bluuebunny/crossref_metadata_2025 huggingface dataset:
P039 Identifying Key Genes in CROHN'S DISEASE and Acute Pancreatitis: A Bioinformatics and Systems Biology Approach
Authors: Wu H , Su T , Zhi M , Yao J
Published: January 2024

Background

Previous studies have shown acute pancreatitis (AP) to be the most common pancreatic disease in inflammatory bowel disease (IBD) patients, with Crohn's disease (CD) patients exhibiting significantly higher incidence than ulcerative colitis (UC) patients. However, the shared biological mechanisms remain elusive. This study aimed to identify the differentially expressed genes (DEGs) between CD and AP and explore their associated molecular mechanisms using bioinformatics approaches.

Methods

Microarray datasets GSE75214 and GSE194331 were obtained from the Gene Expression Omnibus (GEO) database. Comprehensive bioinformatics analyses, including functional annotation, pathway enrichment analysis, expression validation, drug-gene prediction, construction of TF-mRNA-miRNA regulatory networks, comparative analysis of immune infiltration between CD and AP, and correlation assessment between key genes and infiltrating immune cells, were performed after identifying the common DEGs and hub genes.

Results

55 upregulated and 12 downregulated common DEGs were screened from the datasets. Functional and enrichment analyses of these genes indicated their shared pathogenic mechanisms may be relevant to immunity, inflammation, and lipid metabolism. Fifteen hub genes (MNDA, AQP9, S100A12, FPR1, ITGAX, CSF3R, CXCR1, IL1RN, NCF2, VNN2, S100A8, S100A9, IL1B, FCGR2A, and CXCL8) were filtered by constructing the protein-protein interaction (PPI) network. Further bioinformatics analysis of the hub genes highlighted the importance of the immune system in both CD and AP again. Two overlapped immune cells, including upregulated neutrophils and downregulated T cells CD8, were discovered between CD and AP.

Conclusion

Taken together, this study revealed the common hub genes between CD and AP for the first time and constructed a miRNA-gene regulatory network. The analysis of hub genes and immune cell landscape indicated the shared biological mechanisms between CD and acute AP, providing potential therapeutic targets for acute pancreatitis in Crohn's disease patients.
P063 Interleukin-8 mucosal transcript as predictor of response to Vedolizumab treatment in Ulcerative Colitis: preliminary results from a prospective study
Authors: Bota A D , Mușa A M , Dinu M C , Săftoiu A , Mușa M , Coman S , Dobre M , Milanesi E , Țieranu C G
Published: January 2024

Background

Vedolizumab (VDZ) is a safe, well tolerated and efficient biologic agent used for the treatment of inflammatory bowel disease (IBD), as confirmed by phase 3 randomised controlled trials. However, primary non-response and secondary loss-of-response to VDZ represent a clinically significant problem. The objectives of the present study are to assess the differences in mucosal gene expression profiles of patients with Ulcerative Colitis (UC) prior to VDZ initiation and to identify transcriptomic biomarkers capable of discriminating responders and non-responders to VDZ treatment.

Methods

Mucosal samples were collected during colonoscopy from patients with UC prior to VDZ initiation. The minimum extension of disease for study inclusion was left-sided colitis (E2 Montreal), and patients had at least moderate flare of clinical activity based on the total Mayo Score. Patients were dichotomized based on clinical response at week 10 in responders and non-responders. Clinical response at week 10 was defined as a decrease with >50 percent for both rectal bleeding score and stool frequency score according to the latest STRIDE-II recommendations for short-term targets. A commercially available panel of primers for 84 genes associated with IBD were assessed on mucosal samples through quantitative PCR.

Results

Eight patients with previous failure to anti-TNF agents, were sampled prior to VDZ initiation. We identified 3 responders and 5 primary non-responders at week 10 after VDZ treatment initiation. We found 15 genes up-regulated in non-responders compared to responders with a trend towards statistical significance (p=0.057). The highest fold-change was obtained for CXCL8.

Conclusion

We identified 15 mucosal transcripts differentially expressed in VDZ primary non-responder UC patients. Of those, the highest fold change was observed for CXCL8. Enlarging the cohort might contribute to achievement of statistical significance for the data presented. CXCL8 up-regulation seems to predict lack of response to VDZ treatment and represents an interesting future therapeutic target in UC.
P067 Volumetric Assessment of Treatment Response in Newly Diagnosed Crohn Disease: A Pilot Study
Authors: Derinkuyu B E , Bard A , Naim I , Tkach J A , Denson L A , Dillman J R
Published: January 2024

Background

Traditionally, mural thickness and disease length have been the radiological standards for assessing Crohn's Disease (CD) severity and treatment response. Our study aimed to evaluate and compare these linear measurements with volumetric ones in newly diagnosed pediatric CD, as well as to assess the concordance between manual and semi-automated volumetric methods.

Methods

In this single-center, prospective study, 20 children with newly diagnosed ileal CD treated with anti-TNF therapy from Dec 2018 to Oct 2021 (8 females; median age=14.5 years) underwent dedicated research MRI examinations at three timepoints – diagnosis (baseline) as well as 6 weeks and 6 months into therapy. For each exam and using T2-weighted Single Shot Fast Spin Echo (SSFSE) images, a single radiologist measured maximum bowel wall thickness (BWT, mm) and length of disease (cm). The inflamed ileum was manually segmented to measure tissue volume (ml) (Entrolytics; Motilent, London, UK). Semi-automated 3D volumetric measurements of the inflamed ileum (GI Seg tool) were created using the same platform. Estimated maximum BWT also was automatically calculated from manually-edited algorithmically generated masks. Mixed-effects models evaluated measurement changes over time. Intra-class correlation assessed absolute agreement between manual and automated volumetric assessments.

