A global consensus on the definitions, diagnosis and management of fibrostenosing small bowel Crohn's disease in clinical practice.

Fibrostenosis of the small bowel is common in patients with Crohn's disease. No consensus recommendations on definition, diagnosis and management in clinical practice are currently available. In this Consensus Statement, we present a clinical practice RAND/UCLA appropriateness study on the definition, diagnosis and clinical management of fibrostenosing Crohn's disease. It was conducted by a panel of 28 global experts and one patient representative. Following a systematic literature review, 526 candidate items grouped into 136 questions were generated and subsequently evaluated for appropriateness. Strictures are best defined as wall thickening, luminal narrowing and prestenotic dilation. Cross-sectional imaging is required for accurate diagnosis of fibrostenosing Crohn's disease, and it is recommended before making treatment decisions. It should also assess the degree of inflammation in the bowel wall. Multiple options for medical anti-inflammatory, endoscopic and surgical therapies were suggested, including follow-up strategies following therapy. This Consensus Statement supports clinical practice through providing guidance on definitions, diagnosis and therapeutic management of patients with fibrostenosing small bowel Crohn's disease.

Etrasimod for the Treatment of Ulcerative Colitis: Analysis of Infection Events From the ELEVATE UC Clinical Program.

BACKGROUND AND AIMS: Infections are a safety concern in patients with ulcerative colitis (UC). Etrasimod is an oral, once-daily (QD), selective sphingosine 1phosphate (S1P)1,4,5 receptor modulator for the treatment of moderately to severely active UC. It leads to selective and reversible lymphocyte sequestration, and partial peripheral lymphocyte count decrease. We report infection events from the phase 3 ELEVATE program. METHODS: Proportions, incidence rates (IRs; per 100 patient-years) and descriptive analyses of all, serious, severe, herpes zoster, and opportunistic infections are reported in the Pivotal UC cohort (ELEVATE UC 52 and ELEVATE UC 12). Cox regression models evaluated potential baseline risk factors. RESULTS: In this analysis (n=787), proportions (IRs) of all infection events were similar for patients receiving etrasimod 2 mg QD (18.8% [41.1]) or placebo (17.7% [49.0]). Serious infections occurred in three (0.6%) and five (1.9%) patients receiving etrasimod and placebo, respectively. Two herpes zoster events were reported in each group (etrasimod: 0.4%; placebo: 0.8%); all localized and non-serious. One opportunistic infection event was reported in each group. No patient with an absolute lymphocyte count (ALC) <0.2 × 109/L reported serious/severe or opportunistic infections; no baseline risk factors were identified for such events. No deaths occurred. CONCLUSIONS: Patients receiving etrasimod demonstrated no increased risk of infection. The incidence of serious infections and herpes zoster was similar in each group. Among patients receiving etrasimod, no association between ALC <0.5 × 109/L and infection events was observed. Longer-term follow-up will further characterize the etrasimod safety profile.

Ileal mucus viscoelastic properties differ in Crohn's disease.

Crohn's disease (CD) is an inflammatory bowel disease that can affect any part of the gastrointestinal tract, frequently involving the terminal ileum. While colonic mucus alterations in CD patients have been described, terminal ileal mucus and its mechanobiological properties have been neglected. Our study is the first of its kind to decipher the viscoelastic and network properties of ileal mucus. With that aim, oscillatory rheological shear measurements based on an airway mucus protocol that was thoroughly validated for ileal mucus were performed. Our pilot study analyzed terminal ileum mucus from controls (n = 14) and CD patients (n = 14). Mucus network structure was visualized by scanning electron microscopy. Interestingly, a statistically significant increase in viscoelasticity as well as a decrease in mesh size was observed in ileal mucus from CD patients compared to controls. Furthermore, rheological data were analyzed in relation to study participants' clinical characteristics, revealing a noteworthy trend between non-smokers and smokers. In conclusion, this study provides the first data on the viscoelastic properties and structure of human ileal mucus in the healthy state and Crohn's disease, demonstrating significant alterations between groups and highlighting the need for further research on mucus and its effect on the underlying epithelial barrier.

