Evaluating the pharmacokinetics of upadacitinib for the treatment of moderate-to-severe Crohn's disease.

INTRODUCTION: Janus kinases (JAK) are enzymes involved in signaling pathways that activate the immune system. Upadacitinib, an oral small molecule, is the first JAK inhibitor approved by FDA and EMA for the treatment of moderately to severely active Crohn's disease (CD), following successful phase II and III trials. Compared to other JAK inhibitors, upadacitinib has a high selectivity toward JAK1. This characteristic could improve its efficacy and safety. AREAS COVERED: This review provides an overview of the available knowledge on the pharmacokinetics of upadacitinib as induction and maintenance therapy for CD. EXPERT OPINION: The approval of newer targeted small molecules drug, including JAK inhibitors, marked a significant advancement in terms of effectiveness. In fact, the oral administration, the rapid absorption, the excellent bioavailability and the short serum time of maximum concentration are some of the advantages compared to biologics. The selective inhibition of JAK1 by upadacitinib allows for high efficacy while maintaining a reliable safety profile.

Difficult-to-treat inflammatory bowel disease: Effectiveness and safety of 4th and 5th lines of treatment.

BACKGROUND: Many patients with inflammatory bowel disease (IBD) have signs or symptoms of active disease despite multiple treatment attempts. This emerging concept is defined as difficult-to-treat IBD. AIM: The objective of this study was to investigate for the first time the treatment persistence, efficacy and safety of biologics or small molecules used in 4th or 5th line therapy. METHODS: We reviewed all consecutive patients with IBD treated at the Nancy University Hospital between July 2022 and April 2023 with the 4th or 5th line treatment for at least three months. The primary outcome was to assess the persistence rate of 4th and 5th line therapy. RESULTS: We enrolled 82 patients with IBD (4th line: 44; 5th line: 38). On Kaplan-Meier analysis, the duration of risankizumab, ustekinumab or vedolizumab therapy did not differ significantly (p > 0.05) as 4th and 5th line treatment. The restricted mean survival time analysis showed that the persistence rate of risankizumab was the highest as 4th line therapy (risankizumab vs. vedolizumab: 36.0 and 29.4 weeks, respectively, p = 0.008; risankizumab vs. ustekinumab: 36.0 and 32.8 weeks, respectively, p = 0.035). In multivariate regression, Crohn's disease diagnosis (Odd ratio 4.6; 95% confidence interval 1.7-12.4) was significantly associated with treatment persistence. CONCLUSION: In this first real-world setting, risankizumab could have a longer persistence rate as 4th line treatment for IBD than other agents. Persistence of biological agents was greater in Crohn's disease than in ulcerative colitis. More studies are needed to compare treatment efficacy in patients with difficult-to-treat IBD.

Positioning risankizumab in the treatment algorithm of moderate-to-severe Crohn's disease.

Risankizumab is a humanized monoclonal antibody that inhibits the p19 subunit of IL-23 cytokine. Recently it has been approved for the treatment of patients with moderate-to-severe Crohn's disease (CD). We conducted a scoping review to summarize the available data on risankizumab and to define its positioning in the treatment algorithm of CD. Pubmed, Embase and Scopus databases were searched up to Oct 31, 2023 to identify studies reporting efficacy and safety data of risankizumab in patients with CD. Risankizumab is an effective and safe drug for the management of patients with moderate-to-severe CD. It could be used as first-line therapy in biologic-naive patients and in patients who have previously failed other biological therapies.

When we eat the food is processed and absorbed by the gastrointestinal tract. Sometimes, in some people, the gastrointestinal tract gets inflamed, causing problems like tummy ache and diarrhea: this condition is called Crohn's disease. To help turn off this inflammation and make people with Crohn's disease feel better, there's a new treatment called risankizumab. Risankizumab binds to the proteins in the body that cause inflammation and blocks their effects. This helps to reduce gastrointestinal inflammation and relieve its symptoms. Scientific studies have shown that is effective, safe, and it starts working quickly. Patients using this treatment do not have to go to the hospital every time. After three times in the outpatient's clinic, they can continue the treatment comfortably at home using a small device that sticks to the body and administers the medicine.

