Cellular and Molecular Determinants of Biologic Drugs Resistance and Therapeutic Failure in Inflammatory Bowel Disease.

The advent of biologic drugs has revolutionized the treatment of Inflammatory Bowel Disease, increasing rates of response and mucosal healing in comparison to conventional therapies by allowing the treatment of corticosteroid-refractory cases and reducing corticosteroid-related side effects. However, biologic therapies (anti-TNFα inhibitors, anti-α4ß7 integrin and anti-IL12/23) are still burdened by rates of response that hover around 40% (in biologic-naïve patients) or lower (for biologic-experienced patients). Moreover, knowledge of the mechanisms underlying drug resistance or loss of response is still scarce. Several cellular and molecular determinants are implied in therapeutic failure; genetic predispositions, in the form of single nucleotide polymorphisms in the sequence of cytokines or Human Leukocyte Antigen, or an altered expression of cytokines and other molecules involved in the inflammation cascade, play the most important role. Accessory mechanisms include gut microbiota dysregulation. In this narrative review of the current and most recent literature, we shed light on the mentioned determinants of therapeutic failure in order to pave the way for a more personalized approach that could help avoid unnecessary treatments and toxicities.

The first international Rome consensus conference on gut microbiota and faecal microbiota transplantation in inflammatory bowel disease.

BACKGROUND: Several randomised clinical trials (RCTs) performing faecal microbiota transplantation (FMT) for the management of inflammatory bowel disease (IBD), particularly for ulcerative colitis, have recently been published, but with major variations in study design. These include differences in administered dose, route and frequency of delivery, type of placebo and evaluated endpoints. Although the overall outcomes appear to be promising, they are highly dependent on both donor and recipient factors. OBJECTIVE: To develop concensus-based statements and recommendations for the evaluation, management and potential treatment of IBD using FMT in order to move towards standardised practices. DESIGN: An international panel of experts convened several times to generate evidence-based guidelines by performing a deep evaluation of currently available and/or published data. Twenty-five experts in IBD, immunology and microbiology collaborated in different working groups to provide statements on the following key issues related to FMT in IBD: (A) pathogenesis and rationale, (B) donor selection and biobanking, (C) FMT practices and (D) consideration of future studies and perspectives. Statements were evaluated and voted on by all members using an electronic Delphi process, culminating in a plenary consensus conference and generation of proposed guidelines. RESULTS AND CONCLUSIONS: Our group has provided specific statements and recommendations, based on best available evidence, with the end goal of providing guidance and general criteria required to promote FMT as a recognised strategy for the treatment of IBD.

Focus on Anti-Tumour Necrosis Factor (TNF)-α-Related Autoimmune Diseases.

Anti-tumour necrosis factor (TNF)-α agents have been increasingly used to treat patients affected by inflammatory bowel disease and dermatological and rheumatologic inflammatory disorders. However, the widening use of biologics is related to a new class of adverse events called paradoxical reactions. Its pathogenesis remains unclear, but it is suggested that cytokine remodulation in predisposed individuals can lead to the inflammatory process. Here, we dissect the clinical aspects and overall outcomes of autoimmune diseases caused by anti-TNF-α therapies.

Microbiota Composition in Diverticular Disease: Implications for Therapy.

Gut microbiota (GM) composition and its imbalance are crucial in the pathogenesis of several diseases, mainly those affecting the gastrointestinal tract. Colon diverticulosis and its clinical manifestations (diverticular disease, DD) are among the most common digestive disorders in developed countries. In recent literature, the role of GM imbalance in the onset of the different manifestations within the clinical spectrum of DD has been highlighted. This narrative review aims to summarize and critically analyze the current knowledge on GM dysbiosis in diverticulosis and DD by comparing the available data with those found in inflammatory bowel disease (IBD). The rationale for using probiotics to rebalance dysbiosis in DD is also discussed.

Knowledge of Diagnostic and Therapeutic Aspects of IBD Among Nurses Working in Digestive Endoscopy: A Nationwide Italian Survey.

