bluuebunny/crossref_metadata_2025 huggingface dataset:
OP19 Extended mesenterectomy is not superior to mesenteric sparing resection in primary ileocolic resection for Crohn’s Disease in terms of postoperative endoscopic recurrence – results of an international randomised controlled trial
Authors: Van Der Does De Willebois E
Published: January 2024

Background

Extended mesenteric resection has recently been proposed to improve clinical outcomes after an ileocolic resection (ICR) for Crohn’s disease. The aim of this study was to analyse the clinical relevance of extended mesenteric resection, up to the level of the ileocolic trunk (intervention group), compared to conventional mesenteric sparing resection (control group) with regard to postoperative outcomes in patients undergoing primary ICR for Crohn’s disease.

Methods

In an international randomised controlled trial (RCT), patients ≥16 years, were assigned 1:1 to either the intervention- or the control-group. The anastomotic technique was standardised (side-to-side stapled). To demonstrate a relevant difference of 25% in postoperative endoscopic recurrence (defined as a modified Rutgeerts score ≥i2b, according to central reading) at 6 months, a minimum of 62 evaluable patients per arm were required. Secondary outcome parameters were postoperative morbidity, histopathological outcomes and use of Crohn’s medication postoperatively.

Results

In total, of the 129 included patients, 56 (43.3%) were male with a median age of 36 (IQR 22-55). There were no statistically significant differences in baseline characteristics between the two groups. There was no difference in endoscopic recurrence rates between the two groups: 27/62 (43.5%) in the intervention group and 27/64 (42.2%) in the control group, (p=1.0) Fig 1. Median time until endoscopy was 6 months (IQR 6-7). More patients received postoperative medical prophylaxis in the intervention group (28% vs 14%). In the control group, more patients started medication after endoscopy (intervention group 20% vs control group 27%). This resulted in a similar number of patients in both groups being on Crohn’s medication after six months, 48% in the intervention group and 41% in the control group. There was no significant difference in length of resection specimen (median length colon 7cm; ileum 22.5cm), blood-loss or operative time. Overall, a postoperative complication occurred in 28%, with anastomotic leakage in 5 (3.9%).

Conclusion

This is the first RCT to present data on the effect of extended mesenteric resection during ICR for Crohn’s disease. The results of this study showed no superiority of extended mesenteric resection with regard to endoscopic recurrence or other perioperative outcomes.
OP21 Spatial Transcriptomics of Pre-treatment Biopsies Revealing Molecular Maturation State and Chronic Crypt Damage, Reflecting Histological Severity, as Predictors of Primary Responsiveness to TNF-α Inhibitors in Bio-naive Ulcerative Colitis Patients
Authors: Kim S W , Na K , Oh S J , Lee C K
Published: January 2024

Background

Biologic therapies, particularly tumor necrosis factor-alpha inhibitors (TNFi), have greatly advanced the treatment of ulcerative colitis (UC), yet significant number of patients still do not respond to these treatments. For UC management, achieving both histologic and molecular healing is crucial, highlighting the need for more comprehensive therapeutic strategies. Despite extensive research, there is a significant gap in studies that simultaneously assess histologic and molecular changes at both the crypt and lamina propria (LP) levels. Our study addresses this gap by investigating TNFi-resistant UC patients, utilizing spatial transcriptomics to discern specific cell types within histologic sections and integrating these insights to enhance understanding of UC treatment responses.

Methods

We evaluated 56 patients categorized into test (n=23), validation (n=31), and healthy control groups (n=2). Each underwent biopsies at the same sites before (preTx) and after treatment (postTx), as shown in Figure 1A. This study focused on a 3-month follow-up of patients who were administered TNFi as a primary biologic therapy following resistance to conventional treatments. We used digital spatial profiling to analyze gene expression in the crypt and LP, as seen in Figures 1B and 1C. We then correlated molecular data with morphological characteristics and quantitatively evaluated histologic factors, especially crypt distortion and atrophy, reported as percentages (%).

Results

Among the study participants, 29 were classified as responders (R) to TNFi, while 25 were non-responders (non-R). A comparative analysis of gene expression between R and non-R groups revealed a differential expression pattern: 72 genes in the crypt and 105 genes in the LP across varying histologies, as shown in Figure 1D and 1E. Notably, in the preTx samples of non-R, crypts displayed significantly lower expression of genes associated with the maturation of colonocytes, including BEST4, C10orf99, CA2, CA4, CA7, PHGR1, SLC26A2, SLC26A3, LYPD8, CLCA1, and SCNN1, compared to the R group (Figure 1F). Furthermore, when correlating spatial transcriptomic data with histomorphological features, we observed that crypt distortion and atrophy were significantly more pronounced in the non-R group than in the R group in the preTx biopsy samples (Figures 1G and 1H).

Conclusion

Our study's spatial profiling unveils distinct molecular and histologic features between R and non-R to TNFi among bio-naive UC patients. The evaluation of chronic histological features such as crypt distortion, and molecular maturation status, in predicting TNFi response highlights the potential of early histologic assessment in guiding biologic therapy in the UC treatment pathway.
DOP02 Developing explicit thresholds for outcomes to inform (GRADE) Evidence to Decision frameworks for Inflammatory Bowel Disease guidelines
Authors: Shaban N , Sinopoulou V , Vuyyuru S , Moran G , Gordon M
Published: January 2024

Background

Evidence to decision (EtD) frameworks are a key recent development in Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology. They aim to ensure that decisions about healthcare interventions are based on a thorough, transparent and unbiased assessment of the available evidence. Core to this is to agree the importance of outcomes to be used, the specific measures for each outcome that have the most consensus and finally to develop explicit thresholds for interpretation of effect sizes of outcomes to inform (GRADE) evidence to decision frameworks. This ensures decisions are made in an unbiased fashion and allows stakeholders to focus on discussions based on their significant experience and expertise, rather than interpretation of evidence. Therefore, our study aims to develop these thresholds for the EtD framework to establish their use in several key IBD guidelines.

