Crohn's Disease Research Articles

Analysis of Sociodemographic and Clinical Characteristics of Inflammatory Bowel Disease in Catalonia Based on SIDIAP

Background/Objectives: The increasing global prevalence of inflammatory bowel disease (IBD) presents significant challenges to healthcare systems. Our objective was to identify the sociodemographic and clinical characteristics of IBD patients in Catalonia. Methods: A cross-sectional analytical study was carried out on patients diagnosed with IBD in Catalonia (2021). The database of the Information System for the Development of Research in Primary Care of Catalonia was used. Results: In Catalonia, the prevalence of IBD was 474 cases per 100,000 people (pcm), with an average diagnosis age of 42.9 years. Crohn’s disease (CD) represented 34.34% of cases, and 21.2% were smokers and 1% were alcoholics. Nutritional status showed 3% underweight, 36.2% overweight, and 20% obese, with only 0.27% diagnosed as malnutrition. Mental health issues are notable; 36,531 pcm patients were diagnosed with anxiety and 14,656 pcm with depression, and 8.24% had a high risk of mortality measured by the Charlson index. The most prevalent vaccine-preventable infections were influenza (19,356 pcm), herpes zoster (8099 pcm), and varicella zoster (6946 pcm), with 4.56% of patients requiring hospitalisation for one of these reasons and 32.8% of patients for IBD complications, with higher rates observed in cases of CD. Conclusions: The prevalence of IBD was high, especially in urban areas, and patients showed a relevant number of comorbidities. IBD requires a comprehensive evaluation and interdisciplinary management to improve disease control.

Developing a Reproducible Radiomics Model for Diagnosis of Active Crohn's Disease on CT Enterography Across Annotation Variations and Acquisition Differences.

To systematically identify radiomics features on CT enterography (CTE) scans which can accurately diagnose active Crohn's disease across multiple sources of variation. Retrospective study of CTE scans curated between 2013 and 2015, comprising 164 subjects (65 male, 99 female; all patients were over the age of 18) with endoscopic confirmation for the presence or absence of active Crohn's disease. All patients had three distinct sets of scans available (full and reduced dose, where the latter had been reconstructed via two different methods), acquired on a single scanner at a single institution. Radiomics descriptors from annotated terminal ileum regions were individually and systematically evaluated for resilience to different imaging variations (changes in dose/reconstruction, batch effects, and simulated annotation differences) via multiple reproducibility measures. Multiple radiomics models (by accounting for each source of variation) were evaluated in terms of classifier area under the ROC curve (AUC) for identifying patients with active Crohn's disease, across separate discovery and hold-out validation cohorts. Radiomics descriptors selected based on resiliency to multiple sources of imaging variation yielded the highest overall classification performance in the discovery cohort (AUC = 0.79 ± 0.04) which also best generalized in hold-out validation (AUC = 0.81). Performance was maintained across multiple doses and reconstructions while also being significantly better (p < 0.001) than non-resilient descriptors or descriptors only resilient to a single source of variation. Radiomics features can accurately diagnose active Crohn's disease on CTE scans across multiple sources of imaging variation via systematic analysis of reproducibility measures. Clinical utility and translatability of radiomics features for diagnosis and characterization of Crohn's disease on CTE scans will be contingent on their reproducibility across multiple types and sources of imaging variation.

Unveiling the intrinsic role of malnutrition in patients with Crohn's disease undergoing major surgery using entropy balancing weighting analysis.

