bluuebunny/crossref_metadata_2025 huggingface dataset:
P122 Digital spatial profiling reveals the predictive characteristics in patients with immune checkpoint inhibitor-induced colitis
Authors: Shi Q , Zeng Y , Zhou Q , Liu X , Tang H , Lu B , Qian J , Chen M , Xu Y , Wang M , Tan B
Published: January 2024

Background

The increasing use of immune checkpoint inhibitors (ICIs) against cancers is inevitably accompanied with immune-related adverse events (irAEs), and irAE colitis is one of the common types. The overactivation of CD8+ T cells plays a central role in irAEs. However, the local mechanisms related to irAE colitis remain unclear. Hence, we aimed to explore the transcriptional characteristics related to CD8+ T cell responses of irAE colitis.

Methods

Colon biopsy samples were collected from 6 irAE colitis patients and 5 non-irAE controls after ICIs treatment. Leveraging digital spatial profiling, 23 regions of interest (ROI) enriched with CD8+ T cells were selected and divided into 3 groups, which were non-irAE, pre-treatment irAE and post-treatment irAE. Differentially expressed genes (DEGs), protein-protein interaction (PPI) and weighted gene co-expression network analysis (WGCNA) were performed to identify the hub genes, and they were further verified by external single-cell RNA-seq data. Also, the immune infiltration analysis was performed (Figure 1A).

Results

Principal component analysis (PCA) indicated similar distribution among the 3 groups (Figure 1B). The comparisons of non-irAE vs. pre-treatment irAE, and pre-treatment irAE vs. post-treatment irAE yielded 105 and 210 DEGs respectively. WGCNA resulted in 14 clustering modules, with MEturquoise and MEmagenta exhibiting the highest correlation scores (Figure 1C). Importantly, 174 key genes were identified and prominently associated with various mitochondrial processes e.g. oxidative phosphorylation (Figure 1D). PPI analysis revealed a sub-module consisting of 22 nodes in MCODE. Further overlap analysis of CytoHubba and DEGs pinpointed 9 hub genes. Remarkably, COX5B was found at the intersection of both groups (Figure 1E). External single-cell RNA-seq data verified that all the hub genes were significantly highly expressed in the irAE colitis group except COX6A1 (Figure 1F). Besides, immune infiltration analyses revealed the higher levels of endothelial cells (P = 0.043) and fibroblasts (P <0.01) by SpatialDecon, and activated dendritic cells (P <0.001) by xCell in pre-treatment irAE, compared to non-irAE (Figure 1G). Further, immune cells correlation analysis demonstrated highly similar patterns of endothelial cells, fibroblasts, pDCs, and macrophages (Figure 1H).

Conclusion

COX5B related to mitochondrial processes characterized irAE colitis. Expansion of dendritic cells and stromal compartments including endothelial cells and fibroblasts may contribute to irAE development.
P129 Anastomotic healing is functionally not impaired after ileocecal resection in a mouse model of Crohn's-like ileitis
Authors: Berlin P , Fischer A , Reiner J , Schafmeyer C , Lamprecht G , Witte M
Published: January 2024

Background

Anastomotic leakage (AL) is a serious complication after gastrointestinal surgery that seems to occur more frequently in patients with CD than in non-IBD patients. Nucleotide-binding oligomerisation domain-containing protein 2 (NOD2) is a risk gene for CD. We have recently demonstrated that Nod2-deficent mice have impaired anastomotic healing after ileocecal resection (ICR) even in the absence of a Crohn's phenotype. It is not yet understood how CD itself affects anastomotic healing. SAMP1/YitFc mice spontaneously develop Crohn's-like ileitis and show a defect in the NOD2 receptor.

With this study we aimed to investigate whether anastomotic healing is altered after ICR in experimental ileitis.

Methods

SAMP1/YitFc mice (n=17) with histologically manifest ileitis and parental controls (AKR, n=12) were subjected to ICR. Intestinal continuity was established by end-to-end ileocolic anastomosis. On day 5, the strength of the anastomosis was assessed by bursting pressure (BP) measurement. Anastomotic healing was evaluated macroscopically using the anastomotic healing score (AHS). Hydroxyproline content and collagenase activity in the anastomosis were determined. The inflammatory status was determined by mRNA expression of inflammatory cytokines in mesenteric lymph nodes (MLN) and spleen tissue.