In-hospital survival of critically ill COVID-19 patients treated with glucocorticoids: a multicenter real-world data study.

The COVID-19 pandemic has posed a major challenge to healthcare systems globally. Millions of people have been infected, and millions of deaths have been reported worldwide. Glucocorticoids have attracted worldwide attention for their potential efficacy in the treatment of COVID-19. Various glucocorticoids with different dosages and treatment durations have been studied in patients with different severities, with a suitable dosage and treatment duration not yet defined. This study aimed to investigate whether in-hospital survival differs between critically ill patients treated with low-dose glucocorticoids, high-dose glucocorticoids or no glucocorticoids. All critically ill patients admitted to the intensive care unit of the Charité Hospital-Universitätsmedizin Berlin between February 2020 and December 2021 with COVID-19 pneumonia receiving supplemental oxygen were eligible to participate in this multicenter real-world data study. Patients were retrospectively assigned to one of three groups: the high corticosteroid dose (HighC) group (receiving 6 mg parenteral dexamethasone or an equivalent corticosteroid dosage for ten days), the low corticosteroid dose (LowC) group (receiving less than 6 mg parenteral dexamethasone or an equivalent corticosteroid dosage for ten days), or the no corticosteroid (NoC) group. Overall survival and risk effects were compared among groups within the total observation period, as well as at 35 days after the onset of COVID-19 symptoms. Adjusted multivariable Cox proportional hazard regression analysis was performed to compare the risk of death between the treatment groups. Out of 1561 critically ill COVID-19 patients, 1014 were included in the baseline analysis. In the survival study, 1009 patients were assigned to the NoC (n = 346), HighC (n = 552), or LowC group (n = 111). The baseline characteristics were balanced between groups, except for age, BMI, APACHE II score, SOFA and SAPS II. While the 35-day survival did not show any differences, a landmark analysis of the patients surviving beyond 35 days revealed differences between groups. The restricted mean survival time was 112 days in the LowC group [95% CI: 97 - 128], 133 days in the HighC group [95% CI: 124 - 141] and 144 days in the NoC group [95% CI: 121 - 167]. The multivariable-adjusted Cox proportional hazard analysis indicated that, regardless of age, sex, health status or invasive oxygenation, a low-dose treatment increased the hazard of death of critically ill COVID-19 patients by a factor of 2.09 ([95% CI: 0.99, 4.4], p = 0.05) and a high-dose corticosteroid treatment increased the risk by a factor of 1.07 ([95% CI: 0.53, 2.15], p = 0.85) compared to no treatment with glucocorticoids. The analysis reveals that corticosteroid treatment does not influence the survival of critically ill COVID-19 patients in the intensive care unit within 35 days. Our evaluations further suggest that regardless of ventilation status, the decision-making process for administering corticosteroid therapy should account for the individual severity of the illness.

Preventing and managing cardiovascular events in patients with inflammatory bowel diseases treated with small-molecule drugs, an international Delphi consensus.

Janus kinase (JAK) inhibitors and sphingosine 1 phosphate (S1P) receptor modulators are small molecule drugs (SMDs) approved for IBD treatment. Their use in clinical practice might be limited due to cardiovascular concerns. We aimed to provide guidance on risk assessment, monitoring, and management strategies, aiming to minimize potential cardiovascular risks of SMDs and to facilitate an adequate shared decision-making. A systematic literature search was conducted, and proposed statements were prepared. A virtual consensus meeting was held, in which eleven IBD physicians and two cardiovascular specialists from ten countries attended. Proposed statements were voted upon in an anonymous manner. Agreement was defined as at least 75 % of participants voting as 'agree' with each statement. Consensus was reached for eighteen statements. Available evidence does not show a higher risk of cardiovascular events with JAK inhibitors in the overall IBD population, although it might be increased in patients with an unfavorable cardiovascular profile. S1P receptor modulators may be associated with a risk of bradycardia, atrioventricular blocks, and hypertension. Cardiovascular risk stratification should be done before initiation of SMDs. Although the risk of cardiovascular events in patients with IBD on SMDs appears to be low overall, caution should still be taken in certain scenarios.