The negative role of malnutrition in patients with Crohn's disease is known; however, many coexisting disease-related factors could cause misinterpretation of the real culprit. This study aimed to describe the role of malnutrition using a novel methodology, entropy balancing. This was a retrospective analysis of consecutive patients undergoing elective major surgery for Crohn's disease, preoperatively screened following the European Society for Clinical Nutrition guidelines. Two-step entropy balancing was applied to the group of malnourished patients to obtain an equal cohort having a null or low risk of malnutrition. The first reweighting homogenised the cohorts for non-modifiable confounding factors. The second reweighting matched the two groups for modifiable nutritional factors, assuming successful treatment of malnutrition. The entropy balancing was evaluated using the d-value. Postoperative results are reported as mean difference or OR, with a 95 % CI. Of the 183 patients, 69 (37·7 %) were at moderate/high risk for malnutrition. The malnourished patients had lower BMI (d = 1·000), Hb (d = 0·715), serum albumin (d = 0·981), a higher lymphocyte count (d = 0·124), Charlson Comorbidity Index (d = 0·257), American Society of Anaesthesiologists (d = 0·327) and Harvey-Bradshaw scores (d = 0·696). Protective loop ileostomy was more frequently performed (d = 0·648) in the malnourished group. After the first reweighting, malnourished patients experienced a prolonged length of stay (mean difference = 1·9; 0·11, 3·71, days), higher overall complication rate (OR 4·42; 1·39, 13·97) and higher comprehensive complication index score (mean difference = 8·9; 2·2 15·7). After thesecond reweighting, the postoperative course of the two groups was comparable. Entropy balancing showed the independent role of preoperative malnutrition and the possible advantages obtainable from a pre-habilitation programme in Crohn's disease patients awaiting surgery.

Evaluation of the Effectiveness and Safety of Mesenchymal Stem Cell Treatment in Fistulising Crohn's Disease: An International Real-Life Retrospective Multicentre Cohort Study.

Perianal fistulas of Crohn's disease (CD) create a significant burden on patients' lives. However, the efficacy and safety of adipose-derived mesenchymal stem cell treatment are contradicting, and real-world evidence is lacking. To examine the usability of darvadstrocel therapy in managing perianal CD. We enrolled patients with CD and perianal fistulas in this retrospective multicenter study. The primary outcome was perianal clinical remission (defined as all treated fistulas closed) at weeks 26 and 52. Secondary outcomes were clinical response rates (≥ 1 fistulas closed), perianal activity (PDAI), patient satisfaction, and adverse events. Data were recorded at baseline and weeks 12, 26 and 52. Prediction of primary outcomes was performed by logistic regression. Overall, among 223 patients (male/female ratio: 0.48), perianal clinical remission was achieved in 78.2% and 62.3% until weeks 26 and 52. Baseline PDAI score (OR 0.75), number of fistulas (OR 0.28) and the number of weeks after preparation for surgery (OR 0.98) were associated with treatment failure. The clinical response rates were 84.8% and 79.8% at weeks 26 and 52. Improvement of subjective perianal symptoms was achieved in 77.8% and 78.4% of patients, respectively. Adverse events occurred in 13.5% of patients; perianal abscesses and proctalgia were the most frequently reported. Effectiveness data were higher than in clinical trials. The safety profile was reassuring, and patients' satisfaction was high. Appropriate patient selection, fistula preparation and expertise may help to achieve treatment success.

Microfibrillar-associated protein 4 as a predictive biomarker of treatment response in patients with chronic inflammatory diseases initiating biologics: secondary analyses based on the prospective BELIEVE cohort study.

Currently, there are no reliable biomarkers for predicting treatment response in chronic inflammatory diseases (CIDs). To determine whether serum microfibrillar-associated protein 4 (MFAP4) levels can predict the treatment response to biological therapy in patients with CIDs. The BELIEVE study was originally designed as a prospective, multi-center cohort study of 233 patients with either rheumatoid arthritis, psoriatic arthritis, psoriasis, axial spondyloarthritis, Crohn's disease, or ulcerative colitis, initiating treatment with a biologic agent (or switching to another). Clinical assessment and blood sample collection were performed at baseline and 14-16 weeks after treatment initiation. The primary analyses included participants with available blood samples at baseline; missing data were handled as non-responders. The patients were stratified into the upper tertile of serum MFAP4 (High MFAP4) versus a combined category of middle and lower tertiles (Other MFAP4). The primary outcome was the proportion of patients with clinical response to biologic therapy after 14-16 weeks. 211 patients were included in the primary analysis population. The mean age was 43.7 (SD: 14.8) years, and 120 (59%) were female. Positive treatment response was observed in 41 (59%) and 69 (49%) for High MFAP4 and Other MFAP4, respectively. When adjusting for pre-specified variables (CID, age, sex, smoking status, and BMI), the adjusted OR was 2.28 (95% CI: 1.07 to 4.85) for a positive treatment outcome in the High MFAP4 group. A high MFAP4 status before initiating biological treatment is associated with a positive clinical response, when adjusting for confounding factors.