Results

25% of the AKR mice and 29% of the SAMP1/YitFc mice developed perioperative complications. Leakage rate was not higher in mice with ileitis. Functionally, anastomoses were not impaired in SAMP1/YitFc mice (BP SAMP1 93 mmHg vs. AKR 123 mmHg) and AHS did not differ between the groups. However, mice with ileitis were more prone to microscopic abscess formation. Collagenase activity and hydroxyproline content in the anastomotic tissue did also not differ significantly. Preoperatively, mice with ileitis expressed increased IL4 and INF-γ mRNA levels in the MLN compared to AKR controls. After ICR, the local expression of IL4, TNF-α, lysozyme 1 and IL2 was significantly decreased in SAMP1/YitFc mice (p<0.05 SAMP1 d0 vs. d5, MLN). Resection induced significantly increased expression of IL4, lysozyme 1 and IL2 in the spleen of AKR mice, but not in SAMP1/YitFc mice (p<0.05 AKR ICR vs. SAMP1 ICR d5).

Conclusion

The SAMP1/YitFc mouse is a suitable model to study mechanisms of anastomotic healing under the influence of experimental chronic ileitis. Ileitis alone was not a risk factor for impaired healing. Ongoing studies address the local effects of therapeutic immunomodulation on the healing process of the anastomoses.
P132 Overexpression of miR-376a-3p in exosomes circulating in peripheral blood of patients with Crohn's disease
Authors: Caparrós E , García I , Madero Velázquez L , Mira C , Martínez A , Gutiérrez Casbas A , Francés R
Published: January 2024

Background

MicroRNAs (miRs) can modulate the development and/or progression of chronic inflammation in patients with Crohn's disease (CD), influencing the efficacy of treatments.

Aim

The objective was to assess the miRs content of circulating exosomes in the peripheral blood of patients with CD to identify new biomarkers useful in disease management.

Methods

Patients with CD diagnosed and followed up at the Hospital General Universitario de Alicante and healthy controls were included. Extracellular vesicles were isolated from serum and exosomes were quantified by "Nanoparticle Tracking Analysis" (NTA), confirmed by Transmission Electron Microscopy (TEM) and by specific markers (Tsg101, CD63, CD81) by Western blot, performing an expression analysis of a non-targeted panel of human miRs from exosomal RNA. Patient and control samples were also subjected to enzyme-linked immunosorbent assay (ELISA) measurement of different target-predicted protein substrates.

Results

Thirty patients and ten controls were included in the study. Patients were 42±9 years old, disease duration 62±9 months, 40% women and 80% showed ileal or ileocolonic involvement. Six patients (20%) had perianal disease. Ninety-three per cent were undergoing biological treatment with infliximab (IFX, n=13), adalimumab (ADA, n=8) or ustekinumab (USTE, n=7). A significant increase in exosome concentration was observed in the serum of patients vs controls. NTA and TEM confirmed the size and purity of the obtained exosomes. The distribution in the expression of miRs and its differential analysis showed a significant increase in miR-376a-3p as well as a reduction in miR-20a-5p in patients vs. healthy controls. Functional analysis of miR-376a-3p determined its interaction with gene targets involved in autophagy (ATG4C), TGF-b signaling (ACVR1C) and cell survival (PIK3R1, IGF1R). Protein levels of these substrates indicated the potential control of TGF-beta signaling pathway by the downregulation of ACVR1C, and the increase in survival pathway measured by IGFR1 presence in patient’s serum.

Conclusion

CD patients show a higher number of circulating exosomes, with an overexpression of miR-376a-3p. The involvement of this microRNA in different intracellular signaling pathways suggests its participation in the unbalance of the immune activity present in CD.
P133 In vitro pharmacological profile of GLPG3667 suggests differentiation from the TYK2 inhibitors deucravacitinib and TAK-279 at their clinical dose regimens
Authors: Hettema W , Nolain P , Parent I , Blanqué R , Furio L , Lagoutte E , Angella L , Dao J , Galien R
Published: January 2024

Background

Tyrosine kinase 2 (TYK2), a Janus kinase (JAK) family member, is attracting a lot of interest as a new target to treat patients with autoimmune and inflammatory diseases, including inflammatory bowel disease, and several inhibitors are currently in clinical development. In vitro pharmacological profiling of TYK2 inhibitors has been employed to evaluate potency and selectivity; however, such data are best viewed in relation to clinical exposure levels. We compared expected levels of inhibition of TYK2-dependent and -independent pathways for deucravacitinib, TAK-279 and GLPG3667 at their respective clinical dose regimens and demonstrate that relevant differences exist between these compounds.

