Recent advances in clinical practice: a systematic review of isolated colonic Crohn's disease: the third IBD?

A Living Organoid Biobank of Crohn's Disease Patients Reveals Distinct Clinical Correlates of Molecular Subtypes of Disease

Current clinical decision-making lacks reliable preclinical models to predict patient outcomes. Here, we establish patient-derived organoids (PDOs) as predictive tools in Crohn's disease (CD), a complex, heterogeneous disorder. Using a living biobank of adult stem cell-derived colonic-PDOs, we identified two molecular CD subtypes-Immune-Deficient Infectious CD ( IDICD ) and Stress and Senescence-Induced Fibrostenotic CD ( S2FCD )-each with distinct genomic, transcriptomic and functional profiles, along with paired therapeutics. By prospectively linking colonic PDO-derived phenotypes to real-world patient outcomes, we uncovered that while S2FCD associates with severe colonic disease, IDICD associates with severe ileal disease, prior ileocecal surgery, and future disease progression. This approach transforms PDOs from static descriptive models into dynamic tools that capture the past, present, and future of disease behavior and reveals their utility as patient-specific predictive platforms, extending their use beyond oncology to complex inflammatory diseases. Findings also suggest that colonic immune dysfunction may drive ileal-CD, independent of colonic involvement.

GRAPHICAL ABSTRACT

In Brief

In this work, Penrose et al. demonstrate the potential of patient-derived organoids (PDOs) as predictive tools in Crohn's disease (CD) that capture the past, present, and future of disease behavior, thereby advancing PDO-informed precision medicine beyond oncology into complex inflammatory diseases.

HIGHLIGHTS

A living PDO biobank identified two molecular CD subtypes with distinct functional phenotypes.PDO subtyping tracked severity of ileal disease, prior surgery and future disease progression.Colonic immune dysfunction may drive ileal-CD, independent of colonic involvement.Colonic CD-PDOs are dynamic platforms for outcome-deterministic therapeutic testing.

Effectiveness of biologics for endoscopic healing in patients with isolated proximal small bowel Crohn's disease

BACKGROUND

Endoscopic healing (EH) is a key therapeutic target in Crohn's disease (CD). Proximal small bowel (SB) lesions in patients with CD are associated with a significant risk of strictures and bowel resection. Assessing SB in patients with CD is necessary because of its significant therapeutic implications. The advent of biologic therapies, including infliximab, ustekinumab, and vedolizumab, has significantly altered CD treatment. However, data on the efficacy of biologics in achieving EH, specifically in the proximal SB of patients with CD, remain limited.

AIM

To assess the effectiveness of biologics for EH in patients with jejunal and/or proximal ileal CD.

METHODS

Between 2017 and 2023, we retrospectively included 110 consecutive patients with isolated proximal SB CD, identified through baseline balloon-assisted enteroscopy. These patients completed 1-year of treatment with infliximab, ustekinumab, or vedolizumab, and underwent a second balloon-assisted enteroscopy at 1 year. Complete EH was defined as a modified Simple Endoscopic Score for CD (SES-CD) of < 3, while EH of the jejunum and proximal ileum was defined as a segmental modified SES-CD of 0.

RESULTS

In total, 64 patients were treated with infliximab, 28 with ustekinumab, and 18 with vedolizumab. The complete EH rate at 1 year was 20.9% (23/110), with 29.6% (19/64) for infliximab, 10.7% (3/28) for ustekinumab, and 5.5% (1/18) for vedolizumab. The median modified SES-CD significantly decreased compared to baseline [5 (2-8) vs 8 (6-9), P < 0.001]. The jejunal and proximal ileal EH rates at 1 year were 30.8% (12/39) and 15.5% (16/103), respectively. Multiple logistic regression analysis showed that stricturing or penetrating disease [odds ratio (OR) = 0.261, 95%CI: 0.087-0.778, P = 0.016], prior exposure to biologics (OR = 0.080, 95%CI: 0.010-0.674, P = 0.020), and moderate-to-severe endoscopic disease (OR = 0.277, 95%CI: 0.093-0.829, P = 0.022) were associated with a lower likelihood of achieving EH at 1 year.

CONCLUSION

Only 20.9% of patients with isolated proximal SB CD achieved complete EH after 1 year of biologic therapy.

RISE-MX, a real-world study of patients with moderate/severe inflammatory bowel disease returning for hospital follow-up in Mexico: baseline demographics and clinical characteristics, treatment and disease status

Background

Inflammatory bowel disease (IBD) is characterized by periods of remission and relapses, and treatment is based on phenotype, risk factors, and disease severity. Treatments include 5-aminosalicylates (5-ASA), thiopurines, methotrexate, calcineurin inhibitors, corticosteroids (CS), biological therapy (BxT), and, more recently, small molecules.

Objective

To determine the baseline demographics and clinical characteristics, treatment patterns, and disease status of patients in Mexico with a history of moderate/severe IBD returning for hospital follow-up (Index Day).

Design

This was a non-interventional, cross-sectional study.

Methods

Socio-demographics, clinical characteristics, and prescribed treatments were collected from a retrospective review (3 years) of each patient's medical records.

Results

A total of 326 patients with a diagnosis of moderate/severe IBD at least 6 months before the Index Day were included in the analysis: 95 patients (29.2%) had Crohn's disease (CD) and 231 (70.9%) ulcerative colitis (UC). In the CD group, 45.3% (n = 43) had a Harvey Bradshaw Index score ⩾8 or Crohn's Disease Activity Index ⩾220; 10 patients had a B1-non-stenosing, non-penetrating phenotype and 17 had stenosis (B2). In the UC group, 18.2% (n = 42) had moderate/severe disease and the most frequent presentation was pancolitis (n = 56). Regarding treatment over the previous 3 years: for CD, 62 (65.3%) received CS and 20.0% (n = 19) were CS-dependent; 30.5% received 5-ASA + IMS; 27.4% BxT + IMS; and 38.9% 5-ASA + IMS + BxT. In the case of UC, 74.9% (n = 173) received CS and 32.9% (n = 76) were CS-dependent; 64.5% received 5-ASA + IMS; 2.2% BxT + IMS; and 31.6% 5-ASA + IMS + BxT.

Conclusion

In Mexico, 45.3% of CD patients and 18.1% with UC presented with moderate/severe disease activity. Conventional therapy was used to treat the majority of patients, and the availability of more advanced therapies and a personalized treatment approach is needed to improve clinical outcomes in the future.

Pediatric Inflammatory Bowel Disease Type Unclassified: A Nationwide Cohort Study in Scotland With up to 20 Years Follow-up Shows Reclassification in the Majority and Mild Course in Those Whose Diagnosis Is Unchanged

BACKGROUND

Given the paucity of long-term longitudinal data for inflammatory bowel disease type unclassified (IBDU), we aimed to clarify IBDU disease course and reclassification rate by presenting nationwide data with up to 20 years of follow-up.

METHODS

We analyzed a prospectively identified 11-year cohort of pediatric patients diagnosed with IBDU between January 1, 2003 and December 31, 2013 at all Scottish pediatric IBD centers and followed up into adult services until December 31, 2022. Data were obtained from electronic medical records at fixed timepoints (5 and 10 years post-diagnosis) and at the final follow-up.

RESULTS

Overall, 102 patients were included in the analysis (57/102 [56%] male, median [interquartile range {IQR}] age at diagnosis: 11.5 [9.1-13.2] years) with a median (IQR) follow-up length of 10.5 (8.6-14.0) years. A change of diagnosis was made in 61 of 102 patients (60%); of these, 30 patients (29%) were reclassified to Crohn's disease (CD) and 31 patients (30%) to ulcerative colitis (UC). Patients who remained with IBDU had higher 1- to 5-year remission rates (IBDU 30/39 [77%] vs reclassified 16/57 [28%], P < .05), with lower rates of moderate-to-severe disease (IBDU 3/39 [8%] vs reclassified 31/57 [54%], P < .05) and less need for biologics across all timepoints (IBDU vs reclassified: first timepoint 1/39 [3%] vs 17/57 [30%], second timepoint 1/33 [3%] vs 26/56 [46%], third timepoint 0/18 [0%] vs 16/33 [49%]; all P < .05). Higher rates of surgical resections were observed in reclassified patients (reclassified 11/61 [18%] vs IBDU 1/41 [2%], P = .02).

CONCLUSIONS

In our nationwide pediatric IBDU cohort, 60% of patients were reclassified to either UC or CD over 10.5 years of median follow-up; those who remained with IBDU had a milder disease course.

Discordant Effects of Janus Kinase Inhibition Ex Vivo on Inflammatory Responses in Colonic Compared to Ileal Mucosa

BACKGROUND AND AIMS

Janus kinase [JAK] inhibitors are used for treating inflammatory bowel diseases [IBD]. We aimed to identify the molecular effects of JAK inhibition in human intestinal mucosa, considering IBD location and phenotype.