Results

BWT decreased over time with treatment (0.76 vs. 0.58 vs. 0.45 cm; p<0.0001), with a 24% decrease from baseline to 6 weeks and a 41% decrease from baseline to 6 months. Similarly, there was a significant decrease in length of disease over time (19.2 vs. 12.2 vs. 8.0 cm; p=0.002), with a 36% decrease from baseline to 6 weeks and a 58% decrease from baseline to 6 months. Manual volumetric measurements also showed a significant treatment response (19.8 vs. 11.6 vs. 5.1 ml; p<0.0001), with a 41% decrease from baseline to 6 weeks and a 74% decrease from baseline to 6 months. Using the semi-automated segmentation tool, the volume of inflamed bowel also decreased significantly over time (24.0 vs. 15.1 vs. 9.1 ml; p=0.0007), decreasing 37% between baseline and 6 weeks and 62% between baseline and 6 months. There was good agreement between manual and semi-automated volumetric bowel assessments (ICC=0.78 [95% CI: 0.57-0.88]). ICC between manual and code-estimated Max BWT was 0.60 [95% CI: 0.42, 0.72] with a strong positive correlation (r=0.839; p <0.001) between these two methods as shown in the Figure.

Conclusion

Volumetric assessments, along with automatic measurements of bowel wall thickness, show promise in accurately assessing treatment response in pediatric CD. These methods might provide more consistent and repeatable measurements, essential for long-term disease monitoring and management.
P068 Recapitulation of human colonocytes in situ by human colon organoids in vitro and after orthotopic transplantation
Authors: Hausmann A , Post F , Clement D L , Skov J , Steenholdt C , Mund A , Nielsen O H , Mann M , Jensen K B
Published: January 2024

Background

The intestinal epithelium plays a central role in human health and disease, and several chronic inflammatory disorders associate with a weakened epithelial barrier. The organoid model allows the cultivation, expansion and analysis of non-immortalized intestinal epithelial cells and has been instrumental in studying epithelial behavior in homeostasis and disease. Recent advances in human organoid transplantation into mouse and human lay the base for models to study human epithelial cell behavior within the intestinal tissue context, and promise novel therapeutic approaches for diseases such as short bowel syndrome and inflammatory bowel disease. It remained unclear how organoid transplantation into the colon would affect epithelial phenotypes and protein expression, which is key to assess the suitability of this model to study human epithelial cells in situ and safety aspects upon transplantation into human recipients.

Methods

To address this, we employed state-of-the-art deep visual proteomics to compare human colonic epithelial stem and differentiated cells in vivo, upon transplantation in situ, and to organoids cultured in vitro.

Results

We find that organoids transplanted into the murine colon closely resemble human intestinal epithelial cells in vivo compared to organoids grown in vitro, indicating that organoid culture induces a transient shift in epithelial phenotypes, which is reversible upon reintroduction into the mucosa. Phenotypic differences between epithelial cells in vitro and in situ/in vivo were largely driven by hallmarks of high proliferation and lower functional differentiation in organoids, likely due to culture conditions.

Conclusion

Taken together, we demonstrate that transplanted epithelial cells in situ represent a physiological, relevant model for studying functional aspects of mature colonocytes compared to the organoid model. We furthermore show that the proliferative phenotype of organoids in vitro is a transient state driven by culture conditions, which is reversible upon reintroduction into the mucosal environment. This is an important consideration regarding the safety of organoid transplantation into humans as a potential therapeutic strategy.
P076 Dock2 acts as a tumour suppressor via immune cell regulation of IDO1 in Inflammatory Bowel Disease–associated colorectal cancer
Authors: Churchhouse MD A , Billard C V , Pohl S Ö , Donnelly K , Suzuki T , Von Kriegsheim A , Arends M J , Coffelt S B , Myant K B
Published: January 2024

Background

Inflammatory Bowel Disease-associated colorectal cancer (IBDCRC) is a known and serious complication of Inflammatory Bowel Disease (IBD) affecting the colon. However, relatively little is known about the pathogenesis of IBD-associated colorectal cancer in comparison with its sporadic cancer counterpart. Mutations in Dock2 occur in around 10% of IBD-associated colorectal cancers.

Methods

We used an APC-mediated mouse model of inflammation-associated tumourigenesis. VilApcfl/+Dock2tm1b/tm1b and VilApcfl/+ (control) mice were subjected to chronic dextran sodium sulphate (DSS) colitis and aged. After tamoxifen induction, mice were given two seven-day rounds of 0.5% DSS, interspersed with normal drinking water, and then aged to 47 days before culling for analysis. Additionally in vitro, Apc deficient, tumourigenic colonic organoids were generated by deleting Apc from wild type and Dock2tm1a/tm1a colonic organoids using CRISPR/Cas9.

Results

We found that loss of Dock2 increases tumourigenesis (both in terms of tumour number and tumour burden) via immune dysregulation in an APC-mediated model of inflammation-induced tumourigenesis in vivo. The increased tumourigenesis observed is associated with a CD3 and gamma delta (γδ) T-positive immune cell infiltrate, an interferon gamma signature, and a significant upregulation of Ido1 (which catalyses the conversion of amino acid tryptophan to kynurenine). In tumours from VilApcfl/+Dock2tm1b/tm1b mice, tryptophan is reduced whilst the metabolite xanthurenate is increased, demonstrating IDO activity. Separately in vitro, we showed that epithelial IDO1 is induced by administration of interferon gamma. We demonstrated a source of this interferon gamma as γδ T cells, which are increased in tumours of mice lacking Dock2. Critically, inhibition of IDO1 (with 1-L-MT) abrogated the increased tumourigenesis observed as a result of Dock2 loss in mice.