Methods

Potency of the TYK2 inhibitors was compared for TYK2-dependent pathways (IFNα, IL-12), TYK2-independent pathways (IL-6, IL-2, GM-CSF) and the anti-inflammatory IL-10 pathway in in vitro human whole blood assays using STAT phosphorylation (flow cytometry) and cytokine release (ELISA). Sigmoidal Emax models were fitted to the concentration–inhibition data from healthy donors to estimate IC50, Emax and Hill slope for each assay and compound. The obtained relationships were subsequently coupled to the clinical pharmacokinetic (PK) profiles of the compounds (population PK model for GLPG3667, published PK metrics such as Cavg for the other compounds) to estimate the level of inhibition of the various pathways at clinically relevant dose regimens.

Results

Human whole blood assays performed for various JAK pathways demonstrated that all TYK2 inhibitors display selectivity for TYK2 over the JAK1–3 family members, with TAK-279 being the most selective. At exposure levels associated with its clinical dose of 150 mg once daily, GLPG3667 showed inhibition of the IFNα and IL-12 pathways, similar to the expected inhibition for deucravacitinib at its clinical dose regimens, without a measurable impact on TYK2-independent pathways. TAK-279 showed the most sustained inhibition of TYK2-dependent pathways. GLPG3667 showed no measurable inhibition of IL-10-mediated signalling up to the highest concentration tested (~10-fold above clinical concentrations), while inhibition was observed with deucravacitinib and TAK-279 at concentrations corresponding to the respective clinical dose regimens.

Conclusion

At concentrations corresponding to its highest anticipated clinical dose, GLPG3667 shows selective inhibition of TYK2-mediated signalling, with a level of inhibition similar to deucravacitinib clinical dose regimens. While GLPG3667 did not show any impact on IL-10-mediated signalling, inhibition of this anti-inflammatory pathway is expected for the allosteric TYK2 inhibitors at their clinical exposure levels.
P146 Latent activation of the extrinsic coagulation pathway in patients with ulcerative colitis
Authors: Drygiannakis I , Valatas V , Filidou E , Tzenaki N , Archontoulaki E , Dovrolis N , Kandilogiannakis L , Kefalogiannis G , Sidiropoulos P , Kolios G , Koutroubakis I E
Published: January 2024

Background

Ulcerative colitis (UC) is associated with an increased risk of venous thromboembolism. We investigated the correlation of UC severity with latent activation of the extrinsic coagulation pathway and colonic stromal tissue factor (TF) expression.

Methods

Plasma exosomes, microparticles (EM), TF protein, activities of EM-bound TF (EM-TF) and FVIIa, as well as TF mRNA (F3) in primary colonic stromal cells in culture were measured.

Disease extent by Montreal classification, medications, UC clinical activity by partial Mayo score (PMS), endoscopic severity by the MS endoscopic component (eMS; loss of response defines as ≥2), quality of life by the short IBD questionnaire- SIBDQ, complete blood count, CRP, ESR and albumin were retrieved. Statistical significance (p) was assessed with the following tests: Student’s t for 2 groups with normally distributed values, Mann-Whitney U if not, Wilcoxon test for paired data. Correlation of continuous against scale variables was assessed with Pearson’s or Spearman’s r and corresponding p values for linear or logarithmic continuous variables, respectively.

Results

Plasma was obtained from 38 UC patients (31 males, disease duration 151±25 months, 14 with extensive colitis, 5 current smokers) and 28 healthy blood donors (HBD; 20 males) who served as controls. TF mRNA (F3) was measured in primary colonic stromal cells in culture from 12 UC patients (11 males, disease duration 169±53 months, 8 with extensive colitis, 1 current smoker) and from 7 controls undergoing screening colonoscopy.

UC patients had 4- and 3.7- times more exosomes and microparticles than controls, respectively (A). TF protein correlated with PMS (r 0.443), albumin (-0.362), ESR (0.353), PLT (0.575) and endoscopic UC severity (0.468; B). EM-TF activity was 1.6-times higher (C) and correlated to disease extent (E3: 1.9 x E2), albumin (-0.624), endoscopic severity (0.422; D) and SIBDQ (-0.64). Downstream, FVIIa activity was 2.2-times higher. Refractory-to-treatment patients had 5.8-, 1.5-, 2.1- times higher TF protein (E), MP-TF, FVIIa activity, respectively. Within responders, the need for steroids or biologics correlated with 2.2-times higher MP-TF activity. Colonic stromal cells from patients with UC maintained a 2.2-times higher F3 (F), which correlated to PMS (0.56), albumin (Spearman’s r -0.543), endoscopic severity (M3: 8.3 x M2). All the aforementioned were statistically significant with a < 0.05.