METHODS

Colonic and ileal explants from patients with ulcerative colitis [UC], Crohn's disease [CD], and non-IBD controls [NC] were assessed for levels of phosphorylated signal transducers and activators of transcription [p-STAT] and expression of inflammatory genes in response to an ex vivo JAK inhibitor [tofacitinib]. Cytokine production by lamina propria lymphocytes in response to tofacitinib was assessed. Human intestinal organoids were used to investigate the effects of JAK inhibitors on inducible nitric oxide synthase [iNOS] expression.

RESULTS

Explants were collected from 68 patients [UC = 20, CD = 20, NC = 28]. p-STAT1/3/5 inhibition rates varied, being higher in colonic compared to ileal explants. p-STAT1/3 inhibition rates negatively correlated with levels of C-reactive protein [CRP]. While significant alterations in 120 of 255 inflammatory genes were observed in colonic explants, only 30 were observed in ileal NC explants. In colonic explants from UC, significant alterations were observed in five genes, including NOS2. JAK inhibition significantly decreased Th1/Th2/Th17-related cytokine production from lamina propria lymphocytes. Various JAK inhibitors reduced the interferon-γ-induced increase in iNOS expression in organoids.

CONCLUSIONS

A site-specific anti-inflammatory effect of JAK inhibition by tofacitinib was noted, whereby the colon was more robustly affected than the ileum. The ex vivo response to tofacitinib is individual. JAK inhibition may attenuate inflammation by decreasing iNOS expression. Ex vivo mucosal platforms may be a valuable resource for studying personalized drug effects in patients with IBD.

Comparing Environmental Risk Factors at Diagnosis in Faroese and Danish Patients with Inflammatory Bowel Disease

BACKGROUND

The incidence and prevalence of inflammatory bowel disease (IBD) in the Faroe Islands have increased drastically during the past 60 years, presumably due to changing environmental risk factors in a genetically susceptible population.

AIM

This study investigated differing environmental factors present in Faroese and Danish patients.

METHODS

From 2010 to 2022, all incident Faroese patients with IBD were invited to complete the International Organization of IBD (IOIBD) questionnaire about environmental factors at the time of their diagnosis. The findings were compared to a cohort of incident Danish patients diagnosed between 2010 and 2011.

RESULTS

Questionnaires were completed by 293 of 388 Faroese patients (75%), of whom 15% (n = 45) had Crohn's disease (CD), 63% (n = 185) had ulcerative colitis (UC), and 22% (n = 63) had IBD unclassified (IBDU). Faroese patients with IBD and UC were found to have higher pertussis vaccination coverage (p < 0.05), and more childhood infections of measles and pertussis (p < 0.05). Faroese patients with IBD consumed more fast food and less fiber but consumed less sugar (p < 0.001) and more caffeine (p < 0.001). No differences were found regarding gender, having been breastfed, use of oral contraceptives, or the number of first-degree relatives with IBD; however, differences in smoking at diagnosis were found in a subset analysis of Faroese patients diagnosed in 2010-11 compared with Danish patients.

CONCLUSIONS

Faroese patients with IBD were more exposed to some environmental risk factors prior to diagnosis than Danish patients. However, certain beneficial dietary habits were more common in Faroese patients than in Danish patients.

Relationship between histopathological findings, clinical severity and the need for surgery in patients with Crohn's disease

INTRODUCTION

Defining histological variables that make it possible to establish the activity of Crohn's disease (CD) and predict the patients who may present a higher risk of clinical complications and surgical interventions could lead to timely adjustments in medical therapy and elective surgeries that represent a lower risk of complications. The purpose of the study is to determine the relation between the histopathological findings using the Naini and Cortina (N&C) score, the clinical severity, and the indication for surgery in a group of patients with CD.

MATERIALS AND METHODS

Descriptive, retrospective, cross-sectional study of 44 patients diagnosed with CD, treated at the San Vicente Fundación University Hospital in Medellín, Colombia, between 2010 and 2022.

RESULTS

Of the 44 patients, 36 ileum samples and 34 colon samples were obtained. Of the patients with inflammatory behavior, 87.5% did not have surgical intervention (P=.022), a value that remained significant in the ileum subgroup (P=.0058). 91.3% of the patients with ileal involvement did not develop perianal disease (P=.01). Granulomas only occurred in two patients with a colon sample (5.8%). In the histological score of N&C both in the ileum and in the colon, no statistically significant differences were obtained in relation to the surgical outcome (P=.34 and P=.054, respectively).

CONCLUSION

The histological index of N&C was not a predictor in Crohn's disease (CD) related to the surgical outcome.

Roseburia intestinalis-derived extracellular vesicles ameliorate colitis by modulating intestinal barrier, microbiome, and inflammatory responses

Inflammatory bowel disease (IBD) is a chronic disorder characterized by recurrent gastrointestinal inflammation, lacking a precise aetiology and definitive cure. The gut microbiome is vital in preventing and treating IBD due to its various physiological functions. In the interplay between the gut microbiome and human health, extracellular vesicles secreted by gut bacteria (BEVs) are key mediators. Herein, we explore the role of Roseburia intestinalis (R)-derived EVs (R-EVs) as potent anti-inflammatory mediators in treating dextran sulfate sodium-induced colitis. R was selected as an optimal BEV producer for IBD treatment through ANCOM analysis. R-EVs with a 76 nm diameter were isolated from R using a tangential flow filtration system. Orally administered R-EVs effectively accumulated in inflamed colonic tissues and increased the abundance of Bifidobacterium on microbial changes, inhibiting colonic inflammation and prompting intestinal recovery. Due to the presence of Ile-Pro-Ile in the vesicular structure, R-EVs reduced the DPP4 activity in inflamed colonic tissue and increased the active GLP-1, thereby downregulating the NFκB and STAT3 via the PI3K pathway. Our results shed light on the impact of BEVs on intestinal recovery and gut microbiome alteration in treating IBD.

Prevalence of Inflammatory Bowel Disease Unclassified, as Estimated Using the Revised Porto Criteria, among Korean Pediatric Patients with Inflammatory Bowel Disease

Purpose

Few studies have reported the prevalence of inflammatory bowel disease unclassified (IBDU) among Korean pediatric IBD (PIBD) population. To address this gap, we used two tertiary centers and nationwide population-based healthcare administrative data to estimate the prevalence of Korean pediatric IBDU at the time of diagnosis.

Methods

We identified 136 patients aged 2-17 years with newly diagnosed IBD (94 Crohn's disease [CD] and 42 ulcerative colitis [UC]) from two tertiary centers in Korea between 2005 and 2017. We reclassified these 136 patients using the revised Porto criteria. To estimate the population-based prevalence, we analyzed Korean administrative healthcare data between 2005 and 2016, which revealed 3,650 IBD patients, including 2,538 CD and 1,112 UC. By extrapolating the reclassified results to a population-based dataset, we estimated the prevalence of PIBD subtypes.

Results

Among the 94 CD, the original diagnosis remained unchanged in 93 (98.9%), while the diagnosis of one (1.1%) patient was changed to IBDU. Among the 42 UC, the original diagnosis remained unchanged in 13 (31.0%), while the diagnoses in 11 (26.2%), 17 (40.5%), and one (2.4%) patient changed to atypical UC, IBDU, and CD, respectively. The estimated prevalences of CD, UC, atypical UC, and IBDU in the Korean population were 69.5%, 9.4%, 8.0%, and 13.1%, respectively.

Conclusion

This study is the first in Korea to estimate the prevalence of pediatric IBDU. This prevalence (13.1%) aligns with findings from Western studies. Large-scale prospective multicenter studies on PIBDU are required to examine the clinical features and outcomes of this condition.

Serum proteome signatures associated with ileal and colonic ulcers in Crohn's disease

At a clinical level, ileal and colonic Crohn's disease (CD) are considered as separate entities. These subphenotypes need to be better supported by biological data to develop personalised medicine in CD. To this end, we combined different technologies (proximity extension assay, selected reaction monitoring, and high-sensitivity turbidimetric immunoassay (hsCRP)) to measure 207 immune-related serum proteins in CD patients presenting no endoscopic lesions (endoscopic remission) (n = 23), isolated ileal ulcers (n = 17), or isolated colonic ulcers (n = 16). We showed that isolated ileal ulcers and isolated colonic ulcers were specifically associated with 6 and 18 serum proteins, respectively: (high level: JUN, CNTNAP2; low level: FCRL6, LTA, CLEC4A, NTF4); (high level: hsCRP, IL6, APCS, CFB, MBL2, IL7, IL17A, CCL19, CXCL10, CSF3, IL10, CLEC4G, MMP12, VEGFA; low level: CLEC3B, GSN, TNFSF12, TPSAB1). Isolated ileal ulcers and isolated colonic ulcers were detected by hsCRP with an area under the receiver operating characteristics curve of 0.64 (p-value = 0.07) and 0.77 (p-value = 0.001), respectively. We highlighted distinct serum proteome profiles associated with ileal and colonic ulcers in CD, this finding might support the development of therapeutics and biomarkers tailored to disease location. SIGNIFICANCE: Although ileal and colonic Crohn's disease present important clinical differences (eg, progression, response to treatment and reliability of biomarkers), these two entities are managed with the same therapeutic strategy. The biological specificities of ileal and colonic Crohn's disease need to be better characterised to develop more personalised approaches. The present study used robust technologies (selected reaction monitoring, proximity extension assays and turbidimetric immunoassay) to quantify precisely 207 serum immune-related proteins in three groups of Crohn's disease patients presenting: 1) no endoscopic lesions (endoscopic remission) (n = 23); 2) isolated ileal ulcers (n = 17); 3) isolated colonic ulcers (n = 16). We found distinct serum proteome signatures associated with ileal and colonic ulcers. Our findings could foster the development of biomarkers and treatments tailored to Crohn's disease location.