Conclusion

Overall, we have identified a role for γδ T cells in promoting tumour initiation via Ido1 expression, using a Dock2 model to accentuate this phenotype.Further work is now needed to both fully characterise this novel pathway in IBDCRC, and establish how immune dysregulation promotes tumourigenesis, but it opens exciting potential for a therapeutic strategy in preventing cancer as a result of Inflammatory Bowel Disease.
P087 IFN-γ-Induced Intestinal Epithelial Cell Type-Specific Cytotoxic Responses of Human Enteroids: PANoptosis and The Protective Role of Selective JAK1 Inhibitors
Authors: Hong S N , Chansu L , Minjee K , Yujin L , Songee B , Ji Eun K , Young-Ho K
Published: January 2024

Background

Interferon-gamma (IFN-γ) plays an important role in the development of intestinal injury and inflammatory bowel disease (IBD). Using human intestinal organoid (enteorid) models, this study was investigated 1) what is the major response of intestinal epithelial cells (IECs) induced by IFN-γ to elucidate; 2) which programmed cell death (PCD) pathways cause IFN-γ-induced cell death on IECs in the absence of intestinal microbiota and immune cells; 3) how the expression of cell-cell adhesion molecules in epithelial cells is altered by IFN-γ; 4) how epithelial cell differentiation is altered by IFN-γ; 5) whether there is a difference in IFN-γ-induced PCD between different epithelial cell types; and 6) which molecules can block IFN-γ-induced PCD in IECs.

Methods

Using human enteroids, the major response of IECs induced by IFN-γ was evaluated, focusing on the IFN-γ-induced PCD pathway. The intestinal epithelial cell type-specific response to IFN-γ was assessed by bulk and single-cell RNA sequencing (RNA-seq). Furthermore, the molecules to block IFN-γ-induced PCD in IECs were evaluated.

Results

As the concentration of IFN-γ in the culture media increased, disruption of organoid structure, growth arrest, and cell death were observed in IFN-γ-treated enteroids on organoid reconstitution, MTT, and EdU assay. Bulk RNA-seq and western blot were identified the activation of pyroptosis, apoptosis, and necroptosis to form the collective inflammatory cell death pathway of PANoptosis. Single-cell RNA-seq indicated that IFN-γ altered epithelial cell differentiation in human enteroids, including expansion of the intstinal stem cell (ISC) population and depletion of the enterocyte population. PCD-associated gene expression was upregulated in enterocytes and goblet cells, but not in ISCs and paneth cells. Individual PCD inhibitors may be insufficient to prevent IFN-γ-induced cytotoxicity, whereas upadacitinib interferes with the downstream signaling of IFN-γ by inhibiting the activity of JAK1 kinase, resulting in effective blocking of PANoptosis.

Conclusion

PANoptosis is the major mechanism of IFN-γ-induced IEC damage, which was blocked by a selective JAK1 inhibitor. ECs were particularly susceptible to IFN-γ-induced PANoptosis.

* This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (2022R1A2B5B02002092 and 2021R1C1C2095192) and Future Medicine 2030 Project of the Samsung Medical Center (SMO1230011).
P096 Human extrachromosomal circular DNA is an emerging biomarker in Inflammatory Bowel Disease
Authors: Petito V , DI VINCENZO F , Gerovska D , Piazzesi A , Russo A , Turchini L , Masi L , Lopetuso L R , Abreu M T , Regenberg B , Gasbarrini A , Putignani L , Bravo Araúzo M J , Scaldaferri F
Published: January 2024

Background

Inflammatory Bowel Diseases (IBD) are chronic multifactorial disorders, which affect the gastrointestinal tract, including Ulcerative Colitis (UC) and Crohn’s Disease (CD). The existence of extrachromosomal circular DNA fragments (eccDNA) is well established, and it arises from all parts of the genome. eccDNA has mainly been studied in the context of cancer and not in relation to other diseases, and it has become a promising diagnostic and prognostic biomarker for different types of cancer. Herein, we investigate for the first time the role of eccDNA in IBD.

Methods

Forty consecutive IBD patients (19 CD, 21 UC) and 13 HC were enrolled, who underwent screening colonoscopy were prospectively enrolled at our center in this observational, case-controlled study. In IBD patients, disease activity was assessed using PMS and MES for UC, and HBI and SES-CD for CD. Colonic biopsies were collected from both inflamed and healthy mucosa in IBD patients and from HC. eccDNA was enriched, sequenced, and identified with Circle Finder from intestinal biopsies.

Results

Colonic mucosal samples from IBD patients showed increased average of eccDNAs, across all chromosomes than samples from HC. Furthermore, there was a slight yet significant tendency for larger eccDNAs in IBDs compared to HCs. Focusing on eccDNA coming from genic elements ("genic eccDNAs"), approximately 60% were fragments from protein coding genes, 32% from non-coding RNAs and 8% from pseudogenes. IBD patients had, on average, significantly more genic eccDNAs in their intestines as compared to HC. Moreover, IBD in remission had fewer eccDNAs in their intestines than active disease, although not statistically significant. eccDNAs from phosphodiesterase genes and genes involved in lipid metabolism were enriched in patients with active IBD than patients in remission. eccDNA from inflamed mucosa (both in UC and in CD) show an enrichment of genes related to inflammatory and immune pathways, such as MAPK, mTOR, ErB, Rap-1 and cGMP (SPOKE3, GRID2, DLEU1, ITGA8, NRG1).

