bluuebunny/crossref_metadata_2025 huggingface dataset:
P040 Caspase-8 blockade attenuates NSAID-induced colitis and cell death via NLRP3 inflammasome and NF-κB activation
Authors: Singh R , Rossini V , Stockdale S , Draper L , Hill C , Nally K , Shanahan F , Andersson-Engels S , Melgar PhD S
Published: January 2023

Background

Non-steroidal anti-inflammatory drugs (NSAIDs) are believed to exacerbate symptoms and inflammation in patients with inflammatory bowel disease (IBD). Recent studies indicate the gut microbiota may play a role in NSAID-promoted inflammation. However, mechanism(s) underpinning NSAID-induced inflammation are not fully understood. In this study, using the piroxicam-accelerated model of colitis (PAC) in IL-10-/- mice, we examined the mechanism(s) regulating NSAID-induced colitis.

Methods

To establish whether microbiota plays a role in PAC, IL-10-/- mice were treated with streptomycin for 24hrs followed by feeding with 100 ppm piroxicam in their food for 9 days. In the inhibitor study, mice were injected intra-peritoneally with the caspase-8 inhibitor (Z-IETD-FMK, 10mg/kg) every other day starting before piroxicam-feeding. Colon tissue was collected on day 14 for analysis on inflammation and cell death markers by qRT-PCR, MesoScaleDiscovery (MSD)-assay, western blot, and histology. Faecal samples were collected at different time-points for 16S rRNA gene sequencing.

Results

A significantly higher expression of colonic inflammatory markers and a reduced expression of epithelial barrier proteins and elongated crypts were found in PAC-mice, which was independent of microbiota. Piroxicam feeding did not cause major changes in fecal microbiota diversity or composition on day 14. An activation of members of the NLRP3 inflammasome family including caspase-1 and IL-1b, Caspase-8, and the pro-apoptotic markers -cleaved caspase 3 and PARP- were associated with piroxicam-induced colitis. Inhibition of caspase-8 ameliorated NSAID-provoked colitis and apoptosis by preventing mitochondrial damage, and downregulating NF-κB and NLRP3 activation as well as reducing cleaved caspase-3 and PARP levels. Histology analysis revealed an improvement in colonic epithelial morphology associated with shorter crypts and reduced immune cell infiltration to the lamina propria.

Conclusion

Our data provides evidence on how NSAIDs can promote intestinal inflammation by activating caspase-8, NLRP3 inflammasome and NF-κB, resulting in induction of inflammation and apoptosis. Targeting Caspase-8 could be a potential treatment strategy for patients with NSAID-worsened symptoms and inflammation
P047 Osteopontin in colitis-associated carcinoma (CAC)
Authors: Manna S , Sehn M , Cardoso da Silva D , Heldt C , Horstkorte L , Elezkurtaj S , Siegmund B , Weixler B , Hummel M , Gröne J , Schumann M
Published: January 2023

Background

Inflammatory bowel disease (IBD) patients pose a lifelong risk of developing colitis-associated carcinoma (CAC). Current understanding and mechanisms of CAC development stem from murine CAC models while studies on human CAC carcinogenesis are scarce. Thus, we aimed to understand CAC carcinogenesis, using human samples from patients suffering from Crohn′s disease (CD), CD-associated CAC (CD-CAC), ulcerative colitis (UC), and UC-associated CAC (UC-CAC) and further validated the findings in vitro.

Methods

We obtained FFPE specimens from 40 patients that suffered from either one of the IBDs or CACs and furthermore inflammation-free healthy controls (10 patients per group). These samples were micro-dissected, followed by RNA isolation and Nanostring gene expression analysis. Our data revealed a strong upregulation of SPP1 (Secreted Phosphoprotein-1) gene encoding for osteopontin (OPN) upon comparing heathy controls to IBD and to CAC. We then used in vitro-models to elucidate the mechanism of OPN-induced carcinogenesis. We stimulated intestinal epithelial cell lines HT-29/B6 and T84 cells with rhOPN (recombinant human OPN), following bulk RNAseq. We validated the findings using Seahorse assay for analysis of mitochondrial respiration (determining oxygen consumption rate, OCR). Western phospho-blots were done to unravel signal transduction events.

Results

Nanostring gene expression data revealed the following: (i) SPP1 gene encoding for OPN and epithelial-to-mesenchymal (EMT) transcription factors fibronectin-1 (FN1) and ZEB1 were strongly upregulated in UC-CAC and CD-CAC patients when compared to UC and CD. (ii) IL17-pathway genes were significantly downregulated in UC-CAC patients. (iii) Tight junction and polarity genes were altered in both UC-CAC and CD-CAC patients. rhOPN stimulation in vitro to HT29/B6 and T84 cells excluded OPN as the trigger of EMT but uncovered upregulated mitochondrial respiratory chain genes as a potential trigger for tumour cell proliferation. Validation of RNAseq findings by Seahorse assay revealed that after sequential injections of oligomycin, FCCP, rotenone and antimycin A both, HT-29/B6 and T84 cells, had higher basal and maximal OCRs in response to rhOPN (Fig. 1). T84, but not HT-29/B6 cells also showed an upregulated ATP production in response to rhOPN.

Conclusion

SPP1 expression correlates with CAC carcinogenesis. Putative underlying pathways rather include modulation of mitochondrial respiratory chain activity by differential gene expression than induction of EMT.
P053 Ustekinumab decreases circulating Th1, Th17, and MAIT cells in Crohn’s disease
Authors: Lord J , Konecny A , Shows D
Published: January 2023

Background

Ustekinumab is a humanized antibody to a p40 subunit shared by the cytokines IL-12 and IL-23, which has been approved for the treatment of Crohn’s disease. While it is presumed to derive clinical efficacy by blocking the ability of these cytokines to stimulate specific T cell subsets, its actual effect upon the human immune system has not been well-described.