Spatial single cell profiling using imaging mass cytometry - inflammatory versus penetrating Crohn's disease.

BACKGROUND AND AIMS: Fistula formation is a major complication in Crohn's disease (CD) and the role of the immune cell compartment remains to be elucidated. Thus, we compared the immune-cell compartment of CD fistula to inflammatory CD colitis using imaging mass cytometry and immunofluorescence. METHODS: A 36-marker panel including structural, functional and lineage markers for use in imaging mass cytometry (IMC) was established. This panel was applied to analyze paraffin-embedded CD fistula tract (n=11), CD colitis (n=10), and colon samples from non-inflamed controls (n=12). Computational methods for cell segmentation, dimensionality reduction and cell type clustering were used to define cell populations for cell frequency, marker distribution and spatial neighborhood analysis. Multiplex immunofluorescence was used for higher resolution spatial analysis. RESULTS: Analysis of cell frequencies in CD fistulas compared to CD colitis and control colonic samples revealed a significant increase in neutrophils, effector cytotoxic T cells and inflammatory macrophages in CD fistula samples, whereas regulatory T cells were decreased. Neutrophils in CD fistula expressed significantly more matrix metalloproteinase 9 (MMP9), correlating to extracellular matrix remodeling. Neighborhood analysis revealed a strong association between MMP9+ neutrophils and effector cytotoxic T cells in both CD fistulas and colitis. CONCLUSIONS: This study presents the first highly multiplexed single cell analysis of the immune-cell compartment of CD fistulas and their spatial context. It links immune cell dynamics, particularly MMP9+ neutrophils, to extracellular matrix remodeling in CD fistulas, offering insights into the complex network of cellular interactions and potential therapeutic targets for CD complications.

Shared and Distinct Gut Microbiota in Spondyloarthritis, Acute Anterior Uveitis, and Crohn's Disease.

OBJECTIVE: Spondyloarthritis (SpA) is a group of immune-mediated diseases highly concomitant with nonmusculoskeletal inflammatory disorders, such as acute anterior uveitis (AAU) and Crohn's disease (CD). The gut microbiome represents a promising avenue to elucidate shared and distinct underlying pathophysiology. METHODS: We performed 16S ribosomal RNA sequencing on stool samples of 277 patients (72 CD, 103 AAU, and 102 SpA) included in the German Spondyloarthritis Inception Cohort and 62 back pain controls without any inflammatory disorder. Discriminatory statistical methods were used to disentangle microbial disease signals from one another and a wide range of potential confounders. Patients were naive to or had not received treatment with biological disease-modifying antirheumatic drugs (DMARDs) for >3 months before enrollment, providing a better approximation of a true baseline disease signal. RESULTS: We identified a shared, immune-mediated disease signal represented by low abundances of Lachnospiraceae taxa relative to controls, most notably Fusicatenibacter, which was most abundant in controls receiving nonsteroidal antiinflammatory drug monotherapy and implied to partially mediate higher serum C-reactive protein. Patients with SpA showed an enrichment of Collinsella, whereas human leukocyte antigen (HLA)-B27+ individuals displayed enriched Faecalibacterium. CD patients had higher abundances of a Ruminococcus taxon, and previous conventional/synthetic DMARD therapy was associated with increased Akkermansia. CONCLUSION: Our work supports the existence of a common gut dysbiosis in SpA and related inflammatory pathologies. We reveal shared and disease-specific microbial associations and suggest potential mediators of disease activity. Validation studies are needed to clarify the role of Fusicatenibacter in gut-joint inflammation, and metagenomic resolution is needed to understand the relationship between Faecalibacterium commensals and HLA-B27.

