Active Crohn's Disease Research Articles

Fecal transplantation for treatment of inflammatory bowel disease.

Fecal transplantation for treatment of inflammatory bowel disease.

Role of prebiotics, probiotics, and synbiotics in management of inflammatory bowel disease: Current perspectives.

Experimental evidence supports the fact that changes in the bowel microflora due to environmental or dietary factors have been investigated as implicating factors in the etiopathogenesis of inflammatory bowel disease (IBD). The amassing knowledge that the inhabited microbiome regulates the gut physiology and immune functions in IBD, has led researchers to explore the effectiveness of prebiotics, probiotics, and synbiotics in treating IBD. This therapeutic approach focuses on restoring the dynamic balance between the microflora and host defense mechanisms in the intestinal mucosa to prevent the onset and persistence of intestinal inflammation. Numerous microbial strains and carbohydrate blends, along with their combinations have been examined in experimental colitis models and clinical trials, and the results indicated that it can be an attractive therapeutic strategy for the suppression of inflammation, remission induction, and relapse prevention in IBD with minimal side effects. Several mechanisms of action of probiotics (for e.g., Lactobacillus species, and Bifidobacterium species) have been reported such as suppression of pathogen growth by releasing certain antimicrobial mediators (lactic and hydrogen peroxide, acetic acid, and bacteriocins), immunomodulation and initiation of an immune response, enhancement of barrier activity, and suppression of human T-cell proliferation. Prebiotics such as lactulose, lactosucrose, oligofructose, and inulin have been found to induce the growth of certain types of host microflora, resulting in an enriched enteric function. These non-digestible food dietary components have been reported to exert anti-inflammatory effects by inhibiting the expression of tumor necrosis factor-α-related cytokines while augmenting interleukin-10 levels. Although pro-and prebiotics has established their efficacy in healthy subjects, a better understanding of the luminal ecosystem is required to determine which specific bacterial strain or combination of probiotics and prebiotics would prove to be the ideal treatment for IBD. Clinical trials, however, have given some conflicting results, requiring the necessity to cite the more profound clinical effect of these treatments on IBD remission and prevention. The purpose of this review article is to provide the most comprehensive and updated review on the utility of prebiotics, probiotics, and synbiotics in the management of active Crohn's disease and ulcerative colitis/pouchitis.

Changes in the gut mycobiome in pediatric patients in relation to the clinical activity of Crohn's disease

Numerous studies have shown that in Crohn's disease (CD), the gut microbiota is of great importance in the induction and maintenance of inflammation in the gastrointestinal tract. Until recently, studies have focused almost exclusively on bacteria in the gut. Lately, more attention has been paid to the role of intestinal fungi. To study the gut mycobiome analysis of pediatric patients with CD (in different stages of disease activity) compared to healthy children. Fecal samples were collected from patients: With active, newly diagnosed CD (n = 50); active but previously diagnosed and treated CD (n = 16); non-active CD and who were in clinical remission (n = 39) and from healthy volunteers (n = 40). Fungal DNA was isolated from the samples. Next, next generation sequencing (MiSeq, Illumina) was performed. The composition of mycobiota was correlated with clinical and blood parameters. Candida spp. were overrepresented in CD patients, while in the control group, the most abundant genus was Saccharomyces. In CD patients, the percentage of Malassezia was almost twice that of the control (P < 0.05). In active CD patients, we documented a higher abundance of Debaryomyces hansenii (D. hansenii) compared to the non-active CD and control (P < 0.05) groups. Moreover, statistically significant changes in the abundance of Mycosphaerella, Rhodotorula, and Microidium were observed. The analyses at the species level and linear discriminant analysis showed that in each group it was possible to distinguish a specific species characteristic of a given patient population. Moreover, we have documented statistically significant correlations between: D. hansenii and patient age (negative); C. zeylanoides and patient age (positive); C. dubliniensis and calprotectin (positive); C. sake and calprotectin (positive); and C. tropicalis and pediatric CD activity index (PCDAI) (positive). Mycobiome changes in CD patients, and the positive correlation of some species with calprotectin or PCDAI, give strong evidence that fungi may be of key importance in the development of CD.

Expression analysis of IL-2, TBX21 and SOCS1 in peripheral blood cells of celiac disease patients reveals the diagnostic potential of IL-2.