Conclusion

The extent of spontaneous activation of the extrinsic coagulation pathway is associated with clinical and endoscopic UC activity and response to treatment. TF in colonic stromal cells mirrors its systemic activity and indicates the possible contribution of such cells to increased TF plasma bioactivity.
P153 Artificial Intelligence to predict interleukin-23 signalling activity from H&E stained whole slide images of Inflammatory Bowel Disease
Authors: Qaiser T , Hamidinekoo A , Daniel S , Zhang I , Kekic M , Lewis A , Angermann B , Bourke L , Gehrmann U , Neisen J , Tian S , Corridoni D , Marks D , Adissu H , Burlutskiy N
Published: January 2024

Background

Interleukin23 (IL-23) is a cytokine that plays a crucial role in the pathogenesis of inflammatory bowel disease (IBD), making it a highly validated therapeutic target. Understanding the role of IL-23 in IBD at the histopathological level is crucial for determining effective treatment strategies, providing insights into IBD patients who fail to respond to targeted therapies, or predicting those who are likely to lose response. In this context, there is a surge in utilizing artificial intelligence (AI) for histopathological data in IBD and other disease indications. Here, we present an automated computer vision approach to predict IL-23 signalling activity directly from routinely stained Hematoxylin and Eosin (H&E) images

Methods

A total of 1502 samples with matched clinical data and H&E biopsy images were included from 991 Crohn’s disease (CD) and 511 ulcerative colitis (UC) samples. IL-23 signalling activity was calculated using gene set variation analysis on RNA-seq data collected from the same tissue biopsies. The data were obtained from the IBD Plexus program of the Crohn’s & Colitis Foundation. The proposed approach is based on vision transformers (ViTs) which is a type of deep learning model. ViTs divide the input image into fixed-size patches, transform it into linear embedding, and analyze it with the self-attention mechanism. This enables ViTs to incorporate relationships between different patches of the input image to identify regions predictive of IL-23. Our approach was trained in a weakly supervised manner to automatically identify tissue regions that correlate with IL-23 signaling activity. The model produces interpretable heatmaps to interrogate model predictions and allow clinicians to visualize and interpret the significance of different tissue regions predictive of IL-23

Results

We performed 5-fold cross-validation on the splits obtained at the patient level, retaining the data distribution of IL-23 signaling activity, biopsy location, and diagnosis. We separately validated the performance of the proposed model on both disease categories, including CD and UC. The proposed approach achieved an area under the curve (AUC) of 0.82 ± 0.04 on unseen data from CD and an AUC of 0.80 ± 0.02 for UC. The 5-fold results for both disease categories are shown below

Conclusion

The presented results highlight the significance of computational pathology algorithms to identify IL-23 signalling activity from H&E images. Pathological interpretation from the heatmaps may help understand disease pathomechanism and optimize the treatment options for IBD patients by timely identification of IL-23 status. We are further validating the clinical utility of such heatmaps and expanding the use of H&E to predict other patient-centric endpoints
P159 Inhibition of Caspase-1 signalling subtly affect the gut microbiota and reduces Adherent-invasive Escherichia coli (AIEC)-induced inflammasome activation
Authors: Barrett K , Aguilera M , Manning C , O'Sullivan O , Clarke D , Melgar S
Published: January 2024

Background

Inflammatory bowel disease (IBD), encompassing Crohn’s Disease and ulcerative colitis, is a chronic gastrointestinal disorder with increasing incidence worldwide. Microbial factors such as Adherent-invasive Escherichia coli (AIEC) have been suggested to play a significant role in the pathogenesis of IBD. The inflammasome, a multi-protein complex, senses environmental signals, including bacteria, resulting in the activation of caspase-1 leading to the subsequent maturation and secretion of IL-1β. In this study we examined the impact of AIEC on inflammasome activation and on the inhibition of Caspase-1 signaling in AIEC-colonised mice and on intestinal epithelial cells (IECs).