Real-world evidence of combined treatment of biologics and exclusive enteral nutrition in patients with ileum-dominant Crohn's disease: A multicenter study

BACKGROUND & AIMS

Although biologics were prescribed to achieve and maintain clinical remission of active Crohn's disease (CD), almost half of patients experienced a loss of response or intolerance. Here, we investigated the efficacy of combined treatment of biologics and 16-weeks exclusive enteral nutrition (EEN) in moderate-to-severe CD patients with small intestine lesions.

METHODS

This was a real-world, multicenter retrospective study, from October 2016 to March 2023, medical records of patients registered at three IBD centers were reviewed for patients with ileal or ileocolonic CD in moderate-to-severe activity. All patients received treatment of biologics with concomitant 16-week EEN (BioEEN) or biologics alone (Bio). The clinical outcomes and endoscopic outcomes were assessed at week 16 and 52.

RESULTS

There was no statistically significant difference between Bio (97 patients) and BioEEN group (100 patients) at baseline for demographic and clinical characteristics. Compared to treatment with biologics alone, patients with BioEEN treatment achieved higher rates of clinical response (95.0% vs. 66.0%), clinical remission (87.0% vs. 52.6%), endoscopic response (91.4% vs. 47.4%) including mucosal healing (85.7% vs. 23.7%) at week 16. The superiority of BioEEN sustained in maintenance, with 84.7% (vs. 49.1%) clinical response, 77.8% (vs. 38.6%) clinical remission, 69.2% (vs. 32.6%) endoscopic response and 51.9% (vs. 18.6%) mucosal healing at week 52.

CONCLUSIONS

Combined treatment of biologics and 16-week EEN was an efficient therapeutic strategy with affirmative effectiveness for small intestine diseases of active CD.

Dysbiosis and Associated Stool Features Improve Prediction of Response to Biological Therapy in Inflammatory Bowel Disease

BACKGROUND & AIMS

Dysbiosis of the gut microbiota is considered a key contributor to inflammatory bowel disease (IBD) etiology. Here, we investigated potential associations between microbiota composition and the outcomes to biological therapies.

METHODS

The study prospectively recruited 296 patients with active IBD (203 with Crohn's disease, 93 with ulcerative colitis) initiating biological therapy. Quantitative microbiome profiles of pretreatment and posttreatment fecal samples were obtained combining flow cytometry with 16S amplicon sequencing. Therapeutic response was assessed by endoscopy, patient-reported outcomes, and changes in fecal calprotectin. The effect of therapy on microbiome variation was evaluated using constrained ordination methods. Prediction of therapy outcome was performed using logistic regression with 5-fold cross-validation.

RESULTS

At baseline, 65.9% of patients carried the dysbiotic Bacteroides2 (Bact2) enterotype, with a significantly higher prevalence among patients with ileal involvement (76.8%). Microbiome variation was associated with the choice of biological therapy rather than with therapeutic outcome. Only anti-tumor necrosis factor-α treatment resulted in a microbiome shift away from Bact2, concomitant with an increase in microbial load and butyrogen abundances and a decrease in potentially opportunistic Veillonella. Remission rates for patients hosting Bact2 at baseline were significantly higher with anti-tumor necrosis factor-α than with vedolizumab (65.1% vs 35.2%). A prediction model, based on anthropometrics and clinical data, stool features (microbial load, moisture, and calprotectin), and Bact2 detection predicted treatment outcome with 73.9% accuracy for specific biological therapies.

CONCLUSION

Fecal characterization based on microbial load, moisture content, calprotectin concentration, and enterotyping may aid in the therapeutic choice of biological therapy in IBD.

A novel location classification system for Crohn's disease based on small bowel involvement: a better predictor of disease progression

BACKGROUND

Small bowel involvement is related to poor prognosis in Crohn's disease (CD), which may be a potential marker to stratify patients with a high risk of progression. This study aimed to establish a novel location classification system for CD and to develop a predictive model for disease progression.

METHODS

Consecutive patients with non-stricturing/non-penetrating CD were retrospectively included in the Sixth Affiliated Hospital, Sun Yat-sen University (Guangzhou, P. R. China) between January 2012 and January 2018. Patients were classified into two groups according to disease location: small bowel involvement group and isolated colon group. The primary outcome was disease progression to stricturing or penetrating phenotypes. Progression-free survival was estimated using Cox proportional hazards regression analysis and Kaplan-Meier method.

RESULTS

A total of 463 patients were analysed, with a median follow-up time of 55.3 months. Patients with small bowel involvement had a higher risk of disease progression than those with isolated colon disease (hazard ratio = 1.998, P = 0.007), while no differences were found between Montreal location classification and disease progression. Median progression-free survival was higher in the isolated colon group than in the small bowel involvement group (84.5 vs 77.3 months, P = 0.006). Four independent factors associated with disease progression were identified: small bowel involvement, duration of onset of >1 year, deep mucosal ulcer, and C-reactive protein levels of ≥10 mg/L (all P < 0.05). The nomogram model based on these factors showed good performance in predicting disease progression, with a C-index of 0.746 (95% confidence interval, 0.707-0.785).

CONCLUSIONS

Classifying CD based on small bowel involvement and isolated colon was superior to the Montreal location classification for predicting disease progression.

Use of double-balloon endoscopy and an endoscopic scoring system to assess endoscopic remission in isolated small bowel Crohn's disease after treatment with infliximab

Background

It is unclear how clinical and endoscopic factors affect the attainment of endoscopic remission (ER) in patients with small bowel Crohn's disease (SB-CD) who are infliximab-naïve.

Objectives

We aimed to identify the effect of different factors on attaining ER using double-balloon endoscopy (DBE) evaluation.

Design

A single-center retrospective observational study was conducted from 1 January 2018 to 30 November 2022. Among 262 patients who were screened for isolated SB-CD by baseline DBE, 108 patients were assessed for effectiveness during maintenance infliximab therapy by a second DBE evaluation.

Methods

DBE findings before and after infliximab therapy were compared. ER was defined as a simple endoscopic score for CD (SES-CD) below 3, and segmental ER as SES-CD activity of 0. Multivariate regression with calculations of odds ratios (OR) was used to determine the impact of different factors on attaining ER.

Results

In all, 41 patients (38.0%) achieved ER. An elevated C-reactive protein at week 6 was independently associated with a decreased probability of ER [OR: 0.86, 95% confidence interval (CI) = 0.75-0.98, p = 0.03]. Segmental ER of the terminal ileum, rather than the proximal ileum, was associated with a higher rate of ER (60.9% versus 38.2%, p = 0.01). High baseline SES-CD (⩾16) was unrelated to overall ER. For patients with disease in the terminal ileum, those with moderate/severe disease were less likely to attain segmental ER than those with mild disease [adjusted odds ratios (aOR): 0.27, 95% CI: 0.09-0.83, p = 0.02]. A large ulcer in the terminal ileum was associated with a lower rate of segmental ER (aOR: 0.18, 95% CI: 0.06-0.56, p = 0.01).

Conclusion

For infliximab-naïve patients with SB-CD, the overall severity of the endoscopic score was unrelated to attainment of ER. Patients were less likely to attain segmental ER if they had greater endoscopic inflammation or larger ulcers in the terminal ileum.

Colonic involvement in inflammatory bowel diseases: spotlight on the role of magnetic resonance enterography

The large bowel can be affected by inflammatory bowel diseases, namely ulcerative colitis and Crohn's disease, with the latter occurring either as a unique localization or in conjunction with simultaneous ileal involvement. The differential diagnosis among these conditions is challenging and relies on clinical symptoms, laboratory tests and endoscopy with biopsy. However, as these features can overlap, a conclusive diagnosis is not always achievable, and the underlying cause remains indeterminate. Currently, endoscopy is the reference standard for colonic assessment, although its invasiveness limits its use and repetition within a short timeframe. Magnetic Resonance Enterography is a non-invasive, radiation-free technique that has been extensively and effectively employed in the intestinal evaluation of patients with Crohn's disease in recent years. Although the main goal of this technique is generally focused on evaluating small bowel loops, it can also provide important information about the large bowel if an adequate fulfillment by the oral contrast medium is achieved. The purpose of this work is, therefore, to put emphasis on the potential role of Magnetic Resonance Enterography in assessing the large bowel. In fact, this imaging modality is capable of providing valuable information for comprehensive staging and follow-up of inflammatory bowel diseases within the large bowel, thus complementing the clinical picture and the endoscopic features in the context of a differential diagnosis.