Celiac disease (CD) is a chronic immune-mediated enteropathy and a cytokine network is involved in its pathogenesis. Interleukin-2 (IL-2) has a key role in the adaptive immune pathogenesis of CD and has been reported to be one of the earliest cytokines to be elicited after gluten exposure by CD patients. This study aimed at investigating the expression level of IL-2 and functionally related genes SOCS1 and TBX21 in active and treated CD patients compared to controls. Peripheral blood (PB) samples were collected from 40 active CD (ACD), 100 treated CD, and 100 healthy subjects. RNA was extracted, cDNA was synthesized and mRNA expression levels of the desired genes were investigated by Real-time PCR. The gene-gene interaction network was also constructed by GeneMANIA. Our results showed a higher PB mRNA expression of IL-2 in ACD patients compared to controls (p = 0.001) and treated CD patients (p˂0.0001). The mRNA expression level of TBX21 was also significantly up-regulated in ACD patients compared to controls (P = 0.03). SOCS1 mRNA level did not differ between active and treated CD patients and controls (p˃0.05) but showed a significant correlation with the patient's aphthous stomatitis symptom (r = 0.37, p = 0.01). ROC curve analysis suggested that the use of IL-2 levels can reach a high specificity and sensitivity in discriminating active CD patients. The PB level of IL-2 has the potential to be introduced as a diagnostic biomarker for CD. Larger cohort studies, including pediatric patients, are needed to achieve more insights in this regard.

Predicting Crohn's disease severity in the colon using mixed cell nucleus density from pseudo labels.

Crohn's disease (CD) is a debilitating inflammatory bowel disease with no known cure. Computational analysis of hematoxylin and eosin (H&E) stained colon biopsy whole slide images (WSIs) from CD patients provides the opportunity to discover unknown and complex relationships between tissue cellular features and disease severity. While there have been works using cell nuclei-derived features for predicting slide-level traits, this has not been performed on CD H&E WSIs for classifying normal tissue from CD patients vs active CD and assessing slide label-predictive performance while using both separate and combined information from pseudo-segmentation labels of nuclei from neutrophils, eosinophils, epithelial cells, lymphocytes, plasma cells, and connective cells. We used 413 WSIs of CD patient biopsies and calculated normalized histograms of nucleus density for the six cell classes for each WSI. We used a support vector machine to classify the truncated singular value decomposition representations of the normalized histograms as normal or active CD with four-fold cross-validation in rounds where nucleus types were first compared individually, the best was selected, and further types were added each round. We found that neutrophils were the most predictive individual nucleus type, with an AUC of 0.92 ± 0.0003 on the withheld test set. Adding information improved cross-validation performance for the first two rounds and on the withheld test set for the first three rounds, though performance metrics did not increase substantially beyond when neutrophils were used alone.

Development and Validation of the Glasgow Exclusive Enteral Nutrition Index of Compliance.

Treatment adherence is key to the efficacy of exclusive enteral nutrition [100% EN] in active Crohn's disease [CD], but there are no biomarkers to objectively estimate this. We explored faecal parameters as biomarkers of compliance with 100% EN, and subsequently developed and validated the Glasgow Exclusive Enteral Nutrition Index of Compliance [GENIE]. Healthy adults replaced all [100% EN] or part [85% EN, 50% EN, 20% EN] of their diet with a formula for 7 days. Faecal pH, water content, short chain fatty acids, and branched chain fatty acids [BCFAs] were measured before [D0] and after [D7] each intervention. Optimal biomarkers and threshold values were derived using receiver operating characteristic curve analyses and machine learning to develop the GENIE. The GENIE was then validated in 30 CD children, during and after 100% EN. In all, 61 adults were recruited. D7 faecal pH and the ratios of BCFAs to either acetate or butyrate performed the best to differentiate between patients on 100% EN from <100% EN. Two models were generated; one included faecal metabolites (Laboratory GENIE, L-GENIE; sensitivity, specificity, and positive predictive value [PPV] of 88%, 94%, and 92%) and a second one [Clinical Genie, C-GENIE] which considers only faecal pH [sensitivity, specificity, and PPV of 84%, 86%, and 81%]. Validation of GENIE in CD children found that C-GENIE outperformed L-GENIE, producing a sensitivity, specificity, and PPV of 85%, 88%, and 88%, respectively. GENIE can help predict adherence to 100% EN and may complement current conventional dietary assessment.

Subcutaneous Infliximab Monotherapy Versus Combination Therapy with Immunosuppressants in Inflammatory Bowel Disease: A Post Hoc Analysis of a Randomised Clinical Trial