Abdominal Pain in Inflammatory Bowel Disease-Epidemiology, Pathophysiology, and Management: A Narrative Review.

Abdominal pain is a major symptom of inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, and has a significant impact on patients' quality of life. Given the evolving understanding of IBD pathology and management strategies, there is an urgent need to review the recent research findings. In this review, we have analyzed the epidemiology, pathophysiology, and management of abdominal pain in IBD over the past decade. We draw on the current literature and highlight emerging trends, challenges, and advances in this field. By synthesizing key findings, this review provides insights into the complex interplay between abdominal pain, disease progression, and therapeutic interventions for IBD.

Exploring photobiomodulation in the management of bowel diseases: a concise critical review.

The complexity of the gastrointestinal system plays a crucial role in coordinating essential processes such as digestion, nutrient absorption, and waste elimination. inflammatory bowel diseases (IBD) pose significant treatment challenges due to their complex aetiology and varied symptoms. Conventional therapeutic approaches often involve pharmacological interventions, which may have side effects and limited efficacy. Photobiomodulation (PBM), also known as low-level light therapy, has emerged as a promising therapeutic or adjunctive alternative in the treatment of intestinal diseases. The search was conducted in the MEDLINE database via PubMed, SCOPUS, covering the period from 1990 to 2024. A total of 72 studies were selected, of which 9 focused on inflammatory bowel diseases IBD, including ulcerative colitis (UC) and Crohn's disease (CD). Among these studies, 1 was clinical protocol while eight experimental. The results showed that PBM has a significant positive effect in IBD studies in rats, with reduction of intestinal inflammation, improvement of mucosal integrity, and modulation of the immune response. However, no clinical studies were found necessary to obtain results and establish effective and safe treatment protocols. Nevertheless, PBM holds potential as a non-invasive and complementary therapeutic approach for managing IBD, offering new perspectives for the treatment of chronic intestinal diseases. Therefore, this brief review emphasizes the need to transition from preclinical research to clinical research on this topic and highlights the scarcity of clinical studies.

Advancing perioperative optimization in Crohn's disease surgery with machine learning predictions

Advancing perioperative optimization in Crohn's disease surgery with machine learning predictions

Self-Efficacy, Patient Activation, and the Burden of Inflammatory Bowel Disease on Patients' Daily Lives.

The effective management of inflammatory bowel disease (IBD) requires complex self-management behaviors. Both patient activation (the degree to which patients are willing and able to engage in care) and self-efficacy (one's confidence in performing certain behaviors) are thought to play an important role in chronic disease self-management, but patient activation is a broad concept that can be more difficult to precisely target than self-efficacy. We aimed to describe the relationship between patient activation, self-efficacy, and the burden of IBD on patients' daily lives. Patients with IBD were recruited from a single center to complete a survey including the Patient Activation Measure (PAM-13®), the IBD Self-Efficacy Scale (IBD-SES), and an IBD-specific patient-reported outcome measure. Using multivariable linear regression, we examined the relationship between IBD burden, self-efficacy, and patient activation, adjusting a priori for age, gender, IBD type, IBD medications, active corticosteroid use, anxiety, and depression. We performed a post-hoc mediation analysis to examine self-efficacy as a potential mediator in the relationship between patient activation and the burden of IBD on patient's daily lives. A total of 132 patients with IBD completed the survey (59% Crohn's disease, 41% ulcerative colitis, 52% female). Higher levels of patient activation and higher levels of self-efficacy were each associated with lower IBD burden (patient activation: ß = -1.9, p < 0.001, self-efficacy: ß = -2.6, p < 0.001). Post hoc mediation analysis confirmed that the relationship between patient activation and daily IBD burden was mediated by self-efficacy (Average Causal Mediation Effect = -1.00, p < 0.001, proportion mediated = 0.62, p < 0.001). The relationship between patient activation and IBD burden is highly mediated by self-efficacy, suggesting that self-efficacy could be a more precise target for intervention. Future studies could focus on targeting self-efficacy to build individuals' confidence in IBD self-management and testing of IBD-tailored self-management programs to ultimately improve disease outcomes.