Conclusion

We are the first to uncover an IBD-specific pattern of eccDNA production. Furthermore, we identified genic hotspots which characterize active vs. inactive disease and inflamed vs. healthy colonic tissue. We propose that eccDNA identification could be a promising new diagnostic marker for IBD patients.
P100 Salivary exosomes aggravate colitis via oral-gut axis
Authors: Yang C , Chen J , Wu J , Zhao Y , Xu Y , You P , Xu J , Chen N
Published: January 2024

Background

Inflammatory bowel disease (IBD) is a chronic intestinal immune-dysfunctional disease, while the presence of persistent triggering factors leading to relapsing and remitting inflammation in IBD remains undetermined. The oral cavity is one of the most frequently affected extraintestinal organ in IBD, and literature highlights the oral cavity's influence on gastrointestinal conditions. The understanding of alternative mechanisms in the long-distance interaction between the oral cavity and gut is limited. Exosomes exist in various bodily fluids and facilitate intercellular communication. Thus, we aimed to further explore the role of salivary exosomes in aggravating colitis via bridging oral cavity and gut.

Methods

Salivary exosomes were obtained from active IBD patients, remission IBD patients, and healthy donors using ultracentrifugation. In vivo, we established a dextran sulfate sodium (DSS)-induced colitis model to investigate the possible role and mechanisms of salivary exosomes. In vitro, THP-1 cells and Caco-2 cells were stimulated with salivary exosomes respectively and the expression of related inflammatory factors was detected. Moreover, our investigated the immune regulatory mechanism of salivary exosomes by analyzing their microRNA profiles.

Results

DIL-labeled salivary exosomes accumulated in mouse colon at 6 hours post-gavage, indicating their ability to reach and accumulate in the colon through the "oral-gut axis" (Figure 1A). Salivary exosomes of active IBD patients (active IBD-Sexos) exacerbated colitis in DSS mouse, while salivary exosomes derived from remission IBD patients or healthy donors not (Figure1B). The potential mechanisms may include remodeling of macrophage phenotypes by activating the NF-κB signaling pathway (Figure1D-F), impairment of intestinal mucosal barrier function (Figure1C), and modulation of the intestinal microbiota. Co-culture of THP-1 cells and Caco-2 cells with active IBD-Sexos were shown to raise inflammation in macrophages, which lead to increased release of inflammatory factors and promoted macrophage M1 polarization(Figure1G-K). We found 35 differentially expressed microRNAs in active IBD-Sexos compared to exosomes from both remission IBD patients and healthy donors (Figure1L). Specifically, miR-223 regulates the inflammatory response of IBD. MiR-119b-5p and miR-203-5p impact the NF-κB signaling pathway.These microRNAs promote inflammation, suggesting a possible role of salivary exosome delivery in IBD pathogenesis.

Conclusion

In conclusion, our study provides evidence that salivary exosomes play a significant role in the communication between the oral cavity and gut, beyond microorganisms or immune cells, with the potential to exacerbate intestinal inflammation in IBD (Figure1M).
P110 Heterogeneous response of colonoid-derived monolayers to TNFα and IFNγ exposure: functional and morphological characterization
Authors: Parente I , Chiara L , Gaiani F , de’Angelis G L , Barocelli E , Bertoni S
Published: January 2024

Background

Despite the progress made in the diagnosis and treatment of inflammatory bowel diseases (IBD), incidence and prevalence are still growing. Considering the lack of human preclinical studies, reliable models that mimic the inflamed intestinal epithelium are increasingly explored. Patient-derived colonoids are a powerful tool that recapitulate, in vitro,many physiological features of the human colon. The present work aims to characterize, functionally and morphologically, colonoid-derived monolayers (CDMs) and the changes induced by TNFα and IFNγ, comparing their effects with Caco-2 monolayers.

Methods

Colonic crypts, isolated from biopsies of 5 healthy volunteers undergoing colonoscopy for reasons other than IBD, were embedded in 70% (v/v) Matrigel® and grown for 5-7 days. IntestiCultTM OGM was used to generate cystic-like colonoids, further expanded in suspension cultures. After dissociation, cells were seeded at 7.5x105 cells/cm2 onto 24-well inserts coated with Matrigel® (1:50). The integrity of the epithelial barriers was monitored by TEER. When monolayers reached confluence (TEER≥100 Ω·cm2), IntestiCultTM OGM was switched to ODM. Differentiated CDMs were exposed for 24h to 25ng/mL TNFα and 25ng/mL IFNγ. Changes in cell morphology and viability, IL8 and NF-kB p65 levels, and FITC-D4 apparent permeability (Papp) were determined. Caco-2 cells, seeded at 5x104 cells/cm2, were exposed after 21 days to the same cytokine cocktail for 24h: TEER was monitored and IL8 release was quantified.

Results

CDMs developed into robust epithelial barriers, with TEER values increasing over time, indicating that tight junctions were formed. Immunocytochemistry (ICC) staining for villin and MUC2 revealed that cells were polarized and differentiated. Exposure to TNFα and IFNγ impaired significantly, although heterogeneously, the barrier integrity of CDMs and increased the release of IL8. When the barrier damage was more severe, FITC-D4 Papp and NF-kB p65 levels also raised, while cell viability was reduced. ICC images showed a large number of apoptotic cells near the basal side, and a decrease in the expression of villin and MUC2, suggesting that cell polarity and differentiation were impaired. In Caco-2 monolayers, cytokine exposure induced a mild damage on the barrier integrity and a significantly lower release of IL8, when compared to CDMs.