Methods

This online survey using Survey Monkey was conducted by inviting experts and stakeholders from the United Kingdom and British Society of Gastroenterology. Each expert was asked to select important clinically relevant outcomes and were asked about what magnitude of the effect they consider large, moderate, small, or trivial for each of the clinical, endoscopic, radiological, biochemical, histological outcomes and adverse events. Questions were framed as neutral statements without introducing a specific direction. Response options included sliding bars going from 1 to 100% for the desirable magnitude of effect for each outcome (Figure 1). The mean average of responses of experts were calculated.

Results

A total of 89 clinical experts/stakeholders participated in this online survey. Clinical remission, clinical response, endoscopic remission, withdrawal due to adverse events, and serious adverse events were considered critical outcomes. Trivial to small, small to moderate and moderate to large thresholds were as follows - clinical remission (10%, 20% and 31%), clinical response (13 %, 24% and 36%), endoscopic remission (9%, 17% and 28%), withdrawal due to AE (7 %, 14% and 23%), serious AE (6%, 11% and 17%) (Table 1).

Conclusion

This is the first study to develop thresholds for outcomes in IBD which can be used in EtD for the development of IBD guidelines. These thresholds have been used in the development of upcoming British Society of Gastroenterology guidelines for the management of IBD.
DOP03 Gaps between ECCO quality standards of care and the real world: the E-QUALITY survey on processes and outcomes
Authors: Walsh A , Fidalgo C , Adamina M , Barreiro de Acosta M , Burisch J , Drobne D , Faiz O , Ferrante M , Godny L , Iacucci M , Jäghult S , Restellini S , Rosini F , Shouval D , Yanai H , Fiorino G
Published: January 2024

Background

The European Crohn’s and Colitis Organisation (ECCO) Position Paper on Quality-of-Care (QoC) proposed essential standards on process and outcomes for units that manage patients with inflammatory bowel disease (IBD). The E-QUALITY taskforce investigated whether gaps between these standards and real-world practice exist.

Methods

A 74-question web survey accessible to all institutions affiliated with ECCO was developed. One delegate per institution was requested to respond. A descriptive analysis was done.

Results

From March to October 2023, 166 centres from 28 different countries replied to the survey (Fig.1).

At diagnosis, disease extent is assessed by colonoscopy in 96% and completed by small bowel (SB) evaluation in 43%. At least 2 biopsies from each segment are obtained in 55%. SB investigation for Crohn’s disease (CD) takes place in 60%. 54% of centres provide access to endoscopy with deep sedation for the majority of patients. To assess treatment response, faecal calprotectin is used in 65%, endoscopy in 54%, cross-sectional imaging for CD in 36%. In the case of primary failure of any drug, therapeutic decisions are based on objective measures of inflammation in 98%. A scheduled monitoring protocol for asymptomatic patients is followed in 42%. Patients with prolonged use of corticosteroids are being switched to a steroid-sparing treatment in 84%, but there is no protocol to track or act upon high steroid exposure in 43% of centres. 72% centres monitor metabolic bone health. Only 51% of units screen IBD patients for colorectal cancer, but screening is done with high-definition endoscopy in 92%. Chromoendoscopy with targeted biopsies is performed in only 47% units. Patients with perianal fistula are managed by combined medical and surgical approach in 67%, and reassessment by clinical and endoscopy and/or pelvic MRI is done in 62%. Laparoscopic approach for intra-abdominal surgery is used in 76%, and preoperative nutritional assessment in 62%. Patients receive therapies to prevent post-operative recurrence based on risk factors in 70%, standard endoscopy within 6-12 months after surgery is done only in 52% of centres. Although only 8% of centres lack a defined protocol to manage acute severe ulcerative colitis flares, 13% lack a standard algorithm, and 36% do not involve the surgeon in this setting from day 1. 38% of centres have a paediatric to adult transition clinic.

The main reason for not adhering to ECCO standards are difficulty of providing tests in a timely fashion in up to 83% of centres.

Conclusion

Our survey has revealed significant gaps between ECCO standards and real-world practice. These results will help ECCO improve initiatives to help institutions to provide standard QoC.

1) Fiorino et al. JCC 2020;14:1037-48
DOP06 Development of simplified scoring system to predict two-year clinical remission of patients with Ulcerative Colitis after treatment with vedolizumab
Authors: Chaemsupaphan T , Pudipeddi A , Paramsothy S , Kermeen M , Collins G , Lin H , Leong R W
Published: January 2024

Background

No prospective study had been conducted to demonstrate the efficacy of vedolizumab in patients with ulcerative colitis (UC). While several studies have identified predictive factors for achieving mucosal healing, a well-validated algorithm is lacking. We aimed to identify the predictive factors and develop a practical scoring system to assess the efficacy of vedolizumab in patients with UC.