The Effectiveness of Risankizumab as Induction Therapy for Crohn's Disease: Data From the Sicilian Network for Inflammatory Bowel Diseases.

Lay Summary This multicentre cohort study showed that Risankizumab is an effective induction therapy in patients with Crohn’s disease, and that the best results are obtained when Risankizumab is used as second-line therapy following a previous failure with a TNF inhibitor.

Оценка нутритивного статуса и рисков его нарушения у детей с болезнью Крона: одномоментное исследование

Children with Crohn's disease (CD) are at high risk for developing nutritional deficiencies. According to studies in adult patients with CD, loss of lean and skeletal muscle mass and decreased bone mineral density (BMD) are unfavorable prognostic factors for the course of the disease; among children, the prevalence of these changes has not been sufficiently studied as yet. The purpose of this research was to study the frequency and correlation between disorders of body composition and decreased bone mineral density in children with CD. Materials and methods used: medical records of 163 aged 5 to 17 y/o with a confirmed CD diagnosis were assessed for the risk of nutritional deficiency using STRONGkids screening tool, anthropometric parameters, body composition with bioimpedance measurements as well as the disease activity index with PCDAI and endoscopic activity with SES-CD. BMD was assessed in 145 using densitometry. Results: depending on the degree of risk of malnutrition, children were divided into 2 groups as follows: G1 with high and G2 with moderate risks for malnutrition. G1 patients had significantly lower values of both anthropometric indices (Z-scores BMI/age, mid-upper arm circumference/age) and lean and skeletal muscle mass (p&lt;0.001) along with more severe course of CD according to PCDAI (p&lt;0.001). According to bioimpedansometry data, a significant increase in catabolic processes was found in G1 children as a decrease in Z-scores for both the phase angle (p&lt;0.001) and the active cell mass (p&lt;0.001). A decrease in BMD was detected in 9 (37%) of G1 and 26 (21.4%) of G2. A correlation was found between Z-scores lean body mass/age and BMD/age (p&lt;0.001, Rs=0.612). Among children with reduced BMD values, the indicators for BMI, lean, skeletal muscle and active cell mass according to bioimpedance measurements were significantly lower (p&lt;0.001). Conclusion: the data obtained during the study proposes high incidence of decreased bone mineral density along with pathological changes in body composition in children with CD. The use of STRONGkids tool to identify children at high risk of developing malnutrition, especially in the absence of the technical ability to conduct a detailed assessment of nutritional status with determination of body composition and BMD indicators, makes it possible to timely identify patients requiring individual nutritional support aiming to optimizing diets and, if necessary, prescribing addition of specialized food supplements.

Understanding disease-associated metabolic changes in human colon epithelial cells using i ColonEpithelium metabolic reconstruction.

The colon epithelium plays a key role in the host-microbiome interactions, allowing uptake of various nutrients and driving important metabolic processes. To unravel detailed metabolic activities in the human colon epithelium, our present study focuses on the generation of the first cell-type specific genome-scale metabolic model (GEM) of human colonic epithelial cells, named iColonEpithelium. GEMs are powerful tools for exploring reactions and metabolites at systems level and predicting the flux distributions at steady state. Our cell-type-specific iColonEpithelium metabolic reconstruction captures genes specifically expressed in the human colonic epithelial cells. The iColonEpithelium is also capable of performing metabolic tasks specific to the cell type. A unique transport reaction compartment has been included to allow simulation of metabolic interactions with the gut microbiome. We used iColonEpithelium to identify metabolic signatures associated with inflammatory bowel disease. We integrated single-cell RNA sequencing data from Crohn's Diseases (CD) and ulcerative colitis (UC) samples with the iColonEpithelium metabolic network to predict metabolic signatures of colonocytes between CD and UC compared to healthy samples. We identified reactions in nucleotide interconversion, fatty acid synthesis and tryptophan metabolism were differentially regulated in CD and UC conditions, which were in accordance with experimental results. The iColonEpithelium metabolic network can be used to identify mechanisms at the cellular level, and our network has the potential to be integrated with gut microbiome models to explore the metabolic interactions between host and gut microbiota under various conditions.