Are We Ready to Reclassify Crohn's Disease Using Molecular Classification?

Crohn's disease (CD) is a type of inflammatory bowel disease. The number of IBD cases worldwide was estimated to be 4.9 million in 2019. CD exhibits heterogeneity in clinical presentation, anatomical involvement, disease behaviour, clinical course and response to treatment. The classical description of CD involves transmural inflammation with skip lesions anywhere along the entire gastrointestinal tract. The complexity and heterogeneity of Crohn's disease is not currently reflected in the conventional classification system. Though the knowledge of Crohn's pathophysiology remains far from understood, the established complex interplay of the omics-genomics, transcriptomics, proteomics, epigenomics, metagenomics, metabolomics, lipidomics and immunophenomics-provides numerous targets for potential molecular markers of disease. Advancing technology has enabled identification of small molecules within these omics, which can be extrapolated to differentiate types of Crohn's disease. The multi-omic future of Crohn's disease is promising, with potential for advancements in understanding of its pathogenesis and implementation of personalised medicine.

Machine Learning in Antibody Diagnostics for Inflammatory Bowel Disease Subtype Classification

Antibody testing in inflammatory bowel disease (IBD) can add to diagnostic accuracy of the main subtypes Crohn's disease (CD) and ulcerative colitis (UC). Whether modern modeling techniques such as supervised and unsupervised machine learning are of value for finer distinction of subtypes such as IBD-unclassified (IBD-U) is not known. We determined the antibody profile of 100 adult IBD patients from the Swiss IBD cohort study with known subtype (50 CD, 50 UC) as well as of 76 IBD-U patients. We included ASCA IgG and IgA, p-ANCA, MPO- and PR3-ANCA, and xANCA measurements for computing different antibody panels as well as machine learning models. The AUC of an optimized antibody panel was 85% (95%CI, 78-92%) to distinguish CD from UC patients. The antibody profile of IBD-U patients was closely related to UC. No specific antibody profile was predictive for IBD-U nor for re-classification. The panel diagnostic was in favor of UC reclassification prediction with a correct assignment rate of 69.2-73.1% depending on the cut-off applied. Supervised machine learning could not distinguish between CD, UC, and IBD-U. More so, unsupervised machine learning suggested only two distinct clusters as a likely number of IBD subtypes. Antibodies in IBD are supportive in confirming clinical determined subtypes CD and UC but have limited capacity to predict IBD-U and reclassification during follow-up. In terms of antibody profiles, IBD-U is not a distinct subtype of IBD.

The prevalence and clinical characteristics of Clostridium difficile infection in Saudi patients admitted with inflammatory bowel disease: A case-control study

Background

Inflammatory bowel disease (IBD) patients are at increased risk of Clostridium difficile infection (CDI), causing significant morbidity and mortality. This study examined CDI's prevalence, predisposing factors, and clinical outcomes in Saudi hospitalized IBD patients.

Methods

: A retrospective case-control study was conducted at a tertiary medical city in Riyadh, Saudi Arabia. All Saudi adult patients with IBD, admitted over the preceding four years were identified from the hospital's database. Eligible patients were divided into those with CDI and those without CDI. Binary logistic regression was used to determine the predisposing factors for CDI among admitted IBD patients.

Results

During the study period, 95 patients were admitted with IBD. Crohn's disease (CD) was the predominant type (71.6%), whereas 28.4% of the patients were with ulcerative colitis (UC). Only 16 (16.8%) patients had positive CDI. CDI-positive patients tend to have hypertension and previous use of steroids. Patients with UC tend to have a higher risk of CDI than those with CD. Most patients recovered from the CDI (81.3%) with a median time to CDI clearance of 14 days. Three patients (18.8%) had recurrent CDI; among them, one died.

Conclusion

The prevalence of CDI in Saudi IBD patients is similar to that reported elsewhere. UC, steroid treatment, and hypertension are risk factors for CDI in IBD patients. Recurrence of CDI in IBD patients is common and associated with a poor prognosis.

Treatment of inflammatory bowel disease-Asian perspectives: the results of a multinational web-based survey in the 8th Asian Organization for Crohn's and Colitis meeting

BACKGROUND/AIMS

As the characteristics of inflammatory bowel disease (IBD) differ between Asians and Westerners, it is necessary to determine adequate therapeutic strategy for Asian IBD patients. We evaluated the current treatment of IBD in Asian countries/regions using a web-based survey.

METHODS

The Korean Association for the Study of Intestinal Diseases conducted a multinational web-based survey for current IBD care in Asia between September 16, 2020, and November 13, 2020.

RESULTS

A total of 384 doctors treating IBD patients from 24 Asian countries/regions responded to the survey. Anti-tumor necrosis factor (TNF) agents, anti-integrins, and anti-interleukin-12/23 agents were available for use by 93.8%, 72.1%, and 70.1% of respondents in Asian countries/regions. Compared with a previous survey performed in 2014, an increased tendency for treatment with biologics, including anti-TNF agents, was observed. In the treatment of corticosteroid-refractory acute severe ulcerative colitis, 72.1% of respondents chose anti-TNF agents, followed by tacrolimus (11.7%). In the treatment of corticosteroid-refractory Crohn's disease, 90.4% chose anti-TNF agents, followed by thiopurines (53.1%), anti-interleukin-12/23 agents (39.3%), and anti-integrin agents (35.7%). In the treatment of Crohn's disease patients refractory to anti-TNF agents, the most preferred strategy was to measure serum levels of anti-TNF and anti-drug antibodies (40.9%), followed by empiric dose escalation or shortening of dosing intervals (25.3%).

CONCLUSIONS

Although there were some differences, treatment strategies for patients with IBD were mostly similar among Asian doctors. Based on the therapeutic outcomes, it is necessary to identify the most appropriate therapeutic strategy for Asian IBD patients.

Crohn’s disease: Why the ileum?

Crohn’s disease (CD) is an inflammatory bowel disease characterized by immune-mediated flares affecting any region of the intestine alternating with remission periods. In CD, the ileum is frequently affected and about one third of patients presents with a pure ileal type. Moreover, the ileal type of CD presents epidemiological specificities like a younger age at onset and often a strong link with smoking and genetic susceptibility genes. Most of these genes are associated with Paneth cell dysfunction, a cell type found in the intestinal crypts of the ileum. Besides, a Western-type diet is associated in epidemiological studies with CD onset and increasing evidence shows that diet can modulate the composition of bile acids and gut microbiota, which in turn modulates the susceptibility of the ileum to inflammation. Thus, the interplay between environmental factors and the histological and anatomical features of the ileum is thought to explain the specific transcriptome profile observed in CD ileitis. Indeed, both immune response and cellular healing processes harbour differences between ileal and non-ileal CD. Taken together, these findings advocate for a dedicated therapeutic approach to managing ileal CD. Currently, interventional pharmacological studies have failed to clearly demonstrate distinct response profiles according to disease site. However, the high rate of stricturing disease in ileal CD requires the identification of new therapeutic targets to significantly change the natural history of this debilitating disease.

Clinical and endoscopic outcomes of patients with colonic Crohn's disease treated with 5-aminosalicylates as monotherapy

BACKGROUND

In spite of the lack of evidence regarding the clinical benefits of oral 5-aminosalicylic acid (5-ASA) compounds in Crohn's disease (CD), these drugs are frequently used in daily clinical practice, particularly for colonic CD. Our aim is to assess the use and clinical outcomes of 5-ASA of those patients with colonic CD treated with 5-ASA as monotherapy.

METHODS

Patients diagnosed with isolated colonic CD and treated with 5-ASA but never exposed to immunosuppressants or biologicals were identified from the local databases of five referral centres. A retrospective review of clinical and endoscopic outcomes was performed.

RESULTS

Out of 545 patients with isolated colonic CD, 106 (19%) were treated with oral 5-ASA in monotherapy as maintenance therapy. The median follow-up was 144 months (interquartile range [IQR], 48-234). Almost all of the patients (92%) presented an inflammatory pattern and 11% developed perianal disease. Half of the patients had already received 5-ASA at diagnosis, and the median duration of 5-ASA treatment was 107 months (IQR 22.5-187). Endoscopic remission, as defined by the absence of ulcers at the last complete colonoscopy, was observed in 65% of those patients undergoing at least one colonoscopy during follow-up. Male gender and extraintestinal manifestations were associated with a lower likelihood of achieving endoscopic remission. Nine patients required colectomy, but mostly soon after CD diagnosis.

CONCLUSIONS

5-ASA seems to be of benefit in the long-term in one fifth of patients with colonic CD as the only maintenance therapy and should be considered in fragile patients with Crohn's colitis.