Whether benefits and risks of intravenous (IV) infliximab combotherapy with immunosuppressants versus infliximab monotherapy apply to subcutaneous (SC) infliximab is unknown. This post hoc analysis of a pivotal randomised CT-P13 SC 1.6 trial aimed to compare SC infliximab monotherapy with combotherapy in inflammatory bowel disease (IBD). Biologic-naïve patients with active Crohn's disease or ulcerative colitis received CT-P13 IV 5 mg/kg at Week (W) 0 and 2 (dose-loading phase). At W6, patients were randomised (1:1) to receive CT-P13 SC 120 or 240 mg (patients <80 or ≥80 kg) every 2 weeks until W54 (maintenance phase), or to continue CT-P13 IV every 8 weeks until switching to CT-P13 SC from W30. The primary endpoint-non-inferiority of trough serum concentrations-was assessed at W22. We report a post hoc analysis comparing pharmacokinetic, efficacy, safety and immunogenicity outcomes up to W54 for patients randomised to CT-P13 SC, stratified by concomitant immunosuppressant use. Sixty-six patients were randomised to CT-P13 SC (37 monotherapy, 29 combotherapy). At W54, there were no significant differences in the proportions of patients achieving target exposure (5 µg/mL; 96.6% monotherapy vs 95.8% combotherapy; p > 0.999) or meeting efficacy or biomarker outcomes including clinical remission (62.9% vs 74.1%; p = 0.418). Monotherapy and combotherapy groups had comparable immunogenicity (anti-drug antibodies [ADAs]: 65.5% vs 48.0% [p = 0.271], neutralising antibodies [in ADA-positive patients]: 10.5% vs 16.7% [p = 0.630], respectively). Pharmacokinetics, efficacy and immunogenicity were potentially comparable between SC infliximab monotherapy and combotherapy in biologic-naïve IBD patients. ClinicalTrials.gov: NCT02883452.

The Association Between Depression and Activity of Inflammatory Bowel Disease

Background: The association between depression and inflammatory bowel disease (IBD) has been reported worldwide. Objectives: We aimed to investigate the prevalence of active and inactive IBD depression and its associated risk factors among patients with depression and IBD. Materials &amp; Methods: In this cross-sectional study, demographic data and clinical characteristics of 156 IBD patients referred to Razi Hospital, Rasht City, Iran, were recorded from 2015 to 2016. The Beck depression inventory (BDI) was administered to all patients, and their scores were classified as no, mild, moderate, and severe depression. Modified Truelove and Witts severity index (MTWSI) for ulcerative colitis (UC) and Harvey Bradshaw severity index (HBSI) for Crohn’s disease (CD) were used to quantitate IBD activity as active UC (scored ≥10) and active CD (scored ≥7). Results: About 35.9% of the patients (n=56) had depression. Patients with active IBD had significantly higher BDI scores than those with inactive IBD (14.41±10.34 vs 10.14±10.28, respectively, P=0.011). Except for income (P=0.001), no significant associations were detected between IBD status and other background variables (P&gt;0.05). No patients in either active or inactive IBD groups had cancers. Based on the severity of depression, the patients were grouped as follows: 64.1% had no depression, 30.1% had mild depression, 5.8% had moderate depression, and 0.0% had severe depression. However, significant positive associations were seen between an increase in depression severity and having autoimmune diseases, a lower education level, and a history of IBD-related surgeries. Conclusion: It seems that patients with active IBD are more depressed than inactive IBD patients.

Comparison of gastrointestinal ultrasound with capsule endoscopy in patients with small bowel Crohn's disease

ObjectiveWe aimed to investigate the association between gastrointestinal ultrasound (GIUS) and capsule endoscopy (CE) in assessing disease activity in patients with small bowel Crohn's disease (CD).MethodsMedical records of 74 patients with small bowel CD who were treated at our hospital between January 2020 and March 2022 were retrospectively reviewed, including 50 men and 24 women. All patients underwent both GIUS and CE within one week after their admissions. The Simple Ultrasound Scoring of Crohn's Disease (SUS‐CD) and Lewis score were used to assess disease activity during GIUS and CE, respectively. P &lt; 0.05 was considered as statistically significant.ResultsThe area under the receiver operating characteristic curve (AUROC) of SUS‐CD was 0.90 (95% confidence interval [CI] 0.81–0.99; P &lt; 0.001). And the diagnostic accuracy of GIUS was 79.7%, with a sensitivity of 93.6%, a specificity of 81.8%, a positive predictive value of 96.7%, a negative predictive value of 69.2% in predicting active small bowel CD. Furthermore, the agreement between GIUS and CE was assessed using Spearman's correlation analysis and SUS‐CD was correlated with Lewis score (r = 0.82, P &lt; 0.001)ConclusionOur findings demonstrate a strong correlation between GIUS and CE in assessing the disease activity in patients with CD affecting the small intestine.