Methods

We performed a logistic regression analysis from the data of withdrawal versus continuation of thiopurine in vedolizumab-treated patients with ulcerative colitis (VIEWS) study which is a prospective multi-center longitudinal cohort in UC patients in Australia who had clinical and endoscopic remission (Mayo score ≤ 1) at baseline and continued vedolizumab as maintenance treatment. Predictive factors of two-year steroid-free clinical remission were developed into a model that predicted the outcome of treatment. We then validated our scoring system in a separate retrospective cohort of patients with UC who received vedolizumab in routine practice during 2016-2021.

Results

The derivation cohort comprised 62 patients, with 48 patients (77.4%) maintaining clinical remission at 2 years. Patient characteristics are presented in table1. Independent predictive factors used in developing the model included combination of thiopurine continuation (OR 3.6, P-value 0.11), absence of exposure to anti-tumor necrosis factor (TNF) (OR 3.75, P-value 0.047), histologic remission at baseline (OR 10.79, P-value 0.002), and duration of UC < 5 years (OR 9.29, P-value 0.04). The final simplified score is as follows: 3x (thiopurine continuation) + 2x (absence of exposure to anti-TNF) + 3x (histologic remission at baseline) + 2x (duration of UC < 5 years) yielding the area under the receiver operating characteristic curve (AUROC) of 0.86 in the derivation cohort (figure 1). In the validation cohort, there were 43 UC patients who had been initiated and continued vedolizumab as maintenance treatment, with 30 patients (69.8%) remained in clinical remission at two years. The AUROC of validation cohort was 0.75 after applying simplified score. At a cut-off level of 4 points, the model can identify two-year clinical remission with 83% sensitivity and 54% specificity, respectively.

Conclusion

We developed the practical predictive scoring system to determine UC patients who are likely to remain in clinical remission after two years of treatment with vedolizumab. In high-risk UC patients, combination use of vedolizumab and thiopurine is strongly recommended.
DOP07 Monitoring disease activity by intestinal ultrasound predicts biologic treatment persistence in patients with Inflammatory Bowel Disease
Authors: Fremberg Ilvemark J , Christensen K R , Steenholdt C , Brynskov J , Attauabi M , Dahl E , Bjerrum J W , Seidelin J B
Published: January 2024

Background

Current biomarker-based monitoring strategies have limited efficacy in predicting risk of biologic treatment failure in inflammatory bowel disease (IBD). Endoscopic assessment identifies patients at risk of disease progression but is expensive and poorly accepted by patients. Therefore, we examined how intestinal ultrasound (IUS) performed as part of a monitoring program to predict treatment persistence to biologics in IBD patients.

Methods

Data were generated as part of a 1-year prospective, observational, cohort study of patients on biologics comparing tight monitoring to a historic cohort (‘Time It´ study). Data used in the present analysis included Harvey Bradshaw index (HBI), simple clinical colitis activity score (SCCAI), CRP, f-calprotectin (FC), IUS, and ileocolonoscopy all done at inclusion. The following definitions were used: Treatment persistence: no need for dose escalation or switching to another biologic or small molecule; IUS transmural remission (TR): bowel wall thickness ≤3mm in all bowel segments and zero color Doppler activity; endoscopic remission (ER): simple endoscopic score (SES)-CD≤2 or Mayo endoscopic score 0; clinical remission (CR): HBI≤4 or SCCAI≤2; FC remission (FCR): FC≤250; CRP remission (CRPR): CRP≤10 mg/L. Chi-square tests and Kaplan-Meier statistics were used to compare baseline measures in treatment persistent and non-persistent patients.

Results

Of the 91 patients included in 'Time It’, 77 had IUS performed and 69 ileocolonoscopy. Of the 77 patients, 61% were on maintenance treatment at inclusion and 39% were included during induction (Table 1). COVID-19 restrictions were the main reason for missing IUS or endoscopy. As expected, more patients with ER had 1-year treatment persistence (87% vs. 41%; p<0.001). However, patients with IUS TR also had better treatment persistence (78% vs. 38%; p<0.001). CR or FCR were associated with treatment persistence (p<0.05 and p<0.01, respectively), but not CRPR. Combining TR and FCR performed numerically as well as ER (treatment persistence 85% vs. 41%, p=0.002). Survival analysis of TR showed a mean treatment persistence of 318 days vs. 221 days without TR (p<0.001); corresponding treatment persistence data were 327 days vs. 230 days for combined TR and FCR; and 338 days vs. 226 days for ER (both p<0.001; Figure 1). There was no difference in mean treatment persistence between TR and ER (318 vs. 338 days; p=0.36).

Conclusion

IUS alone or combined with FCR was comparable to endoscopy to identify patients with high biologic treatment persistence. Being a non-invasive, patient friendly, cost-effective modality, IUS monitoring may improve current disease monitoring programs aiming to increase treatment persistence.
DOP24 Multi-omic sequencing reveals distinctive gene expression and DNA methylation alterations as potential predictors of primary sclerosing cholangitis development in treatment-naïve paediatric Ulcerative Colitis
Authors: Rodriguez Sosa A , Lawal O , McDonnell C , Grant L , Stephens I , Genua F , O'Brien J , Kirwan G , Kel A , Dominik A , Stack R , Yochum G , Doherty G , Hussey S , Das S
Published: January 2024

Background

Primary sclerosing cholangitis (PSC) is a progressive choleostatic disease and up to 80% of patients also have ulcerative colitis (PSC-UC). This presents a clinical challenge owing to difficulty in diagnosis and increased risk for developing cancer. While several multifactorial processes including inflammation and microbial dysbiosis have been associated with PSC-UC pathogenesis, the precise molecular factors that regulate the phenotype of this disease subtype remain unknown.