Conclusion

CDMs from different patients formed functional barriers that showed heterogenous sensitivity to TNFα and IFNγ exposure. In essence, all CDMs showed compromised epithelial barriers, altered cell morphology, and increased IL-8 levels. Differences between the IL8 released by Caco-2 and CDMs highlight the variation in the inflammatory response of the two models.
P125 MIG (CXCL9) and IL22 are key biomarkers that discriminates between paediatric IBD patients and non-IBD patients in a novel biomarker model
Authors: Eindor A , Tsai K , Jacobson K
Published: January 2024

Background

The current gold standard for diagnosis of Inflammatory bowel disease (IBD) is based on clinical and endoscopic evaluation as well as histologic and radiologic evaluation. However, endoscopic evaluation can be uncomfortable and carry some risks, especially in the paediatric population that requires general anesthesia in order to perform the procedure. Our aim was to investigate whether serum biomarkers can differentiate between paediatric patients with and without IBD. Secondary aims were to determine whether there are biomarkers that can differentiate between Crohn's disease (CD) and Ulcerative colitis (UC), and whether we can predict progression to biologic treatment within one year from diagnosis using these biomarkers.

Methods

Paediatric patients undergoing a first diagnostic colonoscopy at British Columbia Children's Hospital (BCCH) between December 2019 and June 2022 were invited to participate in the study. A 2 ml blood sample was taken from each participant at the time of colonoscopy. Demographic and clinical data were collected from each patient. Blood samples were analyzed using the LegendplexTM flow cytometry kits investigating 12 different inflammatory cytokines and chemokines associated with IBD. Eleven of them were found most significant in an initial analysis performed on 100 patients using 50 biomarkers, and CCL7 was added due to significance in previous studies. A prediction model was built via a supervised learning method to determine how well we can predict the different groups.

Results

Two hundred and forty-six paediatric patients participated in the study. Median age was 13.03 years, 92 were females (37.4%) and 155 (63.01%) were diagnosed with IBD, with 103 (66.45%) diagnosed with Crohn's disease. The AUROC using SPLS-DA classification was 0.805. MIG and Il22 were found to be the key biomarkers to discriminate between pediatric IBD patients and non-IBD patients. In a random forest analysis MIG, Il8 and Il22 were found most important for discrimination.

On a univariate analysis MIG and Il18 were found statistically significant as a predictor of CD (p=0.016 for both). CXCL1 was predictive to progression to biologic treatment within one year of diagnosis (p=0.039). However, the prediction model did not predict well the subclasses nor progression to biologic treatment.

Conclusion

Using serum biomarkers can predict the diagnosis of Paediatric IBD. MIG and Il22 were found to be the key biomarkers in the prediction model.
P165 Guselkumab binding to CD64+ IL-23–producing myeloid cells enhances potency for neutralizing IL-23 signaling
Authors: Atreya R , Abreu M T , Krueger J G , Eyerich K , Greving C , Hammaker D , Stoveken B , Hartman J , Leppard K , Sarabia I , Wertheimer J , Deming J , Kohler K , Li H , Freeman T , Hart A , Keyes B , Ritchlin C , McInnes I B , Allez M , Fourie A , Sachen K
Published: January 2024

Background

IL-23 is implicated in the pathogenesis of inflammatory bowel disease (IBD) and myeloid cells that express FcγRI (CD64) have been identified as the primary cellular source of IL-23 in inflamed IBD gut tissue. Guselkumab (GUS) and risankizumab (RZB) are monoclonal antibodies (mAbs) specifically directed against the IL-23p19 subunit. GUS is a fully human IgG1 mAb with a native Fc region while RZB is a humanized IgG1 mAb with a mutated Fc region. Here, we evaluated CD64 and IL-23 expression in IBD patient gut biopsies, binding of GUS and RZB to CD64, and the functional consequences of CD64 binding by IL-23p19 subunit mAbs, in in vitro assays.

Methods

IL23A and FCGR1A (CD64) expression was analyzed from bulk and single-cell RNAseq datasets. Binding of mAbs to IFNγ-primed human monocytes, as well as binding to IL-23–secreting inflammatory monocytes and capture of endogenously secreted IL-23, were assessed by flow cytometry. Internalization of IL-23, GUS, and RZB within CD64+ macrophages was evaluated using live cell confocal imaging. Potency of GUS and RZB for inhibiting IL-23 signaling was determined in a co-culture of THP-1 (a CD64+ monocyte cell line activated to produce IL-23) and an IL-23 reporter cell line (measuring biologically active IL-23).

Results

Analysis of RNAseq datasets showed that FCGR1A, IL23A, and IL12B were significantly increased in inflamed versus non-inflamed IBD gut biopsies and that IL23A was predominantly expressed by FCGR1A-expressing myeloid cells. In in vitro assays GUS, but not RZB, showed Fc-mediated binding to CD64 on IFNγ-primed monocytes. CD64-bound GUS simultaneously captured IL-23 secreted from the same cells. GUS, but not RZB, bound to the surface of CD64+ macrophages and mediated internalization of IL-23 to low pH intracellular compartments. GUS and RZB demonstrated similar potency for inhibiting signaling by IL-23 present in THP-1–conditioned media. However, in a co-culture of IL-23–producing THP-1 cells with an IL-23–responsive reporter cell line, GUS demonstrated enhanced potency compared to RZB for inhibition of IL-23 signaling.