Case-case genome-wide association analysis identifying genetic loci with divergent effects on Crohn's disease and ulcerative colitis

Crohn's disease (CD) and ulcerative colitis (UC), two major subtypes of inflammatory bowel disease, show substantial differences in their clinical course and treatment response. To identify the genetic factors underlying the distinct characteristics of these two diseases, we performed a genome-wide association study (GWAS) between CD (n = 2359) and UC (n = 2175) in a Korean population, followed by replication in an independent sample of 772 CD and 619 UC cases. Two novel loci were identified with divergent effects on CD and UC: rs9842650 in CD200 and rs885026 in NCOR2. In addition, the seven established susceptibility loci [major histocompatibility complex (MHC), TNFSF15, OTUD3, USP12, IL23R, FCHSD2 and RIPK2] reached genome-wide significance. Of the nine loci, six (MHC, TNFSF15, OTUD3, USP12, IL23R and CD200) were replicated in the case-case GWAS of European populations. The proportion of variance explained in CD-UC status by polygenic risk score analysis was up to 22.6%. The area under the receiver-operating characteristic curve value was 0.74, suggesting acceptable discrimination between CD and UC. This CD-UC GWAS provides new insights into genetic differences between the two diseases with similar symptoms and might be useful in improving their diagnosis and treatment.

Advancing the precision management of inflammatory bowel disease in the era of omics approaches and new technology

There is great heterogeneity among inflammatory bowel disease (IBD) patients in terms of pathogenesis, clinical manifestation, response to treatment, and prognosis, which requires the individualized and precision management of patients. Many studies have focused on prediction biomarkers and models for assessing IBD disease type, activity, severity, and prognosis. During the era of biologics, how to predict the response and side effects of patients to different treatments and how to quickly recognize the loss of response have also become important topics. Multiomics is a promising area for investigating the complex network of IBD pathogenesis. Integrating numerous amounts of data requires the use of artificial intelligence.

Segmental Versus Total Colectomy for Crohn's Disease in the Biologic Era: Results From The SCOTCH International, Multicentric Study

BACKGROUND

The extent of resection in colonic Crohn's disease [cCD] is still a topic of debate, depending on the number of locations, the risk of recurrence and permanent stoma, and the role of medical therapy.

METHODS

The Segmental COlecTomy for CroHn's disease [SCOTCH] international study is a retrospective analysis on six tertiary centre prospective databases, comprising all consecutive, unselected patients operated on between 2000 and 2019 with segmental colectomy [SC] or total colectomy [TC] for cCD. The primary aim was long-term surgical recurrence. Secondary aims were perioperative complications, stoma formation and predictors of recurrence.

RESULTS

Among 687 patients, SC was performed in 285 [41.5%] and TC in 402 [58.5%]. Mean age at diagnosis and surgery, disease duration, and follow-up were 30 ± 15.8, 40.4 ± 15.4, 10.4 ± 8.6 and 7.1 ± 5.2 years respectively. Isolated cCD, inflammatory pattern, perianal CD, younger age, longer disease duration and preoperative maximal therapy were more frequent in TC, while SC presented more small bowel locations and perforating disease, required fewer 90-day re-admissions, and fewer temporary and definitive stomas. Morbidity and mortality were similar. The 15-year surgical recurrence was 44% in TC and 27% in SC [p = 0.006]. In patients with one to three diseased segments, recurrence risk was related to the omission of biological therapy (hazard ratio [HR] 5.6), the number of segments [HR 2.5], perianal disease [HR 1.9] and paediatric diagnosis [HR 2.8].

CONCLUSION

When technically feasible, SC is safe and reduces temporary and permanent stoma. Young age, number of locations and perianal disease adversely affect, but postoperative biological therapy significantly reduces, the long-term surgical recurrence.

Impact of Crohn's Disease Therapies on Histology in Randomized Controlled Trials: Systematic Review With Meta-analysis

BACKGROUND

The effectiveness of Crohn's disease treatments for inducing histological outcomes has not been addressed systematically. We performed a systematic review and meta-analysis of randomized controlled trials in Crohn's disease to assess the impact of therapies on mucosal histopathology.

METHODS

Databases (MEDLINE, CENTRAL, Web of Science, EMBASE) were searched for randomized controlled trials including adult patients and evaluating histological outcomes. Risk of bias was evaluated using the Critical Appraisal Skills Programme. Histological outcomes, pooled frequencies, pooled odds ratios, and standard mean differences of the histological scores were compared between the intervention and placebo groups using a random-effects model.

RESULTS

Out of 2070 records, 10 studies were included. The quality of the studies ranged from moderate to high, but they were clinically and methodologically diverse. All interventions were superior to placebo. Histological response was achieved by 68% of patients, and 38% achieved remission. Pooled odds ratio for histological remission in patients receiving intervention vs placebo was 4.14 (95% CI, 2.28-7.50; I2 0%; P < .01). Heterogeneity in histological response estimates was significant, and subgroup analysis of the odds ratio results was limited by the low number of studies per group. The standard mean difference of histological scores was higher for patients receiving intervention in both induction and maintenance studies (-2.95; 95% CI, -4.17 to -1.74; I2 83% P < .00; and -2.58; 95% CI, -3.89 to -1.27; I2 56% P < .00).

CONCLUSIONS

Crohn's disease therapies are effective for achieving histological outcomes. Adherence to recently published consensus on histopathology harmonization assessment in Crohn's disease would facilitate adequate comparison between studies in the future.

Location-specific signatures of Crohn's disease at a multi-omics scale

BACKGROUND

Crohn's disease (CD), an inflammatory bowel disease (IBD) subtype, results from pathologic interactions between host cells and its resident gut microbes. CD manifests in both isolated disease locations (ileum or colon) or a combination of locations (ileocolonic). To date, a comprehensive understanding of how isolated CD subtypes influence molecular profiles remains outstanding. To address this, we sought to define CD location signatures by leveraging a large cross-sectional feature set captured from the stool of over 200 IBD patients and healthy controls using metaproteomics, shotgun metagenomics, 16S rRNA sequencing, metabolomic profiling, and host genetics paired with clinical endoscopic assessments.

RESULTS

Neither metagenomic nor host genetics alone distinguished CD location subtypes. In contrast, ileal and colonic CD were distinguished using mass spectrometry-based methods (metabolomics or metaproteomics) or a combined multi-omic feature set. This multi-omic feature set revealed colonic CD was strongly associated with neutrophil-related proteins. Additionally, colonic CD displayed a disease-severity-related association with Bacteroides vulgatus. Colonic CD and ulcerative colitis profiles harbored strikingly similar feature enrichments compared to ileal CD, including neutrophil-related protein enrichments. Compared to colonic CD, ileal CD profiles displayed increased primary and secondary bile acid levels and concomitant shifts in taxa with noted sensitivities such as Faecalibacterium prausnitzii or affinities for bile acid-rich environments, including Gammaproteobacteria and Blautia sp. Having shown robust molecular and microbial distinctions tied to CD locations, we leveraged these profiles to generate location-specific disease severity biomarkers that surpass the performance of Calprotectin.

CONCLUSIONS

When compared using multi-omics features, colonic- and ileal-isolated CD subtypes display striking differences that suggest separate location-specific pathologies. Colonic CD's strong similarity to ulcerative colitis, including neutrophil and Bacteroides vulgatus involvement, is also evidence of a shared pathology for colonic-isolated IBD subtypes, while ileal CD maintains a unique, bile acid-driven profile. More broadly, this study demonstrates the power of multi-omics approaches for IBD biomarker discovery and elucidating the underlying biology. Video Abstract.

Categorising Endoscopic Severity of Crohn's Disease Using the Modified Multiplier SES-CD [MM-SES-CD]

BACKGROUND AND AIMS

Current endoscopic scoring indices such as the Simple Endoscopic Score for Crohn's Disease [SES-CD] quantify the degree of mucosal inflammation in Crohn's disease [CD] but lack prognostic potential. The Modified Multiplier of the SES-CD [MM-SES-CD] quantifies the endoscopic burden of CD and can be accessed online [https://www.mcmasteribd.com/mm-ses-cd]. This analysis aims to establish MM-SES-CD thresholds that classify CD endoscopic burden into inactive/very mild, mild, moderate, and severe disease based on the probability of achieving endoscopic remission [ER] on active therapy at 1 year.

METHODS

This post-hoc analysis included pooled data from three CD clinical trials [n = 350 patients, baseline SES-CD ≥3 with ulceration]. Disease category severity was determined using the maximum Youden Index. Achievement of ER between severity categories was compared using chi square tests. Time to clinical remission [CR] was compared using Kaplan-Meier survival curves.

RESULTS

MM-SES-CD severity categories were established as very mild/remission [score <14], mild [≥14 to <31], moderate [≥31 to <45], and severe [≥45], which were predictive of 1-year ER [50%, 30.3%, 21.7%, 8.8%, respectively, p <0.001]. Lower MM-SES-CD scores had numerically higher rates of 1-year clinical remission [CR], and time to 1-year CR was superior to those with higher scores [p = 0.0492]. MM-SES-CD thresholds for achieving 1-year ileal ER among 75 patients with isolated ileal disease were established as mild [score <14], moderate [≥14 to <33], and severe [≥33], which were predictive of 1-year ER [66.7%, 33.3%, 13.3%, respectively, p = 0.027].