Methods

We applied methyl-capture sequencing and mRNA sequencing to colonic mucosal biopsies derived from the DOCHAS study (GEN-193/11), to identify transcriptomic and epigenetic differences between treatment naïve paediatric UC (n=10), PSC-UC (n=10) and healthy controls (n=10) samples.

Results

Differential gene expression between UC and PSC-UC identified 9 up-regulated genes - ADMTS14, PNCK, NLRP3, SLC6A19, DLL1, FCGR2C, KLHL17, APOB, EHBP1L1 and 5 downregulated - SLC37A2, SLC14A2, RPL27, RPS25, SLC38A4 in PSC-UC relative to UC. Importantly, we show that expression of these genes was intricately regulated by master transcriptional regulators (pro-caspases, IL7RA) and transcription factors (TFs) :AR, p53, JUND, CEBPA. Similarly, differential methylation analysis between PSC-UC and UC identified 22 differentially methylated regions (DMRs) relative to controls, where 5 were hypermethylated and 8 hypomethylated. Intriguingly, in general we show that these DMRs are largely localised in gene promoter regions as opposed to enhancers. Importantly, we show that these DMR’s identified between PSC-UC vs UC is enriched for binding sites for the TF: ASCL1, suggesting its activity likely is effected due to the altered methylation of its binding site in PSC-UC patients. Collectively, these results highlight the importance of TF’s in driving molecular differences between PSC-UC and UC paediatric patients in a treatment naïve setting.

Conclusion

In summary, for the first time this study provides a critical insight into the transcriptional differences between treatment naïve children with PSC-UC vs UC as well as highlights the intricate regulatory processes involving master transcriptional regulators, transcription factors and DNA methylation. These processes thus warrant further examination in larger cohorts to rationalise their role as diagnostic/therapeutic targets.
DOP25 Antibodies against Neutrophil Extracellular Traps (ANETAs) are associated with more severe disease course in Ulcerative Colitis
Authors: Mendieta Escalante E A , Parada-Venegas D , Roozendaal C , Hermoso M , Bourgonje A R , Faber K N , Gerard D
Published: January 2024

Background

Antibodies against Neutrophil Extracellular Traps (ANETAs) have emerged as markers in multiple autoimmune disorders (i.e. rheumatoid arthritis and systemic lupus) associated with disease activity. We investigated the presence of ANETAs and their influence on disease course in Inflammatory Bowel Disease (IBD).

Methods

Serum samples from UC (n=33), Crohn's Disease (CD; n=28), and healthy controls (HC; n=8) underwent incubation with non-lytic Neutrophil Extracellular Traps (NETs) for immunofluorescence microscopy. For clinical relevance, these patients were followed over ten years to track treatment resistance, extraintestinal manifestations, surgeries, and disease recurrence (Table 1). For functional relevance, in vitro generated NETs were exposed to ANETAs, followed by quantifying macrophage-mediated clearance of these ANETA pre-treated NETs by real-time microscopy via pHrodo for 24 hours, as well as assessing pro-inflammatory cytokine (IL-6, TNF-α, IL-8, and IL-23) genetic expression levels in these macrophages.

Results

Among UC patients, ANETA positivity correlated with high rates of treatment resistance, extraintestinal manifestations, colorectal surgeries, and recurrence of disease like pouchitis (93.3% vs. 6.7%, 61.5% vs. 38.5%; 71.4% vs. 28.6%; 87.5% vs. 12.5%, for ANETA+ and ANETA- UC patients, respectively). CD patients with ANETAs exhibited high rates of resistance to treatment (75% vs 25%) and lower rates of extraintestinal manifestations, colectomy, and disease recurrence (38.1% vs 61.9%, 40% vs 60%, 33.3% vs 66.7%) (Fig 1A). Macrophages displayed robust engulfment of untreated NETs and those treated with healthy control sera, while ANETA-coated NETs exhibited reduced susceptibility to macrophage phagocytosis (Fig 1B). Gene expression analysis revealed a significant upregulation of pro-inflammatory cytokines (IL-6, TNF-α, IL-8, and IL-23) when NETs were incubated with serum from ANETA-positive individuals compared to sera from healthy controls (p<0.05).

Conclusion

ANETAs may serve as markers for a distinct subgroup of UC patients characterized by aggressive disease and poorer prognosis. The potential mechanism might involve impaired NETs clearance by, and inducing a proinflammatory response in macrophages. Discrepancies observed between UC and CD suggest diverse pathophysiological mechanisms in both diseases. Further research is imperative to comprehensively understand the underlying pathophysiology, function, and potential clinical applications of ANETAs in IBD.
DOP30 Cross-ethnic microbiome analyses identify shared and specific signals for Northern Indian IBD patients
Authors: Singh A , Gacesa R , Juyal G , Joshi M , Midah V , Thelma B K , Weersma R K , Sood A
Published: January 2024

Background

Clinical manifestation of the inflammatory bowel disease (IBD) shows considerable variation across the world. We hypothesized these differences may be influenced by geographical differences in gut microbiome. To test this, we investigated the correlation between gut microbiota and the disease phenotypes of IBD in a cohort form the Northern part of India.

