Non-TGFß profibrotic signaling in ulcerative colitis after in vivo experimental intestinal injury in humans.

Although impaired regeneration is important in many gastrointestinal diseases including ulcerative colitis (UC), the dynamics of mucosal regeneration in humans are poorly investigated. We have developed a model to study these processes in vivo in humans. Epithelial restitution (ER) and extracellular matrix (ECM) regulation after an experimental injury of the sigmoid colonic mucosa was assessed by repeated high resolution endoscopic imaging, histologic assessment, RNA sequencing, deconvolution analysis, and 16S rDNA sequencing of the injury niche microbiome of 19 UC patients in remission and 20 control subjects. Human ER had a 48-hour lag before induction of regenerative epithelial cells (WAE and TA cells) along with increase of fibroblast derived stem cell growth factor Gremlin 1 mRNA (GREM1). However, in UC deconvolution data showed aby rapid induction of inflammatory fibroblasts, and upregulation of major structural ECM collagen mRNAs and along with tissue inhibitor of metalloproteinase 1 (TIMP1) suggesting increased profibrotic ECM deposition. No change was seen in transforming growth factor ß (TGFß) mRNA whereas and the profibrotic cytokines interleukin 13 (IL13) and IL11 were upregulated in UC suggesting that human post injury responses could be TGFß-independent. In conclusion, we found distinct regulatory layers of regeneration in the normal human colon and a potential targetable profibrotic dysregulation in UC that could lead to long-term end organ failure - i.e., intestinal damage.

Intestinal ultrasound in inflammatory bowel disease.

Intestinal ultrasound (IUS) is non-invasive, fast, cheap, and well-tolerated and requires no preparation and is thus applicable as a point-of-care monitoring tool of inflammatory bowel disease (IBD). Evidence suggests that IUS is comparable to other standard monitoring modalities, i.e., endoscopy, MRI, calprotectin, and C-reactive protein and might be more accurate in predicting response to treatment at an early stage consequently allowing for timely optimised treatment. This review finds that integrating IUS as the standard of care in every IBD outpatient clinic and as the primary outcome in future medical trials seems inevitable.

Tofacitinib and faecal microbiota transplantation in treating checkpoint inhibitor-induced enterocolitis: case report.

BACKGROUND: Immune checkpoint inhibitors (ICIs) can induce a wide range of immune-related adverse events (irAEs), potentially affecting any organ. ICI-induced colitis is a frequently reported irAE, whereas enteritis is rare and not well documented. CASE PRESENTATION: We are presenting a patient with metastatic melanoma who developed severe ICI-induced enterocolitis multirefractory for glucocorticoids, infliximab and vedolizumab, partially responding to faecal microbiota transplantation and final complete response to tofacitinib. CONCLUSION: This case supports that tofacitinib may be an(other) effective agent in managing multirefractory ICI-induced diarrhoea caused by colitis and/or enteritis.

COLAR: open-label clinical study of IL-6 blockade with tocilizumab for the treatment of immune checkpoint inhibitor-induced colitis and arthritis.

BACKGROUND: Immune-related adverse events due to immune checkpoint inhibitors (ICIs) are not always effectively treated using glucocorticoids and it may negatively affect the antitumor efficacy of ICIs. Interventional studies of alternatives to glucocorticoids are lacking. We examined whether interleukin-6 blockade by tocilizumab reduced ICI-induced colitis and arthritis. PATIENTS AND METHODS: Patients with solid cancer experiencing Common Terminology Criteria for Adverse Events (CTCAE v5.0) grade >1 ICI-induced colitis/diarrhea (n=9), arthritis (n=9), or both (n=2) were recruited and treated with tocilizumab (8 mg/kg) every 4 weeks until worsening or unacceptable toxicity. Patients were not allowed to receive systemic glucocorticoids and other immunosuppressive drugs within the 14-day screening period. The primary endpoint was clinical improvement of colitis and arthritis, defined as ≥1 grade CTCAE reduction within 8 weeks. Secondary endpoints were improvements and glucocorticoid-free remission at week 24; safety; radiologic, endoscopic, and histological changes; and changes in plasma concentrations of C reactive protein, cytokines (IL-6, IL-8, and IL-17), and YKL-40. RESULTS: Nineteen patients were available for efficacy analysis; one patient was excluded due to pancreatic insufficiency-induced diarrhea. Patients received treatment with pembrolizumab (n=10) or nivolumab (n=4) as monotherapy or ipilimumab and nivolumab (n=5) combined. Seven patients had been initially treated with glucocorticoids, and two of them also received infliximab. Ten patients continued ICI therapy during tocilizumab treatment. The primary endpoint was achieved in 15 of 19 (79%) patients. Additional one patient had ≥1 grade reduction at week 10, and another patient had stabilized symptoms. At week 24, ongoing improvement without glucocorticoids (n=12), including complete remission (n=10), was noted. Five patients had grades 3-4 treatment-related adverse events, which were manageable and reversible. CONCLUSIONS: Tocilizumab showed promising clinical efficacy and a manageable safety profile in the treatment of ICI-induced colitis and arthritis. Our findings support the feasibility of randomized trials of immune-related adverse events. TRIAL REGISTRATION NUMBER: NCT03601611.