Myenteric Plexus Immune Cell Infiltrations and Neurotransmitter Expression in Crohn's Disease and Ulcerative Colitis.

BACKGROUND AND AIMS: Pain is a cardinal symptom in inflammatory bowel disease [IBD]. An important structure in the transduction of pain signalling is the myenteric plexus [MP]. Nevertheless, IBD-associated infiltration of the MP by immune cells lacks in-depth characterisation. Herein, we decipher intra- and periganglionic immune cell infiltrations in Crohn´s disease [CD] and ulcerative colitis [UC] and provide a comparison with murine models of colitis. METHODS: Full wall specimens of surgical colon resections served to examine immune cell populations by either conventional immuno-histochemistry or immunofluorescence followed by either bright field or confocal microscopy. Results were compared with equivalent examinations in various murine models of intestinal inflammation. RESULTS: Whereas the MP morphology was not significantly altered in IBD, we identified intraganglionic IBD-specific B cell- and monocyte-dominant cell infiltrations in CD. In contrast, UC-MPs were infiltrated by CD8+ T cells and revealed a higher extent of ganglionic cell apoptosis. With regard to the murine models of intestinal inflammation, the chronic dextran sulphate sodium [DSS]-induced colitis model reflected CD [and to a lesser extent UC] best, as it also showed increased monocytic infiltration as well as a modest B cell and CD8+ T cell infiltration. CONCLUSIONS: In CD, MPs were infiltrated by B cells and monocytes. In UC, mostly CD8+ cytotoxic T cells were found. The chronic DSS-induced colitis in the mouse model reflected best the MP-immune cell infiltrations representative for IBD.

IL-20 controls resolution of experimental colitis by regulating epithelial IFN/STAT2 signalling.

OBJECTIVE: We sought to investigate the role of interleukin (IL)-20 in IBD and experimental colitis. DESIGN: Experimental colitis was induced in mice deficient in components of the IL-20 and signal transducer and activator of transcription (STAT)2 signalling pathways. In vivo imaging, high-resolution mini-endoscopy and histology were used to assess intestinal inflammation. We further used RNA-sequencing (RNA-Seq), RNAScope and Gene Ontology analysis, western blot analysis and co-immunoprecipitation, confocal microscopy and intestinal epithelial cell (IEC)-derived three-dimensional organoids to investigate the underlying molecular mechanisms. Results were validated using samples from patients with IBD and non-IBD control subjects by a combination of RNA-Seq, organoids and immunostainings. RESULTS: In IBD, IL20 levels were induced during remission and were significantly higher in antitumour necrosis factor responders versus non-responders. IL-20RA and IL-20RB were present on IECs from patients with IBD and IL-20-induced STAT3 and suppressed interferon (IFN)-STAT2 signalling in these cells. In IBD, experimental dextran sulfate sodium (DSS)-induced colitis and mucosal healing, IECs were the main producers of IL-20. Compared with wildtype controls, Il20-/-, Il20ra-/- and Il20rb-/- mice were more susceptible to experimental DSS-induced colitis. IL-20 deficiency was associated with increased IFN/STAT2 activity in mice and IFN/STAT2-induced necroptotic cell death in IEC-derived organoids could be markedly blocked by IL-20. Moreover, newly generated Stat2ΔIEC mice, lacking STAT2 in IECs, were less susceptible to experimental colitis compared with wildtype controls and the administration of IL-20 suppressed colitis activity in wildtype animals. CONCLUSION: IL-20 controls colitis and mucosal healing by interfering with the IFN/STAT2 death signalling pathway in IECs. These results indicate new directions for suppressing gut inflammation by modulating IL-20-controlled STAT2 signals.

[A critical DRG-evaluation of cases with inflammatory bowel disease]. / Ein kritischer DRG-Blick auf Fälle mit chronisch entzündlichen Darmerkrankungen.