The importance of inflammatory bowel disease (IBD) dedicated nurses in endoscopy services is poorly explored. Non-IBD healthcare professionals who work in endoscopy units may underestimate the discomfort and the secondary psychological distress that endoscopic procedures cause in IBD patients. We performed a nationwide survey to evaluate the level of knowledge of nurses working in endoscopy facilities throughout Italy related to IBD patients' needs undergoing endoscopic procedures. A non-validate 45 items questionnaire divided into six sections was assembled by a group of experts and supervised by nurses and IBD-physicians as part of the board of IGIBD, ANOTE-ANIGEA and AGGEI. The questionnaire was sent to 397 nurses of which 335 (84.4%) responded to the questionnaire. The median level of knowledge registered was 29 ± 12, corresponding to a medium level of knowledge based on the scores described in the method section. One hundred eighty-three nurses (54.6%) reported a high score, 113 (33.7%) a medium score, and 39 (11.6%) a low score. The majority of nurses worked in high volume endoscopy centers, where the 48% were educated in IBD management. A Low level of knowledge was recorded regarding disease severity definition, bowel preparation strategies in severe colitis and evaluation of perianal fistula. This nationwide survey clearly shows that there is a need for endoscopic nurses to acquire specific knowledge in the IBD field. Dedicated pathways for IBD management in endoscopy, continuous educational programs for nurses and further studies to improve nurse education are needed.

Human herpesvirus 8-associated colonic Kaposi's sarcoma during vedolizumab treatment in ulcerative colitis: a case report and review of the literature.

BACKGROUND: Kaposi's sarcoma (KS) is a rare vascular tumor associated with human herpesvirus (HHV)-8 infection. One of the variants of KS is defined iatrogenic and is overall reported in transplanted patient but also, although less frequently, in patients treated with long-standing immunosuppressive therapy, such as in inflammatory bowel disease including ulcerative colitis and Crohn's disease. CASE PRESENTATION: Herein, we report the first case of KS in a human immunodeficiency virus (HIV)-negative 47-year old male with UC after treatment with the α4-ß7 integrin inhibitor vedolizumab (VDZ). The patient underwent to colectomy for a medical refractory disease and the histological examination of the surgical specimen showed the typical findings of KS together with the HHV-8 positivity. The patient achieved a good health status, without any sign of disease recurrence. CONCLUSIONS: In the present case, we can assume that VDZ may have promoted the reactivation of a latent HHV-8 infection endowed with oncogenic potentialities and, in turn, the onset of KS. We also briefly reviewed all the cases of KS in HIV-negative patients with inflammatory bowel disease.

Bacteriocins and Bacteriophages: Therapeutic Weapons for Gastrointestinal Diseases?

Bacteriocins are bactericidal peptides, ribosomally synthesized, with an inhibitory activity against diverse groups of undesirable microorganisms. Bacteriocins are produced by both gram-positive and gram-negative bacteria, and to a lesser extent by some archaea. Bacteriophages are viruses that are able to infect bacterial cells and force them to produce viral components, using a lytic or lysogenic cycle. They constitute a large community in the human gut called the phageome, the most abundant part of the gut virome. Bacteriocins and bacteriophages may have an influence on both human health and diseases, thanks to their ability to modulate the gut microbiota and regulate the competitive relationship among the different microorganisms, strains and cells living in the human intestine. In this review, we explore the role of bacteriocins and bacteriophages in the most frequent gastrointestinal diseases by dissecting their interaction with the complex environment of the human gut, analyzing a possible link with extra-intestinal diseases, and speculating on their possible therapeutic application with the end goal of promoting gut health.

Gut Microbiota in Health, Diverticular Disease, Irritable Bowel Syndrome, and Inflammatory Bowel Diseases: Time for Microbial Marker of Gastrointestinal Disorders.