Safety and efficacy of infliximab and corticosteroid therapy in checkpoint inhibitor-induced colitis.

BACKGROUND: Cancer patients treated with immune check point inhibitors are at risk of developing severe colitis. However, the efficacy and safety of treatment of severe colitis is poorly understood. AIMS: To explore the safety and efficacy of infliximab and corticosteroids in severe immune-mediated enterocolitis (IMC) METHOD: We performed a nationwide retrospective cohort study on 140 cancer patients treated with infliximab due to IMC in Denmark from 2011 to 2021. RESULTS: The rate of complete remission with infliximab was 52% after one dose, increasing to 73% after two or more doses. Thirteen patients (10%) required additional treatment with vedolizumab. Patients were heavily exposed to corticosteroids and received a median accumulated dose of 3978 mg (interquartile range [IQR] 2552-6414). Age- and cancer-adjusted Cox regression analysis found that a high dose of prednisolone at start of tapering ≥75 mg/day was associated with increased mortality (HR 1.67, 1.04-2.69, p = 0.035). Patients responding to infliximab experienced an improvement of symptoms after 3 days (IQR 2-4) and complete remission after 31 days (IQR 14-61). Twenty-four percent required hospitalisation for infection during treatment for IMC, lasting 7 days (median). Secondary gastrointestinal infections occurred in 16%, with Clostridioides difficile being most common (64%). Further, 10% had a thromboembolic event during the first 90 days after infliximab treatment. CONCLUSIONS: Infliximab led to complete resolution of symptoms in 73% of patients with IMC. High prednisolone dose at tapering was associated with increased mortality rate and a high incidence of infections and hospitalisations in patients with severe IMC. We suggest optimised infliximab treatment before escalation of steroid doses.

Early Intestinal Ultrasound Predicts Intravenous Corticosteroid Response in Hospitalised Patients With Severe Ulcerative Colitis.

BACKGROUND AND AIMS: Our aim was to determine if transabdominal intestinal ultrasound changes after 48 ±â€…24 h of intravenous corticosteroids can predict treatment outcomes in hospitalised patients with severe ulcerative colitis. METHODS: We performed a blinded observational multicentre study. Ultrasound parameters were assessed before treatment initiation, after 48 ±â€…24 h, and 6 ±â€…1 days. Treatment response was determined within 7 days by two outcome measures: 1] partial Mayo score reduction; 2] no administration of rescue therapy. RESULTS: Out of 69 recruited patients, 56 were included in the final analysis, with 37 responders. The colon segment with the highest baseline bowel wall thickness was analysed, being the sigmoid in all patients. There was no difference in baseline bowel wall thickness between responders and non-responders in the partial Mayo score outcome. At 48 ±â€…24 h, a significant difference between responders and non-responders was identified in both absolute bowel wall thickness [median 3.1 mm vs 4.9 mm; p <0.0001], absolute reduction [-1.9 mm vs -0.2 mm; p <0.001], and relative reduction [-35.9% vs -4.1%; p <0.0001]. A ≤20% reduction had a sensitivity of 84.2% (95% confidence interval [CI] 60.4, 96.6%) and a specificity of 78.4% [61.8, 90.2%] for determining non-response [area under the curve 0.85]. In the multivariable analysis, a >20% reduction had the highest odds ratio (22.6 [4.2, 201.2]; p = 0.001) for determining response. Similar results were seen for the rescue therapy outcome. CONCLUSIONS: Changes in bowel wall thickness, after 48 ±â€…24 h following intravenous corticosteroid treatment in hospitalised patients with severe ulcerative colitis, identify responders with high accuracy and might be used as an early marker to guide accelerated rescue therapy.

Influence of Genetics, Immunity and the Microbiome on the Prognosis of Inflammatory Bowel Disease (IBD Prognosis Study): the protocol for a Copenhagen IBD Inception Cohort Study.