Methods

Stool samples and clinical metadata were collected from 226 IBD patients (198 ulcerative colitis and 28 Crohn’s disease) and 66 controls from a population cohort from the Northern India. We used metagenomic shotgun sequencing to determine diversity, composition and function of the gut microbiota of the participants. Microbiome was then associated to IBD and its subtypes and clinical metadata (e.g. medication use, drug response, and disease activity). We replicated our results in 436 IBD patients and 903 population controls from the Netherlands analyzed using an identical workflow and used machine learning to assess how well do the Indian IBD signals generalize to Dutch IBD.

Results

We identified reduction in microbiome diversity and changes in beta diversity in Indian IBD patients (FDR < 0.05, replicated in Dutch population) and identified that 319 taxa and 71 biochemical pathways are altered in Indian patients (FDR < 0.05). Of note, 39% of these signals were replicated in the Dutch cohort (at FDR < 0.05 level). We identified strong dysbiosis shared across Indian and Dutch IBD patients, characterized by expansion of opportunistic pathogens (e.g. Genera Clostridium, Streptococcus and Lactobacilli) and oral bacteria (e.g. Streptococcus oralis and Bifidobacterium dentium) as well as reduction in butyrate producers such as Faecalibacterium prausnitzii, Roseburia hominis and Blautia massiliensis. In addition, we found novel pathobionts specific to the Indian cohort (including oral bacteria from Genus Scardovia and Oribacterium; Actinomyces dentalis and Klebsiella pneumoniae). Machine-learning models trained on the Indian cohort were highly predictive in the Indian test set (Sensitivity 0.84, Specificity 0.95) and generalized to Dutch cohort (Sensitivity 0.77, Specificity 0.69).

In addition to IBD-associated dysbiosis, we identified links between medication use and gut microbiota independent of the disease activity: use of Tofacitinib (used by 26 UC patients) was linked to decrease in Lactobacilliales and increase in Clostridia, while Prednisolone and Azathioprine associated to reduction in Roseburia and increase in Streptococcus and Granulicatella.

Conclusion

The IBD patients from Northern India show gut dysbiosis similar to European patients, but also show enrichment in India-specific pathobionts. The microbiome-based diagnostic models generalize across these populations.
DOP31 Gene correlation network analyses reveal transcript modules and pathogenic mechanisms associated with resistance and response to ustekinumab therapy in Ulcerative Colitis
Authors: Saifuddin A , Cozzetto D , Olbei M , Hart A , Korcsmaros T , Powell N
Published: January 2024

Background

Precision medicine in ulcerative colitis (UC) remain elusive. The heterogeneity in patients’ mucosal transcriptomic profiles suggests that stratification based on molecular mechanisms might be possible, which may link to treatment response. We interrogated a dataset of ustekinumab-treated patients treated to determine transcript modules (TMs) in active UC, investigate pathogenic pathways and consider which cells might be driving ustekinumab resistance.

Methods

Pre-treatment mucosal transcriptomes and outcome data were available for 358 ustekinumab-treated patients enrolled in the UNIFI programme. Modules of co-expressed genes were defined with weighted gene correlation network analysis (WGCNA) and their functional roles and regulatory interactions inferred with Fisher tests. Multivariate regression was used to test the ability of clinical and transcriptomic data to predict treatment resistance. Further insights into the cellular and molecular features of ustekinumab resistance were gauged from the analysis of single cell data (Single Cell Portal accession SCP259). Analyses were performed in R 4.2.3 (Vienna, Austria).

Results

WGCNA generated 23 transcript modules (TMs) whose correlation with mucosal healing ranged from -0.26 to 0.25. The three TMs most negatively correlated with response comprised genes enriched in neutrophil degranulation, extracellular matrix activity and endoplasmic reticulum function. The modules correlating highest with response were enriched in genes involved in mitochondrial function. The constituents of the ustekinumab resistance-related modules are regulated by a hierarchy of transcription factors downstream of NFKB1, AHR, JUN and RELA. They are also densely connected by regulatory protein-protein interactions (Figure 1). A multivariate model including TM1 enrichment score and clinical variables predicts resistance with area under the curve 0.76 (95% confidence interval: 0.69–0.82). Notably, TM1 included TREM1 and OSM, which were previously associated with anti-TNF resistance. Surmising that cell populations co-expressing these genes might be key to ustekinumab resistance too, we identified TREM1+ OSM+ inflammatory monocytes (IMs). These showed higher expression of genes such as IL1B, IL8 and CXCL2 compared to other IMs, and increased activity in pathogenic processes including interleukin (IL)10, IL4 and IL13 signalling and G-protein-coupled receptor signalling.

Conclusion

Gene co-expression analysis identified transcripts and molecular mechanisms associated with response and predictive of resistance to ustekinumab. TREM1+ OSM+ IMs may be key to driving resistance, suggesting an important role for innate immunity. These findings are important for developing precision medicine approaches in UC.
DOP41 Mucosal single-cell profiling of Crohn's-like disease of the pouch reveal unique pathogenesis and therapeutic targets
Authors: Cao S , Deepak P , Colonna M
Published: January 2024

Background

After restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC), a subset of patients develop Crohn’s-like disease of the pouch (CDP), a chronic inflammatory condition that affects both the pouch body and extra-pouch organs including the pre-pouch ileum. The cellular and molecular identities of CDP are unknown, and its diagnosis and treatment remain challenging. To define the pathophysiology of CDP, we examined mucosal cells from patients after IPAA with and without CDP using single cell analyses.