INTRODUCTION: Whether inpatients with inflammatory bowel disease (IBD) are reimbursed in a cost-covering manner in German hospitals has not yet been investigated. In this context, the present study analyses the reimbursement situation (cost-revenue comparison) of IBD in German hospitals with regard to the complexity of the disease and the type of care. METHODS: For this retrospective study, anonymized case data, including cost data from the InEK calculation (§ 21-4 KHEntgG) of the DRG project of the German Society for Gastroenterology, Digestive and Metabolic Diseases (DGVS) from 2019, were available. 3385 cases with IBD the as main diagnosis from 49 hospitals were analyzed. To investigate the impact of disease complexity on reimbursement, different variables were analyzed, including gastroenterological complications, infections, the reason for admission, and additional charges. To investigate possible center effects, hospitals were grouped by type of care, mostly defined by the number of beds. RESULTS: The present study shows that all types of care can be classified as not cost-covering on average. The under-recovery is, on average, 10% (296 € absolute under-recovery) and varies between the types of care. Cases with higher complexity show a higher cost under-recovery than cases with lower complexity. At the DRG level, the analyzed costs of the three most common IBD DRGs for inlier patients are higher than the InEK costs; however, the difference is not significant. Nonetheless, cases with the admission reason transfer of specific DRGs bear significantly higher costs. DISCUSSION: Our results show that CED is not reimbursed in a cost-covering manner. This is due to inadequate reimbursement for gastroenterological complications, infections, specific procedures, and emergency and transfer cases. Transfer cases bear significantly higher costs.

Implementation of regulatory guidance for JAK inhibitors use in patients with immune-mediated inflammatory diseases: An international appropriateness study.

BACKGROUND AND AIMS: The Pharmacovigilance Risk Assessment Committee (PRAC) proposed measures to address severe side effects linked to Janus kinase inhibitors (JAKi) in immune-mediated inflammatory diseases (IMID). Use of these medications in individuals aged 65 and older, those at high cardiovascular risk, active or former long-term smokers, and those with increased cancer risk should be considered only if no alternatives exist. Caution is advised when administering JAKi to patients at risk of venous thromboembolism. We aim to implement recommendations from regulatory guidelines based on areas of uncertainty identified. METHODS: A two-round modified Research and Development/University of California Los Angeles appropriateness methodology study was conducted. A panel of 21 gastroenterologists, dermatologists and rheumatologists used a 9-point Likert scale to rate the appropriateness of administering a JAKi for each proposed clinical scenario. Scores for appropriateness were categorized as appropriate, uncertain, or inappropriate. Two rounds were performed, each with online surveys and a virtual meeting to enable discussion and rating of each best practice. RESULTS: Round 1 involved participants rating JAKi appropriateness and suggesting descriptors to reduce uncertainty. Survey results were discussed in a virtual meeting, identifying areas of disagreement. In round 2, participants rated their agreement with descriptors from round 1, and the level of uncertainty and disagreement reduced. Age flexibility is recommended in the absence of other risk factors. Active counseling on modifiable risks (e.g., overweight, mild hyperlipidemia and hypertension) and smoking cessation is advised. Uncertainty persists regarding cancer risk due to various factors. CONCLUSIONS: We outlined regulatory guidance without a personalized evaluation of the patient's risk profile might lead to uncertainty and become an arid technicality. Therefore, we identified gaps and implemented PRAC recommendations to help health professionals in clinical practice.

[Pregnancy and breastfeeding in Crohn's disease]. / Schwangerschaft und Stillzeit bei Morbus Crohn.

Inflammatory bowel disease (IBD) is often diagnosed in young adults. Starting a family is an important step in life and can be further complicated by Crohn's disease. Therefore, family planning should be discussed with every patient early in the disease course. Counseling about the importance of disease remission and the safety of IBD medication during pregnancy can ameliorate the pregnancy outcome. Active disease during pregnancy can lead to adverse pregnancy outcomes such as preterm birth and low birthweight. To maintain disease remission most therapies should be continued despite the wish to have children. Only a few substances currently used to treat Crohn's disease are contraindicated during pregnancy and should be stopped before conception. This includes Januskinase (JAK)-inhibitors and Methotrexate. Biologics including anti-TNF-therapy, anti-IL-12/anti-IL-23 and anti-integrin therapies should be continued during pregnancy.