INTRODUCTION: Inflammatory bowel diseases (IBD), encompassing Crohn's disease and ulcerative colitis, are chronic, inflammatory diseases of the gastrointestinal tract. We have initiated a Danish population-based inception cohort study aiming to investigate the underlying mechanisms for the heterogeneous course of IBD, including need for, and response to, treatment. METHODS AND ANALYSIS: IBD Prognosis Study is a prospective, population-based inception cohort study of unselected, newly diagnosed adult, adolescent and paediatric patients with IBD within the uptake area of Hvidovre University Hospital and Herlev University Hospital, Denmark, which covers approximately 1 050 000 inhabitants (~20% of the Danish population). The diagnosis of IBD will be according to the Porto diagnostic criteria in paediatric and adolescent patients or the Copenhagen diagnostic criteria in adult patients. All patients will be followed prospectively with regular clinical examinations including ileocolonoscopies, MRI of the small intestine, validated patient-reported measures and objective examinations with intestinal ultrasound. In addition, intestinal biopsies from ileocolonoscopies, stool, rectal swabs, saliva samples, swabs of the oral cavity and blood samples will be collected systematically for the analysis of biomarkers, microbiome and genetic profiles. Environmental factors and quality of life will be assessed using questionnaires and, when available, automatic registration of purchase data. The occurrence and course of extraintestinal manifestations will be evaluated by rheumatologists, dermatologists and dentists, and assessed by MR cholangiopancreatography, MR of the spine and sacroiliac joints, ultrasonography of peripheral joints and entheses, clinical oral examination, as well as panoramic radiograph of the jaws. Fibroscans and dual-energy X-ray absorptiometry scans will be performed to monitor occurrence and course of chronic liver diseases, osteopenia and osteoporosis. ETHICS AND DISSEMINATION: This study has been approved by Ethics Committee of the Capital Region of Denmark (approval number: H-20065831). Study results will be disseminated through publication in international scientific journals and presentation at (inter)national conferences.

Low-dose azathioprine and allopurinol versus azathioprine monotherapy in patients with ulcerative colitis (AAUC): An investigator-initiated, open, multicenter, parallel-arm, randomised controlled trial.

Background: Retrospective studies suggest that for patients with ulcerative colitis (UC) combination therapy with low-dose azathioprine and allopurinol (L-AZA/ALLO) may result in higher remission rates than monotherapy with azathioprine (AZA). We prospectively investigated the effects of these drugs for remission in patients with moderate-to-severe UC. Methods: Open-label, unblinded, randomised, controlled, investigator-initiated, multicentre study conducted at eight hospital sites in Denmark. Adult patients with established UC, who were steroid dependent/refractory, thiopurine naïve, had a normal thiopurine methyltransferase, and achieved remission with steroids or infliximab were eligible for inclusion. Patients were randomly assigned by the investigators (1:1) to 52 weeks of treatment with once daily oral AZA (median dose 50 mg) combined with ALLO 100 mg versus AZA monotherapy (median dose 200 mg), using a computer-generated randomisation list with blocks of six. The trial was open without masking. All randomised patients who received at least one dose of study drug were included in primary and safety analyses (intention to treat population). The primary outcome was steroid and infliximab free remission after 52 weeks, defined as a Mayo Score of ≤1 and no rectal bleeding. The trial is completed and is registered in ClinicalTrials.gov (ClinicalTrials.gov NCT03101800). Findings: Between January 9, 2017 and February 10, 2021, 47 patients were randomised to l-AZA/ALLO and 42 to AZA and received at least one dose of the study drug. After 52 weeks, 20 of 47 (43%) patients in the l-AZA/ALLO group and nine of 42 (21%) patients in the AZA group achieved remission (odds ratio 2·54 [95% CI 1·00 to 6.78, p < 0·048]). Fourteen patients (30%) in the l-AZA/ALLO group and 16 (38%) in the AZA group were withdrawn from the study due to adverse events. Interpretation: This study suggests that after one year l-AZA/ALLO therapy may be associated with a beneficial effect on steroid- and infliximab-free clinical remission in patients with moderate-to-severe UC and should be considered as first line therapy. Funding: Funding for AAUC was provided by The Capital Region of Denmark (Regionernes Medicinpulje (6062/16)).

[Practical guide to the use of thiopurinesin patients with inflammatory bowel diseases].

Despite the increasing availability of biological treatment in recent years, thiopurines remain an important treatment option in patients with inflammatory bowel diseases (IBD) both as monotherapy and in combination therapy with biologicals. Pre-treatment screening of thiopurine-methyltransferase activity and monitoring of thiopurine metabolites during treatment are essential to optimize the effectiveness and safety of thiopurines. This review provides an evidence-based practical guide to prescribing and monitoring thiopurines in patients with IBD.

