.

Development of Anti-fibrotic Therapy in Stricturing Crohn's Disease: Lessons from Randomized Trials in Other Fibrotic Diseases

Intestinal fibrosis is considered an inevitable complication of Crohn's disease (CD) that results in symptoms of obstruction and stricture formation. Endoscopic or surgical treatment is required to treat the majority of patients. Progress in the management of stricturing CD is hampered by the lack of effective anti-fibrotic therapy; however, this situation is likely to change because of recent advances in other fibrotic diseases of the lung, liver and skin. In this review, we summarized data from randomized controlled trials (RCT) of anti-fibrotic therapies in these conditions. Multiple compounds have been tested for the anti-fibrotic effects in other organs. According to their mechanisms, they were categorized into growth factor modulators, inflammation modulators, 5-hydroxy-3-methylgultaryl-coenzyme A (HMG-CoA) reductase inhibitors, intracellular enzymes and kinases, renin-angiotensin system (RAS) modulators and others. From our review of the results from the clinical trials and discussion of their implications in the gastrointestinal tract, we have identified several molecular candidates that could serve as potential therapies for intestinal fibrosis in CD.

Real world analysis on the efficacy and safety of anti-tumor necrosis factor therapy in patients with stricturing Crohn's disease

Crohn’s disease (CD) is often complicated by strictures and associated with increased risk for surgery. Inflammatory strictures respond to medical therapy, and anti-tumor necrosis factor (TNF) therapy is often used after the failure of steroids. However, data on efficacy of anti-TNF therapy in stricturing CD is limited. We retrospectively analysed the records of patients with stricturing CD who were treated with anti-TNF therapy and were prospectively followed from January 2005 to July 2020. Treatment success was defined as continuation of anti-TNF without the requirement for steroids or parenteral nutrition, switch to other anti-TNF, endoscopic dilation, surgery and severe adverse events leading to the withdrawal of anti-TNF. Fifty-nine patients were included [50-infliximab, 9-adalimumab; mean age-30.1 ± 15 years; males-69.5%; median disease duration-124 (range 30–396) months; median follow-up duration-42 (range 8–180) months]. Ileum was the most common site of stricture (69.5%), 20.3% of patients had colonic strictures, and 64.4% had multiple strictures. 55.9% of patients were steroid dependent and 37.3% were steroid refractory. The median duration of anti-TNF therapy was 14 (range 2–96) months, and 54.2% (n = 32) patients received concomitant immunomodulators. 88% improved with induction (11.8% primary non-response), secondary loss of response was seen in 52.2%, and the cumulative probability of treatment success at 1, 2 and 5 years was 69%, 51%, and 28% respectively. Anaemia at presentation predicted poor response. Only 30% of patients retained biologics on long-term (lack of response, cost, adverse events). 16.9% had adverse events, the commonest being reactivation of tuberculosis (5.1%). Anti-TNF therapy is associated with good short-term treatment success with modest long-term response in stricturing CD.

Novel mechanisms and clinical trial endpoints in intestinal fibrosis

The incidence of inflammatory bowel diseases (IBD) worldwide has resulted in a global public health challenge. Intestinal fibrosis leading to stricture formation and bowel obstruction is a frequent complication in Crohn's disease (CD), and the lack of anti-fibrotic therapies makes elucidation of fibrosis mechanisms a priority. Progress has shown that mesenchymal cells, cytokines, microbial products, and mesenteric adipocytes are jointly implicated in the pathogenesis of intestinal fibrosis. This recent information puts prevention or reversal of intestinal strictures within reach through innovative therapies validated by reliable clinical trial endpoints. Here, we review the role of immune and non-immune components of the pathogenesis of intestinal fibrosis, including new cell clusters, cytokine networks, host-microbiome interactions, creeping fat, and their translation for endpoint development in anti-fibrotic clinical trials.

Therapeutic strategies for stricturing Crohn’s disease in childhood: a systematic review

PURPOSE

Childhood stricturing Crohn's disease (CD) has significant morbidity. Interventions including resection, stricturoplasty and endoscopic balloon dilatation (EBD) are often required. Optimal intervention modality and timing, and use of adjuvant medical therapies, remains unclear. We aim to review the therapies used in paediatric stricturing CD.

METHODS

A systematic review in accordance with PRISMA was performed (PROSPERO: CRD42020164464). Demographics, stricture features, interventions and outcomes were extracted.