Methods

Peripheral blood mononuclear cells (PBMC) were cryopreserved from 20 Crohn’s patients before and during ustekinumab therapy. Thawed PBMC were then analyzed by flow cytometry for cell surface markers and, after overnight stimulation, intracellular cytokines. Success (n=9) or failure (n=11) of ustekinumab therapy was at the discretion of the treating physician, blinded to flow cytometry data.

Results

A significant decrease in IL-17A-producing Th17 (p=0.001) and CD161+/TCRVα7.2+ MAIT (p=0.005) cells was seen overall in response to ustekinumab. While no significant effect was seen overall in IFN-γ -producing CD4 (Th1) and CD8 T cells, there was a dichotomy between treatment responders and non-responders, with Th1 cells decreasing in responders (p=0.004) and increasing in non-responders (p=0.03) after ustekinumab initiation. IFN-γ+ CD8 T cells likewise increased in non-responders (p=0.01), although their decrease in responders was less significant (p=0.12). While there was no difference in the pre-treatment frequency of Th17’s or IFN-γ+ T cells between responders and non-responders, MAIT cells were significantly more common in the blood of responders (p=0.03).

Conclusion

While the IL-23-blocking effect of ustekinumab on Th17 and MAIT cells was seen across all recipients, its IL-12-blocking effect on IFN-γ-producing T cells was restricted to treatment-responsive patients, suggesting that its mechanism of action may differ from newer, IL-23-specific agents. Whether the frequency of MAIT cells before or a rise in IFN-γ-producing T cells during therapy can predict treatment failure warrants additional study.
P061 Response to anti-α4β7 therapy in Ulcerative colitis is associated with lymphoid aggregate attrition through impaired recruitment of naïve lymphocytes
Authors: Canales-Herrerias P , Uzzan M , Seki A , Czepielewski R S , Verstockt B , Dunn A , Dai D , Ko H M , Furtado G C , Tokuyama M , Tankelevich M , Meringer H , Cossarini F , Jha D , Paulsen J D , Nakadar M Z , Wong J , Sharma K , Rosenstein A , Dawson T , Singh H , Lim J , Lira S A , Yajnik V , Reboldi A , Petralia F , Vermeire S , Polydorides A D , Randolph G J , Colombel J F , Mehandru S
Published: January 2023

Background

Vedolizumab (VDZ) is a frontline drug for Ulcerative colitis (UC) and Crohn’s disease (CD) that targets integrin α4β7, a gut-homing receptor. Despite significant use, the mechanism(s) of action (MOA) of VDZ remain unclear.

Methods

Peripheral blood mononuclear cells (PBMC) from UC patients (n=43) and paired intestinal biopsies in a subset (n=12) were examined at week 0 (pre-infusion) and 14, by multiparameter flow cytometry (FC). TNF inhibitor (TNFi)-treated UC patients served as controls. Drug MOA was further examined in detail in murine models using single-cell RNA-seq, FC, conventional and immunofluorescent microscopy (IF). Photoconvertible (Kikumi) mice were used to study cellular trafficking after anti-α4β7 (DATK32) antibody (mAb) administration. Two distinct UC cohorts (n=42 and n=21 respectively) were used to correlate GI immune alterations following VDZ with mucosal healing.

Results

A significant decrease of colonic and ileal naïve B and T cells was noted in VDZ- but not in TNFi-treated patients (Fig 1A), while total T cell-frequencies were unchanged. Circulating gut-homing plasmablasts (β7+) were significantly decreased post-VDZ.

Peyer’s patches (PP) in anti-α4β7-treated mice showed a rapid loss of cellularity associated with decreased follicular naïve B cells (Fig 1B). Single-cell RNA-seq also demonstrated a significant loss of follicular B cells, including a unique population of epithelium-associated B cells following anti-α4β7 mAb. In Kikumi mice, anti-α4β7 mAb impaired non-photoconverted follicular B cells and T cells into photoconverted PPs (Fig 1C) demonstrating that loss of PP cellularity was due to impaired cellular ingress.

In VDZ-treated (but not TNFi-treated) UC patients, lymphoid aggregate (LA) size was significantly reduced in treatment responders compared to non-responders (defined by absence of histological inflammation). A distinct validation cohort further confirmed that reduced lymphoid aggregate size was associated with response to VDZ-therapy (Fig 1D).

Conclusion

VDZ is associated with impaired ingress of naïve B and T cells, resulting in attrition of intestinal LA. Reduced LA size is associated with VDZ response. Immune inductive site targeting represents a novel MOA of VDZ in patients with UC.
P063 Host-mycobiome interactions during the resolution of inflammation in experimental colitis
Authors: De Salvo C , Wargo H , Vidmar K , Di Martino L , Mahabaleshwar G , Cominelli F , Ghannoum M , Pizarro T
Published: January 2023

Background

Recent studies have documented the complexity of the intestinal fungal community (‘mycobiome’) in mice, and clinical and experimental observations have shown that the mycobiome influences both gut health and disease, e.g., IBD. In fact, prior studies have shown that CD patients, compared to healthy controls, harbor higher levels of intestinal Candida tropicalis (Ct), which is the major fungal species detected in the colons of colitic mice after dextran sodium sulfate (DSS) challenge. Moreover, proteins encoded by genes within IBD susceptibility loci, such as the pattern recognition receptor (PRR), NOD2, are known not only to recognize bacterial components, but also a fungal cell wall element, chitin. In fact, the role of PRRs in regulating immunity against intestinal fungi, and how fungi influence IBD remains poorly defined.