Lipidomic Trajectories Characterize Delayed Mucosal Wound Healing in Quiescent Ulcerative Colitis and Identify Potential Novel Therapeutic Targets.

Improving the long-term prognosis of ulcerative colitis (UC) requires sustained deep mucosal colonic healing with histologic remission, making the study of colonic tissue regeneration essential. In experimental colitis models, lipid metabolites are recognized as pivotal components of this process. This study aimed to describe the kinetics of wound healing and lipid metabolites engaged in regeneration in the normal colonic mucosa and how they are affected in UC to reveal new therapeutic targets. Experimental colonic wounds were created endoscopically in quiescent UC (n=21) and controls (n=9), and the healing process was surveilled by serial endoscopies and cross-sectional wound biopsies post-wounding. Biopsies were analyzed by liquid chromatography coupled with mass spectrometry. Endoscopic wound scores were significantly higher in UC at day two (p=0.001) and seven (p<0.0001) post-wounding, demonstrating a prolonged wound healing process. The wound scores were correlated with lipid mediators crucial for normal regeneration and sustained UC-specific changes in key phospholipids and eicosanoids, i.e., lysophosphatidylcholine, phosphatidylcholine, lysophosphatidic acid, phosphatidylglycerol, phosphatidylinositol, prostaglandin D2, and prostaglandin E1, were observed. A prolonged wound healing process is identified in quiescent UC with altered disease specific lipidomic trajectories providing potential novel therapeutic avenues for stimulating mucosal regeneration as an add-on to the traditional immune suppression treatment.

IBD metabonomics predicts phenotype, disease course, and treatment response.

Metabonomics in inflammatory bowel disease (IBD) characterizes the effector molecules of biological systems and thus aims to describe the molecular phenotype, generate insight into the pathology, and predict disease course and response to treatment. Nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and integrated NMR and MS platforms coupled with multivariate analyses have been applied to create such metabolic profiles. Recent advances have identified quiescent ulcerative colitis as a distinct molecular phenotype and demonstrated metabonomics as a promising clinical tool for predicting relapse and response to treatment with biologics as well as fecal microbiome transplantation, thus facilitating much needed precision medicine. However, understanding this complex research field and how it translates into clinical settings is a challenge. This review aims to describe the current workflow, analytical strategies, and associated bioinformatics, and translate current IBD metabonomic knowledge into new potential clinically applicable treatment strategies, and outline future key translational perspectives.

Acute Experimental Barrier Injury Triggers Ulcerative Colitis-Specific Innate Hyperresponsiveness and Ulcerative Colitis-Type Microbiome Changes in Humans.

BACKGROUND AND AIMS: The trigger hypothesis opens the possibility of anti-flare initiation therapies by stating that ulcerative colitis (UC) flares originate from inadequate responses to acute mucosal injuries. However, experimental evidence is restricted by a limited use of suitable human models. We thus aimed to investigate the acute mucosal barrier injury responses in humans with and without UC using an experimental injury model. METHODS: A standardized mucosal break was inflicted in the sigmoid colon of 19 patients with UC in endoscopic and histological remission and 20 control subjects. Postinjury responses were assessed repeatedly by high-resolution imaging and sampling to perform Geboes scoring, RNA sequencing, and injury niche microbiota 16S ribosomal RNA gene sequencing. RESULTS: UC patients had more severe endoscopic postinjury inflammation than did control subjects (P < .01), an elevated modified Geboes score (P < .05), a rapid induction of innate response gene sets (P < .05) and antimicrobial peptides (P < .01), and engagement of neutrophils (P < .01). Innate lymphoid cell type 3 (ILC3) markers were increased preinjury (P < .01), and ILC3 activating cytokines were highly induced postinjury, resulting in an increase in ILC3-type cytokine interleukin-17A. Across groups, the postinjury mucosal microbiome had higher bacterial load (P < .0001) and lower α-diversity (P < .05). CONCLUSIONS: UC patients in remission respond to mucosal breaks by an innate hyperresponse engaging resident regulatory ILC3s and a subsequent adaptive activation. The postinjury inflammatory bowel disease-like microbiota diversity decrease is irrespective of diagnosis, suggesting that the dysbiosis is secondary to host injury responses. We provide a model for the study of flare initiation in the search for antitrigger-directed therapies.

Metabonomics in Gastroenterology and Hepatology.

Attempts have been made to reveal the true nature of a range of puzzling diseases within gastroenterology and hepatology using different kinds of omics, namely genomics, transcriptomics, proteomics, and metabonomics [...].