RESULTS

Fourteen studies were selected, including 177 patients (183 strictures). Strictures presented at 40.6 months (range 14-108) following CD diagnosis. Medical therapy was used in 142 patients for an average of 20.4 months (2-36), with a complete response in 11 (8%). Interventions were undertaken in 138 patients: 53 (38%) resections, 39 (28%) stricturoplasties, and 17 (12%) EBD. Complications occurred in 11% of resections, versus 15% stricturoplasties, versus 6% EBD (p = 0.223). At a median follow-up of 1.9 years (interquartile range 1.2-2.4) pooled stricture recurrence was 22%. Resection had 9% recurrence, versus 38% stricturoplasty, versus 47% EBD (p < 0.001).

CONCLUSIONS

Resection is associated with a low incidence of recurrence and complications. There remains a paucity of evidence regarding adjuvant medical therapy and the role of EBD. We propose a minimum reported dataset for interventions in paediatric stricturing CD.

Molecular targets and the use of biologics in the management of small bowel fibrosis in inflammatory bowel disease

PURPOSE OF REVIEW

Small bowel fibrosis is a significant burden on Crohn's disease patients with limited effective medical treatments that then requires surgery. A better understanding of the molecular mechanisms causing fibrosis and the evidence of benefit of available biologics will potentially lighten this burden and avoid the need for surgery.

RECENT FINDINGS

Transforming growth factor-beta and it's associated pathways remain the central cog in the wheel of fibrosis formation. Various new enzymes, cellular pathways, interleukins and molecules have been associated with beneficial modification of the fibrotic process. Licensed biologics such as antitumour necrosis factors continue to show evidence of efficacy in the treatment of fibrostenotic small bowel disease as well as the newer biologics ustekinumab and vedolizumab.

SUMMARY

Fibrostenotic disease of the small bowel is a significant and common debilitating complication in Crohn's disease patients. Multiple new molecular targets have been identified that may prove to become effective therapies in future. Antitumour necrosis factors remain the treatment with the best available evidence to date in fibrostenotic Crohn's disease.

Prevention and Treatment of Stricturing Crohn's Disease - Perspectives and Challenges

Introduction: Fibrostenosis is a hallmark of Crohn's disease (CD), remains a challenge in today's clinical management of inflammatory bowel disease patients and represents a key event in the disease course necessitating improved preventative strategies and a multidisciplinary approach to diagnosis and management. With the advent of anti-fibrotic therapies and well-defined clinical endpoints for stricturing CD, there is promise to impact the natural history of disease.Areas covered: This review summarizes current evidence in the natural history of stricturing Crohn's disease, discusses management approaches as well as future perspectives on intestinal fibrosis.Expert opinion: Currently, there are no specific therapies to prevent progression to fibrosis or to treat it after it becomes clinically apparent. In addition to the international effort by the Stenosis Therapy and Anti-Fibrotic Research (STAR) consortium to standardize definitions and propose endpoints in the management of stricturing CD, further research to improve our understanding of mechanisms of intestinal fibrosis will help pave the way for the development of future anti-fibrotic therapies.

Efficacy of drug and endoscopic treatment of Crohn's disease strictures: A systematic review

BACKGROUND AND AIMS

Strictures are the commonest complication in Crohn's disease. Surgery and endoscopic dilation are the mainstays of treatment, while drug therapy has often been considered contraindicated. The benefit of nonsurgical treatments, particularly drug and endoscopic therapy, need to be defined.

METHODS

Ovid MEDLINE, Embase, Emcare, PsycINFO, CINAHL and the Cochrane Library (inception until August 30, 2019) were searched. Studies with ≥ 10 patients with Crohn's disease strictures, reporting on outcomes following medication or endoscopic treatment, were included.

RESULTS

Of 3480 records, 85 studies met inclusion criteria and formed the basis of this analysis. Twenty-five studies assessed drug therapy; none were randomized trials. Despite study heterogeneity anti-tumor necrosis factor (TNF) therapy appeared effective, with 50% of patients avoiding surgery after 4 years of follow up. No other drug therapy was of demonstrable benefit. Sixty studies assessed endoscopic therapy including 56 on endoscopic balloon dilation, two assessed needle knife stricturotomy, and two stent insertion. Dilation was equally effective for de novo and anastomotic strictures ≤ 5 cm in length, with most studies reporting a subsequent surgical rate of 30% to 50%. Repeat dilation was required in approximately half of all patients.

CONCLUSIONS

Anti-TNF drug therapy and endoscopic balloon dilation are effective strategies for avoiding surgery in patients with stricturing Crohn's disease. Additional endoscopic therapies require further evaluation. Early data suggest that combining these therapies may provide greater benefit than individual therapies. Optimization of current drug and endoscopic therapy, and the incorporation of newer therapies, are needed for stricturing Crohn's disease.