Methods

We challenged DSS colitic wildtype (WT) and Nod2-/- mice with Ct 2 days before DSS administration and subsequently on day 0, 3 and 6. Bone marrow-derived macrophages (BMDMs) from untreated mice were administered chitin in vitro.

Results

Our data confirms previous studies that Ct challenge does not exacerbate colitis in DSS-treated C57BL/6 WT mice, however, Ct-infected Nod2-/- mice possess a higher fungal burden and exhibit worse colitis symptoms, such as weight loss, decreased stool consistency, and presence of blood in stools, vs. Ct-infected WT mice, indicating an essential and protective role for NOD2 during colitis recovery after Ct challenge. Our results also show that Ct-infected Nod2-/- mice display a marked reduction in colonic Il22 and Il17, which are cytokines previously reported to be important in maintaining epithelial barrier integrity during DSS colitis. These data were confirmed in colons of Ct infected DSS challenged, ileitis prone SAMP1/YitFc (SAMP) mice NOD2 deficient. Moreover, our in vitro data show, a decrease in Il1ß and Il23 in BMDM from SAMP Nod2-/- mice compared to WT after 2h of exposure to chitin. IL-17+ innate lymphoid cells (ILCs) are also known to control fungal burden during opportunistic fungal infections, and interestingly, our findings indicate that Ct infection of Nod2-/- vs. WT mice results in a decreased frequency of mesenteric lymph node–derived type 3 ILCs (ILC3s), suggesting that delay in fungal clearance and recovery in Nod2-/-mice may be due to the inability to mount protective type 3 immune responses.

Conclusion

Taken together, the data collected suggests that NOD2 is essential to maintain gut mycobiome homeostasis and drives protective innate immune responses, via a macrophage-mediated ILC3 recruitment and IL-17 mechanism, by preventing the overgrowth of opportunistic fungi that may contribute to chronic intestinal inflammation, such as that observed in CD.
P072 Circadian misalignment by simulated night shifts decreases colonoid barrier integrity in Ulcerative Colitis
Authors: Swanson G , Shaikh M , Keshavarzian A , Scheer F
Published: January 2023

Background

Circadian rhythms orchestrate multiple biological processes with 24-hour oscillations that regulate diverse bodily functions. The central clock is in the suprachiasmatic nucleus and orchestrates peripheral circadian clocks in every organ system including the gastrointestinal tract (GIT). Previous work has shown that circadian misalignment in Ulcerative Colitis (UC) is associated with increased colonic permeability, and colonic organoids recapitulate the host circadian phenotype. The goals of this study were to examine whether circadian misalignment would disrupt the colonic barrier integrity in UC.

Methods

5 subjects, 2 UC and 3 Healthy Controls (HC), were recruited into the study. All UC subjects were inactive (partial Mayo Score ≤ 1) and stable medications with no flares for the last 3 months. For two weeks prior to entry into the circadian lab all subjects were on a prescribed regular sleep schedule. Subjects were then kept in the circadian lab for 6 days with strict control of their light/dark cycle (Figure 1). All subjects then underwent two unprepped flexible sigmoidoscopies at: (1) baseline with circadian alignment and (2) after three days of simulated night shifts with circadian misalignment. Colonic organoids generated created from the colon tissue biopsies grown in Matrigel and barrier integrity was assessed in apical-out colonoids by FITC-Dextran (4 kDa) Net Fluorescence was estimated by ImageJ.

Results

Colonic organoids at baseline had significantly decreased ZO-1 in UC versus HC, Figure 2. At baseline there was an increase in UC colonic organoid barrier integrity as measured by net fluorescence (density/area). In UC vs HC barrier integrity was 855 ± 203.8 vs 333.1 ± 52.9, p<0.05. After three days of simulated night shifts, barrier integrity significantly increased in both groups at was 1100 ± 342 vs 656 ± 197.9,p <0.5 (Figure 3). After 24 hours of treatment with cytokines, barrier integrity in HC, UC, misaligned HC, and misaligned UC was 2227 ± 376, 2030 ± 264, 1787 ± 402, and 1506 ± 332, (Figure 4).

Conclusion

Circadian misalignment by alternation of light:dark cycles (simulated night shift) causes misalignment of host central clock and impacts circadian regulated biological process like tight junction proteins which decreases colonic barrier integrity. This study highlights the importance of studying environmental factors that impact circadian timing in UC including night shift work which may be a significant risk factor for a disease flare. Further in vivo and in vitro studies are ongoing to determine the mechanisms through which circadian misalignment impacts colonic barrier integrity in UC (NCT05180279).
P076 Abdominal pain severity for IBD in remission correlates with genetic clustering and enzymatic activity of faeces-derived Candida albicans strains
Authors: Van Thiel I , Maasland T , van Wassenaer E , Hoekman D , Spooren C , Hakvoort T , Admiraal I , Theelen B , Levin E , Benninga M , Jonkers D , D’Haens G , Rosendahl S , Boekhout T , Hagen F , de Jonge W , van den Wijngaard R
Published: January 2023

Background

Abdominal pain is a common occurrence for approximately 39% of patients with inflammatory bowel diseases in remission (quiescent IBD; qIBD). There is increasing evidence for a contributing role of the gastrointestinal fungal community (i.e., mycobiome) in relation to intestinal inflammation and irritable bowel syndrome (IBS). As such, abundance of Candida spp. and sub-species variation of Candida albicans were previously associated with IBD severity. In the current study, we aim to investigate mycobiome of patients with qIBD and qIBD with abdominal pain (qIBD–AP).