Gut Microbiota Metabolites: Unveiling Their Role in Inflammatory Bowel Diseases and Fibrosis.

In recent years, there has been a growing focus on the intricate interplay between the gut microbiota and host health, specifically in the context of inflammatory bowel diseases (IBDs). The gut microbiota produces a diverse array of metabolites, influencing the host's immune response and tissue homeostasis. Noteworthy metabolites, such as short-chain fatty acids, bile acids, and indoles, exert significant effects on intestinal inflammation and fibrosis. This review integrates current research findings to clarify the mechanisms through which gut microbiota metabolites contribute to the progression of IBD and fibrosis, offering insights into potential therapeutic targets and strategies for managing these intricate gastrointestinal conditions. The unraveling of the complex relationship between gut microbiota metabolites and inflammatory processes holds promise for the development of targeted interventions that could lead to more effective and personalized treatment approaches for individuals affected by IBD and subsequent intestinal fibrosis.

Microbiota profiling in esophageal diseases: Novel insights into molecular staining and clinical outcomes.

Gut microbiota is recognized nowadays as one of the key players in the development of several gastro-intestinal diseases. The first studies focused mainly on healthy subjects with staining of main bacterial species via culture-based techniques. Subsequently, lots of studies tried to focus on principal esophageal disease enlarged the knowledge on esophageal microbial environment and its role in pathogenesis. Gastro Esophageal Reflux Disease (GERD), the most widespread esophageal condition, seems related to a certain degree of mucosal inflammation, via interleukin (IL) 8 potentially enhanced by bacterial components, lipopolysaccharide (LPS) above all. Gram- bacteria, producing LPS), such as Campylobacter genus, have been found associated with GERD. Barrett esophagus (BE) seems characterized by a Gram- and microaerophils-shaped microbiota. Esophageal cancer (EC) development leads to an overturn in the esophageal environment with the shift from an oral-like microbiome to a prevalently low-abundant and low-diverse Gram--shaped microbiome. Although underinvestigated, also changes in the esophageal microbiome are associated with rare chronic inflammatory or neuropathic disease pathogenesis. The paucity of knowledge about the microbiota-driven mechanisms in esophageal disease pathogenesis is mainly due to the scarce sensitivity of sequencing technology and culture methods applied so far to study commensals in the esophagus. However, the recent advances in molecular techniques, especially with the advent of non-culture-based genomic sequencing tools and the implementation of multi-omics approaches, have revolutionized the microbiome field, with promises of implementing the current knowledge, discovering more mechanisms underneath, and giving insights into the development of novel therapies aimed to re-establish the microbial equilibrium for ameliorating esophageal diseases..

Gut virome in inflammatory bowel disease and beyond.

OBJECTIVE: The gut virome is a dense community of viruses inhabiting the gastrointestinal tract and an integral part of the microbiota. The virome coexists with the other components of the microbiota and with the host in a dynamic equilibrium, serving as a key contributor to the maintenance of intestinal homeostasis and functions. However, this equilibrium can be interrupted in certain pathological states, including inflammatory bowel disease, causing dysbiosis that may participate in disease pathogenesis. Nevertheless, whether virome dysbiosis is a causal or bystander event requires further clarification. DESIGN: This review seeks to summarise the latest advancements in the study of the gut virome, highlighting its cross-talk with the mucosal microenvironment. It explores how cutting-edge technologies may build upon current knowledge to advance research in this field. An overview of virome transplantation in diseased gastrointestinal tracts is provided along with insights into the development of innovative virome-based therapeutics to improve clinical management. RESULTS: Gut virome dysbiosis, primarily driven by the expansion of Caudovirales, has been shown to impact intestinal immunity and barrier functions, influencing overall intestinal homeostasis. Although emerging innovative technologies still need further implementation, they display the unprecedented potential to better characterise virome composition and delineate its role in intestinal diseases. CONCLUSIONS: The field of gut virome is progressively expanding, thanks to the advancements of sequencing technologies and bioinformatic pipelines. These have contributed to a better understanding of how virome dysbiosis is linked to intestinal disease pathogenesis and how the modulation of virome composition may help the clinical intervention to ameliorate gut disease management.