The Efficacy of Anti-Tumor Necrosis Factor Alpha for Symptomatic Stricturing Small Bowel Crohn's Disease

Introduction

Crohn’s disease (CD) is a chronic inflammatory disease. Current treatment aims to prevent complications and the need for surgical intervention. In patients with symptomatic complications, such as strictures, the possible benefits of anti-tumor necrosis factor-alpha (anti-TNF-α) therapy are currently the subject of considerable debate. This study aims to determine whether anti-TNF-α therapy could decrease the need for or delay the time until surgery in patients with CD presenting with symptomatic strictures of the small bowel in the King Abdulaziz University Hospital (KAUH), Saudi Arabia.

Methods

We conducted a retrospective, single-center study that assessed the need for surgical treatment in adult patients with symptomatic stricturing CD who were treated conventionally or with TNF-α inhibitors. Simple logistic regression was used to examine the association between surgical resection and biologics therapy and stepwise elimination logistic regression analysis was used to identify predictors of surgical resection.

Results

In total, 75 patients fulfilled the study criteria with 50 in the anti-TNF-α arm and 25 in the conventional arm. Surgical resection was required for six patients (12.2%) in the anti-TNF-α treatment arm and one patient (4%) in the conventional treatment arm (P=0.26). Endoscopic balloon dilatation was performed in two patients (4%) in the anti-TNF-α arm and one patient (4%) in the conventional arm (P=0.69). No statistically significant association was observed between surgical resection and treatment with biologic therapy (odds ratio [OR]=0.50, 95% CI: 0.16-1.53, P=0.22). Stepwise elimination identified age (OR=4.54, 95% CI: 0.79-25.11, P=0.09) and disease duration (OR=1.01, 95% CI: 1.00-1.02, P=0.004) as significant predictors of surgery.

Conclusions

In this cohort, anti-TNF-α therapy did not provide additional benefits with regards to avoiding or delaying surgery in CD patients with stricturing of the small bowel.

Doppler Activity and Ultrasonographic Detection of Intra-Abdominal Fistulas Are Predictors of Surgery in Crohn's Disease

Bakground and Aim: Predictors of the need for surgery in sticturing Crohn's disease (SCD) are lacking. Bowel ultrasound (US) is a harmless, noninvasive, and inexpensive diagnostic procedure that has proven to be a valuable tool in the management of Crohn's disease (CD). Our aim was to identify ultrasonographic findings in SCD that may associate with a higher risk of surgery, allowing us to make early choices regarding treatment election in this specific group of patients.

MATERIALS AND METHODS

This was a retrospective, case-control study. Twenty-four patients diagnosed with SCD between 2013 and 2017 with a past history of stricture-related surgery were included and then matched with 46 non-operated controls. Prior US from patients in both groups were analyzed. US features considered for analysis were as follows: bowel wall thickness, degree of parietal vascularization (measured by Doppler activity), prestenotic dilation, involvement of mesenteric fat, and newly detected concomitant fistulas or abscess.

RESULTS

Doppler activity (p < 0.001), enteroenteric fistulas (p = 0.04), enteromesenteric fistulas (p = 0.003), and associated abscess (p = 0.004) were significantly associated with the need for surgery in the short-term period. Multivariate analysis showed strong association of these features with the risk of surgery but failed to reach statistical significance.

CONCLUSION

US features may potentially be used as point-of-care tools to aid clinicians in the assessment of the surgical risk in patients with SCD.

The New Proactive Approach and Precision Medicine in Crohn's Disease

The proactive approach to Crohn's disease (CD) management advocates moving toward algorithmic tight-control scenarios that are designed for each CD phenotype to guide remission induction, maintenance therapy, active monitoring, and multidisciplinary care to manage the complexities of each inflammatory bowel disease (IBD) patient. This requires accurate initial clinical, laboratory, radiological, endoscopic, and/or tissue diagnosis for proper phenotypic stratification of each CD patient. A substantial proportion of patients in symptomatic remission have been reported to demonstrate evidence of active disease, with elevated fecal calprotectin(FC) and C-reactive protein (CRP) levels as a hallmark for mucosal inflammation. Active mucosal inflammation, and elevated CRP and fecal calprotectin (FC) have been shown to be good predictors of clinical relapse, disease progression, and complications in IBD patients. The next frontier of treatment is personalized medicine or precision medicine to help solve the problem of IBD heterogeneity and variable responses to treatment. Personalized medicine has the potential to increase the efficacy and/or reduce potential adverse effects of treatment for each CD phenotype. However, there is currently an unmet need for better elucidation of the inflammatory biopathways and genetic signatures of each IBD phenotype, so personalized medicine can specifically target the underlying cause of the disease and provide maximal efficacy to each patient.