Few data exist on differences in gut microbiota composition among principal gastrointestinal (GI) diseases. We evaluated the differences in gut microbiota composition among uncomplicated diverticular disease (DD), irritable bowel syndrome (IBS) and inflammatory bowel diseases (IBD) patients. DD, IBS, and IBD patients along with healthy controls (CT) were enrolled in our Italian GI outpatient clinic. Stool samples were collected. Microbiota composition was evaluated through a metagenomic gene-targeted approach. GI pathology represented a continuous spectrum of diseases where IBD displayed one extreme, while CT displayed the other. Among Phyla, Biplot PC2/PC3 and dendogram plot showed major differences in samples from IBS and IBD. DD resembled species CT composition, but not for Bacteroides fragilis. In IBS, Dialister spp. and then Faecalibacterium prausnitzii were the most representative species. Ulcerative colitis showed a reduced concentration of Clostridium difficile and an increase of Bacteroides fragilis. In Crohn's disease, Parabacteroides distasonis was the most represented, while Faecalibacterium prausnitzii and Bacteroides fragilis were significantly reduced. Each disorder has its definite overall microbial signature, which produces a clear differentiation from the others. On the other hand, shared alterations constitute the "core dysbiosis" of GI diseases. The assessment of these microbial markers represents a parameter that may complete the diagnostic assessment.

Harmful Effects and Potential Benefits of Anti-Tumor Necrosis Factor (TNF)-α on the Liver.

Anti-tumor necrosis factor (TNF)-α agents represent an effective treatment for chronic inflammatory diseases. However, some concerns about their potentially undesirable effects on liver function have been reported. On the other hand, evidence of their therapeutic effects on certain liver diseases is accumulating. Many data showed the safety of anti-TNF-α in patients with chronic hepatitis B and C and in liver transplanted patients even if a strict follow-up and prophylaxis are recommended in well-defined subgroups. On the other side, anti-TNF-α-induced liver injury is not a rare event. However, it is often reversible after anti-TNF-α withdrawal. Anti-TNF-α agents have been tested in advanced stages of severe alcoholic hepatitis and non-alcoholic fatty liver disease. Limited data on the efficacy of anti-TNF-α in patients with autoimmune hepatitis and primary biliary cholangitis are also available. In this review, we explored the hepatic safety concerns in patients receiving anti-TNF-α agents with and without pre-existent hepatic diseases. In addition, the available evidence on their potential benefits in the treatment of specific hepatic diseases is discussed.

Can We Predict the Efficacy of Anti-TNF-α Agents?

The use of biologic agents, particularly anti-tumor necrosis factor (TNF)-α, has revolutionized the treatment of inflammatory bowel diseases (IBD), modifying their natural history. Several data on the efficacy of these agents in inducing and maintaining clinical remission have been accumulated over the past two decades: their use avoid the need for steroids therapy, promote mucosal healing, reduce hospitalizations and surgeries and therefore dramatically improve the quality of life of IBD patients. However, primary non-response to these agents or loss of response over time mainly due to immunogenicity or treatment-related side-effects are a frequent concern in IBD patients. Thus, the identification of predicting factors of efficacy is crucial to allow clinicians to efficiently use these therapies, avoiding them when they are ineffective and eventually shifting towards alternative biological therapies with the end goal of optimizing the cost-effectiveness ratio. In this review, we aim to identify the predictive factors of short- and long-term benefits of anti-TNF-α therapy in IBD patients. In particular, multiple patient-, disease- and treatment-related factors have been evaluated.

Hypoxic Functional Regulation Pathways in the GI Tract: Focus on the HIF-1α and Microbiota's Crosstalk.

Hypoxia is an essential gastrointestinal (GI) tract phenomenon that influences both physiologic and pathologic states. Hypoxia-inducible factors (HIFs), the primary drivers of cell adaptation to low-oxygen environments, have been identified as critical regulators of gut homeostasis: directly, through the induction of different proteins linked to intestinal barrier stabilization (ie, adherent proteins, tight junctions, mucins, integrins, intestinal trefoil factor, and adenosine); and indirectly, through the regulation of several immune cell types and the modulation of autophagy and inflammatory processes. Furthermore, hypoxia and HIF-related sensing pathways influence the delicate relationship existing between bacteria and mammalian host cells. In turn, gut commensals establish and maintain the physiologic hypoxia of the GI tract and HIF-α expression. Based on this premise, the goals of this review are to (1) highlight hypoxic molecular pathways in the GI tract, both in physiologic and pathophysiologic settings, such as inflammatory bowel disease; and (2) discuss a potential strategy for ameliorating gut-related disorders, by targeting HIF signaling, which can alleviate inflammatory processes, restore autophagy correct mechanisms, and benefit the host-microbiota equilibrium.