Conclusion

Our transcriptomic analysis supported previous observations of CD64+ myeloid cells as a key source of IL-23 production in inflamed IBD gut tissue. GUS binding to CD64 on IL-23–producing cells likely contributed to the enhanced functional potency of GUS compared to RZB for inhibition of IL-23 signaling in the co-culture assay. These in vitro data support a hypothesis for optimal enrichment of GUS in inflamed tissues where CD64+ IL-23–producing myeloid cells are increased and in proximity to IL-23–responsive lymphoid cells, enabling GUS to more potently neutralize IL-23 by targeting IL-23 at its source of production.
P174 Treg Cell and Human Intestinal Myoﬁbroblast-Derived Amphiregulin induced by TGF-β Promotes Colitis-Associated Intestinal Fibrosis
Authors: Wang L , Zhang H , Zhao X
Published: January 2024

Background

Intestinal fibrosis is one of the most threatening complications of Crohn’s disease (CD). Intestinal fibrosis is usually the result of chronic inflammation, and T cell response is the main driver of intestinal inflammation. At present, there are few researches on the mechanism of Treg cells in intestinal fibrosis, and the role of Treg-derived Areg in intestinal fibrosis has not been studied.

Methods

AREG and TGF-β expression was assessed in patients with CD with or without intestinal ﬁbrosis by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). In this study, dextran sulfate sodium (DSS)-induced chronic colitis model in wild-type (WT) and Areg-/- mice and T-cell transfer model with WT and Areg-/- Treg cells were used. CD4+ T cell expression of AREG induced by Treg cell differentiation-related cytokines and self-secreted cytokines was determined by Western blotting. Human intestinal myoﬁbroblasts expression of AREG induced by different cytokines was determined by qRT-PCR. The effect of AREG on proliferation/migration in human intestinal myoﬁbroblasts was determined.

Results

AREG and TGF-β expression was increased in ﬁbrotic sites compared with nonﬁbrotic sites from patients with CD. Although DSS-induced more severe colitis in Areg-/- mice, which developed less severe intestinal fibrosis compared with WT mice on DSS insults. Transfer of Areg-/- Treg cells induced less severe ﬁbrosis in Rag-/- mice compared with WT Treg cells. TGF-β promoted AREG expression in Treg cells by activating Smad3. In addition, TGF-β promoted the AREG expression in Treg cells in a time and dose dependent manner. TGF-β also promoted the AREG expression in human intestinal myoﬁbroblastss from CD patients with fibrosis. AREG promoted human intestinal myoﬁbroblast proliferation and motility.

Conclusion

These findings revealed that Treg and human intestinal myoﬁbroblast-derived AREG induced by TGF-β promotes intestinal fibrotic responses in experimental colitis and human patients with CD.
P187 Validation of Disease Severity Index for Predicting Complicated Disease in Crohn’s Disease: A comparison study with Lémann Index
Authors: Zhou L , Qiu Y , Lu B , Lin X , Chen B , He Y , Zeng Z , Chen M , Li X , Mao R
Published: January 2024

Background

The recently developed Disease Severity Index (DSI) provides a comprehensive assessment of structural bowel damage (BD) in addition to short-term signs and symptoms. We aimed to evaluate DSI in identifying patients with Crohn’s disease (CD) at high risk of disease progression, compared to Lémann Index (LI).

Methods

This was a retrospective observational study. The consecutive patients with CD in a referral center between 2017 and 2019 were reviewed. DSI and LI were calculated at diagnosis. A complicated CD course (composite outcome of corticosteroid dependency, treatment escalation, CD-related hospitalization, and surgery) and associated risk factors were further analyzed.

Results

The median LI and DSI of included 300 patients were 1.63 (interquartile ranges [IQR], 1.25-3.13) and 42 (IQR 32-51), respectively. 152 patients (50.7%) experienced a complicated disease course (median 5.1 months; IQR 1.1-20.2). DSI (AUC 0.67; 95% CI 0.60-0.72) showed a better performance in predicting a complicated course of CD over LI (AUC 0.57; 95% CI 0.50-0.62; P=0.01). The cumulative probability of complicated CD course in severe patients was higher compared to those with ‘mild CD’ (P<0.001) when stratified by a cut-off value (DSI>43). The Cox analysis identified DSI>43 (HR 2.18; 95% CI 1.54-3.09; P<0.001), B2/3 vs. B1 (HR 2.80; 95% CI 1.99-3.94; P<0.001), and a higher level of CRP (HR 1.01; 95% CI 1.00-1.02; P=0.005) as independent prognostic factors for complicated CD. In contrast, LI was not associated with complicated CD (P=0.164).

Conclusion

Higher DSI was validated to be associated with a complicated disease outcome. DSI might play a better role than LI in identifying patients at high risk of disease progression.
P190 Identification of clinical risk factors for postoperative endoscopic recurrence in Crohn’s disease: a prospective, multicenter cohort study
Authors: Bak M , Beelen E , van der Bilt J , Camps M , Dijkstra G , van der Marel S , Stassens L , Maljaars J , Buskens C , Jansen S , Jharap B , Horjus C , van Schaik F , West R , de Boer N , van der Woude J , van Ruler O , de Vries A
Published: January 2024

Background

Further refinement of clinical risk stratification for postoperative endoscopic recurrence in patients with Crohn’s disease is required to identify patients who will benefit from prophylactic therapy. Therefore, we aimed to assess risk factors for endoscopic recurrence in a large prospective, multicenter cohort study.

Methods

CD patients (≥16 years) scheduled for ileocolic (re-)resection (ICR) and those who underwent an ileocolonoscopy at 6 months following ICR were included. Primary outcome of the study was endoscopic recurrence (modified Rutgeerts’ score ≥ i2b at 6 months). Multivariable logistic regression was performed to identify clinical risk factors. The model included a random effect for the study center to correct for potential correlation between treating center and the outcome.