CONCLUSIONS

We have established numerical MM-SES-CD cut-offs that categorise endoscopic disease severity and have demonstrated that they are prognostic for 1-year ER and CR.

Moringa oleifera Lam. Peptide Remodels Intestinal Mucosal Barrier by Inhibiting JAK-STAT Activation and Modulating Gut Microbiota in Colitis

Ulcerative colitis is a chronic inflammatory bowel disease (IBD), but progress in exploring its pathogenesis and finding effective drugs for its prevention and treatment has stalled in recent years. The seeds of Moringa oleifera Lam. are rich in proteins known to have multiple physiological activities. In our earlier work, we had isolated and purified a peptide (MOP) having the sequence KETTTIVR, from M. oleifera seeds; however, its anti-inflammatory activity and mechanism in vivo were unclear. Here we used the dextran sulfate sodium (DSS)-induced colitis model to study the anti-inflammatory activity and mechanism of this MOP. Our results are the first to show that MOP can ameliorate the pathological phenotype, inflammation, and intestinal barrier disruption in mice with colitis. Furthermore, RNA sequencing revealed that MOP inhibits the Janus kinase/signal transducer and activator of transcription (JAK-STAT) pathway activation. Next, by using 16s rRNA gene sequencing, we found that MOP can ameliorate DSS-induced gut microbiota dysbiosis. In addition, an untargeted metabolomics analysis suggested that MOP is able to modulate the level of lipid and amino acid metabolites in IBD-stricken mice. Altogether, these results indicate that MOP ameliorates colitis by remodeling intestinal mucosal barrier by inhibiting JAK-STAT pathway’s activation and regulating gut microbiota and its metabolites, thus providing a basis for further processing and design of bioactive foods from M. oleifera seeds.

Downregulated Mucosal Autophagy, Alpha Kinase-1 and IL-17 Signaling Pathways in Active and Quiescent Ulcerative Colitis

Background

Improved mucosal immune profiling in active and quiescent colonic inflammatory bowel disease (IBD) is needed to develop therapeutic options for treating and preventing flares. This study therefore aimed to provide a comprehensive mucosal characterization with emphasis on immunological host response of patients with active ulcerative colitis (UC active), UC during remission (UC remission) and active colonic Crohn’s disease (CD active).

Methods

Colonic biopsies from 47 study subjects were collected for gene expression and pathway analyses using the NanoString host-response panel, including 776 genes and 56 immune-related pathways.

Results

The majority of mucosal gene expression and signaling pathway scores were increased in active IBD (n=27) compared to healthy subjects (n=10). However, both active IBD and UC remission (n=10) demonstrated decreased gene expression and signaling pathway scores related to autophagy, alpha kinase-1 and IL-17 signaling pathways compared to healthy subjects. Further, UC remission was characterized by decreased scores of several signaling pathways linked to homeostasis along with increased mononuclear cell migration pathway score as compared to healthy subjects. No major differences in the colonic mucosal gene expression between CD active (n=7) and UC (n=20) active were observed.

Conclusion

This study indicates that autophagy, alpha kinase-1 and IL-17 signaling pathways are persistently downregulated in UC irrespective of disease activity. Further, UC patients in remission present a unique mucosal environment, potentially preventing patients from reaching and sustaining true homeostasis. These findings may enable better comprehension of the remitting and relapsing pattern of colonic IBD and guide future treatment and prevention of flares.

3,4-Methylenedioxy-β-Nitrostyrene Alleviates Dextran Sulfate Sodium–Induced Mouse Colitis by Inhibiting the NLRP3 Inflammasome

Inflammatory bowel disease (IBD) has been reported to be associated with NLRP3 inflammasome activation. Therefore inhibiting inflammasome activation could be a new approach to treat IBD. Inflammasome inhibitors NLRP3-IN-2, JC124, and 3,4-methylenedioxy-β-nitrostyrene (MNS) were previously reported to exert anti-inflammatory effects in various disease models but not in the dextran sulfate sodium (DSS)–induced colitis model. Here, we showed that MNS was more efficient in inhibiting the secretion of interleukin-1β (IL-1β) by blocking oligomerization of apoptosis-associated speck-like protein (ASC) than NLRP3-IN-2 and JC124. To investigate the protective effects of MNS on enteritis, we administered intragastric MNS to DSS-induced colitis mice. The results demonstrated that MNS attenuated DSS-induced body weight loss, colon length shortening, and pathological damage. In addition, MNS inhibited the infiltration of macrophages and inflammatory cells and reduced IL-1β and IL-12p40 pro-inflammatory cytokines but had no significant effect on tumor necrosis factor α (TNF-α) and IL-6. Furthermore, we also found that the differentiation of IL-17A⁺interferon-γ (IFN-γ)⁺CD4⁺ T cell was decreased in the colon after MNS treatment, which might be mediated by IL-1β, etc. cytokine release. Taken together, MNS alleviated DSS-induced intestinal inflammation by inhibiting NLRP3 inflammasome activation, which may function as an effective therapeutic for IBD.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Time to Revisit Disease Classification in Inflammatory Bowel Disease: Is the Current Classification of Inflammatory Bowel Disease Good Enough for Optimal Clinical Management?

Inflammatory bowel disease (IBD), historically subdivided into Crohn's disease and ulcerative colitis, is a very heterogeneous condition. While the tendency in medicine is to try to reduce complexity, IBD is a disease that cannot justify a one-size-fits-all principle. Our current clinical classification tools are suboptimal and need further refinement to capture, at least in part, the variety of phenotypes encountered in daily clinical practice. Although these revised classification tools alone will not be sufficient and should be complemented by more detailed molecular subclassifications, optimized clinical phenotypes can contribute to improved trial designs, future translational research approaches, and better treatment outcomes. In the current review, we discuss key clinical features important in IBD disease heterogeneity, tackle limitations of the current classification systems, propose some potential improvements, and raise priorities for future research in this domain.

Ileal and colonic Crohn'´s disease: Ddoes location makes a difference in therapy efficacy?

Within the IBD entity of Crohn's disease, there is currently no differentiation between ileal and colonic manifestation for recruitment of patients in clinical trials, well-powered analysis of study results or therapeutic decisions in daily clinical practice. However, there is accumulating evidence from epidemiological, genetic, microbial, immunological, and clinical characteristics that clearly indicate that ileal Crohn's disease represents a distinct disease entity, which differentiates itself from colonic Crohn's disease. This is also reflected by lower efficacy of targeted therapies in isolated ileal compared to colonic Crohn's disease. The distinct site-specific mechanisms that drive heightened non-response in ileal disease need to be analysed in-depth in the future, to enable optimized therapy in the individual Crohn's disease patient.

Clinical Features and Outcomes of Paediatric Patients With Isolated Colonic Crohn Disease

OBJECTIVES

Adult studies suggest that patients with isolated colonic Crohn disease (L2 CD) exhibit unique characteristics differentiating them from patients with ileo-caecal (L1) CD and ulcerative colitis (UC). We aimed to characterize clinical features and outcomes of paediatric patients with L2.

METHODS

Retrospective data was collected through the Porto Inflammatory Bowel Disease group of the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) on Paediatric patients with L2, L1 or UC at different time-points. Outcome measures included time to first flare, hospital admissions, initiation of anti-tumor necrosis factor-alpha (TNFα) drug, stricture and surgery.

RESULTS

Three hundred patients were included: 102 L1, 94 L2 and 104 UC. Rates of hematochezia at presentation were 14.7%, 44.7% and 95.2%, while rates of fever were 12.7%, 26.6% and 2.9%, for patients with L1, L2 and UC, respectively (P < 0.001 for all comparisons). Skip lesions were identified in 65% of patients with L2, and granulomas in 36%, similar to L1 patients. Rates of anti-Saccharomyces cerevisiae antibodies (ASCA) and perinuclear antineutrophil cytoplasmic (pANCA) positivity significantly differed between the three groups: 25.4% and 16.7% for patients with L2, compared with 55.2% and 2.3%, and 1.8% and 52.9% for patients with L1 and UC, respectively. Response rates to exclusive enteral nutrition were comparable between L1 and L2 (78.3-82.4%), as was the response to oral steroids (70.4-76.5%) in the three groups. While times to first flare and admission were similar between groups, patients with L1 were commenced on anti-TNFα earlier. Moreover, stricturing phenotype and need for colectomy were very rare in patients with L2.

CONCLUSIONS

Significant differences are observed in the clinical presentation and outcomes of Paediatric patients with L2, compared to patients with L1 and UC.

Guidelines for the management of patients with Crohn's disease. Recommendations of the Polish Society of Gastroenterology and the Polish National Consultant in Gastroenterology

This paper is an update of the diagnostic and therapeutic recommendations of the National Consultant for Gastroenterology and the Polish Society of Gastroenterology from 2012. It contains 46 recommendations for the diagnosis and treatment, both pharmacological and surgical, of Crohn's disease in adults. The guidelines were developed by a group of experts appointed by the Polish Society of Gastroenterology and the National Consultant in the field of Gastroenterology. The methodology related to the GRADE methodology was used to assess the quality and strength of the available recommendations. The degree of expert support for the proposed statement, assessment of the quality of evidence and the strength of the recommendation was assessed on a 6-point Likert scale. Voting results, quality and strength ratings with comments are included with each statement.