In recent years, hypoxic conditions, with subsequent hypoxia-inducible factor activation, and the gut's microbiota composition have both received significant attention due to their correlation with gut homeostasis maintenance. However, their potential synergic action needs further investigation.

Gut microbiota, intestinal permeability, and systemic inflammation: a narrative review.

The intestine is the largest interface between the internal body and the external environment. The intestinal barrier is a dynamic system influenced by the composition of the intestinal microbiome and the activity of intercellular connections, regulated by hormones, dietary components, inflammatory mediators, and the enteric nervous system (ENS). Over the years, it has become increasingly evident that maintaining a stable intestinal barrier is crucial to prevent various potentially harmful substances and pathogens from entering the internal environment. Disruption of the barrier is referred to as 'leaky gut' or leaky gut wall syndrome and seems to be characterized by the release of bacterial metabolites and endotoxins, such as lipopolysaccharide (LPS), into the circulation. This condition, mainly caused by bacterial infections, oxidative stress, high-fat diet, exposure to alcohol or chronic allergens, and dysbiosis, appear to be highly connected with the development and/or progression of several metabolic and autoimmune systemic diseases, including obesity, non-alcoholic fatty liver disease (NAFLD), neurodegeneration, cardiovascular disease, inflammatory bowel disease, and type 1 diabetes mellitus (T1D). In this review, starting from a description of the mechanisms that enable barrier homeostasis and analyzing the relationship between this complex ecosystem and various pathological conditions, we explore the role of the gut barrier in driving systemic inflammation, also shedding light on current and future therapeutic interventions.

Transition from intravenous to subcutaneous biological therapies in inflammatory bowel disease: An online survey of patients.

BACKGROUND: The transition from in-hospital intravenous administration to subcutaneous therapies to treat inflammatory bowel disease (IBD) can raise some concerns among patients due to the self-administration concerns, the management of potential side effects and the overall worries related to a change of treatment. This study aimed at evaluating patients' opinion about the switch from intravenous to subcutaneous formulations and their knowledge on new available therapeutic options. METHODS: We conducted a survey using a questionnaire prepared by a team of gastroenterologists and nurses working at the IBD unit. It consists of 31 items and has been divided into four sections: descriptive, commitment, knowledge and passage mode opinion. The questions were formulated in Italian and conceived according to daily consultations with patients in everyday practice, without any previous piloting or specific medical literature reference. The survey was administered to consecutive IBD patients in intravenous biological treatment; patients currently or previously treated with subcutaneous therapy were excluded. RESULTS: Four hundred questionnaires were distributed to participants. As many as 311 patients (77.7%) completed the survey, while the remaining were excluded from the analysis; 155 (49.8%) patients were favorable to switch from intravenous to subcutaneous therapy, while only 78 (25.1%) disagreed. In univariate and multi-variate analysis, the approval rate for home therapy was significantly associated with the distance from the IBD center and work/family/personal commitments. Surprisingly, only a quarter of the IBD patients knew that almost all available therapeutic agents have a subcutaneous administration route. Regarding patients' opinion on the efficacy of subcutaneous administration of biological agents compared to intravenous drugs, 194 (63%) had no definite idea, while 44 (14%) believed that the effectiveness could be reduced. CONCLUSION: The transition from in-hospital to subcutaneous therapeutic management of biological therapy at home was generally viewed favorably by patients, especially if they have commitments or were residents far from the IBD center.

Multimodal dynamic ultrasound approach as predictor of response in patients with Crohn's disease treated with ustekinumab.