Results

In total, 298 patients underwent ICR (79.2% primary ICR, 20.8% re-resection) after a median disease duration of 5.3 years (IQR 1.0 – 12.4). 60.4% of patients were female with a median age at surgery of 34.1 years (IQR 25.7 – 50.5). 67.8% of the patients were exposed to ≥1 biological prior to surgery. Postoperative prophylactic medication (<12 weeks to ICR) was initiated in 85/298 (28.5%) patients; 24.7% immunomodulator, 29.4% anti-TNF, 27.1% combination therapy [immunomodulator with anti-TNF agent], 4.7% vedolizumab, 14.1% ustekinumab. Mean time to postoperative ileocolonoscopy was 6.2 months (SD 1.3). Endoscopic recurrence was diagnosed in 37.9% of the patients. Multivariable logistic regression identified active smoking (adjusted OR [aOR] 3.12; 95% CI 1.63 – 5.98) and penetrating disease behaviour (aOR 1.92; 95% CI 1.04 – 3.57) as risk factors for endoscopic recurrence, whilst ileocolic disease (versus ileal disease; aOR 0.27; 95% CI 0.15 – 0.49) and postoperative prophylactic medication (aOR 0.24; 95% CI 0.12 – 0.47) were identified as protective factors for endoscopic recurrence (Table 1).

Conclusion

Active smoking and penetrating disease behaviour at time of surgery were identified as risk factors for early postoperative recurrence in Crohn’s disease. Reversely, ileocolic disease at time of surgery and initiation of postoperative prophylactic medication were identified as protective factors for early endoscopic recurrence. Young age at surgery, perianal disease and a prior intestinal resection, included as risk factors in the current international guidelines, were not associated with early endoscopic postoperative recurrence in this large prospective cohort study.
P216 Urine Metabolomic Characteristics of Anxiety and Depression Disorders in Patients with Inflammatory Bowel Disease
Authors: Huang X P , Zhou M S , Dang Y , Xu F , Xu C Y , Wang Z , Xu X Y , Wang C S E , Zhu S Y , Li P , Wu J , Shi H Y
Published: January 2024

Background

Up to 25%-35% of patients with inflammatory bowel disease (IBD) suffer from anxiety or depression. We aimed to depict the urine metabolic profile of IBD patients with anxiety and depression disorders and investigate the urinary metabolites that could characterize the mental disorders in IBD patients.

Methods

Urine samples were collected from IBD patients, and the Liquid Chromatography-Mass Spectrometry (LC-MS) was used to detect the metabolites. The Hospital Anxiety and Depression Scale (HADS) was used to assess the anxiety and depression symptoms. Least absolute shrinkage and selection operator (LASSO) regression model with 10-fold cross-validation was used to establish a metabolite-based prediction model for mental disorders in patients with IBD.

Results

Among the involved IBD patients (n=23, median age 41, women 61%), 35% had anxiety and 35% had depression. The urine metabolic profiles of IBD patients with anxiety or depression disorders were largely separated from those without mental symptoms (Figure 1 a-b). There were 36 metabolites up-regulated and 25 metabolites down-regulated in the anxiety group, while 10 metabolites up-regulated and 35 metabolites down-regulated in the depression group (Figure 1 c-d). The LASSO model identified the metabolites predicting IBD patients with mental disorders (Figure 2 a-b). Six metabolites (L-Carnitine, Riboflavin-5-phosphate, 2-Ethyl-2-phenylmalonamide, 3-Indoxyl sulphate, Sodium cholate, Tritylalcohol) were selected to construct the prediction model for anxiety, and another six metabolites (D-(-)-Glutamine, dAMP, DL-Stachydrine, dCMP, 5'-Deoxy-5'-(Methylthio)Adenosine, Sakuranin) were selected to construct the prediction model for depression in IBD patients. Both models showed excellent performances with an AUC of 0.992 (95%CI:0.97-1.00) and 0.933 (95%CI: 0.83-1.00) for predicting anxiety and depression, respectively, among patients with IBD (Figure 2 c-d).

Conclusion

We found significantly different urine metabolic profiles between IBD patients with and without anxiety and depression disorders. The specific urinary metabolites panel may become effective biomarkers for the prediction of anxiety and depression disorders in IBD patients.
P231 Impact of the depth of mucosal healing on the burden of ulcerative colitis : a cross-sectional study
Authors: Yzet C , Brazier F , Robert C , Moreau C , Meudjo E , Richard N , Chatelain D , Fumery M
Published: January 2024

Background

Ulcerative colitis (UC) is a major cause of disability, affecting physical, emotional and social well-being. The recent STRIDE II international guidelines consider disability-free and normal quality of life as therapeutic targets. Today, the degree of mucosal healing required to reduce disability, incontinence and bowel urgencies is poorly known.

Methods

We conducted a single-center cross-sectional study between January 2021 and June 2023. All consecutive patients with UC and endoscopic healing (Mayo ≤ 1) underwent IBD-disk disability assessment the day of the colonoscopy. Histological healing was defined as Nancy score 0 or 1 (2 biopsies per segment from rectum to right colon). Moderate to severe disability was defined as an overall score ≥ 40. Incontinence was defined by a Wexner score >5 and bowel urgency by an NRS urgency score > 1).

Results

A total of 57 patients were included, with 34 (59.6%) women. Median age and disease duration were 47.4 (interquartile range [IQR] [43.5; 51.2]) and 13.0 years (IQR, 13.1-18.4), respectively. 37/57 (65%) patients had complete endoscopic healing Mayo 0 and 43/54 (80%) histological healing. The median overall IBD-Disk score was 29 [25.5; 37.5] and 27 (47%) had moderate to severe disability. There were no differences in terms of age, gender, body mass index, smoking status, disease extension and treatment for the 3 groups Mayo 1, Mayo 0 and histological healing. The rate of moderate to severe disability was not different among patients with Mayo 0 (7/20, 35%) vs. Mayo 1 (20/37, 54%) patients (p=0.26), or in patients with (22/43, 51%) or without histological healing (4/11,36%) (p =0.51). Of the 35 patients assessed, bowel urgency were reported in 11 (31.4%), with no difference between the two definitions of endoscopic healing (p=0.72) or histological healing (p=0.37). Among the 35 patients with a Wexner score evaluation, incontinence was observed in 19% (4/21) and 14% (2/14) of Mayo 0 and Mayo 1 patients respectively (p=0.99), and 24% (6/25) vs. 0% (0/7) of patients with or without histological healing (p=0.3).