Tissue and Circulating MicroRNA-31, MicroRNA-200b, and MicroRNA-200c Reflects Disease Activity in Crohn‘s Disease Patients: Results from the BIOMIR Study

MicroRNAs (miR) have altered expression in multiple autoimmune disorders including inflammatory bowel disease. The aim of the study was to assess the tissue and circulating miR-31, miR-200b, and miR-200c expression levels as potential biomarkers for intestinal disease activity in patients with Crohn's disease (CD). The study included 45 patients with histopathological confirmed CD and active disease (defined as fecal calprotectin >50 μg/g and Simple Endoscopic Score (SES) of CD >3), and 21 subjects as controls for the validation cohort. Demographic and clinical data, biomarkers (fecal calprotectin), endoscopy data, the expression levels of miR-31, miR-200b, and miR-200c in tissue and serum were assessed (by RT-PCR). Receiver operating characteristic analysis was performed to assess the miR-31, miR-200b, and miR-200c expression levels as potential biomarkers for active CD. Mean fecal calprotectin was 1540±890 μg/g. Mean SES-CD was 8.9±4.2. Tissue and circulating miR- 31 were significantly correlated with fecal calprotectin (r=0.81, r=0.83, p<0.01) and with SES-CD (r=0.82, r=0.79, p<0.01). The expression level of miR-31 was significantly upregulated in CD tissue cases compared to the control tissue samples (6.24±1.57 vs. 3.70±1.44; p <0.01). Similarly, serum miR-31 expression levels in CD patients were significantly upregulated compared to the control serum samples (0.78±0.42 vs. -2.07±1.00; p<0.01). The expression levels of tissue miR-200b and miR-200c were significantly upregulated in CD tissue cases compared to the control tissue samples (-5.25±0.93 vs. -4.69±0.80, p=0.03 for miR-200b, and -0.86±0.96 vs. 0.39±0.66, p<0.01 for miR-200c). Similarly, serum miR-200b and miR-200c expression levels in CD patients were significantly upregulated compared to the control serum samples (p < 0.05). Receiver operating characteristic analysis revealed that the expression levels of the selected miRNAs could help to discriminate active CD patients from healthy controls with very good specificity and sensitivity. Tissue and circulating miR-31, miR-200b, and miR-200c reflect disease activity in CD patients and can be used as biomarkers for active disease.

Perfusion Computed Tomography May Help in Discriminating Gastrointestinal Tuberculosis and Crohn’s Disease

Gastrointestinal tuberculosis (GITB) and Crohn's disease (CD) are close mimics. This prospective study aimed to evaluate the diagnostic performance of perfusion computed tomography (CT) in differentiating GITB from CD. Consecutive patients with ileocaecal thickening underwent perfusion CT of the ileocaecal region between January 2019 and July 2020. Two radiologists (blinded to the final diagnosis) independently assessed blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability at perfusion CT. These parameters were compared among the patients with GITB as well as active and inactive CD. Receiver operating characteristic curves were utilized for determining the diagnostic performance of perfusion CT. Interclass correlation coefficient and Bland-Altman analysis were performed to compare the observations of the two radiologists. During the study period, 34 patients underwent perfusion CT. Eight patients had diagnoses other than intestinal tuberculosis or CD. Thus, 26 patients (mean age 36 ± 14 years, 18 males) with GITB (n = 11), active CD (n = 6), and inactive CD (n = 9) were evaluated. BF, MTT, and permeability showed significant differences among the groups, while BV did not differ significantly among the groups. BF and permeability had 100% sensitivity and 100% specificity, while MTT had 61.5-100% sensitivity and 70-100% specificity for differentiating GITB from active CD and active from inactive CD. The interclass correlation coefficient for perfusion CT parameters was 0.88-1. Perfusion CT is a novel imaging technique that can improve the diagnostic performance of differentiating tuberculosis from CD.

A Phase 2b, Randomised, Double-blind, Placebo-controlled, Parallel-arm, Multicenter Study Evaluating the Safety and Efficacy of Tesnatilimab in Patients with Moderately to Severely Active Crohn's Disease.

Tesnatilimab, a monoclonal antibody targeting NKG2D, was evaluated in Crohn's disease [CD] patients who had failed or were intolerant to biologic or conventional therapy. TRIDENT was a phase 2b, two-part, randomised, double-blind, placebo-controlled, parallel-arm, multicenter study. In Part 1 [proof of concept], 145 patients who were biologic intolerant or refractory [Bio-IR] or had not failed biologic therapy [Bio-NF] were randomised in a 1:1 ratio to placebo subcutaneously [SC] or tesnatilimab 400 mg SC. In Part 2 [dose ranging], 243 Bio-IR and Bio-NF patients were randomised in a 1:1:1:1:1 ratio to placebo, tesnatilimab [50 mg, 150 mg, 400 mg], or intravenous infusion of ustekinumab ~6 mg/kg at Week 0 and 90 mg SC at Weeks 8 and 16. The primary endpoint was mean change from baseline in Crohn's Disease Activity Index [CDAI] at Week 8 [Part 1] and Week 12 [Part 2]. Clinical and endoscopic remission/response were evaluated. Efficacy analyses were also assessed by NKG2D and MICB single nucleotide polymorphism [SNP] status [SNP-positive means positive in at least one of two SNPs]. Safety events were summarised. In Part 1, mean change from baseline in CDAI score was significantly greater with tesnatilimab vs placebo at Week 8 [-103.6 vs -60.0; p < 0.01]. In Part 2, no dose-response signal was detected. Mean changes from baseline in CDAI at Week 12 were -93.2, -72.2, and -84.3 for low, middle, and high doses of tesnatilimab, respectively, vs -59.2 for placebo and -148.8 for ustekinumab. Similar reductions from baseline in CDAI score were observed in patients receiving tesnatilimab, regardless of SNP status. Clinical remission rates were greater with tesnatilimab than placebo in Parts 1 and 2, whereas endoscopic response rates were greater with tesnatilimab only in Part 1. No unexpected safety events occurred. Tesnatilimab was well tolerated. The efficacy of tesnatilimab in patients with CD was significant for the primary endpoint in Part 1; however, no dose-response signal was detected for the primary endpoint in Part 2. Based on these inconsistent findings, tesnatilimab was not considered an effective treatment for patients with CD and no further development is planned. NCT02877134.