Background: The approval of ustekinumab (UST) has opened new options for the treatment of Crohn's disease (CD), but potential markers predicting the efficacy of this interleukin-12/23 inhibitor are lacking. Contrast-enhanced ultrasound (CEUS) is non-invasive alternative to endoscopy, demonstrating early transmural changes after treatment induction. Objectives: We conducted a prospective monocentric study aiming to explore the value of multimodal intestinal ultrasound (IUS) in predicting the response to UST in patients with active CD who have been previously exposed to anti-tumour necrosis factor α (TNFα). Design and methods: Consecutive patients with moderate-to-severe CD involving the terminal ileum who were scheduled to begin UST therapy were enrolled between January 2020 and October 2021 in the inflammatory bowel diseases outpatient centre. A complete IUS evaluation, including B-mode, Doppler, dynamic CEUS and elastography, was performed at the time of induction (T0) and after 8 (T1), 16 (T2), 24 (T3) and 48 (T4) weeks of therapy. Each IUS parameter and their variations from baseline were correlated with endoscopic response and mucosal healing after 1 year. Results: A total of 52 patients were included, 29 (55.8%) of which reached endoscopic response at T4. The univariate analysis revealed that, between T3 and T0, the percentage changes of bowel wall thickness, Limberg score, mean signal intensity, rise time, wash-in rate, C reactive protein and Harvey-Bradshaw Index were associated with long-term therapeutic outcome. Based on the above parameters, we developed an IUS score that showed a good performance in predicting 1 year-endoscopic response (area under the curve: 0.91). Conclusion: Multimodal ultrasound could be helpful to predict long-term therapeutic outcome in patients with CD treated with UST. Registration: NCT05987501.

Using ultrasound to predict how well ustekinumab works in Crohn's disease patients Background:The introduction of Ustekinumab (UST) as a treatment for Crohn's disease (CD) has provided new options, but there's a need for reliable markers predicting how well this interleukin-12/23 inhibitor will work. Contrast-enhanced ultrasound (CEUS) is a non-invasive alternative to endoscopy, showing early transmural changes post-treatment. Objectives: In a prospective monocentric study, researchers aimed to explore the value of multimodal intestinal ultrasound (IUS) in predicting UST response in patients with active CD who had previous exposure to anti-tumor necrosis factor α (TNFα). The study involved patients with moderate to severe CD in the terminal ileum, scheduled for UST therapy. Design and methods: Consecutive patients were enrolled between January 2020 and October 2021. Complete IUS evaluations, including B mode, Doppler, dynamic CEUS, and elastography, were conducted at induction (T0) and after 8 (T1), 16 (T2), 24 (T3), and 48 (T4) weeks of therapy. Various IUS parameters and their changes from baseline were correlated with endoscopic response and mucosal healing after 1 year. Results: Of the 52 patients, 29 (55.8%) achieved endoscopic response at T4. The analysis showed that changes in bowel wall thickness, Limberg score, mean signal intensity, rise time, wash-in rate, C-reactive protein, and Harvey-Bradshaw Index between T3 and T0 were associated with long-term therapeutic outcomes. An IUS score developed from these parameters demonstrated good performance in predicting 1-year endoscopic response (area under the curve: 0.91). Conclusion: The study suggests that multimodal ultrasound could be a valuable tool in predicting the long-term therapeutic outcome for patients with CD treated with UST. This non-invasive approach offers insights into treatment response, potentially aiding in personalized treatment strategies for individuals with Crohn's disease.

Solute Transporter OCTN1/Slc22a4 Affects Disease Severity and Response to Infliximab in Experimental Colitis: Role of Gut Microbiota and Immune Modulation.

BACKGROUND: Inflammatory bowel diseases are chronic disabling conditions with a complex and multifactorial etiology, still incompletely understood. OCTN1, an organic cation transporter, could have a role in modulating the inflammatory response, and some genetic polymorphisms of this molecule have been associated with increased risk of inflammatory bowel diseases. Until now, limited information exists on its potential in predicting/modulating patient's response to therapies. The aim of this study was to evaluate the role of OCTN1 in modifying gut microbiota and mucosal immunity in response to infliximab therapy in murine colitis. METHODS: A dextran sodium sulphate model of colitis was used to assess the clinical efficacy of infliximab administered intravenously in ocnt1 gene knockout mice and their C57BL/6 controls. Stool, colon, and mesenteric lymph node samples were collected to evaluate differences in gut microbiota composition, histology, and T cell populations, respectively. RESULTS: Octn1 -/- influences the microbiota profile and is associated with a worse dysbiosis in mice with colitis. Infliximab treatment attenuates colitis-associated dysbiosis, with an increase of bacterial richness and evenness in both strains. In comparison with wild type, octn1-/- mice have milder disease and a higher baseline percentage of Treg, Tmemory, Th2 and Th17 cells. CONCLUSIONS: Our data support the murine model to study OCTN1 genetic contribution to inflammatory bowel diseases. This could be the first step towards the recognition of this membrane transporter as a biomarker in inflammatory conditions and a predictor of response to therapies.