How Do Men Who Post Publicly on Social Media Author Themselves and Their Experiences of Crohn's Disease? A Dialogical Analysis of Three Cases.

Despite distinct sex- and gender-related differences in the presentation and manifestation of Crohn's disease (CD), little research to date has considered men's particular experiences. Whilst hegemonic masculine ideals have been reported to negatively impact men's mental and physical health, increasingly research has emphasized that men engage in a diverse range of practices, including those beneficial to health. One such practice is posting about their illness experiences on social media. The interactive nature of posting online means that a dialogical approach, based on a relational epistemology, is particularly useful. This study therefore asked: "How do men who post publicly on social media author themselves and their experiences of CD?" Three participants were recruited, all of whom had a diagnosis of CD, wrote a blog, and posted on other social networking sites (SNSs) about CD. Two resided in Canada and one in the United Kingdom. All were white. For each participant, 2years of multimodal social media data was downloaded. After screening, in-depth analysis was conducted using a dialogical approach focusing on three key dialogical concepts: genre, chronotope, and forms of authorship. The key findings emphasized the participants' different responses to the lack of predictability caused by CD and the different ways they used social media to gain a greater sense of control over their illness stories and identities, providing important insights into the interaction between masculine identities and illness. Finally, the potential deployment of such methods in future research and within therapeutic contexts was considered.

Early-Life Infections, Antibiotics and Later Risk of Childhood and Early Adult-Onset Inflammatory Bowel Disease: Pooled Analysis of Two Scandinavian Birth Cohorts.

Childhood antibiotic use has been associated with inflammatory bowel disease (IBD), although the potential contribution of infection frequency remains uncertain. To explore the association between early-life infections, antibiotics and IBD development. We used population-based data from ABIS (Sweden) and MoBa (Norway) cohorts following children from birth (1997-2009) until 2021. Prospectively collected questionnaires identified infection frequency (any, gastrointestinal and respiratory) and antibiotics (any, penicillin and non-penicillin) until age 3. IBD diagnosis required ≥ 2 records in national health registries. Cohort-specific hazard ratios (aHR), adjusted for parental education, smoking and IBD were estimated and pooled using a random-effects model. Antibiotic analyses were adjusted for infection frequency. There were 103,046 children (11,872 ABIS and 91,174 MoBa), contributing to 1,663,898 person-years of follow-up, during which 395 were diagnosed with IBD. The frequency of any infection at 0 to < 1 and 1 to < 3 years showed a pooled aHR of 1.01 (95% confidence interval [CI] = 0.96-1.07) and 1.00 (95% CI = 0.99-1.01) per additional infection for IBD. Adjusting for infections, any versus no antibiotics in the first year was associated with IBD (pooled aHR = 1.33 [95% CI = 1.01-1.76]). The aHR for additional antibiotic course was 1.17 (95% CI = 0.96-1.44), driven by penicillin (per additional course, aHR = 1.28 [95% CI = 1.02-1.60]). Although antibiotics at 1 to < 3 years did not show an association with IBD or Crohn's disease, non-penicillin antibiotics were associated with ulcerative colitis (per additional course, aHR = 1.95 [95% CI = 1.38-2.75]). Early-life antibiotic use was, a significant risk factor for childhood and early adult-onset IBD, independent of infection frequency.

Collagen Paste Injection in Crohn's Disease Perianal Fistula: Long-term Outcomes of a Pilot, Prospective Cohort Study.