Methods

Endoscopic samples from the pouch body and pre-pouch ileum of 50 patients with an IPAA were collected for single-cell RNA sequencing (scRNA-seq) or mass cytometry (or CyTOF). We analyzed immune and non-immune cells from both pouch body and pre-pouch ileum of patients with normal pouch/ileum and CDP using scRNA-seq. CyTOF was performed on mucosal immune cells from independent cohorts of patients with normal pouch/ileum, CDP, and pouchitis. Mucosal samples from patients with familial adenomatous polyposis (FAP) after colectomy and pouch formation were also analyzed by CyTOF. ScRNA-seq and CyTOF findings were independently validated using immunohistochemistry.

Results

We revealed distinct cell clusters in normal pouch body versus normal pre-pouch ileum in UC patients. Colitogenic immune cells expanded in normal UC pouch body compared to normal FAP pouch body. Compared to normal pouch/ileum, CDP pouch/ileum exhibited expanded TCR clonotypes, elevated Th17 signaling, and diminished T cell exhaustion markers. Elevated plasma cells, inflammatory fibroblasts and monocytes were noted in CDP pouch/ileum (Figure 1). CDP also harbored elevated Th17-inducing cytokines such as IL23, IL1B, and IL6 produced by myeloid cells. ScRNA-seq and CyTOF identified increased CD14+TREM1+ pathogenic monocytes in both pouch body and pre-pouch ileum of CDP. Ligand-receptor analysis further revealed a stromal – myeloid – lymphocyte circuit in CDP. Integrated analysis showed that upregulated immune mediators in CDP tissues were similar to those in CD and pouchitis, but not UC. In addition, the pouch body and pre-pouch ileum of CDP exhibited prominent activation of the unfolded protein response (UPR) across all major immune and non-immune cell compartments (Figure 2), which was not present in UC, CD or pouchitis based on reanalysis of published databases.

Conclusion

CDP demonstrates altered immune and non-immune cell populations/states in the pouch body and pre-pouch ileum. CDP represents a distinct entity of inflammatory bowel disease with extensive UPR activation, a unique feature that may serve as novel diagnostic markers and therapeutic targets using ER stress-alleviating agents including chemical chaperones.
DOP45 Blood-derived neutrophils give rise to differentially activated populations in the mucosa of active Inflammatory Bowel Disease patients
Authors: Veny M , Sanzo-Machuca A , Corraliza A M , Strobbe F , Garrido-Trigo A , Gudiño V , Melón-Ardanaz E , Esteller M , Teubel I , Masamunt M C , Ordás I , Prieto C , Giner À , Martin-Cardona A , Esteve M , Ricart E , Salas A
Published: January 2024

Background

Infiltration of neutrophils is the main histological feature in active inflammatory bowel disease (IBD). Recent data suggests that tissue- and tumour-infiltrating neutrophils can adopt remarkably different phenotypes with potentially different functions. However, the heterogeneity of this population in IBD remains unknown.

Methods

Single-cell RNA sequencing (scRNA-seq) data was generated from colonic biopsies of 92 individuals including 6 healthy controls (HC), 36 inactive IBD, 19 active Crohn’s disease (CD) and 31 active ulcerative colitis (UC) patients. Neutrophils (6038 cells) found in the inflamed colon of CD and UC patients were analysed using a curated pipeline in Seurat (v4.0.2)1. Posterior analysis included the FindAllMarkers function (differentially expressed genes), Jaccard index similarity and the AddModuleScore function (comparisons with literature-described neutrophils), Monocle3 algorithm (developmental trajectory) and clusterProfiler (v3.0.4; enrichment and pathway analysis). For in vitro stimulation, neutrophils were isolated from the blood of HC donors (n=4) using a double Ficoll gradient 1. Cells and supernatants were analysed for qPCR and ELISA determinations.

Results

We identified 6 different clusters/states of colonic neutrophils (Figure 1A). In agreement with our previous results1 we found a population of S100A12/S100A8/S100A9 neutrophils (N0), IFN-response neutrophils (N3) and CCL3/CCL4 neutrophils (N2), in addition to N1.1 and N1.2 neutrophils. N3 neutrophils were enriched in the inflamed colon of CD patients compared to UC (17.2% vs 5.8%, p-value= 0.0021; Figure 1C). Comparative analysis with published datasets revealed that N0, N1.2 and N3 resemble populations of neutrophils found in blood2,3. In contrast, N1.1 and N2-like clusters showed some similarity to umbilical cord blood3 and tumour-infiltrating neutrophils4. Trajectory analysis, originating from N0 (peripheral-like) neutrophils, showed two potential branches of differentiation, with N1.2 leading towards N3 (IFN-response) and N1.1 differentiating into N2 (CCL3) neutrophils (Figure 1B). Finally, pathway analysis showed that N2 neutrophils presented enriched gene expression of the TNF signalling pathway, and together with the N1.1 state, an enrichment of the IL1β signalling pathway as well. In vitro experiments revealed that TNF, IL1β and LPS can all induce expression of CCL3 and CCL4, top differentially expressed genes of N2 neutrophils.