Conclusion

Half of patients with UC who achieved endoscopic healing reported a moderate to severe disability. Mayo 0 (vs. 1) endoscopic healing and histological healing do not appear to provide any short-term benefit in terms of disability, fecal incontinence or bowel urgency.
P233 Cytomegalovirus colitis in patients with moderate-to-severe Ulcerative Colitis: diagnosis, clinical impact and treatment efficacy
Authors: Melotti L , Salice M , Rinaldi M , Dussias N , Vanigli N , Scaioli E , Privitera Hrustemovic H , Rizzello F , Gionchetti P
Published: January 2024

Background

Cytomegalovirus (CMV) colitis is a serious concern worsening the prognosis of patients with ulcerative colitis (UC), involving mainly those who are not responding to immunosuppressive therapy. CMV colitis is an independent predictor of hospitalisation and surgery. Diagnosis of CMV colitis can be obtained either via immunohistochemistry (ICH) or tissue polymerase chain reaction (PCR), possibly both.

We aimed to assess the prognostic impact of CMV colitis in patients with UC and the clinical utility of testing for CMV plasma-DNA reactivation.

Methods

We conducted a retrospective, observational, monocentric study in our IBD center in Bologna.

Consecutive patients hospitalized for moderate-to-severe ulcerative colitis from January 2020 to June 2023 were included. Patients were tested for CMV colitis at hospitalization, along with other concomitant infections. Diagnosis of CMV-colitis was made either by ICH on colonic mucosa histological samples or on resected colon specimens. Need of surgery was evaluated at 28, 180 and 365 days.

Basal characteristics of patients according to the presence or absence of CMV organ disease were compared with Mann-Whitney, X2 or Fischer tests, as appropriate.

A Kaplan-Meier survival analysis was calculated to verify whether antiviral treatment for CMV organ disease had an impact on avoiding surgery.

Results

A total of 135 patients were included. CMV organ disease was present in 37 (27.4%). Around half (51.4%) were diagnosed endoscopically, and 62.2% had evidence of plasma reactivation with a median of 1008 cp/mL CMV-DNA viral load (IQR 318-2980).

Differences between the two groups (CMV colitis vs non CMV) included age (p = 0.004), Charlson Comorbidity Index (CCI) (p = 0.003), refractory disease (p = 0.007), and median CMV-DNA viral load (p < 0.001).

Patients with CMV colitis needed surgery in 24/37 cases within 1 year from the diagnosis, compared to 41/98 in the non-CMV group. Interestingly, among the first group, 54% of cases underwent colectomy within 28 days, whereas only 34.1% underwent colectomy in the non-CMV group (p = 0.049).

At multivariable analysis, steroid refractory disease, CCI and serum CMV-DNA reactivation were associated with CMV colitis. The latter had the highest OR (17.7 p < 0.001).

Kaplan-Meier showed that patients who were treated with anti-viral therapy had a significant reduction of the risk of receive surgical treatment (p<0.001) [Table 1].

Conclusion

CMV-DNA plasma reactivation is independently associated to CMV colitis. The use of anti-viral treatment is able to reduce the risk to underwent surgery, suggesting that screening of CMV colitis is mandatory in patients with moderate-to-severe UC.
P271 Impact of Biologics on Surgical Trends in Inflammatory Bowel Disease: Insights from a Lower-endemic Region
Authors: Chuang C H , Yang E H , Chen N Y , Po-Jun C , Kang J W , Chang Y C , Cheng C L
Published: January 2024

Background

Biologics have revolutionized inflammatory bowel disease (IBD) treatment, yet their impact on surgery rates remains variable in real-world studies. This nationwide cohort study in Taiwan aims to investigate the influence of biologics on surgery trends and identify associated risk factors in a region with lower IBD endemicity.

Methods

A retrospective population-based cohort study was conducted using data from Taiwan's National Health Insurance Database, spanning from January 1, 2003, to December 31, 2018. The cohort included 2676 eligible IBD patients, 725 Crohn's Disease (CD) and 1951 ulcerative Colitis (UC). Patient characteristics, surgery outcomes, and the related risk factors were analyzed.

Results

During the study period, 292 CD and 186 UC patients underwent surgery, with 245 in the pre-biologic era and 233 in the post-biologic era. Cumulative probabilities of intestinal surgery (IS) for CD patients were 20%, 35%, and 44% at 1st, 5th, and 10th years, while anal surgery (AS) rates were 3%, 5%, and 7%, respectively (Figure 1). UC patients exhibited lower surgery rates. Cox model analysis revealed age at diagnosis > 60 years as a significant risk factor for IS, but not AS, in both CD and UC groups. Gender and biologics era showed no association (Table 1). After the first IS, CD and UC patients had high 2nd IS rates of 31% and 24%, respectively.

Conclusion

This nationwide study in a lower endemic area provides insights into IBD surgery trends. The first 7 years of the biologics era did not alter surgery rates, but age at diagnosis > 60 years was associated with a higher IS rate. After the initial operation, IBD patients demonstrated a higher rate of subsequent surgeries.