The role of filgotinib in ulcerative colitis and Crohn's disease.

Filgotinib is an oral small molecule that selectively inhibits JAK1. It is already approved for the treatment of moderately to severely active ulcerative colitis (UC). Ongoing studies are evaluating the efficacy and safety of filgotinib in Crohn's disease (CD). The purpose of this review is to summarize the available data regarding filgotinib in the management of UC and CD. We used Pubmed, Embase and clinicaltrials.gov websites to search all available data and currently ongoing studies regarding the efficacy and safety of filgotinib in inflammatory bowel diseases. Filgotinib is an effective and safe drug for the management of biologic-naive and biologic-experienced patients with moderate-to-severe UC. The same efficacy results have not been achieved in CD.

Filgotinib is an oral medication that inhibits the activity of the JAK1 enzyme. It has received approval from the European Medicines Agency for the treatment of moderate-to-severe ulcerative colitis, a condition characterized by inflammation in the lower part of the digestive tract. Filgotinib has a rapid mechanism of action and is effective at relieving the symptoms of ulcerative colitis and maintaining this improvement. However, its use is recommended with caution in patients who have risk factors such as heart and blood vessel issues, active smoking, a history of cancer, or those who are elderly (over 65 years old), and only when there are no other viable treatment options available. Although filgotinib was also studied for managing moderate-to-severe Crohn's disease, a chronic inflammatory condition affecting the digestive system, it did not pass phase III clinical trials and will not be available for this indication.

Treat-to-Target and Regular Surveillance of Inflammatory Bowel Disease Are Associated with Low Incidence and Early-Stage Detection of Malignancies: A Retrospective Cohort Study.

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), increase the risk of malignancies, particularly colorectal cancer (CRC). We aimed to assess the incidence of malignancies in IBD patients managed using a treat-to-target approach and recommended surveillance. We retrospectively searched the electronic databases of two tertiary IBD centers in Milan from 2010 to 2019 for new diagnoses of malignancy in patients with pre-existing IBD. A total of 5239 patients with a follow-up of 19,820 years were included. In total, 71 malignancies were diagnosed in 70 patients (38 CD, 32 UC) with a mean age of 52.9 years, of whom 64% were former or active smokers. The annual incidence of all malignancies was 358 per 100,000 patient years (95% CI 275-444), and the standardized incidence rate (SIR) was 0.93 (95% CI 0.73-1.16). Gastrointestinal cancers were the most frequent (n = 17, 23.9%), in particular, CRC (n = 9), with an incidence of 45 per 100,000 (95% CI 15-74) and an SIR of 1.18 (95% CI 0.54-2.09). CRC occurred mainly in UC patients (6/8), while small bowel cancer was seen in CD patients (5/9). Melanoma and breast cancer (n = 8 each) were the most common non-GI cancers. No significant difference in incidence was found between CD or UC. Death occurred in nine patients (11%) and was due to cancer in eight of these cases, two of which were IBD-related. Most malignancies included in the surveillance were diagnosed at early (I-II) stages (20 vs. 4, p < 0.05). In patients with IBD, treat-to-target and strict surveillance were associated with a low incidence of cancer, similar to that of the general population, and the detection of malignancies at an early stage.

Leaving behind the Mucosa: Advances and Future Directions of Intestinal Ultrasound in Ulcerative Colitis.