Methods

Patients with qIBD (defined as faecal calprotectin (FCP) ≤250 μg/g) with (n=91) or without (n=58) abdominal pain provided faecal samples. Abdominal pain was scored based on either the Irritable Bowel Syndrome Symptom Severity Scale (IBS–SSS) or Gastrointestinal Symptom Rating Score (GSRS) questionnaire. Faecal fungal communities were determined based on Internal Transcribed Spacer 1 (ITS1) sequencing. Cultivable yeasts from faecal samples were identified using Matrix Assisted Laser Deionization Time–of–Flight Mass Spectrometry. C. albicans strains (n=137 from 29 patients) were genotyped by ITS Sanger sequencing analysis and typing of seven microsatellite loci. Release of virulence-related enzymes (proteinase, phospholipase, lipase, esterase) by C. albicans was assessed through determination of precipitation zones on solid agar mediums containing enzyme-specific substrates.

Results

Descriptive mycobiota analysis revealed limited differences between compositions of qIBD and qIBD–AP patients, but a discriminative signature for abdominal pain was extracted using machine-based learning models. While ITS Sanger sequencing of faeces-derived C. albicans was insufficient to elucidate genetic variability, analysis of microsatellite loci revealed extensive variability and clustering into six clone clusters and a likely distinction between qIBD and qIBD-AP patients (Fig. 1). Phospholipase enzymatic activity of C. albicans strains correlated with GSRS–Abdominal Pain sub-score, as did proteinase activity with severity of abdominal pain according to the IBS–SSS (Fig. 2). Additionally, lipase activity inversely correlated with faecal calprotectin (Fig. 2).

Conclusion

The faecal gut mycobiome is associated with self–reported abdominal pain in patients with IBD in remission. This notion is based on both compositional and culture-dependent methods and specified clones of C. albicans may selectively contribute to abdominal pain for qIBD patients. This study opens further possibilities to investigate the role of faecal gut fungi in light of abdominal pain for qIBD-AP patients.
P078 Physiological hypoxia improves growth and functional differentiation of human intestinal epithelial organoids
Authors: Walaas G A , Gopalakrishnan S , Bakke I , Skovdahl H K , Flatberg A , Østvik A E , Sandvik A K , Bruland T
Published: January 2023

Background

The epithelium in the colonic mucosa is implicated in the pathophysiology of various diseases, including inflammatory bowel diseases and colorectal cancer. Intestinal epithelial organoids from the colon (colonoids) can be used for disease modelling and personalized drug screening. Colonoids are usually cultured at 18-21% oxygen without accounting for the physiological hypoxia in the colonic epithelium (3% to <1% oxygen). We hypothesize that recapitulating the in vivophysiological oxygen environment (i.e., physioxia) will enhance the translational value of colonoids as pre-clinical models. Here we evaluate whether human colonoids can be established and cultured in physioxia for the entire in vitro culture period and compare growth, differentiation, and immunological responses at 2% and 20% oxygen.

Methods

Growth from single cells to differentiated colonoids was monitored by brightfield images and evaluated with a linear mixed model. Cell composition was identified by immunofluorescence staining of cell markers and single-cell RNA-sequencing (scRNA-seq). Enrichment analysis was used to identify transcriptomic differences within cell populations. Pro-inflammatory stimuli induced chemokines and Neutrophil gelatinase-associated lipocalin (NGAL) release were analysed by Multiplex profiling and ELISA. Direct response to a lower oxygen level was analysed by enrichment analysis of bulk RNA sequencing data.

Results

Colonoids established in a 2% oxygen environment acquired a significantly larger cell mass compared to a 20% oxygen environment. No differences in expression of cell markers for cells with proliferation potential (KI67 positive), goblet cells (MUC2 positive), absorptive cells (MUC2 negative, CK20 positive) and enteroendocrine cells (CGA positive) were found between colonoids cultured in 2% and 20% oxygen. However, the scRNA-seq analysis identified differences in the transcriptome within stem-, progenitor- and differentiated cell clusters. Both colonoids grown at 2% and 20% oxygen secreted CX3CL1, CXCL2, CXCL5, CXCL6, CXCL10, CXCL12, CCL20, CCL25, and NGAL upon TNF + poly(I:C) treatment, but there appeared to be a lower pro-inflammatory response in 2% oxygen. Reducing the oxygen environment from 20% to 2% in differentiated colonoids altered the expression of genes related to differentiation, metabolism, mucus lining, and immune networks.

Conclusion

Our results suggest that colonoids studies can and should be performed in physioxia when the resemblance to in vivo conditions is important.
P084 Response to appendectomy in refractory Ulcerative Colitis appears based on two distinct inflammatory phenotypes
Authors: Becker drs. M , Heuthorst L , van Roest M , van der Bilt J , Buskens C , Wildenberg M
Published: January 2023

Background

Appendectomy has been suggested to decrease the risk of disease flares in UC, but we recently showed that even in therapy refractory patients, appendectomy may improve symptoms in a subset of patients. Despite several hypotheses, the effector mechanism of this phenomenon remains unclear. In this study we characterized gene expression profiles of appendices from therapy refractory UC patients either responding or non-responding to appendectomy, with the aim to identify pathways involved in response as well as guide selection of patients who are optimal candidates for appendectomy.

Methods

Appendix specimen from responders (N=10) and non-responders (N=10) to appendectomy for therapy refractory UC were included (COSTA-study NCT03912714 or off-label appendectomy). Endoscopic response was defined as steroid-free remission at 12 months without intensified medical treatment. The control group consisted of patients with acute appendicitis(N=2). Post-operative biopsies were taken from the appendix and the coecal base and snap frozen. RNA was isolated and expression profiling was performed using RNAseq.