Transient Suppression of Bacterial Populations Associated with Gut Health is Critical in Success of Exclusive Enteral Nutrition for Children with Crohn's Disease.

Exclusive enteral nutrition [EEN] is a dietary intervention to induce clinical remission in children with active luminal Crohn's disease [CD]. While changes in the gut microbial communities have been implicated in achieving this remission, a precise understanding of the role of microbial ecology in the restoration of gut homeostasis is lacking. Here we reconstructed genomes from the gut metagenomes of 12 paediatric subjects who were sampled before, during and after EEN. We then classified each microbial population into distinct 'phenotypes' or patterns of response based on changes in their relative abundances throughout the therapy on a per-individual basis. Our data show that children achieving clinical remission during therapy were enriched with microbial populations that were either suppressed or that demonstrated a transient bloom as a function of EEN. In contrast, this ecosystem-level response was not observed in cases of EEN failure. Further analysis revealed that populations that were suppressed during EEN were significantly more prevalent in healthy children and adults across the globe compared with those that bloomed ephemerally during the therapy. These observations taken together suggest that successful outcomes of EEN are marked by a temporary emergence of microbial populations that are rare in healthy individuals, and a concomitant reduction in microbes that are commonly associated with gut homeostasis. Our work is a first attempt to highlight individual-specific, complex environmental factors that influence microbial response in EEN. This model offers a novel, alternative viewpoint to traditional taxonomic strategies used to characterize associations with health and disease states.

Serum leucine-rich alpha-2 glycoprotein and calprotectin in children with inflammatory bowel disease: A multicenter study in Japan.

Serum leucine-rich alpha-2 glycoprotein (LRG) and calprotectin have been studied as disease activity markers in adults with inflammatory bowel disease (IBD). We evaluated them in pediatric IBD patients. Subjects under 17years old undergoing care at 11 Japanese pediatric centers were retrospectively assigned to 3 groups representing Crohn's disease (CD), ulcerative colitis (UC), and normal controls (NC) with irritable bowel syndrome or no illness. Serum LRG and calprotectin were measured using commercial enzyme-linked immunosorbent assay kits. We enrolled 173 subjects, including 74 with CD, 77 with UC, and 22 NC. Serum LRG concentrations in active CD (median, 200μg/mL) were significantly greater than in remission (81μg/mL; P<0.001) or NC (69μg/mL; P<0.001). Serum calprotectin concentrations in active CD (2941ng/mL) also were significantly greater than in remission (962ng/mL; P<0.05) or NC (872ng/mL; P<0.05). Serum LRG concentrations in active UC (134μg/mL) were significantly greater than in remission (65μg/mL; P<0.01) but not significantly greater than in NC (69μg/mL); serum calprotectin concentrations in active UC (1058ng/mL) were not significantly different from those in remission (671ng/mL) or NC (872ng/mL). In receiver operating characteristic analyses of LRG, calprotectin, C-reactive protein, and erythrocyte sedimentation rate for ability to distinguish active IBD from remission, CD and UC showed areas under receiver operating characteristic curves for LRG (0.77 and 0.70, respectively), exceeding those for calprotectin, C-reactive protein, or erythrocyte sedimentation rate. In pediatric IBD, serum LRG may better reflect disease activity than serum calprotectin, particularly in CD.