Characterization of the enhancer and promoter landscape of inflammatory bowel disease from human colon biopsies.

Inflammatory bowel disease (IBD) is a chronic intestinal disorder, with two main types: Crohn's disease (CD) and ulcerative colitis (UC), whose molecular pathology is not well understood. The majority of IBD-associated SNPs are located in non-coding regions and are hard to characterize since regulatory regions in IBD are not known. Here we profile transcription start sites (TSSs) and enhancers in the descending colon of 94 IBD patients and controls. IBD-upregulated promoters and enhancers are highly enriched for IBD-associated SNPs and are bound by the same transcription factors. IBD-specific TSSs are associated to genes with roles in both inflammatory cascades and gut epithelia while TSSs distinguishing UC and CD are associated to gut epithelia functions. We find that as few as 35 TSSs can distinguish active CD, UC, and controls with 85% accuracy in an independent cohort. Our data constitute a foundation for understanding the molecular pathology, gene regulation, and genetics of IBD.

Metabonomics uncovers a reversible proatherogenic lipid profile during infliximab therapy of inflammatory bowel disease.

BACKGROUND: One-third of inflammatory bowel disease (IBD) patients show no response to infliximab (IFX) induction therapy, and approximately half of patients responding become unresponsive over time. Thus, identification of potential treatment response biomarkers are of great clinical significance. This study employs spectroscopy-based metabolic profiling of serum from patients with IBD treated with IFX and healthy subjects (1) to substantiate the use of spectroscopy as a semi-invasive diagnostic tool, (2) to identify potential biomarkers of treatment response and (3) to characterise the metabolic changes during management of patients with tumour necrosis factor-α inhibitors. METHODS: Successive serum samples collected during IFX induction treatment (weeks 0, 2, 6 and 14) from 87 IBD patients and 37 controls were analysed by 1H nuclear magnetic resonance (NMR) spectroscopy. Data were analysed with principal components analysis and orthogonal projection to latent structures discriminant analysis using SIMCA-P+ v12 and MATLAB. RESULTS: Metabolic profiles were significantly different between active ulcerative colitis and controls, active Crohn's disease and controls, and quiescent Crohn's disease and controls. Metabolites holding differential power belonged primarily to lipids and phospholipids with proatherogenic characteristics and metabolites in the pyruvate metabolism, suggestive of an intense inflammation-driven energy demand. IBD patients not responding to IFX were identified as a potentially distinct group based on their metabolic profile, although no applicable response biomarkers could be singled out in the current setting. CONCLUSION: 1H NMR spectroscopy of serum samples is a powerful semi-invasive diagnostic tool in flaring IBD. With its use, we provide unique insights into the metabolic changes taking place during induction treatment with IFX. Of distinct clinical relevance is the identification of a reversible proatherogenic lipid profile in IBD patients with active disease, which partially explains the increased risk of cardiovascular disease associated with IBD.

Alpha-1 antitrypsin and granulocyte colony-stimulating factor as serum biomarkers of disease severity in ulcerative colitis.

BACKGROUND: Initial assessment of patients with ulcerative colitis (UC) is challenging and relies on apparent clinical symptoms and measurements of surrogate markers (e.g., C-reactive protein [CRP] or similar acute phase proteins). As CRP only reliably identifies patients with severe disease, novel biomarkers are currently needed for identification of patients with mild or moderate disease activity. Using a commercially available platform, we aimed at identifying serum biomarkers that are able to grade the disease severity. METHODS: Serum samples from 65 patients with UC with varying disease activity (Mayo score) and from 40 healthy controls were analyzed by multiplex enzyme-linked immunosorbent assay for 78 potential disease biomarkers. Using the statistical software SIMCA-P+ and GraphPad Prism, multivariate statistical analyses were conducted to identify a limited number of biomarkers to assess disease severity. RESULTS: Alpha-1 antitrypsin (AAT) differentiated between mild and moderate UC (area under the curve [AUC] = 0.79) with a sensitivity of 0.90 and a specificity of 0.70, thereby exceeding the predictive ability of CRP (AUC = 0.52). Combining alpha-1 antitrypsin and granulocyte colony-stimulating factor produced a predictive model with an AUC of 0.72 when differentiating mild and moderate UC, and an AUC of 0.96 when differentiating moderate and severe UC, the latter being as reliable as CRP. CONCLUSIONS: Alpha-1 antitrypsin is identified as a potential serum biomarker of mild-to-moderate disease activity in UC. With the ability to differentiate between mild, moderate, and severe stages of UC using a simple serum biomarker that is already commercially available, clinicians can initiate individualized treatment regimens at an earlier stage before endoscopic examinations are available.