Dose-dependent pro- or anti-fibrotic responses of endometriotic stromal cells to interleukin-1β and tumor necrosis factor α

Endometriosis are characterized by dense fibrous tissue. Numerous studies have investigated roles of inflammation on the pathophysiology of endometriosis. However, the interplay of inflammation and fibrosis remains to be clarified. Here we show that low levels of interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNFα) promoted a fibrotic phenotype, whereas high levels of IL-1β and TNFα inactivated the fibrotic phenotype of endometriotic stromal cells (Ectopic-ES). IL-1β 10 pg/mL and TNFα 100 and 1,000 pg/mL had minimal effects, whereas the highest dose of IL-1β (100 pg/mL) significantly decreased collagen gel contraction in Ectopic-ES. Furthermore, in Ectopic-ES, low levels of IL-1β (1 pg/mL) and/or TNFα 10 pg/mL significantly increased Col I mRNA expression, whereas higher doses of IL-1β (10 and/or 100 pg/mL) and/or TNFα (100 and/or 1,000 pg/mL) significantly decreased Col I and/or αSMA mRNA expression and the percentage of cells with Col I + and/or αSMA + stress fibers. In contrast, in either menstrual endometrial stromal cells of patients with endometriosis or those of healthy women, varying doses of IL-1β and/or TNFα had no significant effects on either Col I or αSMA mRNA/protein expression. The present findings bring into question whether we should still continue to attempt anti-inflammatory treatment strategies for endometriosis.

A nationwide, multi-center, retrospective study of symptomatic small bowel stricture in patients with Crohn's disease

BACKGROUND

Small bowel stricture is one of the most common complications in patients with Crohn's disease (CD). Endoscopic balloon dilatation (EBD) is a minimally invasive treatment intended to avoid surgery; however, whether EBD prevents subsequent surgery remains unclear. We aimed to reveal the factors contributing to surgery in patients with small bowel stricture and the factors associated with subsequent surgery after initial EBD.

METHODS

Data were retrospectively collected from surgically untreated CD patients who developed symptomatic small bowel stricture after 2008 when the use of balloon-assisted enteroscopy and maintenance therapy with anti-tumor necrosis factor (TNF) became available.

RESULTS

A total of 305 cases from 32 tertiary referral centers were enrolled. Cumulative surgery-free survival was 74.0% at 1 year, 54.4% at 5 years, and 44.3% at 10 years. The factors associated with avoiding surgery were non-stricturing, non-penetrating disease at onset, mild severity of symptoms, successful EBD, stricture length < 2 cm, and immunomodulator or anti-TNF added after onset of obstructive symptoms. In 95 cases with successful initial EBD, longer EBD interval was associated with lower risk of surgery. Receiver operating characteristic analysis revealed that an EBD interval of ≤ 446 days predicted subsequent surgery, and the proportion of smokers was significantly high in patients who required frequent dilatation.

CONCLUSIONS

In CD patients with symptomatic small bowel stricture, addition of immunomodulator or anti-TNF and smoking cessation may improve the outcome of symptomatic small bowel stricture, by avoiding frequent EBD and subsequent surgery after initial EBD.

Systematic review: medical therapy for fibrostenosing Crohn's disease

BACKGROUND

Medical therapy and/or endoscopic balloon dilation with intralesional therapies are options for the treatment of small bowel fibrostenotic Crohn's disease (CD).

AIM

To perform a systematic review summarising evidence for efficacy of systemic and endoscopic intralesional medical therapy in established small bowel strictures in adult CD patients.

METHODS

A systematic search of MEDLINE, EMBASE, CENTRAL and Scopus was conducted. Primary outcomes were rates of surgical resection and repeat endoscopic dilation. Pooled event rates from random effects models across studies with 95% confidence intervals were reported.

RESULTS

Ten studies describing systemic medical therapy and eight studies of intralesional injection were included. One randomised controlled trial each for systemic therapy and intrastricture injection were identified. Only observational studies were found for systemic biologic therapies, which exclusively included tumour necrosis factor (TNF) antagonists, while intralesional therapies all involved corticosteroids except for one study that evaluated infliximab. Pooled event rates for surgical resection after systemic and intralesional therapy were 28.3% (95% CI: 18.2%-41.3%) and 18.5% (95% CI: 8.3%-36.2%), respectively over a median follow-up of 23 months (range 5.5-105.8), and 21.8 months (range 5-47). Risk of repeat endoscopic balloon dilation in those with intralesional therapy was 58.3% (95% CI: 36.6%-77.3%) over a median follow-up of 21.8 months (range 5-47).