Immunological Networks Defining the Heterogeneity of Inflammatory Bowel Diseases

Current practice in IBD is to classify patients based on clinical signs and symptoms and provide treatments accordingly. However, the response of IBD patients to available treatments is highly variable, highlighting clinically significant heterogeneity among patients. Thus, more accurate patient stratification is urgently needed to more effectively target therapeutic interventions to specific patients. Here we review the degree of heterogeneity in IBD, discussing how the microbiota, genetics, and immune system may contribute to the variation among patients. We highlight how molecular heterogeneity may relate to clinical phenotype, but in other situations may be independent of clinical phenotype, encouraging future studies to fill the gaps. Finally, we discuss novel stratification methodologies as a foundation for precision medicine, in particular a novel stratification strategy based on conserved genes across species. All of these dimensions of heterogeneity have potential to provide strategies for patient stratification and move IBD practice towards personalised medicine.

Role of Extended Mesenteric Excision in Postoperative Recurrence of Crohn's Colitis: A Single-Center Study

INTRODUCTION

The mesentery is involved in Crohn's disease. The impact of the extent of mesenteric resection on postoperative disease progression in Crohn's disease remains unconfirmed. This study aimed to determine the association between resection of the mesentery and postoperative outcomes in patients with Crohn's colitis (CC) undergoing colorectal surgery.

METHODS

Patients with CC who underwent colorectal resection between January 2000 and December 2018 were reviewed, and the data were gathered from a prospectively maintained database. Patients were divided into 2 groups according to the extent of mesenteric resection, the extensive mesenteric excision (EME) group and the limited mesenteric excision (LME) group. Outcomes including early postoperative morbidities and surgical recurrence were compared between the 2 groups.

RESULTS

Of the 126 patients included, 60 were in the LME group and 66 in the EME group. There was no significant difference between the 2 groups in early postsurgical outcomes except the intraoperative blood loss was increased in the LME group (P = 0.002). Patients in the EME group had a longer postoperative surgical recurrence-free survival time when compared with those in the LME group (P = 0.01). LME was an independent predictor of postoperative surgical recurrence (hazard ratio 2.67, 95% confidence interval 1.04-6.85, P = 0.04). This was further confirmed in the subgroup analysis of patients undergoing colorectal resection and anastomosis (hazard ratio 2.83, 95% confidence interval 1.01-7.96, P = 0.048).

DISCUSSION

In patients undergoing surgery for CC, inclusion of the mesentery is associated with similar short-term outcomes and improved long-term outcomes compared with those seen when the mesentery is retained.

Review article: distinctions between ileal and colonic Crohn's disease: from physiology to pathology

BACKGROUND

Ileal and colonic Crohn's disease seem to be two separate entities.

AIMS

To describe the main physiological distinctions between the small and the large intestine and to analyse the differences between ileal and colonic Crohn's disease.

METHODS

The relevant literature was critically examined and synthesised.

RESULTS

The small and large intestine have fundamental distinctions (anatomy, cellular populations, immune defence, microbiota). The differences between ileal and colonic Crohn's disease are highlighted by a heterogeneous body of evidence including clinical features (natural history of the disease, efficacy of treatments, and monitoring), epidemiological data (smoking status, age, gender) and biological data (genetics, microbiota, immunity, mesenteric fat). However, the contribution of these factors to disease location remains poorly understood.

CONCLUSION

The classification of ileal and colonic Crohn's disease as distinct subphenotypes is well supported by the literature. Understanding of these differences could be exploited to develop more individualised patient care.

5-Aminosalicylic Acid Prevents Disease Behavior Progression and Intestinal Resection in Colonic and Ileocolonic Crohn's Disease Patients: A Retrospective Study

BACKGROUND AND AIMS

The efficacy of 5-aminosalicylic acid (5-ASA) in the long-term outcome of Crohn's disease (CD) patients was uncertain. This study aimed to evaluate the efficacy of the 5-ASA in preventing disease behavior progression and intestinal resection in CD patients.

METHODS

CD patients were prospectively enrolled from January 2008 to September 2019 in Xijing Hospital. Disease behavior progression was defined as the development of stricturing (B2) or penetrating disease (B3) in patients with nonstricturing/nonpenetrating disease (B1) at diagnosis. Cox regression analyses were used to investigate the associations between disease location progression, disease behavior progression, and intestinal resection and multiple covariates.

RESULTS

In total, 122 CD patients were followed up for 4.3 years. At the time of diagnosis, disease location was ileal in 19.7% (24/122), colonic in 41.0% (50/122), and ileocolonic in 39.3% (48/122). A total of 87 (71.3%) patients had B1 at diagnosis. The disease behavior progression and intestinal resection rates were 42.5% (37/87) and 29.5% (36/122). The use of 5-ASA reduced the risk of disease behavior progression (HR 0.30, 95% CI 0.14-0.61, P = 0.001) and intestinal resection (HR 0.33, 95% CI 0.17-0.90, P = 0.027) in colonic and ileocolonic CD patients. Patients who presented with ileal disease at diagnosis did not have the same protective effects when taking 5-ASA (P > 0.05).

CONCLUSIONS

The use of 5-ASA could improve the long-term outcome of CD patients with colon involvement. The result emphasized the importance of early use of 5-ASA in the daily management of colonic involved CD.

Randomized Trial of Ciprofloxacin Doxycycline and Hydroxychloroquine Versus Budesonide in Active Crohn's Disease

BACKGROUND

Increased mucosa-associated E. coli are present in Crohn's disease, but their role in pathogenesis is uncertain.

AIMS

To assess efficacy and safety of an antibiotic/hydroxychloroquine combination effective against E. coli inside macrophages.

METHODS

Adults with moderately active disease (CDAI > 220-450 plus C reactive protein ≥ 5 mg/l and/or fecal calprotectin > 250 μg/g) were randomized to receive (open-label) oral budesonide (Entocort CR 9 mg/day 8 weeks, 6 mg/day 2 weeks, 3 mg/day 2 weeks) or oral ciprofloxacin 500 mg bd, doxycycline 100 mg bd, hydroxychloroquine 200 mg tds for 4 weeks, followed by doxycycline 100 mg bd and hydroxychloroquine 200 mg tds for 20 weeks. Primary endpoints were remission (CDAI ≤ 150) at 10 weeks, remission maintained to 24 weeks, and remission maintained to 52 weeks. Patients not responding (CDAI fall by > 70) by 10 weeks were invited to crossover onto the alternative therapy.

RESULTS

Fifty-nine patients were recruited across 8 sites. Including crossover, 39 patients received antibiotics/hydroxychloroquine and 39 received budesonide. At 10 weeks, 24 weeks, and 52 weeks on initial therapy, only 2/27, 2/27, and 1/27 were in remission on antibiotics/hydroxychloroquine compared with 8/32, 1/32, and 1/32 on budesonide (P = 0.092 at 10 weeks). Withdrawals by 10 weeks due to adverse events were seen in 15 receiving antibiotics/hydroxychloroquine and 6 budesonide. Results including crossover were more promising with 9/24 patients receiving antibiotics/hydroxychloroquine per protocol in remission by 24 weeks. No correlation was seen between response to antibiotics/hydroxychloroquine and ASCA/OmpC antibody status or disease location.

CONCLUSION

Overall results with this antibiotic/hydroxychloroquine combination were unimpressive, but long-term remission is seen in some patients and justifies further study.

Location is important: differentiation between ileal and colonic Crohn's disease

Crohn's disease can affect any part of the gastrointestinal tract; however, current European and national guidelines worldwide do not differentiate between small-intestinal and colonic Crohn's disease for medical treatment. Data from the past decade provide evidence that ileal Crohn's disease is distinct from colonic Crohn's disease in several intestinal layers. Remarkably, colonic Crohn's disease shows an overlap with regard to disease behaviour with ulcerative colitis, underlining the fact that there is more to inflammatory bowel disease than just Crohn's disease and ulcerative colitis, and that subtypes, possibly defined by location and shared pathophysiology, are also important. This Review provides a structured overview of the differentiation between ileal and colonic Crohn's disease using data in the context of epidemiology, genetics, macroscopic differences such as creeping fat and histological findings, as well as differences in regard to the intestinal barrier including gut microbiota, mucus layer, epithelial cells and infiltrating immune cell populations. We also discuss the translation of these basic findings to the clinic, emphasizing the important role of treatment decisions. Thus, this Review provides a conceptual outlook on a new mechanism-driven classification of Crohn's disease.

Features and Outcomes of Children with Ulcerative Colitis who Undergo a Diagnostic Change: A Single-Center Experience

PURPOSE

A change in diagnosis from ulcerative colitis (UC) to Crohn's disease (CD) has been reported in pediatric inflammatory bowel disease; however, only a few clinical characteristics and predictors of this diagnostic change have been reported. We aimed to describe the clinical characteristics of patients with UC who underwent a change in diagnosis to CD and identify variables associated with the change.