Results

Unsupervised clustering indicated two separate clusters, one containing a more stromal phenotype expressing ADH1B, IGFBP5, Desmin and FLNA and the other expressing a more intestinal/B cell phenotype (OLMF4, PIGR, CEACAM5 and IHGA2). Stainings for the presence of collagen (stromal) versus pancytokeratin (epithelial) confirmed this analysis on protein level. Both clusters contained subclusters of responders and non-responders. In both the ‘responder’ subclusters, markers of immune activation were increased, but the type of response differed between ‘stromal responders’ and ‘epithelial responders’. In ‘stromal responders’ increased expression of acute phase genes was present (FABP4, ADIPOQ, SAA1 and CXCL8). In the ‘epithelial responders’, immune activity was more characterized by increased mitochondrial activation/oxidative phosphorylation. In both subclusters, non-responders lacked these immune activation markers. We also evaluated the expression of the differentiating genes in biopsies of the coecal bottom. Indeed, the coecal samples also largerly clustered according to response based on the gene expression profile of the matching appendices.

Conclusion

Patients responding to appendectomy showed two distinct gene expression patterns, suggesting two separate mechanisms of action. Although in both cases it clearly identified the requirement of active immune responses for response, the identifying markers differed between the two groups. This finding has consequences for both further functional studies into the effector mechanism of appendectomy in UC, but also in future efforts to identify patients suitable for this surgery.
P092 Punica Granatum affects gut biofilm-forming bacteria and promotes intestinal mucosal healing regulating the crosstalk between epithelial cells and intestinal fibroblasts
Authors: Rizzo G , Pineda Chavez S E , Vandenkoornhuyse E , Cardenas C , Cento V , Meanti L , Roda G , Loy L , Dal Buono A , Gabbiadini R , Lovisa S , Rusconi R , Repici A , Armuzzi A , Vetrano S
Published: January 2023

Background

Punica Granatum (PG), is a bioactive compound of Pomegranate exerting anti-inflammatory activities. Clinical studies have demonstrated an improvement of clinical response in inflammatory bowel diseases (IBD) patients when PG was taken as a complement to standard medications. However, the molecular mechanisms underlying its beneficial effects are still scarcely investigated. In this study, we assessed the effects of PG on bacterial biofilm formation, and we investigated the properties of the PG to promote mucosal wound healing.

Methods

Bacterial biofilm formation was assessed using microfluidic devices for 24 or 48 hours. Acute colitis model was induced in C57BL/6N mice by 3% dextran sodium sulfate administration in their drinking water for 5 days. During the recovery phase of colitis, mice received saline or PG (200 mg/kg body weight) oral gavage for 11 days. . Colitis was scored daily evaluating the body weight loss, bleeding and consistency of stool. In vivo intestinal permeability was performed by fluorescein isothiocyanate-conjugated dextran assay, bacterial translocation by Fluorescence in situ hybridization on tissues, whereas epithelial and mucus integrity by immunostaining for JAM-A and MUC-2 markers. Primary fibroblasts, isolated from healthy and inflamed area of 6 IBD patients, and Caco-2 cells were stimulated with or without PG (15 ug/ml). Inflammatory mediators were measured at mRNA and protein levels by RT-PCR, WB or by Bio-plex multiplex immunoassay respectively.

Results

Microfluidic experiments revealed beneficial effects of PG to inhibit biofilm formation of GRAM- bacteria and to promote the expansion of some intestinal commensal Gram+ bacteria. In vivo, PG boosted the recovery phase of colitis promoting a complete restoration of intestinal barrier with the regeneration of the mucus layer compared to saline group as also demonstrated by no traces of bacteria spread into the mucosa. The PG enriched crypt-associated fibroblasts. In vitro, inflamed fibroblasts responded to PG by down-regulating the release of metalloproteinases, IL-6, IL-8 and up-regulating the levels of HGF. Caco-2 cells cultured in medium supplemented with PG increased the expression of Sox-9 and CD44, whereas in the presence of HGF or when plated with fibroblast-conditioned medium displayed a decrease expression of Sox-9 and CD44 and increase of AXIN2, a negative regulator of Wnt signaling.

Conclusion

These data provide new insight of the multiple effects of PG on promoting mucosal homeostasis in IBD by affecting biofilm formation of pathogens, promoting expansion of commensals and favoring the regeneration of intestinal barrier by regulating the crosstalk between epithelial cells and stromal cells.
P121 Clinicomic profiles new feature patterns based on a simplified location classification for Crohn’s disease
Authors: Hu W , Liang X , Luo J , Li P , Shen K , Li J , Li S , Xin J , Jiang J , Shi D , Wang X , Xu D , Yu Q , Zhang H , Zhang X , Song X , Guo H , Ge Q , Chen Y , Chen X , Chen Y , Li J
Published: January 2023

Background

Crohn’s disease (CD) is a heterogeneous and complicated condition that often has delayed diagnoses and poor outcomes. Disease location and site-specific mechanisms have received increasing attention in recent studies. Suboptimal classification adds complexity to clinical management for CD and the interpretation of its characteristics. This study aims to clarify the clinicopathological characteristics of CD patients through a prospective cohort.

Methods

The clinical data from 1173 patients with definite CD diagnoses and a simplified location classification based on anatomical traits (G1: esophagus+stomach+duodenum; G2: jejunum+ileum; G3: ileocecum; G4: colon+rectum) were used to clarify the feature patterns (Figure 1).