Crohn's perianal fistula represents a challenging condition to treat. Sphincters-preserving surgical techniques are increasingly being adopted as repeated surgical procedures may lead to various degrees of incontinence. This prospective study aims to assess the long-term efficacy of collagen paste application in patients with simple and complex Crohn's perianal fistulas. Patients with Crohn's perianal fistula (simple or complex) and inactive luminal disease were enrolled. The fistula tract was treated by curettage and injection of acellular, porcine dermal collagen paste between 2019 and 2021. The primary endpoint was the clinical healing of the fistula at 12 and 24 months, defined as the absence of suppuration on clinical examination. The trial was preregistered on a public repository (ClinicalTrials.gov; NCT03776825). Fourteen patients were included in the study, ten patients (71%) had complex perianal fistula. All patients underwent previous fistula operations. Nine patients (64%) reached complete clinical remission at 12 months, two patients (14%) had a clinical recurrence six months after surgery, and three patients (21%) at 12 months follow-up. Three relapsed patients presented postoperative abscesses. Twelve patients (86%) were followed up at 24 months, no further clinical recurrences or complications were observed and the complete healing rate was 58%. No continence disturbances were recorded after collagen paste injection. The results suggest that collagen paste injection may represent a safe and effective option for Crohn's perianal fistulas, worth further investigation in larger trials.

Association of Childhood Abuse with Incident Inflammatory Bowel Disease.

A link between inflammatory bowel disease (IBD), stressful life events and psychological factors has previously been reported. Our objective was to examine the relationship between childhood emotional, physical, and sexual abuse and risk of IBD using a large cohort of female health professionals. We included participants in the Nurses' Health Study II who completed the Physical and Emotional Abuse Subscale of the Childhood Trauma Questionnaire and the Sexual Maltreatment Scale of the Parent-Child Conflict Tactics Scale in 2001. Diagnosis of IBD was determined by self-report and confirmed independently by two physicians through review of medical records. We used Cox proportional hazard modeling to estimate the risk of Crohn's disease (CD) and ulcerative colitis (UC) while adjusting for covariates. Among 68,167 women followed from 1989 until 2017, there were 146 incident cases of CD and 215 incident cases of UC. Compared to women with no history of abuse, the adjusted hazard ratios of CD were 1.16 (95% CI 0.67 - 2.02) for mild, 1.58 (95% CI 0.92 - 2.69) for moderate, and 1.95 (95% CI 1.22 - 3.10) for severe abuse (Ptrend = 0.002). We did not observe an association between childhood abuse and risk of UC. Women who reported early life severe abuse had an increased risk of CD. These data add to the growing body of evidence on the critical role of early life stressors in development of CD.

Development of an Educational Website for Patients With Cancer and Preexisting Autoimmune Diseases Considering Immune Checkpoint Blockers: Usability and Acceptability Study.

Patients with cancer and an underlying autoimmune disease who are considering immune checkpoint blockers (ICBs) need to know about the benefits and risks of severe immune-related adverse events and flares of the autoimmune condition. This study aims to develop and alpha test an educational website for patients with cancer. Learning topics, images, and website architecture (including flow and requirements) were developed and iteratively reviewed by members of a community scientist program, a patient advisory group, and content experts. Alpha testing was performed, measuring the site's usability using the Suitability Assessment of Materials and its acceptability using the Ottawa Acceptability Measure. The website included a home page; general information about ICBs; comprehensive modules on the benefits and risks of ICBs for patients with cancer and preexisting autoimmune diseases; general wellness information; and features such as a quiz, additional resources, and a glossary. For the alpha testing, 9 users assessed the newly developed website. Patient reviewers (n=5) had rheumatoid arthritis, Crohn disease, Sjogren syndrome, or vasculitis. Health care provider reviewers (n=4) were medical oncologists or rheumatologists. The median Suitability Assessment of Materials rating was 75 (IQR 70-79; range 0-100) for patients versus 66 (IQR 57-72; range 0-100) for providers (scores ≥70 indicate no substantial changes needed). Recommendations for improvement, mostly involving navigation and accessibility, were addressed. All participants expressed that the website was acceptable and balanced in terms of discussion of benefits and harms. Because half (2/4, 50%) of the providers suggested we increase the amount of information, we extended the content on the impact of having an autoimmune disease when considering ICB treatment, the probability of flares, and the management of flares in this context. The feedback led to minor revisions to enhance readability, navigation, and accessibility, ensuring the website's suitability as a decision-making aid. The newly developed website could become a supporting tool to facilitate patient-physician discussion regarding ICBs.