Conclusion

We show that active IBD is associated with a highly heterogeneous population of infiltrating neutrophils. Some of them resemble neutrophils in peripheral blood, while others most likely differentiate in response to inflammatory cues present in the colon of active IBD patients.
DOP72 Pregnancy for IBD-patients with an enterostomy is feasible but is associated with complications
Authors: Bouwknegt D G , van der Weide A H C , Dijkstra G , van Dop W , Prins J R , Hoogenboom F J , van der Woude C J , Visschedijk M C
Published: January 2024

Background

As inflammatory bowel disease (IBD) is frequently diagnosed in young adults, the disease often coincides with pregnancy. There are several indications for enterostomies in the treatment of IBD. Literature on enterostomy complications during pregnancy and pregnancy-outcomes remains scarce. Gaining insight in the incidence of complications and the course of these pregnancies serves as a first step in developing guidelines for the difficult question of how, when and by whom complications during pregnancy should be monitored and treated. The aim of this study was to assess enterostomy related complications and pregnancy-outcomes in female IBD patient with an enterostomy during pregnancy.

Methods

For this multicenter cohort and survey study, all patients who have been pregnant while having an enterostomy and who gave birth between 2016 and 2023 in three Dutch university medical centers were included. Complications of the enterostomy and pregnancy-outcomes were collected retrospectively from electronic patient files. In collaboration with gastroenterologists, surgeons, gynaecologists and IBD-patients, a survey was designed. Through this digital questionnaire, all participants were asked about their experience during pregnancy and any long-term enterostomy related complaints.

Results

Data was collected on 37 patients (mean age at conception 32.6 years; 64.9% Crohn’s disease (CD), 32.4% ulcerative colitis (UC), 2.7% IBD undetermined (IBD-U)), comprising 48 pregnancies of which four ended in a miscarriage. Enterostomy related complications occurred in thirty of the full-term pregnancies (68.2%), with decreased stoma-output (43.2%), small-bowel obstruction (29.6%) and leakage (25%) being the most prevalent. In a quarter of the pregnancies, surgical revision of the stoma was needed due to obstruction (27.3%), prolapse (27.3) and peristomal herniation (45.6%). A full overview of documented complications can be found in table 1. Of the fourteen women who completed the questionnaire, six reported non-resolved complications at least six months after delivery (42.9%). Eighteen pregnancies ended in a caesarean section (40.9%). There were 45 infants (one gemelli pregnancy), of whom eight (17.8 %) were born prematurely,eight (17.8 %) had low birth weight (17.8%) and eight (17.8 %) were small for their gestational age.

Conclusion

Being pregnant and giving birth with an enterostomy is feasible, but is in two third of pregnancies associated with complications. A reduced stoma output and leakage can be prevented by early counseling. Proper guidance before, during pregnancy and postpartum is therefore crucial for IBD-patients with an enterostomy.
DOP88 Lipids drive myofibroblast activation and the epithelial-mesenchymal transition process in Crohn’s Disease
Authors: Rizzo G , Wozny M , Pineda Chavez S E , Mori G , Carriles Linares A , Morosi L , Martano G , Ghisletti S M L , Gandolfi F , Vallelonga V , Loy L , Bezzio C , Spaggiari P , Dal Buono A , Gabbiadini R , Carvello M , Spinelli A , Repici A , Armuzzi A , Vetrano S
Published: January 2024

Background

Fibrostenosis represents one of the major clinical complications of Crohn’s Disease (CD). However, the molecular mechanisms underlying intestinal fibrogenesis remain poorly understood and anti-fibrotic therapy has not yet been developed. Growing evidences supports that oxidative stress and the epithelial-mesenchymal transition (EMT) process contribute to the development and progression of fibrosis. Here, we assessed the role of lipids in fibrogenesis and whether mitochondria dysfunction can support fibrosis formation.

Methods

Spatial metabolomics analysis and adipophilin (ADFP) staining were performed on surgical specimens from fibrotic ileum and the surrounding region (healthy) derived from CD patients. Fibroblasts isolated from fibrotic and healthy ileum and human induced pluripotent stem cell-derived intestinal organoids (iHOs) were treated for 1-3 weeks with lipid mix (2%) and analyzed by RNA sequencing. Pathways significantly modulated were validated by RT-PCR, WB, FACS analysis, and proliferative, migratory and contraction assays, and mitochondrial functions by Seahorse analyzer.

Results

Spatial metabolomics revealed a significant accumulation of lipids characterized by very long-chain fatty acids in the fibrotic area compared to surrounding healthy regions, which was further confirmed by ADFP staining. RNA-seq analysis showed overlapping dysregulated pathways between healthy fibroblasts stimulated with lipids and fibrotic fibroblasts, in particular genes related to cell cycle, cytoskeletal reorganization, migration, contractility and cell metabolism (oxidative stress) which were further confirmed by functional assays. Among the genes related to oxidative stress, lipid stimulation significantly decreased NFE2L2 and promoted an increase in CPT1A, gene encoding for a fatty oxidation mediator. Moreover, lipid-stimulated fibroblasts showed a reduction in mitochondrial respiration, particularly basal and maximal respiration, and spare respiratory capacity by Seahorse analysis. On the other hand, long exposure of iHOs to lipids promoted the EMT process through the upregulation of TWIST, ZEB, VIM, and S100a4.

Conclusion

Lipid stimulation induced myofibroblast activation through oxidative stress and alteration of mitochondrial metabolism, and increased the expression of EMT transcription factors in intestinal epithelial cells (iHOs) that may support fibroblast-mediated pro-fibrotic activity. These data indicate that regulators of fatty acid oxidation involved in the fibrotic process may represent new potential targets for the treatment of fibrostenotic CD patients.
DOP89 Unfolded protein response controls group 3 innate lymphoid cells in IBD
Authors: Cao S , Colonna M
Published: January 2024

Background

Group 3 innate lymphoid cells (ILC3s) have recently emerged as important regulators and potential drug targets for IBD. However, the response of ILC3s to environmental stimuli during intestinal inflammation remains elusive. IRE1a-XBP1 serves as the regulatory hub of endoplasmic reticulum stress and the unfolded protein response (UPR) that plays a vital role in intestinal inflammation.