Inflammatory Bowel Diseases (IBD), mainly Ulcerative Colitis (UC) and Crohn's Disease (CD), are disorders characterized by chronic inflammation with severe morbidity and long-term disabling quality of life outcomes. UC mainly affects the mucosal and sub-mucosal layers of the colon, without embracing the peri-intestinal structures. Considering the predominant mucosal location of UC inflammation, the implementation of transmural evaluation by cross-sectional imaging techniques, mainly Intestinal Ultrasound (IUS), has been left behind for ages, especially if compared to CD. Nevertheless, studies analyzing intestinal ultrasound parameters accuracy in disease activity detection reported a good-to-optimal correlation of IUS markers with colonic inflammation, suggesting comparable feasibility of IUS monitoring in UC as in CD. The easy-to-use, costless and point-of-care available status of IUS is therefore crucial in order to improve the diagnostic process and, according to the recent literature, to monitor the response to treatment leading to speeding up decision making and therapy adjustments. Recent studies have demonstrated the correlation between transmural healing in UC with favorable outcomes even in the long term. An evidence gap still exists in the assessment of the rectum, with trans-perineal ultrasound (TPUS) a potential answer to reach a more precise evaluation of rectal inflammation. Eventually, IUS is also increasingly showing promises in emergent or post-surgical UC settings, considering various efforts put in line to demonstrate its feasibility in predicting response to salvage therapy for surgery avoidance and in studying inflammation relapse after procto-colectomy with ileo-pouch-anal anastomosis (IPAA) creation.

Validation of a new optical diagnosis training module to improve dysplasia characterization in inflammatory bowel disease: a multicenter international study.

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) increases risk of dysplasia and colorectal cancer. Advanced endoscopic techniques allow for the detection and characterization of IBD dysplastic lesions, but specialized training is not widely available. We aimed to develop and validate an online training platform to improve the detection and characterization of colonic lesions in IBD: OPtical diagnosis Training to Improve dysplasia Characterization in Inflammatory Bowel Disease (OPTIC-IBD). METHODS: We designed a web-based learning module that includes surveillance principles, optical diagnostic methods, approach to characterization, and classifications of colonic lesions using still images and videos. We invited gastroenterologists from Canada, Italy, and the United Kingdom with a wide range of experience. Participants reviewed 24 educational videos of IBD colonic lesions, predicted histology, and rated their confidence. The primary endpoint was to improve accuracy in detecting dysplastic lesions after training on the platform. Furthermore, participants were randomized 1:1 to get additional training or not, with a final assessment occurring after 60 days. Diagnostic performance for dysplasia and rater confidence were measured. RESULTS: A total of 117 participants completed the study and were assessed for the primary endpoint. Diagnostic accuracy improved from 70.8% to 75.0% (P = .002) after training, with the greatest improvements seen in less experienced endoscopists. Improvements in both accuracy and confidence were sustained after 2 months of assessment, although the group randomized to receive additional training did not improve further. Similarly, participants' confidence in characterizing lesions significantly improved between before and after the course (P < .001), and it was sustained after 2 months of assessment. CONCLUSIONS: The OPTIC-IBD training module demonstrated that an online platform could improve participants' accuracy and confidence in the optical diagnosis of dysplasia in patients with IBD. The training platform can be widely available and improve endoscopic care for people with IBD. (Clinical trial registration number: NCT04924543.).

Recent advances in the use of ultrasound in Crohn's disease.

INTRODUCTION: A clear consensus exists on the role of IUS for the assessment and monitoring of Crohn's disease (CD) in the 'treat-to-target' strategy. AREAS COVERED: IUS is an accurate tool for the management of CD. It is noninvasive and well tolerated. IUS has good-to-optimal inter-operator reliability either for assessing disease activity or for evaluating treatment response, especially combining Bowel Wall Thickness (BWT) and Color Doppler Signals (CDS). IUS is able to evaluate transmural remission (TR), the ultimate goal of the 'treat-to-target' strategy. Several studies confirmed its accuracy in the assessment of the post-operative recurrence (POR). Thanks to recent advances in trans-perineal ultrasound technique (TPUS), it allows to characterize peri-anal disease and its complications. Small intestine contrast ultrasound (SICUS) and contrast-enhancement ultrasound (CEUS) may improve IUS performance, particularly in stricturing or penetrating CD. Ultrasound elastography (USE) is raising interest for its accuracy in differentiating CD phenotypes (fibrotic versus inflamed). EXPERT OPINION: IUS is a pivotal step in the management of CD, in early assessment as in therapeutic monitoring, with advantages of evaluating transmural response. Development and validation of novel ultrasound biomarkers of activity and fibrosis, especially those linked to advanced ultrasound techniques, are expected in the coming years.