Results

Of the enrolled patients, 437 were newly diagnosed, and 736 were prevalent patients. A higher proportion of L4 involvement (45.8%) and a lower proportion of L2 (6.8%) patients were observed under the Montreal location classification. Single G2 (17.8%), G2+G3 (22.2%), G3+G4 (12.5%) and G2+G3+G4 (27.8%) were the four major types in the simplified location classification (Figure 2A-2B). The patients with G4 presented with higher C-reactive protein, G2 patients had more stricturing/penetrating behavior, and single G2 patients had the oldest age at diagnosis (Table 1). A clinicomic study with machine learning methods including principal component analysis, cluster analysis and partial least squares discriminant analysis, identified hemoglobin, platelet count and C-reactive protein as the three key indicators. A decision tree based on the three indicators and disease behavior stratified all patients into six feature patterns (simply/complicatedly active, simply/complicatedly anemia and simply/complicatedly stable), which formed a two-twisted-cycle model for natural disease history (Figure 2C). Most patients started their cycles at the active phase, and the “simply” cycle was mainly advanced by medications, while most patients in the “complicatedly” cycle needed multidisciplinary care. Comparisons among the six subgroups showed that age at diagnosis had the same rise-and-fall pattern as the G2+G4- proportion, while the G2-G4+ proportion showed the opposite trend (Table 2, Figure 2D-2E). An external validation group (n=301) confirmed the above results. The role of disease location could be interpreted as an important factor determining its start point and site-specific trajectory in the two-twisted-cycle model.

Conclusion

Site-specific clinical characteristics clarified by the simplified location classification, the new feature patterns profiled by the clinicomic study may provide new insights into CD phenotyping, risk stratification and precision treatment.
P130 Intestinal ultrasound combined to fecal calprotectin is effective to predict endoscopic mucosal healing in ulcerative colitis: a cross-sectional study
Authors: Yzet C , Meudjo E , Moreau C , Brazier F , Hautefeuille V , Decrombecque C , Sarba R , Pichois R , Meynier J , Fumery M
Published: January 2023

Background

In the “treat-to-target” era, the development of non-invasive markers to assess endoscopic healing in ulcerative colitis (UC) is essential. Fecal calprotectin (FC) and intestinal ultrasound (IUS) are alternatives to colonoscopy to assess UC activity. The objective of this study was to evaluate the performance of IUS and FC to assess endoscopic mucosal healing in UC patient.

Methods

All consecutive patients between January 2021 and August 2022 with UC who underwent (1) a complete colonoscopy (2) an intestinal ultrasound and/or (3) a fecal calprotectin (4) within 4 weeks were included in a prospective cohort. Bowel wall thickness (BWT) and color doppler signal (CDS) were assessed on each segment. Endoscopic mucosal healing was defined by a MAYO score of 0-1.

Results

A total of 57 patients were included, 57.9% had endoscopic healing (22/57 MAYO 0 and 11/57 MAYO 1). Thirty-two (56.1%) were female, the median age and disease duration were respectively 43 years (IQR, 30-58) and 29 years (IQR, 18-39). Respectively 16 (16/57, 28.1%) and 41 (41/57, 71.9%) patients had BWT < 3 mm and an absence of Doppler signal. The sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of BWT < 3 mm to predict endoscopic mucosal healing were 37%, 77%, 72% and 44%. The association of the absence of CDS with normal BWT did not modify these performances. The same values for fecal calprotectin < 150 µg/g were respectively 81%, 78%, 84% and 74%. The association of a fecal calprotectin < 150 µg/g, with a BWT < 3mm and the absence of Doppler signal increased the specificity and the PPV (Se 33%, Sp 94%, PPV 89%, VPN 48%). The same values were found for patients classified as MAYO 0 or MAYO 0-1 (Table 1).

Conclusion

The combination of intestinal ultrasound and fecal calprotectin is effective to identify endoscopic mucosal healing in UC.
P132 Prognosis and molecular characteristics of IBD-associated colorectal cancer: experience from a French tertiary-care center
Authors: Hammoudi N , Lehmann-Che J , Lambert J , Amoyel M , Maggiori L , Salfati D , Tran Minh M L , Baudry C , Asesio N , Poirot B , Lourenco N , Corte H , Allez M , Aparicio T , Gornet J M
Published: January 2023

Background

Little is known about the prognosis of colorectal cancer associated with inflammatory bowel disease (CRC-IBD) in a real-world cohort in France.

Methods

We conducted a retrospective observational study including all patients presenting CRC-IBD in a tertiary French center between 1990 and 2021. Clinical and molecular data were collected. We analyzed overall survival (OS), progression free survival (PFS) and factors associated with prognosis. Outcome probabilities were analyzed using the Kaplan-Meier method.

Results

Among 6510 patients, the incidence rate of CRC was 0.8% (N =49) with a median delay of 19.5 years after IBD diagnosis. The median age was 46 years, the main IBD was ulcerative colitis (59%), the primary tumor was rectal in 49% and localized at diagnosis in 69%. There was a previous exposure to immunosuppressants (IS) in 57% and anti-TNF in 29% of the cases. The most frequent mutation was TP53 (56%). A RAS mutation was observed in 37% of the whole population and 13% of metastatic patients. OS of the whole cohort was 45 months OS and PFS of synchronous metastatic patients was 20.4 months and 8.5 months respectively. Among the patients with localized tumor those previously exposed to IS had a better progression-free survival (39 months vs 23 months; p =0.05) and a better OS (74 vs 44 months; p =0.03). Only 2 patients (4%) experienced IBD relapse during follow-up despite IS and biologics discontinuation in all exposed patients. Chemotherapy exposure was 53% and 93% in the adjuvant and metastatic setting respectively. No unexpected side-effect was observed, the only reason for discontinuation was oxaliplatin-sensitive neuropathy.

Conclusion

Incidence of CRC is elevated in IBD patients with a poor OS in metastatic patients although IBD is not associated with under-exposure or increased toxicity to chemotherapy. Previous IS exposure may be associated with a better prognosis.
P133 Risk Factors for the Occurrence and Severity of Vertebral Fractures in Inflammatory Bowel Disease Patients: A Nationwide Population-Based Cohort Study
Authors: Jung S H , Kim T O , Kang S B , Kim J
Published: January 2023

Background

The risk of vertebral fractures is increased in inflammatory bowel disease (IBD) patients. However, whether the severity of vertebral fractures differs between IBD patients and the general population, or between patients with Crohn’s disease and ulcerative colitis, is unknown.