The Safety, Tolerability, Pharmacokinetics and Clinical Efficacy of the NLRX1 agonist NX-13 in Active Ulcerative Colitis: Results of a Phase 1b Study.

BACKGROUND AND AIMS: NX-13 activation of NLRX1 reduces intracellular reactive oxygen species and decreases inflammation in animal models of colitis. A phase 1a trial demonstrated a gut-selective pharmacokinetic (PK) profile with good tolerability. This phase Ib study aimed to evaluate the safety, tolerability, and PK of NX-13 in patients with active ulcerative colitis (UC). METHODS: We conducted a multicenter, randomized, double-blinded, placebo-controlled trial of NX-13 in patients with active UC. Patients with a Mayo Clinic Score of 4-10 were randomly assigned (3:3:3:1 ratio) to three NX-13 oral dose groups (250mg Immediate Release (IR), 500mg IR, or 500mg Delayed Release (DR) or placebo) once daily for 4 weeks. Safety and PK were the primary and secondary objectives, respectively. RESULTS: Thirty-eight patients (11 females) were recruited and randomized to placebo (5), NX-13 250mg IR (11), NX-13 500mg IR (11), or NX-13 500mg DR (11) and received at least one dose. There were no Serious Adverse Events (SAEs) or deaths during the trial. One patient (500mg DR, 1/11) withdrew for worsening of UC and a second (500mg IR, 1/11) on the last day of treatment after a panic attack associated with atrial fibrillation. In the efficacy population (36 patients), clinical improvement in rectal bleeding and stool frequency scores relative to placebo were seen as early as week 2 and endoscopic response was seen at week 4. CONCLUSIONS: NX-13 was generally safe and well tolerated with early signs of rapid symptom and endoscopic improvement. This novel mechanism of action warrants further investigation. ClinicalTrials.gov: NCT04862741.

A Core Outcome Set for inflammatory bowel diseases: development and recommendations for implementation in clinical practice through an international multi-stakeholder consensus process.

BACKGROUND AND AIMS: Standardising health outcome measurements supports delivery of care, enables data-driven learning systems, and secondary data use for research. As part of the Health Outcomes Observatory initiative and building on existing knowledge, a core outcome set (COS) for inflammatory bowel diseases (IBD) was defined through an international modified Delphi method. METHODS: Stakeholders rated 90 variables on a 9-point importance scale twice, allowing score modification based on feedback displayed per stakeholder group. Two consecutive consensus meetings were held to discuss results and formulate recommendations for measurement in clinical practice. Variables scoring 7 or higher by ≥80% of the participants, or based on consensus meeting agreement, were included in the final set. RESULTS: In total, 136 stakeholders (45 IBD patients (advocates), 74 healthcare professionals/researchers, 13 industry representatives and 4 regulators), from 20 different countries participated. The final set includes 18 case-mix variables, 3 biomarkers (haemoglobin to detect anaemia, C-reactive protein and faecal calprotectin to detect inflammation) for completeness and 28 outcomes (including 16 patient-reported outcomes (PROs) and 1 patient-reported experience). The PRO-2 and IBD-Control questionnaires were recommended to collect disease-specific PROs at every contact with an IBD practitioner, and the Subjective Health Experience model questionnaire, PROMIS Global Health and Self-Efficacy short form to collect generic PROs annually. CONCLUSIONS: A COS for IBD, including a recommendation for use in clinical practice, was defined. Implementation of this set will start in Vienna, Berlin, Barcelona, Leuven and Rotterdam, empowering patients to better manage their care. Additional centres will follow worldwide.