Human small intestine contains 2 functionally distinct regulatory T-cell subsets

Regulatory T (Treg) CD4 cells in mouse gut are mainly specific for intestinal antigens and play an important role in the suppression of immune responses against harmless dietary antigens and members of the microbiota. However, information about the phenotype and function of Treg cells in the human gut is limited. We performed a detailed characterization of Foxp3+ CD4 Treg cells in human normal small intestine (SI) as well as from transplanted duodenum and celiac disease lesions. Treg cells and conventional CD4 T cells derived from SI were subjected to extensive immunophenotyping and their suppressive activity and ability to produce cytokines assessed. SI Foxp3+ CD4 T cells were CD45RA-CD127-CTLA-4+ and suppressed proliferation of autologous T cells. Approximately 60% of Treg cells expressed the transcription factor Helios. When stimulated, Helios-negative Treg cells produced IL-17, IFN-γ, and IL-10, whereas Helios-positive Treg cells produced very low levels of these cytokines. By sampling mucosal tissue from transplanted human duodenum, we demonstrated that donor Helios-negative Treg cells persisted for at least 1 year after transplantation. In normal SI, Foxp3+ Treg cells constituted only 2% of all CD4 T cells, while in active celiac disease, both Helios-negative and Helios-positive subsets expanded 5- to 10-fold. The SI contains 2 subsets of Treg cells with different phenotypes and functional capacities. Both subsets are scarce in healthy gut but increase dramatically in active celiac disease.

Fecal microbiota transplantation for induction of remission in Crohn's disease: a systematic review and meta-analysis.

Fecal microbiota transplantation (FMT) has been found to be a potential treatment for Crohn's disease (CD). We sought to perform a systematic review and meta-analysis to evaluate the efficacy and safety of FMT in CD. Electronic databases were searched for studies until January 2023. Clinical remission was established as the primary outcome. The secondary outcome was clinical response, endoscopic remission, minor adverse events, serious adverse events, and changes in disease activity indices, biochemical indicators, and microbial diversities. Pooled effect sizes and 95% confidence intervals (CIs) were calculated under the random effects model. Eleven cohort studies and one randomized controlled trial involving 228 patients were included. In a meta-analysis, the pooled proportion of adult patients with active CD that achieved clinical remission 2 to 4weeks after FMT was 57% (95% CI = 49-64%) with a low risk of heterogeneity (I2 = 37%). Furthermore, our results showed that FMT significantly (standardized mean difference = -0.66; 95% CI = -1.12 to -0.20; I2 = 0) reduced Crohn's disease activity index scores 4 to 8weeks after FMT. Subgroup analyses showed no difference between FMT methodologies, except for pre-FMT treatment with antibiotics (P = 0.02). Most adverse events were self-limiting and disappeared spontaneously within hours or days after FMT. Microbiota analysis showed an increased Shannon diversity and a shift toward donor-like microbiome after FMT. FMT could be a promising therapy in the short-term treatment of active CD. More placebo-controlled randomized trials with a long-term follow-up treatment are necessary. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022322694 No. CRD42022322694.

A29 HIGH DIMENSIONAL SINGLE CELL ANALYSIS OF IL-4 TREATED MACROPHAGES REVEALS A HETEROGENIC PHENOTYPE AND THE ABSENCE OF CD206+ SUBSETS IN CROHN'S DISEASE PATIENTS

Abstract Background Individuals with IBD have a reduced quality of life and while treatment has improved, a cure remains elusive. Interleukin-4 differentiated macrophages (M(IL4)s) from healthy donors and IBD patients in remission promote epithelial wound repair and reduce the severity of colitis in a mouse model: findings that support the autologous transfer of M(IL4)s to treat IBD. However, issues remain if this novel therapy is to advance to clinical evaluation: a much greater understanding of the possible heterogeneity within the human M(IL4) population, the biology of any sub-groups therein and the biology of any M(IL4) subtypes is needed. Purpose To determine if cryopreservation, sex, and disease status in Crohn's disease (CD) impact the phenotype and function of M(IL4) Method Blood mononuclear cells were collected from healthy donors, and individuals with active CD or in remission (n=6/group), and differentiated to macrophages with GMP-grade recombinant human M-CSF (10 ng/ml, 7 days). Macrophages (2.5 x105) were activated with IL-4 (10ng/ml, 48h). Fresh and cryopreserved M(0) and M(IL4) were stained using a panel of 18 metal-conjugated antibodies. Data were acquired on a Helios CyTOFII mass cytometer. FCS files were imported into Cytobank for manual gating (viable CD45+CD3-CD19- singlet cell events) and exported for meta-clustering in R with the CATALYST package using the FlowSOM function with 10 metaclusters. Result(s) FlowSOM analysis on M(IL4) from healthy donors indicated clear differences between M(0) and M(IL4), with 8 metaclusters &amp;gt;1.5% of M(IL4)s: the most abundant metaclusters express high and intermediate CD206, PDL1, CD11b, CD33, CD64, HLA-DR and low CD14 levels. There were no significant differences in these M(IL4)s metaclusters between males and females, or fresh vs. cryopreserved cells using this characterization strategy. M(IL4) from patients with active CD, were markedly different with the absence of three high-intermediate CD206+PDL1+ metaclusters and a general lack of CD206+ metaclusters compared to healthy controls. Surprisingly, and despite M(IL4)s from CD patients in remission showing increased CD206 mRNA, CYTOF analysis revealed that the macrophages were more similar to those from individuals with active disease than those from healthy controls Conclusion(s) Here human macrophages activated with IL4 in vitro are revealed as a heterogeneous population, and subsets characterized by increased high CD206 expression are generally absent in active Crohn’s disease. Intriguing while prior experiments with M(IL4) from CD patients in remission reduced the severity of colitis in rag1-/- mice, the characterization of these cells via 18 protein markers indicates they are more like M(IL4)s from patients with active disease compared to healthy controls. While presenting autologous M(IL4) transfer as a novel approach for IBD, a much fuller understanding of the phenotype and function of M(IL4)s (and sub-populations therein) is required before this would become a therapeutic option Please acknowledge all funding agencies by checking the applicable boxes below CAG Disclosure of Interest None Declared