Methods

We investigated risk factors associated with the occurrence and severity of vertebral fractures in IBD patients using The National Healthcare Insurance Service (NHIS) database.

Results

From 2008 to 2018, there were 33,778 patients with IBD (24,370 UC patients and 9408 CD patients) and 101,265 patients in the reference population. The incidence rate ratio of vertebral fractures in IBD patients was 1.27 per 1000 person-years (95% CI 1.26–1.27). The risk of vertebral fracture was higher in CD and UC patients than in the matched reference group (HR 1.593; 95% CI 1.317–1.927; p < 0.001 and HR 1.269; 95% CI 1.141–1.412; p < 0.01 respectively). The occurrence of vertebral fracture was associated with Crohn’s disease, older age, female sex, high Charlson Comorbidity Index (CCI) score, and long-term steroid use. The severity of vertebral fractures was associated with IBD and older age.

Conclusion

Vertebral fractures occur frequently and more severely in IBD patients, particularly those with CD. Therefore, we suggest monitoring of bone density, regular vitamin D supply, and reducing the use of corticosteroids to prevent vertebral fractures in IBD patients who are older, female, or have comorbidities.
P135 Atopic dermatitis is associated with the clinical course of inflammatory bowel disease
Authors: Kim K W , Koh S J , Kang H W , Park H , Ha H , Park J , Kim K , Jun Y , Lee H J , Yoon H , Im J P , Park Y S , Kim J W , Kim J S ,   Seoul National University Inflammatory Bowel Disease Research Network (SIRN)
Published: January 2023

Background

There are a few studies about the relationship between inflammatory bowel disease (IBD) and atopic dermatitis (AD). It implies that both diseases have common pathophysiologic mechanisms and can affect each other. However, little information is available on the effect of AD on the clinical course of patients with IBD.

Methods

This is a multicenter, retrospective, observational study. Patients with concurrent IBD and AD were defined as case group. AD was defined as chronic eczematoid dermatosis diagnosed by dermatologists. Age-, gender-, and IBD subtype-matched patients without AD were included as reference group. The ratio of the case and reference group is 1:2.

Results

The numbers of patients in the case and reference group were 61 and 122, respectively. There was a significantly shorter biologics-free survival in the case group than that in the reference one after the multivariable adjusted Cox regression analysis with the onset age, disease duration, smoking status, use of steroid, use of immunomodulator, presence of other allergic diseases and initial disease severity [hazard ratio (HR) 1.743, 95% confidence interval (CI) 1.048-2.901, p = 0.032]. The trend was shown consistently in the subgroup analysis with ulcerative colitis (HR 4.769, 95% CI 1.625-13.995, p = 0.004), but not with Crohn’s disease (HR 1.393, 95% CI 0.736-2.636, p = 0.308).

Conclusion

AD showed a significant effect on the biologics-free survival of patients with IBD, especially UC. Further mechanistic research is required to elucidate the pathogenesis of AD on the clinical course of IBD.
P138 The use of video capsule endoscopy (vce) in patinets with a new diagnosis of Crohn's disease: the experience of one center
Authors: Nicolaou P , Theodoropoulou A , Psistakis A , Arna D , Velegraki M , Fragkaki M , Karmiris K , Vardas E , Paspatis G
Published: January 2023

Background

Crohn’s disease can involve any segment of the gastrointestinal tract, with terminal ileum being the most common affected part. The wireless or video capsule endoscopy (VCE) is a valuable diagnostic tool in detecting lesions in the small bowel beyond terminal ileum. The findings of the procedure in combination with other clinical, endoscopic and laboratory factors can determine the therapeutic plan.

Herein, we analyzed the findings of VCE in patients with suspicious or definite Crohn’s disease, and assessed its contribution to the therapeutic plan.

Methods

We evaluated these parameters in a retrospective analysis of 127 patients who underwent wireless capsule endoscopy in our department since June 2020.

Results

49/127 patients (51% male) were included in the study. The mean age was 40.24 years (SD ±14.30, IQR= 73–15). The majority of them (93.9 %) presented with a newly diagnosed Crohn’s disease or terminal ileitis. The VCE examination was performed to detect any other lesions in the small bowel. 6.1% had chronic diarrhea without endoscopic findings. 57.1% had findings of Crohn’s disease across the entire small bowel, 26.6% had sparse ulcers in the terminal ileum. In 12.2% multiple aphthous ulcers and edema were found in the terminal ileum and 4.1% had no findings. After VCE examination, initiation of treatment was considered in 57.1%. Magnetic enterography (MRE) was performed in 24.5% of the patients. VCE showed more extended lesions in the small bowel compared to MRE which showed non-specific terminal ileitis up to 15 cm in all patients.

Conclusion

In patients with mild terminal ileitis wireless capsule endoscopy reveals extended lesions in the small bowel leading to adjustments in the therapeutic plan. In patients with newly diagnosed or suspected Crohn’s disease, VCE can contribute to the assessment of the severity and location of the lesions as well as to the therapeutic plan.
P142 Evaluation of quantitative phase imaging for automated assessment of histopathological remission in patients with Ulcerative Colitis
Authors: Bokemeyer A , Buskermolen J , Ketelhut S , Tepasse P , Vollenberg R , Vieth M , Kemper B , Bettenworth D
Published: January 2023

Background

Ulcerative colitis (UC) is characterized by chronic intestinal inflammation. Histological remission has become an efficacy outcome in clinical trials and might have the potential to modify the course of UC. Quantitative phase imaging including digital holographic microscopy (DHM) can be used for objective and automated evaluation of tissue morphology and density. Our study aimed to evaluate DHM for quantifying histological inflammation in UC patients.