Methods

We generated conditional knockout Ire1aflo/flox,Rorc-Cre (Ire1aΔRorc) and Rag-/-Ire1aΔRorc mice with Ire1a deleted in ILC3s. Intestinal infections were induced by Citrobacter rodentium and Clostridium difficile. ILC3s-derived cytokines including IL-22 is crucial for host defense in the acute phase of C. rodentium and C. difficile infection. Dextran sodium sulfate (DSS) was given in drinking water to induce acute colitis. We recruited patients with active Crohn’s disease (CD) and collected ileal biopsies during routine colonoscopy before starting ustekinumab, a non-selective anti-IL-23 antibody. Mucosal ILC3s were isolated for analysis of ILC3s by flow cytometry.

Results

In murine intestinal ILC3s, the activity of IRE1a-XBP1 pathway follows a robust 24h circadian rhythm which parallels that of clock genes and cytokines including IL-22. XBP1s is activated in ILC3s ex vivo by vasoactive intestinal peptide, which was previous shown to orchestrate the circadian expression of IL-22 by ILC3s. IRE1a-XBP1 in intestinal ILC3s is further activated in response to IL-23 and colitis in mice, as well as in inflamed IBD tissues compared to normal tissues from healthy individuals. We further showed that IRE1a-XBP1 activation in stimulated ILC3s requires mitochondrial reactive oxygen species (mtROS) (Fig 1). Using the Ire1aΔRorc mice, we demonstrated that IRE1a-XBP1 is critical for cytokine expression by ILC3s. Ire1aΔRorc mice are highly susceptible to acute C. rodentium and C. difficile infection as well as acute DSS colitis (similar vulnerabilities were found in Rag-/-Ire1aΔRorc mice compared to Rag-/-Ire1aflox/flox littermates). Ire1aΔRorc mice exhibit reduced IL-22 and IL-17A in ILC3s and impaired epithelial barrier function with diminished expression of mucins and antimicrobial peptides. The susceptibilities of Ire1aΔRorc and Rag-/-Ire1aΔRorc mice to colitis were rescued by administration of recombinant IL-22 (Fig 2). Moreover, the frequency of XBP1s+ ILC3s in ileal mucosa from CD patients before initiation of ustekinumab positively correlates with response to therapy.

Conclusion

We demonstrate that a non-canonical mtROS-IRE1a-XBP1 pathway augments cytokine production by intestinal ILC3s. We also identify XBP1+ ILC3s as a potential biomarker for predicting responsiveness to anti-IL-23 therapies in IBD.
DOP90 Amphiregulin promotes colitis-associated intestinal fibrosis through activation of PI3K/AKT signaling in Intestinal fibroblasts
Authors: Wang S , Zhang H , Zhao X
Published: January 2024

Background

Intestinal fibrosis is one of the most threatening complications of Crohn’s disease (CD). Amphiregulin (AREG) expression is increased in patients with CD with fibrosis.

Methods

The role of AREG in activating intestinal fibroblasts and driving fibrogenesis is largely unexplored. In this study, fibrotic and nonfibrotic tissues were obtained from CD patients undergoing surgical resection while normal intestinal tissues were obtained from patients with diverticulum of small intestine. Fibrosis index score for fibrosis were assessed by Masson staining. AREG, collagen Ⅰ and α-SMA expression were determined in intestinal tissues of patients with CD with fibrosis or without fibrosis by qRT-PCR. Wild-type (WT) and Areg knockout (Areg-/-) mice were induced into intestinal fibrosis by dextran sulfate sodium (DSS). We induced intestinal fibrosis in WT mice using a chronic DSS-induced colitis model with or without AREG intraperitoneal injection. The fibrotic indicators in colons were evaluated. Fibroblasts were isolated from fibrotic intestinal surgical resections of patients with CD. The effect of AREG on activation and proliferation in human intestinal fibroblasts was determined. RNA-sequencing of human intestinal fibroblasts treated with or without AREG was performed.

Results

AREG expression was increased in intestinal fibrotic sites compared with nonfibrotic sites from patients with CD. Mice with Areg deficiency represented with severer intestinal inflammation but alleviated fibrosis in colons. Although additional given AREG attenuated intestinal inflammation in mice with DSS-induced chronic colitis, it promoted more severe intestinal fibrosis. AREG promoted human intestinal fibroblast activation and proliferation by activating PI3K/AKT signaling. PI3K inhibitor suppressed AREG-induced fibroblast activation and proliferation, thus lightened intestinal fibrosis in mice. Besides, AREG promoted secretion of LPA (Lysophosphatidic acid) from intestinal fibroblast, which activated fibroblast through LPAR3/PI3K/AKT pathway.

Conclusion

These findings reveal that AREG promotes intestinal fibrotic responses in experimental colitis and human patients with CD by promoting fibroblast activation and proliferation through PI3K/AKT pathway. Moreover, LPA secreted from intestinal fibroblast induced by Areg is involved in formation of CD intestinal fibrosis. Thereby, PI3K, AKT, LPA might serve as potential therapeutic targets for fibrosis in CD.