In this article, we evaluated the role of OCTN1, an organic cation transporter, in modifying gut microbiota and immune T cell populations, as well as its effects on experimental colitis and the response to infliximab treatment.

Insights into Mesalazine Use in Clinical Practice of Young Gastroenterologists.

BACKGROUND: Mesalazine is among the medications most prescribed by gastroenterologists, with variable and controversial use in different settings. We aimed to explore the use of mesalazine in the clinical practice of young gastroenterologists. METHODS: A web-based electronic survey was distributed to all participants of the National Meeting of the Italian Young Gastroenterologist and Endoscopist Association. RESULTS: A total of 101 participants took part in the survey, with a majority (54.4%) being aged >30 years, 63.4% of whom were trainees in academic hospitals, and 69.3% of whom were involved in the clinical management of inflammatory bowel disease (IBD). While both non-dedicated and IBD physicians generally agreed on the appropriate dose of mesalazine for mild ulcerative colitis (UC), significant differences were observed between the two groups for moderate-severe ulcerative colitis (UC). Additionally, in IBD patients who were starting immuno-modulators and/or biologics, 80% of IBD-dedicated physicians continued to prescribe mesalazine, compared to 45.2% of non-dedicated physicians (p = 0.002). Indeed, 48.4% of non-dedicated IBD physicians did not acknowledge mesalazine for colorectal cancer chemoprevention. With regards to Crohn's disease, it is mainly used by 30.1% of IBD physicians for preventing postoperative recurrence of Crohn's disease. Finally, 57.4% used mesalazine for symptomatic uncomplicated diverticular disease, and 84.2% did not recommend its use for irritable bowel syndrome. CONCLUSIONS: This survey showed heterogeneous behaviors in the daily use of mesalazine, mainly in the management of IBD. Educational programs and novel studies are needed to clarify its use.

Focus on Immune Checkpoint Inhibitors-related Intestinal Inflammation: From Pathogenesis to Therapeutical Approach.

Recently, antitumor immunotherapies have witnessed a breakthrough with the emergence of immune checkpoint inhibitors (ICIs) including programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors. Unfortunately, the use of ICIs has also led to the advent of a novel class of adverse events that differ from those of classic chemotherapeutics and are more reminiscent of autoimmune diseases, the immune-related adverse events (IRAEs). Herein, we performed an insight of the main IRAEs associated with ICIs, focusing on gastroenterological IRAEs and specifically on checkpoint inhibitor colitis, which represents the most widely reported IRAE to date. We comprehensively dissected the current evidence regarding pathogenesis, diagnosis, and management of ICIs-induced colitis, touching upon also on innovative therapies.

Immune checkpoint inhibitors (ICIs)-induced colitis is the most widely reported immune-related adverse event following the use of ICIs. In this review, we comprehensively discuss current evidence regarding pathogenesis, diagnosis, and management of ICIs-induced colitis, including a focus on innovative therapies.

Radiomics could predict surgery at 10 years in Crohn's disease.

BACKGROUND: Predicting clinical outcomes represents a major challenge in Crohn's disease (CD). Radiomics provides a method to extract quantitative features from medical images and may successfully predict clinical course. AIMS: The aim of this pilot study is to evaluate the use of radiomics to predict 10-year surgery for CD patients. METHODS: We selected a cohort of CD patients with CT scan enterographies and a 10-year follow up. The R library Moddicom was used to extract radiomic features from each lesion of CD, segmented in the CT scans. A logistic regression model based on selected radiomic features was developed to predict 10-year surgery. The model was evaluated by computing the area under the curve (AUC) of the receiver operating characteristic curve, sensitivity, specificity, positive and negative predictive values (PPV, NPV). RESULTS: We enroled 30 patients, with 44 CT scans and 93 lesions. We extracted 217 radiomic features from each lesion. The developed model was based on two radiomic features and presented an AUC (95% CI) of 0.83 (0.73-0.91) in predicting 10-year surgery. Sensitivity, specificity, PPV, NPV of the radiomic model were equal to 0.72, 0.90, 0.79, 0.86, respectively. CONCLUSION: Radiomics could be a helpful tool to identify patients with high risk for surgery and needing a stricter monitoring.