Efficacy, Safety, and Concerns on Microbiota Modulation, Antibiotics, Probiotics, and Fecal Microbial Transplant for Inflammatory Bowel Disease and Other Gastrointestinal Conditions: Results from an International Survey.

The gut microbiota play a pivotal role in human health. Dysbiosis, alterations in microbiota composition and function, is associated with gastrointestinal disorders, including inflammatory bowel disease (IBD). This international survey aimed to assess physicians' experiences, perceptions, and practices related to microbiome modulation for gastrointestinal conditions, with a focus on IBD. Results from 142 healthcare professionals, predominantly gastroenterologists, confirmed a consensus on the relevance of the gut microbiota in IBD pathogenesis. However, the utilization of microbial composition analysis and probiotics in clinical practice was limited, primarily due to the lack of standardized guidelines and supporting evidence. Physicians held conflicting views on antibiotics, recognizing their potential for inducing remission but also causing flares in IBD. Respondents also had varying opinions on the efficacy of fecal microbiota transplantation (FMT) for different gastrointestinal conditions, with higher confidence in FMT effectiveness for irritable bowel syndrome with diarrhea, pouchitis, and ulcerative colitis. Concerns on FMT included uncertainty about effect duration, administration intervals, and conflicting evidence. Donor selection was believed to be a crucial factor in FMT outcomes. This survey highlights the need for further research and evidence-based guidelines to optimize the use of microbiome-based therapies in clinical practice. As our understanding of the gut microbiome continues to evolve, these insights will contribute to more informed and personalized approaches to managing gastrointestinal disorders.

Efficacy and Safety of S1P1 Receptor Modulator Drugs for Patients with Moderate-to-Severe Ulcerative Colitis.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that negatively impacts patients' quality of life. In the last decades, the therapeutic options available for the management of patients with moderate to severe UC have increased significantly, including not only biological drugs but also small molecules. However, there is a persistent need to develop new drugs that act on new targets while minimizing the risk of adverse events. Sphingosine-1-phosphate (S1P) is a membrane-derived lysophospholipid. The S1P gradient between tissues and the circulatory system has a key role in regulating the trafficking of immune cells as autoreactive B and T lymphocytes. S1P receptor modulators could be a safe and efficacious alternative mechanism for reducing inflammation in immune-mediated disorders, including UC, by reducing lymphocyte egress from the lymph nodes to the bloodstream. Several S1P receptor modulators have been developed and tested in UC. Ozanimod is already approved by Food and Drug Administration (FDA) and European Medical Agency (EMA), while etrasimod and VTX002 are still under approval. Oral administration route, rapidity and reliable safety profile are the main advantages of this class of drugs. The aim of this review is to summarize the available evidence for the efficacy, safety, and pharmacokinetics of ozanimod, etrasimod, and VTX002 in UC.

Difficult-to-treat inflammatory bowel disease: results from an international consensus meeting.

Many patients with inflammatory bowel disease (IBD) have persistent symptoms and disease activity despite the best available medical or surgical treatments. These patients are commonly referred to as having difficult-to-treat IBD and need additional therapeutic strategies. However, the absence of standard definitions has impeded clinical research efforts and comparisons of data. Under the guidance of the endpoints cluster of the International Organization for the Study of Inflammatory Bowel Disease, we held a consensus meeting to propose a common operative definition for difficult-to-treat IBD. 16 participants from 12 countries voted on 20 statements covering various elements of difficult-to-treat IBD, such as failure of medical and surgical treatments, disease phenotypes, and specific complaints from patients. "Agreement" was defined as at least 75% consensus. The group agreed that difficult-to-treat IBD is defined by the failure of biologics and advanced small molecules with at least two different mechanisms of action, or postoperative recurrence of Crohn's disease after two surgical resections in adults, or one in children. In addition, chronic antibiotic-refractory pouchitis, complex perianal disease, and comorbid psychosocial complications that impair disease management also qualified as difficult-to-treat IBD. Adoption of these criteria could serve to standardise reporting, guide enrolment in clinical trials, and help identify candidates for enhanced treatment strategies.