CONCLUSIONS

There are no favoured therapies for patients with stricturing small bowel CD. Data are lacking for ustekinumab and vedolizumab. No endoscopic intralesional medications provided a clear benefit for prevention of repeat EBD or surgery.

The Role of Immunomodulators and Biologics in the Medical Management of Stricturing Crohn's Disease

Crohn's disease is a progressive and disabling inflammatory disease involving the gastrointestinal tract. It usually produces inflammatory lesions in the ileocolonic region, but up to half of patients will also develop complications such as strictures in the long term. Indeed, a proportion of patients have progression of the disease with the development of stricturing lesions because there are no drugs that effectively prevent or reverse established fibrosis, and hence these patients are usually treated with surgery or endoscopic balloon dilation. Fibrotic lesions are always associated with some degree of inflammatory changes, but there is little evidence supporting the use of medical therapy in this context. Here, we discuss the most important findings on the possible use of immunomodulators or biologics in the prevention and treatment of intestinal strictures in Crohn's disease patients. Recent evidence demonstrates that these drugs may also be effective in treating lesions with high levels of collagen deposition, and thus might, at least in some patients, reduce the progression of the disease and bowel damage, and further avoid the need for surgery and a disabling course in the long term.

Efficacy of anti-TNFα drugs in patients with stricturing Crohn's disease

INTRODUCTION

Half of Crohn's disease patients develop stenosis around 20 years after the disease onset. For a long time, surgery has been the only therapeutic approach for strictures. The introduction of anti-TNFα could be revolutionary in the management of these patients due to their potential role in stenoses' treatment. The aim of our work was to summarize efficacy data of anti-TNFα drugs in stricturing CD patients.

AREAS COVERED

Several case series and observational studies have shown that infliximab and adalimumab are effective in determining improvement and remission of stenosis in CD patients in both clinical trials and clinical practice. The injection of intralesional infliximab could be a valid alternative in patients not responding to systemic therapy.

EXPERT OPINION

Despite the promising literature data, the low level of evidence and the heterogeneity of the available studies do not allow to draw definitive conclusions on the use of TNFα inhibitors for the treatment of strictures. Further prospective randomized studies are needed to confirm and validate this therapeutic approach.

Natural history, diagnosis and treatment approach to fibrostenosing Crohn's disease

Stricturing Crohn's disease (CD) is a significant clinical problem. The presence of a stricture may be suggested by clinical symptoms. Cross-sectional imaging using computed tomography or magnetic resonance enterography is essential in diagnosing strictures as it allows further characterization and evaluation for complications such as abscess, fistulizing disease or malignancy. Managing small bowel stricturing CD should be approached in a multidisciplinary fashion. Medical therapy can be considered in strictures which are not associated with complications, with most of the data supporting anti-TNF strategies in this setting. If the disease is refractory to medical therapy, endoscopic therapy or surgery should be performed. Endoscopic balloon dilation (EBD) is an option for short, uncomplicated and straight strictures that are within reach of a colonoscope. Although EBD has good short-term outcomes, repeat dilation is often required. Surgical options mainly include resection and strictureplasty. Strictures refractory to medical therapy, not amenable or refractory to EBD, or associated with complications or malignancy should be managed surgically. However, surgery may also be considered at an earlier stage depending on disease characteristics and patient preference. Postoperative recurrence is common, highlighting the importance of careful monitoring of the patient postoperatively and optimization of medical management accordingly. There is a pressing need to develop anti-fibrotics for the treatment of stricturing CD. This requires the development of standardized diagnostic criteria, patient-reported outcome measures and validation of endpoints in fibrostenotic CD. The STAR consortium is pioneering this effort in order to allow development and testing of anti-fibrotics in future clinical trials.

Early Initiation of Anti-TNF is Associated with Favourable Long-term Outcome in Crohn's Disease: 10-Year-Follow-up Data from the Swiss IBD Cohort Study

BACKGROUND AND AIMS

The optimal timing of treatment escalation in Crohn's disease [CD] remains a challenging issue, and very little is known about its long-term development following early versus late administration of anti-TNF antibodies. The long-term outcome of Swiss CD patients was comparatively assessed in an up to 10-year follow-up, using patients participating in the Swiss Inflammatory Bowel Disease Cohort Study [SIBDCS].

METHODS

Prospectively collected SIBDCS patient data, including disease history, baseline characteristics at enrolment, and course of disease, were analysed in patients with early versus late [<24 versus ≥24 months after diagnosis] and no anti-TNF treatment.