A17 EVIDENCE OF PROTEASE-MEDIATED PRO-NOCICEPTIVE EFFECTS OF FECAL SUPERNATANTS FROM CROHN'S DISEASE PATIENTS

Abstract Background Abdominal pain is a debilitating symptom of Crohn’s disease (CD). Despite the current treatment options for this disease, abdominal pain is an unresolved problem that commonly persists in the absence of active inflammation. This suggests that something other than inflammation is driving the pain during the quiescent phase. We have previously reported that microbial proteases can directly modulate the excitability of dorsal root ganglia (DRG) neurons, many of which are pain-sensing. We hypothesize that luminal proteases of CD patients are contributing to their abdominal pain. Purpose Determine whether luminal mediators in CD fecal samples induce changes in pain signalling. Method The effects of patient (active CD [n = 3] and healthy volunteer (HV) [n = 3]) fecal supernatant (FS) samples on pain-sensing neurons were assessed using ex-vivo single unit afferent nerve recordings from mouse colons. Each sample was tested in colonic preparations from a least 5 mice. To further examine cellular mechanisms, DRG neurons were isolated and incubated overnight in media containing CD FS or HV FS media. Changes in neuronal excitability were recorded by determining the rheobase (lower rheobase=increased excitability) using patch clamp recordings (n ≥ 9 DRG neurons/group). Protease inhibitors were applied in both bioassays to determine whether these inhibited the excitatory effect of FS. Lastly, total proteolytic activity in the CD and HV fecal samples was calculated using a casein colorimetric protease detection assay. Result(s) FS from HV had no effect on afferent nerve excitability (p = 0.8920). FS from active CD patients increased action potential discharge from colonic afferent nerves by 85% (p&amp;lt;0.0001) and selectively increased the activation of high-threshold units, which are putative nociceptors, by 44% (p=0.0074). A protease inhibitor cocktail (1:1000) and protease-activated receptor (PAR)-2 antagonist GB83 (10µM) both blocked the excitatory effects of CD FS (p&amp;lt;0.05). Overnight incubation with CD FS also had an excitatory effect on DRG neurons compared to HV FS (rheobase decreased by 46%, p&amp;lt;0.05). The effect of CD FS was blocked by GB83 (10µM) (p&amp;lt;0.001) and a serine protease inhibitor (FUT175; 100µM) (p&amp;lt;0.05) independently, but the activity was not blocked by E64 (30nM) a cysteine protease inhibitor. A 200-fold increase (p&amp;lt;0.0001) in total proteolytic activity was found in CD FS compared to HV FS. Conclusion(s) Luminal serine proteases, but not cysteine proteases, appear to be driving nociceptive signalling in CD patients. This provides insight into the generation of pain in CD patients and may be a potential target to mitigate this action. Further research is required to elucidate whether these pro-nociceptive proteases are of bacterial or host origin and their effects in the quiescent phase. Disclosure of Interest None Declared

The ClC-2 Chloride Channel Activator, Lubiprostone, Improves Intestinal Barrier Function in Biopsies from Crohn's Disease but Not Ulcerative Colitis Patients.

The prostone analog, lubiprostone, is approved to manage constipation-predominant irritable bowel syndrome. Lubiprostone also protects intestinal mucosal barrier function in animal models of colitis. The aim of this study was to determine if lubiprostone improves barrier properties in isolated colonic biopsies from Crohn's disease (CD) and ulcerative colitis (UC) patients. Sigmoid colon biopsies from healthy subjects, CD and UC patients in remission, and CD patients with active disease were mounted in Ussing chambers. Tissues were treated with lubiprostone or vehicle to determine the effects on transepithelial electrical resistance (TER), FITC-dextran 4kD (FD4) permeability, and electrogenic ion transport responses to forskolin and carbachol. Localization of the tight junction protein, occludin, was determined by immunofluorescence. Lubiprostone significantly increased ion transport across control, CD and UC remission biopsies but not active CD. Lubiprostone selectively improved TER in both CD remission and active disease biopsies but not in control or UC biopsies. The improved TER was associated with increased membrane localization of occludin. Lubiprostone selectively improved barrier properties of biopsies from CD patients vs. UC and independent of an ion transport response. These data indicate that lubiprostone has potential efficacy in improving mucosal integrity in Crohn's disease.