Inflammatory Bowel Diseases: Does One Histological Score Fit All?

Mucosal healing (MH) is the main treatment target in ulcerative colitis (UC) and Crohn's disease, and it is defined by the combination of complete endoscopic and histologic remission. The complete resolution of mucosal inflammation should be confirmed by histology but its assessment is not always univocal. Neutrophil infiltration represents the unique histological marker in discriminating the active vs. quiescent phases of the disease, together with crypt injuries (cryptitis and crypt abscesses), erosions, and ulcerations. On the contrary, basal plasmacytosis is not indicative of activity or the remission of inflammatory bowel diseases (IBDs) but instead represents a diagnostic clue, mostly at the onset. Several histological scoring systems have been developed to assess grade severity, particularly for UC. However, most are complex and/or subjective. The aim of this review was to summarize available scores, their characteristics and limitations, and to present the advantages of a simplified mucosa healing scheme (SHMHS) based on neutrophils and their distribution in the gut mucosa. Finally, we overview future developments including artificial intelligence models for standardization of disease assessments and novel molecular markers of inflammation with potential application in diagnostic practice.

Real-world use of endoscopic and histological indices in ulcerative colitis: Results of a global survey.

BACKGROUND: Treatment targets of ulcerative colitis (UC) have evolved to include not only endoscopic but also histologic remission. However, the concept of histological activity is still in its early days. We aimed to capture the attitudes toward UC histology and the uptake of standardized reporting of endoscopy and histology of UC in daily practice. METHODS: We conducted a cross-sectional survey of physicians involved in the care of inflammatory bowel disease worldwide. The survey included 21 questions divided into three sections. The first recorded demographics, specialty, and level of experience of participants; the second covered clinical practices and attitudes toward the use and reporting of endoscopy; and the third covered histology. RESULTS: In total, 359 participants from 60 countries and all levels of experience completed the survey. UC histology was used by nearly all respondents (90.5%) for initial diagnosis, by 72% to monitor disease course, by 62.4% to determine the microscopic extension, by 59.9% to confirm deep remission when considering to stop treatment, and 42.3% to increase/optimize treatment. Nevertheless 77.2% of participants reported that no standard histological index was available in their daily practice. Instead, endoscopy reports included the Mayo Endoscopic score in 90% of cases. The majority of respondents welcomed as useful or very useful an artificial intelligence system to automate scoring of endoscopy (69%) or histology (73%). CONCLUSION: UC histology reports are less standard than endoscopy reports, although most physicians consider histological activity useful when managing UC and would welcome artificial intelligence systems to automate endoscopic and histological scoring.

Advances in pharmacotherapy for ulcerative colitis: a focus on JAK1 inhibitors.

INTRODUCTION: Janus kinase (JAK) inhibitors are an emerging class of small-molecule drugs, providing targeted therapy for a variety of diseases, and have made their way into the treatment of armamentarium of ulcerative colitis (UC) in recent years. AREAS COVERED: This review focuses on the pharmacokinetics, safety, and efficacy of selective JAK1 inhibitors in the treatment of moderate-to-severe UC. The PubMed database and clinicaltrials.gov were consulted using keywords - further expanded in the methods section. The search was focused on full-text publications in English. No publication date restrictions were imposed. EXPERT OPINION: JAK1 inhibitors are small-molecule drugs used in the treatment of ulcerative colitis and other immune mediated inflammatory diseases. They are orally bioavailable and have a rapid mechanism of action and no immunogenicity. JAK inhibitors can be used for the management of both naïve patients and biological-experienced patients.Particular attention should be paid to elderly patients or those with cardiovascular or oncological risk factors, in whom JAK inhibitors should be recommended only if no alternatives are available. In addition, JAK inhibitors have the potential to be combined with other biological drugs or small molecules for the management of difficult-to-treat cases.