METHODS

The medical records of pediatric patients with UC who were followed up at the National Center for Child Health and Development between 2006 and 2019 were retrospectively reviewed. Clinical data on disease phenotype, laboratory parameters, endoscopic findings, and treatment of patients whose diagnosis changed to CD (cCD) were compared to those of patients whose diagnosis remained UC (rUC).

RESULTS

Among the 111 patients initially diagnosed with UC, 11 (9.9%) patients were subsequently diagnosed with CD during follow-up. There was no significant difference between the cCD and rUC groups in terms of sex, age at initial diagnosis, and the extent and severity of disease at initial diagnosis. Albumin and hemoglobin levels were significantly lower in the cCD group than in the rUC group. The proportion of patients who required biologics was significantly higher in the cCD group than in the rUC group (p<0.05).

CONCLUSION

Approximately 10% children initially diagnosed with UC were subsequently diagnosed with CD. Hypoalbuminemia and anemia at initial diagnosis and use of biologics could be predictors of this diagnostic change.

Long term remission after ileorectal anastomosis in Crohn's colitis

BACKGROUND

Crohn's disease represents a heterogeneous entity, but its location tends to be relatively stable overtime. For extensive refractory Crohn's colitis, ileorectal anastomosis after colectomy is an engaging option, since the necessity of a permanent ileostomy is avoided.

AIMS

In our study, the long-term outcome of two groups of patients with Crohn's colitis who underwent colectomy and ileorectal anastomosis was compared. The first group had isolated colonic Crohn's disease without rectal involvement and perianal disease, while the second group included patients who had rectal and/or ileal involvement, with or without perianal disease.

METHODS

Between 1996 and 2016, in a single IBD tertiary center, 80 patients with a history of colectomy and ileorectal anastomosis for refractory Crohn's colitis were retrospectively identified.

RESULTS

Recurrence of disease was diagnosed in 57/64 of patients with Crohn's colitis with rectal and/or ileal and/or perianal involvement compared with 1/16 of patients with isolated Crohn's colitis without rectal and perianal disease in a median time of recurrence of 2 years (IQR 1-6 years, minimum to maximum, 1-18 years, p < 0.001). Only 6 patients (7,5%) underwent definitive end ileostomy without proctectomy (1 in the noIRP group and 5 in the IRP group).

CONCLUSION

Our data suggest that colectomy with ileorectal anastomosis may represent a curative option in patients with refractory isolated colitis without rectal and perianal involvement.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

Introduction

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

Materials/Methods

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

Results

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

Conclusions

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

Down-Regulation of Colonic ACE2 Expression in Patients With Inflammatory Bowel Disease Responding to Anti-TNF Therapy: Implications for COVID-19

Background and Aims: Angiotensin-converting enzyme II (ACE2) is the key molecule for understanding the pathophysiology of COVID-19. The risk of COVID-19 and impact of immunosuppressive treatment on disease course in patients with inflammatory bowel disease (IBD) remain controversial. We aimed to determine the change of intestinal ACE2 expression before and after biologics treatment including anti-tumor necrosis factor α (anti-TNFα), anti-integrin, and anti-interleukin (IL)12/23 in IBD patients. Methods: We analyzed the ACE2 expression through the public database of paired intestinal biopsies from IBD patients before and after biologic therapy. Change of ACE2 RNA and protein expression were validated in two independent cohorts (Birmingham cohort and Guangzhou cohort). The correlation between ACE2 expression and disease activity was also analyzed. Results: Mining information from the GEO database showed that compared with healthy control, intestinal ACE2 expression was downregulated in ileum of CD patients, while upregulated in colon of both CD and UC patients. Colonic ACE2 RNA expression was decreased significantly in patients responding to anti-TNFα but not anti-integrin and anti-IL12/23, which was validated in the Birmingham cohort. Using the Guangzhou cohort including 53 patients matched by pre- and post-anti-TNFα therapy, colonic ACE2 protein expression was significantly downregulated after anti-TNFα treatment in responders (P < 0.001) rather than non-responders. Colonic ACE2 expression was significantly higher in patients with severe histologically active disease compared with those with moderate (P < 0.0001) and mild (P = 0.0002) histologically active disease. Conclusion: Intestinal inflammation influences the expression of intestinal ACE2 in IBD patients, with different alterations in the ileum and colon. Colonic ACE2 expression was downregulated after anti-TNFα therapy in IBD patients responding to treatment. This might provide new clues regarding the risk of SARS-CoV-2 infection and the potential benefit of sustaining anti-TNFα treatment in patients with IBD.

Classifying Crohn's disease into colon-involving versus non-colon-involving groups is a better predictor of clinical outcomes than the Montreal classification

BACKGROUND

A suitable disease classification is essential for individualized therapy in patients with Crohn's disease (CD). Although a potential mechanistic classification of colon-involving and non-colon-involving disease was suggested by recent genetic and microbiota studies, the clinical implication has seldom been investigated. We aimed to explore the association of this colonic-based classification with clinical outcomes in patients with CD compared with the Montreal classification.

METHODS

This was a retrospective study of CD patients from a tertiary referral center. Patients were categorized into colon-involving and non-colon-involving disease, and according to the Montreal classification. Clinico-demographic data, medications, and surgeries were compared between the two classifications. The primary outcome was the need for major abdominal surgery.

RESULTS

Of 934 patients, those with colonic involvement had an earlier median (interquartile range) age of onset [23.0 (17.0-30.0) versus 26.0 (19.0-35.0) years, p = 0.001], higher frequency of perianal lesions (31.2% versus 14.5%, p < 0.001) and extraintestinal manifestations (21.8% versus 14.5%, p = 0.010), but lower frequency of stricture (B2) (16.3% versus 24.0%, p = 0.005), than those with non-colon-involving disease. Colon-involving disease was a protective factor against major abdominal surgery [hazard ratio, 0.689; 95% confidence interval (CI), 0.481-0.985; p = 0.041]. However, patients with colon-involving CD were more prone to steroids [odds ratio (OR), 1.793; 95% CI, 1.206-2.666; p = 0.004] and azathioprine/6-mercaptopurine (AZA/6-MP) treatment (OR, 1.732; 95% CI, 1.103-2.719; p = 0.017) than were patients with non-colon-involving disease. The Montreal classification was not predictive of surgery or steroids and AZA/6-MP treatment.

CONCLUSION

This study supports the rationale for disease classification based on the involvement of colon. This new classification of CD is a better predictor of clinical outcomes than the Montreal classification.

Appraisal of the PIBD-classes Criteria: A Multicentre Validation

INTRODUCTION

The PIBD-classes criteria were developed to standardise the classification of children with inflammatory bowel disease [IBD], from Crohn's disease [CD], through IBD-unclassified [IBD-U], to typical ulcerative colitis [UC]. We aimed to further validate the criteria and to explore possible modifications.

METHODS

This was a multicentre retrospective cohort study of children diagnosed with IBD with at least 1 year of follow-up. Clinical, radiological, endoscopic, and histological data were recorded at diagnosis and latest follow-up, as well as the 23 items of the PIBD-classes criteria. The PIBD-classes criteria were assessed for redundant items, and a simplified algorithm was proposed and validated on the original derivation cohort from which the PIBD-classes algorithm was derived.

RESULTS

Of the 184 included children [age at diagnosis 13 ± 3 years, 55% males], 122 [66%] were diagnosed by the physician with CD, 17 [9%] with IBD-U, and 45 [25%] with UC. There was high agreement between physician-assigned and PIBD-classes generated diagnosis for CD [93%; eight patients moved to IBD-U] and for UC [84%; six moved to IBD-U and one to CD]. A simplified version of the algorithm with only 19 items is suggested, with comparable performance to the original algorithm [81% sensitivity and 81% specificity vs 78% and 83% for UC; and 79% and 95% vs 80% and 95% for CD, respectively].

CONCLUSIONS

The PIBD-classes algorithm is a useful tool to facilitate standardised objective classification of IBD subtypes in children. A modified version of the PIBD-classes maintains accuracy of classification with a simplified algorithm.

Crohn's disease at radiological imaging: focus on techniques and intestinal tract

Over recent years, inflammatory bowel diseases have become an issue of increased attention in daily clinical practice, due to both a rising incidence and improved imaging capability in detection. In particular, the diagnosis of Crohn's disease is based on clinical picture, laboratory tests and colonoscopy with biopsy. However, colonoscopic evaluation is limited to the mucosal layer. Thus, imaging modalities play a pivotal role in enriching the clinical picture, delivering information on intestinal and extraintestinal involvement. All the imaging modalities can be employed in evaluation of Crohn's disease patients, each of them with specific strengths as well as limitations. In this wide selection, the choice of a proper diagnostic framework can be challenging for the clinician. Therefore, the aim of this work is to offer an overview of the different imaging techniques, with brief technical details and diagnostic potential related to each intestinal tract.