Selection of cross-reactive T cells by commensal and food-derived yeasts drives cytotoxic TH1 cell responses in Crohn's disease.

Aberrant CD4+ T cell reactivity against intestinal microorganisms is considered to drive mucosal inflammation in inflammatory bowel diseases. The disease-relevant microbial species and the corresponding microorganism-specific, pathogenic T cell phenotypes remain largely unknown. In the present study, we identified common gut commensal and food-derived yeasts, as direct activators of altered CD4+ T cell reactions in patients with Crohn's disease (CD). Yeast-responsive CD4+ T cells in CD display a cytotoxic T helper cell (TH1 cell) phenotype and show selective expansion of T cell clones that are highly cross-reactive to several commensal, as well as food-derived, fungal species. This indicates cross-reactive T cell selection by repeated encounter with conserved fungal antigens in the context of chronic intestinal disease. Our results highlighted a role of yeasts as drivers of aberrant CD4+ T cell reactivity in patients with CD and suggest that both gut-resident fungal commensals and daily dietary intake of yeasts might contribute to chronic activation of inflammatory CD4+ T cell responses in patients with CD.

Disease Clearance as a New Outcome in Ulcerative Colitis: a Systematic Review and Expert Consensus.

The concept of disease clearance has been proposed as a potential target in ulcerative colitis (UC). We conducted a systematic review to investigate the role of disease clearance, defined as a composite outcome including simultaneous clinical, endoscopic, and histologic remission of disease in the management of patients with UC. Based on the literature data, statements regarding disease clearance were developed and voted on by the members of the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) according to a Delphi methodology. A definition of disease clearance was proposed to standardize its use in clinical practice and clinical trials and to provide practical recommendations for its implementation as a therapeutic target in UC.

Feasibility of in vivo magnetic resonance elastography of mesenteric adipose tissue in Crohn's disease.

Background: Although there is growing evidence that functional involvement and structural changes of mesenteric adipose tissue (MAT) influence the course of Crohn's disease (CD), its viscoelastic properties remain elusive. Therefore, we aimed to investigate the viscoelastic properties of MAT in CD using magnetic resonance elastography (MRE), providing reference values for CD diagnosis. Methods: In this prospective proof-of-concept study, 31 subjects (CD: n=11; healthy controls: n=20) were consecutively enrolled in a specialized care center for inflammatory bowel diseases (tertiary/quaternary care). Inclusion criteria for the CD patients were a clinically and endoscopically established diagnosis of CD based on the clinical record, absence of other concurrent bowel diseases, scheduled surgery for the following day, and age of at least 18 years. Diagnoses were confirmed by histological analysis of the resected bowel the day after MRE. Subjects were investigated using MRE at 1.5-T with frequencies of 40-70 Hz. To retrieve shear wave speed (SWS), volumes of interest (VOIs) in MAT were drawn adjacent to CD lesions (MATCD) and on the opposite side without adjacent bowel lesions in patients (MATCD_Opp) and controls (MATCTRL). The presented study is not registered in the clinical trial platform. Results: A statistically significant decrease in mean SWS of 7% was found for MATCD_Opp vs. MATCTRL (0.76±0.05 vs. 0.82±0.04 m/s, P=0.012), whereas there was a nonsignificant trend with an 8% increase for MATCD vs. MATCD_Opp (0.82±0.07 vs. 0.76±0.05 m/s, P=0.098) and no difference for MATCD vs. MATCTRL. Preliminary area under the receiver operating characteristic curve (AUC) analysis showed diagnostic accuracy in detecting CD to be excellent for SWS of MATCD_Opp [AUC =0.82; 95% confidence interval (CI): 0.64-0.96] but poor for SWS of MATCD (AUC =0.52; 95% CI: 0.34-0.73). Conclusions: This study demonstrates the feasibility of MRE of MAT and presents preliminary reference values for CD patients and healthy controls. Our results motivate further studies for the biophysical characterization of MAT in inflammatory bowel disease.