RESULTS

A reduced risk of developing bowel stenosis was found in patients who received early anti-TNF treatment. This association was seen in patients overall and also in the subgroups of CD patients without pre-existing complications [Log-rank test: p < 0.001].Furthermore, osteoporosis and anaemia were observed significantly less frequently in patients who received early anti-TNF treatment, compared with either patients who received treatment late [p < 0.001 and p = 0.046, respectively] or were never [p < 0.001 for both] treated with anti-TNF antibodies. Patients with early anti-TNF administration sought medical consultations significantly less often, including gastroenterologists in private practice [p = 0.017], ambulatory [outpatient] hospital visits [p = 0.038], and a composite of any medical visits [p = 0.001]. The percentage of patients unable to work was lowest for early-anti-TNF-treated patients, in comparison with patients who were treated late or never [3.6% vs 8.8% vs 3.7%, p = 0.016].

CONCLUSIONS

In CD patients within the SIBDCS, early anti-TNF administration was found to be associated with several indicators of a more favourable long-term outcome.

Anti-tumor necrosis factor agents in Crohn's disease and ulcerative colitis: Beyond luminal disease

Anti-tumor necrosis factor agents (anti-TNF) drugs are commonly used in patients with inflammatory bowel disease (IBD) and have proven effective in both induction and maintenance therapy in luminal Crohn's disease and ulcerative colitis. Their efficacy has also been proven in fistulising perianal Crohn's disease. However, the evidence in other scenarios, such as stricturing, penetrating and non-fistulising perianal Crohn's disease, extraintestinal IBD manifestations and ileoanal reservoir complications, is not as robust. The aim of this review was to perform an analysis of the available literature and to determine the role of anti-TNF drugs in common clinical practice in patients affected by these complications.

Identification of Endpoints for Development of Antifibrosis Drugs for Treatment of Crohn's Disease

BACKGROUND & AIMS

Intestinal fibrosis is a challenge to management of patients with Crohn's disease (CD); there is an urgent need to expedite development of antifibrosis drugs for this disease. The International Organization for the Study of Inflammatory Bowel Disease (IOIBD) aimed to identify a set of endpoints that can be used to determine efficacy of antifibrosis agents tested in clinical trials of patients with CD.

METHODS

We conducted a systematic review to identify clinical, radiologic, biochemical, endoscopic, and composite endpoints used in assessing activity of fibrostenosing CD and response to treatment, and determined their operational properties. A panel of IOIBD experts performed a consensus process to identify the best endpoints for inclusion in clinical trials, through a 2-round, Delphi-style online survey.

RESULTS

A total of 36 potentially relevant endpoints for intestinal fibrosis were selected and assessed. Forty-eight physicians with expertise in inflammatory bowel disease, from 5 regions (North America, Europe, Middle East, Asia/Pacific, and Latin America), participated in the Delphi consensus process. A core set of 13 endpoints (complete clinical response, long-term efficacy, sustained clinical benefit, treatment failure, radiological remission, normal quality of life, clinical remission without steroids, therapeutic failure, deep remission, complete absence of occlusive symptoms, symptom-free survival, bowel damage progression, and no disability) were rated as critical. Agreement was high among the experts.

CONCLUSIONS

Members of the IOIBD reached expert consensus on a set of endpoints that can be used to assess antifibrosis agents in trials of patients with CD. Studies are needed to clarify methods for measuring these outcomes and validate measurement instruments.

Efficacy of adalimumab in patients with Crohn's disease and symptomatic small bowel stricture: a multicentre, prospective, observational cohort (CREOLE) study

OBJECTIVE

The efficacy of anti-tumour necrosis factors (anti-TNFs) in patients with Crohn's disease (CD) and symptomatic small bowel stricture (SSBS) is controversial. The aim of this study was to estimate the efficacy of adalimumab in these patients and to identify the factors predicting success.

DESIGN

We performed a multicentre, prospective, observational cohort study in patients with CD and SSBS. The included patients underwent magnetic resonance enterography at baseline and subsequently received adalimumab. The primary endpoint was success at week 24, defined as adalimumab continuation without prohibited treatment (corticosteroids after the eight week following inclusion, other anti-TNFs), endoscopic dilation or bowel resection. The baseline factors independently associated with success were identified using a logistic regression model, leading to a simple prognostic score. Secondary endpoints were prolonged success after week 24 (still on adalimumab, without dilation nor surgery) and time to bowel resection in the whole cohort.

RESULTS

From January 2010 to December 2011, 105 patients were screened and 97 were included. At week 24, 62/97 (64%) patients had achieved success. The prognostic score defined a good prognosis group with 43/49 successes, an intermediate prognosis group with 17/28 successes and a poor prognosis group with 1/16 successes. After a median follow-up time of 3.8 years, 45.7%±6.6% (proportion±SE) of patients who were in success at week 24 (ie, 29% of the whole cohort) were still in prolonged success at 4 years. Among the whole cohort, 50.7%±5.3% of patients did not undergo bowel resection 4 years after inclusion.