Methods

In a monocentric prospective study, UC patients undergoing colonoscopy were included. Disease activity was measured by the total Mayo Score. DHM was used to determine the refractive index (RI) in mucosal biopsy samples obtained during colonoscopy. RI values were correlated with histological disease activity as assessed by the Nancy histological index [NHI].

Results

In total, mucosal biopsy samples from 21 UC patients were included to the analysis. On average, UC patients had a moderate disease activity as reflected by a partial Mayo score of 3.1 (SEM ± 0.6), an endoscopic Mayo subscore of 1 (SEM ± 0.2) and a total Mayo score of 4.1 (SEM ± 0.8). The mean NHI was 1.3 (SEM ± 0.2) and the mean RI was 1.349 (SEM ± 0.0003).

RI values as determined by DHM correlated strongly with the histological disease activity as determined the NHI (p<0,001 and R2=0.282). Similarly, a marked correlation was found using alternative histopathological indices (Geboes score, Riley index, Robarts histopathological index; all p<0.001).

Conclusion

Our data demonstrate that DHM is appropriate to assess intestinal inflammation in UC patients and that it may be an alternative or supplemental tool to conventional histopathological assessment.
P147 Trends in choice of first line biologic therapy for patients with Inflammatory Bowel Disease. An observational cohort study
Authors: Fernando S , Abu-Rgeef R , Menon S , So K , Venugopal K , Picardo S
Published: January 2023

Background

Biologic therapies have revolutionised the management of Inflammatory Bowel Disease (IBD) with increasing utilisation over the last decade. The anti-Tumour Necrosis Factor-alpha (anti-TNF) agents (Infliximab (IFX) and Adalimumab (ADA)) as well as newer agents (Ustekinumab (UST) and Vedolizumab (VED)) all have well demonstrated safety and efficacy profiles in the management of IBD. The choice of an optimal first line biologic remains unclear due to lack of comparative randomised trials and real-world studies; however, certain patient and disease characteristics may influence this choice. The aims of this study were to explore temporal trends in choice of 1st-line biologic therapy and factors that influence this choice.

Methods

A retrospective observational cohort study of all patients with IBD that commenced induction and completed at least one maintenance dose of a biologic therapy between 1st January 2015 and 31st December 2021. Relevant patient and disease-specific factors were collected, including patient comorbidities (ischaemic heart disease, malignancy and opportunistic infections) at time of diagnosis, for each eligible patient. Factors affecting choice of biologic therapy were compared using ANOVA and c2 test.

Results

280 patients were included, with 50.7% being male and median age of IBD diagnosis of 29 years. There was a progressive increase in biologic use over time, with 15 patients commencing1st biologic therapy in 2015, rising to 58 patients in 2021. UST has overtaken IFX and ADA as first line choice for Crohn’s disease (CD) since its introduction in 2018 (Figure 1). IFX has remained preferred first line therapy for ulcerative colitis (UC) over VED and ADA, with stable trend in choice over time. Factors with significant differences in choice of first line biologic therapy included age (UST for older age of commencement), IBD subtype (higher proportion of patients commencing ADA had CD, whereas higher proportion of patients commencing VED had UC), disease location (VED was preferred for colonic over ileal CD), and malignancy (UST was preferred) (Table 1).

Conclusion

- There has been a steady rise in the number of patients commencing biologic therapies, with an average increase of 24% per year from 2015 to 2021.

- Ustekinumab has replaced anti-TNF therapy as the preferred first line biologic for Crohn’s disease; a trend likely secondary to the comparatively favourable safety profile of ustekinumab. Ustekinumab was preferred in older patients and those with history of malignancy.

- Infliximab remains the preferred first line therapy for ulcerative colitis with stable trends in choice.

- The presence of perianal disease was not a significant factor affecting choice.
P163 Is Peri-appendiceal Inflammation of Clinical Significance in Patients with Ulcerative Colitis?
Authors: Kim S J , Kim E J , Lee S M , Park H S , Noh Y K , Lee J
Published: January 2023

Background

Peri-appendiceal inflammation (PAI) is often found in patients with left-sided ulcerative colitis (UC) or proctitis. However, there is still no consensus on the clinical significance of PAI. This study aimed to identify the clinical significance of PAI in UC as a prognosis factor.

Methods

We retrospectively collected medical records and endoscopic results of patients with diagnosed left side UC or proctitis between January 2013 and December 2021. According to the presence of PAI, we divided the patients into PAI and non-PAI groups. Demographic features and clinical course of the two groups were collected and analyzed.

Results

A total of 107 patients (41 of left site UC, 56 of proctitis) were enrolled, of which 52 were in the PAI group and 55 were in the non-PAI group There was no difference in most of the demographic and clinical variables between the PAI and non-PAI groups. During the follow-up period of 51 months for the PAI group and 46 months for the non-PAI group, respectively, there was no difference in disease relapse rate (47.1% vs 49.1%, p=0.823), cumulative rate of disease relapse at 1, 3, and 5 years (10.7%, 26.2%, 34.8% vs 8.39%, 23.0%, 36.7%, p=0.823), rate of treatment escalation (59.6% vs 41.8%, p=0.066) and proximal disease extension (25% vs 25.5%, p=0.957) however, new occurrence of PAI during the follow-up period in the non-PAI group was associated with proximal disease extension (55.6% vs 19.6%, p=0.037) In this study, oral 5-aminosalicylate (ASA) was administered to most patients regardless of the extent of the disease. In patients with proctitis with PAI, oral 5-ASA did not affect relapse rate (37.1% vs 66.7%, p=0.550) and proximal disease extension rate (28.6% vs 33.3%, p=1.000).

Conclusion

PAI at diagnosis did not affect the course of the disease nor did oral 5-ASA in proctitis, however new occurrences of PAI during follow-up were associated with proximal disease extension.