Artificial Intelligence Enabled Histological Prediction of Remission or Activity and Clinical Outcomes in Ulcerative Colitis.

BACKGROUND & AIMS: Microscopic inflammation has significant prognostic value in ulcerative colitis (UC); however, its assessment is complex with high interobserver variability. We aimed to develop and validate an artificial intelligence (AI) computer-aided diagnosis system to evaluate UC biopsies and predict prognosis. METHODS: A total of 535 digitalized biopsies (273 patients) were graded according to the PICaSSO Histologic Remission Index (PHRI), Robarts, and Nancy Histological Index. A convolutional neural network classifier was trained to distinguish remission from activity on a subset of 118 biopsies, calibrated on 42 and tested on 375. The model was additionally tested to predict the corresponding endoscopic assessment and occurrence of flares at 12 months. The system output was compared with human assessment. Diagnostic performance was reported as sensitivity, specificity, prognostic prediction through Kaplan-Meier, and hazard ratios of flares between active and remission groups. We externally validated the model in 154 biopsies (58 patients) with similar characteristics but more histologically active patients. RESULTS: The system distinguished histological activity/remission with sensitivity and specificity of 89% and 85% (PHRI), 94% and 76% (Robarts Histological Index), and 89% and 79% (Nancy Histological Index). The model predicted the corresponding endoscopic remission/activity with 79% and 82% accuracy for UC endoscopic index of severity and Paddington International virtual ChromoendoScopy ScOre, respectively. The hazard ratio for disease flare-up between histological activity/remission groups according to pathologist-assessed PHRI was 3.56, and 4.64 for AI-assessed PHRI. Both histology and outcome prediction were confirmed in the external validation cohort. CONCLUSION: We developed and validated an AI model that distinguishes histologic remission/activity in biopsies of UC and predicts flare-ups. This can expedite, standardize, and enhance histologic assessment in practice and trials.

Gut virome-colonising Orthohepadnavirus genus is associated with ulcerative colitis pathogenesis and induces intestinal inflammation in vivo.

OBJECTIVES: Ulcerative colitis (UC) is a chronic inflammatory disorder of unknown aetiology. Gut virome dysbiosis is fundamental in UC progression, although its role in the early phases of the disease is far from fully understood. Therefore, we sought to investigate the role of a virome-associated protein encoded by the Orthohepadnavirus genus, the hepatitis B virus X protein (HBx), in UC aetiopathogenesis. DESIGN: HBx positivity of UC patient-derived blood and gut mucosa was assessed by RT-PCR and Sanger sequencing and correlated with clinical characteristics by multivariate analysis. Transcriptomics was performed on HBx-overexpressing endoscopic biopsies from healthy donors.C57BL/6 mice underwent intramucosal injections of liposome-conjugated HBx-encoding plasmids or the control, with or without antibiotic treatment. Multidimensional flow cytometry analysis was performed on colonic samples from HBx-treated and control animals. Transepithelial electrical resistance measurement, proliferation assay, chromatin immunoprecipitation assay with sequencing and RNA-sequencing were performed on in vitro models of the gut barrier. HBx-silencing experiments were performed in vitro and in vivo. RESULTS: HBx was detected in about 45% of patients with UC and found to induce colonic inflammation in mice, while its silencing reverted the colitis phenotype in vivo. HBx acted as a transcriptional regulator in epithelial cells, provoking barrier leakage and altering both innate and adaptive mucosal immunity ex vivo and in vivo. CONCLUSION: This study described HBx as a contributor to the UC pathogenesis and provides a new perspective on the virome as a target for tailored treatments.