CONCLUSIONS

A successful response to adalimumab was observed in about two-thirds of CD patients with SSBS and was prolonged in nearly half of them till the end of follow-up. More than half of the patients were free of surgery 4 years after treatment initiation.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01183403; Results.

Risk factors for surgery in patients with retention of endoscopic capsule

OBJECTIVES

Surgery is still the main means for removing retained endoscopic capsules. This study intended to evaluate risk factors for surgery in patients with capsule retention.

MATERIALS AND METHODS

The data of 5348 consecutive capsule endoscopy examinations were retrospectively analyzed. Cox regression analysis was used to evaluate risk factors.

RESULTS

Seventy-seven patients (1.4%) had capsule retention. Spontaneous passage occurred in 16 patients, of which 14 were asymptomatic. Successful retrieval by double-balloon enteroscopy (DBE) was achieved in 14 patients, of which 11 did not need surgery during clinical follow-up. A total of 50 patients underwent surgery. The cumulative rates of surgery were 44.2%, 53.2%, 55.8%, 62.3% and 64.9% at 1, 3, 6, 12 and 60 months after capsule retention, respectively. Intestinal obstruction [hazard ratio (HR) 2.05, 95% confidence interval (CI) 1.12-3.76; p = .020] and overt small bowel bleeding (HR 2.01, 95%CI 1.08-3.71; p = .027) during capsule retention were independently associated with an increased risk for surgery. Specific treatment for primary disease (HR 0.22, 95%CI 0.07-0.74, p = .014) and successful endoscopic retrieval (HR 0.20, 95%CI 0.06-0.66; p = .008) were independently associated with a decreased risk for surgery.

CONCLUSIONS

For asymptomatic patients, specific medical treatment for primary disease can be maintained until the capsule spontaneously passes or symptoms appear. For patients with slight abdominal pain, DBE can be performed. For patients with intestinal obstruction or overt small bowel bleeding, early surgical consultation should be considered.

The Role of Cytokines in the Fibrotic Responses in Crohn's Disease

Crohn’s disease is an idiopathic disorder of the gut thought to be caused by a combination of environmental and genetic factors in susceptible individuals. It is characterized by chronic transmural inflammation of the terminal ileum and colon, with typical transmural lesions. Complications, including fibrosis, mean that between 40 and 70% of patients require surgery in the first 10 years after diagnosis. Presently, there is no evidence that the current therapies which dampen inflammation modulate or reverse intestinal fibrosis. In this review, we focus on cytokines that may lead to fibrosis and stenosis and the contribution of experimental models for understanding and treatment of gut fibrosis.

Efficacy of tumour necrosis factor antagonists in stricturing Crohn's disease: A tertiary center real-life experience

BACKGROUND

Stenosis is the most common complication of Crohn's disease (CD). Long-term outcome of patients receiving tumour necrosis factor (TNF) antagonists for such disease complication is poorly understood.

METHODS

51 CD patients (from July 2006 to November 2015) who had a diagnosis of small bowel or colonic stenosis, diagnosed by colonoscopy and/or MRI enterography, and were treated with TNF antagonists (adalimumab or infliximab) were enrolled. The primary outcome was to assess the rate of success of TNF antagonists on avoiding abdominal surgery for stricturing CD patients.

RESULTS

20 patients (39.2%) underwent surgery during the follow-up period. The overall incidence of abdominal surgery was 1.8 per 100 person-months at risk, while the median time to surgery was 37.9 months. The univariable and multivariable Cox's proportional hazards analysis of baseline parameters indicated that disease location (colonic vs ileal, HR: 28.2, 95% CI: 2.45-324, p=0.007; ileocolonic vs ileal, HR: 3.38, 95% CI: 1.09-10.5, p=0.035), prestenotic dilatation (per 1-mm increase, HR: 1.08, 95% CI: 1.01-1.15, p=0.022) and the existence of non-perianal fistula (HR: 9.77, 95% CI: 2.99-31.9, p<0.001) are independent risk factors for abdominal surgery.

CONCLUSIONS

In stricturing CD, anti-TNFs are effective in up to about two-thirds of the patients.

Medical Therapies for Stricturing Crohn's Disease: Efficacy and Cross-Sectional Imaging Predictors of Therapeutic Failure

BACKGROUND

Medical therapy efficacy remains controversial in stricturing Crohn's disease. Cross-sectional imaging, especially magnetic resonance imaging, has been suggested as very helpful to guide therapeutic decision making.