Early Biologic Treatment for Inflammatory Bowel Disease

This rapid review updates the evidence for early biologic treatment versus conventional step-up therapy for patients with luminal Crohn disease, fistulizing Crohn disease, or ulcerative colitis. Findings are based on 4 systematic reviews, 2 randomized controlled trials, and 3 updated clinical guidelines. Luminal Crohn Disease Three systematic reviews showed that early biologic treatment, initiated within 36 months of diagnosis, significantly improved clinical remission, mucosal healing, and reduced relapse rates, surgery needs, and disease progression compared to conventional strategies. Two randomized controlled trials found that early infliximab treatment led to better remission rates, quality of life, and safety outcomes compared with conventional treatment for both adults and children with newly diagnosed moderate-to-severe Crohn disease. These results are consistent with previous evidence suggesting that early biologic drugs improve clinical benefits compared with conventional strategies. Clinical guidelines generally recommend biologic drugs as third-line treatment. One guideline targets adults and children with severe, active Crohn disease, and another focuses on children and adolescents with luminal Crohn disease regardless of severity. Of these, 1 guideline recommends first-line biologics for high-risk pediatric patients. Fistulizing Crohn Disease One guideline recommends third-line infliximab for patients with active fistulizing Crohn disease who did not respond, did not tolerate or had a contraindication to conventional therapy. First-line anti–tumour necrosis factor therapy was only recommended for children and adolescents with fistulizing perianal Crohn disease. No evidence was identified for this population. Ulcerative Colitis In 1 systematic review, early biologics were found to be associated with a higher risk of colectomy. However, these findings should be interpreted with caution as they are based on evidence from 3 observational studies. One guideline recommends infliximab as a third-line option for acute severe cases contraindicated to or clinically inappropriate with ciclosporin.

Host-pathobiont interactions in Crohn's disease.

The mammalian intestine is colonized by trillions of microorganisms that are collectively referred to as the gut microbiota. The majority of symbionts have co-evolved with their host in a mutualistic relationship that benefits both. Under certain conditions, such as in Crohn's disease, a subtype of inflammatory bowel disease, some symbionts bloom to cause disease in genetically susceptible hosts. Although the identity and function of disease-causing microorganisms or pathobionts in Crohn's disease remain largely unknown, mounting evidence from animal models suggests that pathobionts triggering Crohn's disease-like colitis inhabit certain niches and penetrate the intestinal tissue to trigger inflammation. In this Review, we discuss the distinct niches occupied by intestinal symbionts and the evidence that pathobionts triggering Crohn's disease live in the mucus layer or near the intestinal epithelium. We also discuss how Crohn's disease-associated mutations in the host disrupt intestinal homeostasis by promoting the penetration and accumulation of pathobionts in the intestinal tissue. Finally, we discuss the potential role of microbiome-based interventions in precision therapeutic strategies for the treatment of Crohn's disease.

Types, behaviour and therapeutic requirements of inflammatory pouch disorders: Results from the RESERVO study of GETECCU

Background and AimsInflammatory pouch disorders exhibit a heterogeneous clinical spectrum and therapeutic requirements have not been properly studied. MethodsThis retrospective, multicentre study included ulcerative colitis patients with ileal pouch construction and were later diagnosed with an inflammatory pouch disorder between 1995 and 2020. Classifications, behaviour and therapies applied were recorded and compared in the long-term. ResultsOverall, 338 patients were recruited. The most common disorders were pouchitis (n = 258, 76%), Crohn's disease of the pouch (n = 55, 16%) and cuffitis (n = 25, 7%). Pouchitis presented mainly as chronic (65.2%) and recurrent (87%) forms. Crohn's disease manifested as stricturing/penetrating in 53% of cases and perianal disease in 42%. Patients received multiple therapies: 86% antibiotics, 42% steroids, 27% immunosuppressants, 43% biologics and 27% surgery. Compared with pouchitis, Crohn's disease of the pouch was characterised by a later diagnosis (99 vs. 55 months, p < 0.001) and greater needs for immunosuppressants (OR 3.53, 1.79–6.94, p < 0.0001), biologics (OR 5.45, 2.78–10.6, p < 0.0001) and surgeries (OR 2.65, 1.43–4.89, p < 0.001). ConclusionsChronic pouchitis is the most common pouch disorder presentation. These entities have diverse therapeutics requirements, particularly for Crohn's disease of the pouch.