Tumor necrosis factor-related apoptosis-inducing ligand gene polymorphism and its plasma phenotype in relation to Crohn's disease

Objectives: To investigate the associations of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene polymorphism and plasma soluble TRAIL level (sTRAIL) with Crohn's disease (CD) and to retrospectively analyze the effects of TRAIL gene variants and plasma sTRAIL levels on clinical response to infliximab (IFX). Methods: From January 2012 to January 2021, 312 CD patients [205 males, 107 females, average age (33.9±9.8) years] and 514 age-and gender-matched healthy controls [304 males, 210 females, average age (34.9±9.4) years] were recruited from the Department of Gastroenterology, the Second Affiliated Hospital of Wenzhou Medical University. Among them, 72 patients with active CD who were ineffective or intolerant to traditional drug therapy regularly received IFX (5 mg/kg) treatment. According to the changes in the Harvey-Bradshaw index (HBI) and the Simplified Endoscopic Score for Crohn's Disease (SES-CD) in the 14th week, these patients were classified into response group (a decrease in HBI≥3 or a decrease in SES-CD≥50%) and non-response group. TRAIL (rs1131568) gene polymorphism was analyzed by matrix-assisted laser desorption/ionization time of flight mass spectrometry technique. The plasma sTRAIL level was examined by enzyme-linked immunosorbent assay (ELISA). Based on the Montreal CD classification criteria, all CD patients were divided into different subgroups. Finally, a comprehensive analysis was performed to investigate the relationship between TRAIL (rs1131568) gene polymorphism, the plasma sTRAIL level and the risk of CD, the clinicopathological characteristics of CD patients, and the clinical response to IFX. Results: The recessive model analysis showed that the homozygous variant genotype (CC) was more prevalent in patients with moderately to severely active CD than in those with mildly active CD (45.34% vs 29.23%, P=0.005). Both variant allele (C) and homozygous variant genotype (CC) in patients with stricturing and penetrating CD were more frequent than those in patients with non-stricturing and non-penetrating CD (65.48% vs 57.53%, P=0.046; 49.21% vs 31.18%, P=0.001). The dominant model analysis showed that variant allele (C) and variant genotype (TC+CC) was higher in CD patients with perianal lesions than in those without perianal lesions (66.83% vs 58.17%, P=0.037; 92.31% vs 78.37%, P=0.002). The average plasma sTRAIL level was higher in CD patients than in healthy controls [(243.04±42.74) ng/L vs (194.16±31.14) ng/L, P<0.001]. Compared with the patients with mildly active CD, the plasma sTRAIL level was increased in those with moderately to severely active CD [263.47(242.09, 281.91) ng/L vs 231.13(211.11, 247.11) ng/L, P<0.001]. The same conclusion was also drawn for the patients with stricturing and penetrating CD in contrast to those with non-stricturing and non-penetrating CD [266.18 (246.68, 289.91) ng/L vs 227.19 (204.57, 249.59) ng/L, P<0.001]. The plasma sTRAIL level was also higher in patients with perianal disease than in those without perianal disease [(261.40±41.51) ng/L vs (233.86±40.41) ng/L, P<0.001]. Multiple linear regression analysis further showed that disease activity (β=22.640, P<0.001) and homozygous variant genotype (CC) (β=16.814, P<0.001) may be positively related to the plasma sTRAIL level in CD patients independently. At the 14th week of IFX treatment, the plasma sTRAIL level in the response group was lower than that in the non-response group [205.98(190.72, 214.56) ng/L vs (238.33±29.38) ng/L, P<0.001]. Compared with week 0, the plasma sTRAIL level was decreased in the response group in the 14th week [(205.98 (190.72, 214.56) ng/L vs (239.89±42.43) ng/L, P<0.001]. Non-conditional logistic regression analysis showed that variant allele (C) and variant genotype (TC+CC) were less frequent in the response group than in the non-response group (53.33% vs 70.83%, P=0.037; 70.00% vs 91.67%, P=0.036). Conclusions: The increased plasma sTRAIL level may be a risk factor for CD. TRAIL (rs1131568) gene variation and the increase of plasma sTRAIL level may be associated with the increased disease activity of CD and may be the risk factors for stenosis, penetration, and perianal lesions in CD patients. In addition, TRAIL (rs1131568) gene variation or the increase of plasma sTRAIL level may be related to no response to IFX treatment in CD patients.