AIM

To assess efficacy and predictors of therapeutic failure in patients receiving medical treatments for stricturing Crohn's disease.

METHODS

In this retrospective study, therapeutic failure was defined as symptomatic stricture leading to surgical or endoscopic therapeutics, hospitalization, treatment discontinuation or additional therapy and short-term clinical response as clinical improvement assessed by two physicians. The 55 cross-sectional imaging examinations (33 magnetic resonance imaging and 22 CT scan) before starting medical therapy were analyzed independently by two radiologists. Results were expressed as hazard ratio (HR) or odds ratio (OR) with 95% confidence intervals (95% CI).

RESULTS

Among 84 patients, therapeutic failure rate within 60 months was 66.6%. In multivariate analysis, Crohn's disease diagnosis after 40 years old (HR 3.9, 95% CI [1.37-11.2], p = 0.011), small stricture luminal diameter (HR 1.34, 95% CI [1.01-1.80], p = 0.046), increased stricture wall thickness (HR 1.23, 95% CI [1.04-1.46], p = 0.013) and fistula with abscess (HR 5.63, 95% CI [1.64-19.35], p = 0.006) were associated with therapeutic failure, while anti-TNF combotherapy (HR 0.17, 95% CI [0.40-0.71], p = 0.015) prevented it. Considering 108 therapeutic sequences, the short-term clinical response rate was 65.7%. In multivariate analysis, male gender (OR 0.15, 95% CI [0.03-0.64], p = 0.011), fistula with abscess (OR 0.09, 95% CI [0.01-0.77], p = 0.028) and comb sign (OR 0.23, 95% CI [0.005-0.97], p = 0.047) were associated with short-term clinical failure.

CONCLUSION

Anti-TNF combotherapy seemed to prevent therapeutic failure, and cross-sectional imaging should be systematically performed to help medical management in stricturing Crohn's disease.

Mechanisms, Management, and Treatment of Fibrosis in Patients With Inflammatory Bowel Diseases

In the last 10 years, we have learned much about the pathogenesis, diagnosis, and management of intestinal fibrosis in patients with inflammatory bowel diseases. Just a decade ago, intestinal strictures were considered to be an inevitable consequence of long-term inflammation in patients who did not respond to anti-inflammatory therapies. Inflammatory bowel diseases-associated fibrosis was seen as an irreversible process that frequently led to intestinal obstructions requiring surgical intervention. This paradigm has changed rapidly, due to the antifibrotic approaches that may become available. We review the mechanisms and diagnosis of this serious complication of inflammatory bowel diseases, as well as factors that predict its progression and management strategies.

Biosimilars in Inflammatory Bowel Disease: Facts and Fears of Extrapolation

Biologic drugs such as infliximab and other anti-tumor necrosis factor monoclonal antibodies have transformed the treatment of immune-mediated inflammatory conditions such as Crohn's disease and ulcerative colitis (collectively known as inflammatory bowel disease [IBD]). However, the complex manufacturing processes involved in producing these drugs mean their use in clinical practice is expensive. Recent or impending expiration of patents for several biologics has led to development of biosimilar versions of these drugs, with the aim of providing substantial cost savings and increased accessibility to treatment. Biosimilars undergo an expedited regulatory process. This involves proving structural, functional, and biological biosimilarity to the reference product (RP). It is also expected that clinical equivalency/comparability will be demonstrated in a clinical trial in one (or more) sensitive population. Once these requirements are fulfilled, extrapolation of biosimilar approval to other indications for which the RP is approved is permitted without the need for further clinical trials, as long as this is scientifically justifiable. However, such justification requires that the mechanism(s) of action of the RP in question should be similar across indications and also comparable between the RP and the biosimilar in the clinically tested population(s). Likewise, the pharmacokinetics, immunogenicity, and safety of the RP should be similar across indications and comparable between the RP and biosimilar in the clinically tested population(s). To date, most anti-tumor necrosis factor biosimilars have been tested in trials recruiting patients with rheumatoid arthritis. Concerns have been raised regarding extrapolation of clinical data obtained in rheumatologic populations to IBD indications. In this review, we discuss the issues surrounding indication extrapolation, with a focus on extrapolation to IBD.

European Crohn's and Colitis Organisation Topical Review on Prediction, Diagnosis and Management of Fibrostenosing Crohn's Disease

This ECCO topical review of the European Crohn's and Colitis Organisation [ECCO] focused on prediction, diagnosis, and management of fibrostenosing Crohn's disease [CD]. The objective was to achieve evidence-supported, expert consensus that provides guidance for clinical practice.