Methods

Human IECs (CaCO2Bee1 cells) were cultured for 3hr with AIEC (HM605 and its invasiveness mutant), washed with antibiotics and further cultured in full cell media for 13hrs, followed by analysis on cytokine and inflammasome gene expression and activation by qRT-PCR, ELISA, imaging and flow cytometry. To inhibit caspase-1 activation, cells were pre-treated for 1 hr with the caspase-1 inhibitor zVAD-fmk. To establish AIEC colonisation, C57BL/6 and IL-10-/- mice were treated with streptomycin for 24hrs followed by oral gavage of AIEC-HM605 (10-8 cfu/mL) and faecal and tissue samples were collected at 6 days post AIEC-infection. Caspase-1 inhibitor was orally gavaged every in mice. Faecal samples were prepared for 16S rRNA gene sequencing and colon tissue was analysed for cytokines and inflammasome markers by qRT-PCR and ELISA.

Results

IECs cultured with AIEC and AIEC-colonised C57BL/6 and IL-10-/- mice resulted in an increased expression and activation of both canonical (Caspase-1) and non-canonical inflammasome (caspase 4). The AIEC-induced inflammasome response was dependent on the invasiveness of AIEC. Treatment with a caspase-1 inhibitor reduced the AIEC-induced inflammasome markers in IECs and in C57BL/6 mice. No major changes in alpha or beta-diversity was detected in AIEC-colonised mice or upon Caspase-1 inhibition. AIEC-colonisation resulted in an increased abundance of Bacteroides and Alistipides and reduced abundance of Lachnospiraceae, alterations reversed by Caspase-1 inhibition.

Conclusion

We show that the invasion of AIEC in IECs and colonisation of murine intestine results in activation of caspase-1 inflammasome. AIEC colonisation provoke subtle microbiota alterations which are reversed by caspase-1 inhibition. In summary, our data supports a role of AIEC in IBD pathogenesis through the activation of caspase-1 inflammasome.
P163 PI(4,5)P2 alleviates colitis by inhibiting intestinal epithelial cell pyroptosis through NNMT-mediated RBP4 m6A modification
Authors: Yang Q , Na D , Xiang G , Kang C
Published: January 2024

Background

Lipid metabolism disorder is a critical feature of Crohn’s disease (CD). We previously reported that phosphatidylinositol (PI), and its derivative phosphatidylinositol bisphosphate (PIP2) were significantly associated with CD activity. The underlying mechanisms remained unknown. We aimed to explore the function of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], the major PI derivative, in modulating CD pathogenesis.

Methods

Lipidomics was used to analyse the relationship between CD activity and PI or PIP2. The mucosal expression of PI(4,5)P2 in patients with CD was measured by immunofluorescence. Dextran sodium sulfate (DSS)-induced colitis mice and lipopolysaccharide (LPS)-induced Caco-2 cell model were established to explore the function and mechanism of PI(4,5)P2. MeRIP and mRNA sequencing were applied to further reveal the mechanism of PI(4,5)P2.

Results

Lipid PIP2 was substantially negatively associated with disease activity and high-sensitivity C-reactive protein. PI(4,5)P2 expression was downregulated in the inflamed mucosa of patients with CD. PI(4,5)P2 alleviated mice colitis, with improvements in survival rate, colon length, body weight, and disease activity index. PI(4,5)P2 also alleviated DSS-induced tissue damage, tight junction loss, and intestinal epithelial cell (IEC) pyroptosis. In the in vitro LPS-induced cell model, PI(4,5)P2 inhibited pyroptosis, NLRP3, and caspase-1 expression, and reduced IL-18, IL-1β, and lactate dehydrogenase (LDH) secretion. PI(4,5)P2 mediated NNMT upregulation in mice and Caco-2 cells. NNMT knockdown restricted the inhibitory effect of PI(4,5)P2 on IEC pyroptosis. NNMT inhibited the stability of RBP4 mRNA via the m6A modification to prevent pyroptosis upon PI(4,5)P2 treatment.

Conclusion

PI(4,5)P2 inhibited IEC pyroptosis through NNMT-mediated RBP4 m6A modification, which ameliorating colitis. PI(4,5)P2 may be a therapeutic target for CD.
P166 Optimizing PD-1 agonist signaling with membrane proximal binding of rosnilimab, a clinical stage PD-1 agonist IgG1 antibody
Authors: Parmley S , Szlyk B , Frank R T , Hsu M , Brodsky P , Sibley C , Lizzul P , Dahl M
Published: January 2024

Background

Checkpoint agonism represents a promising class of therapies for the treatment of autoimmune and inflammatory diseases, including ulcerative colitis (UC), where unmet needs persist despite available therapies. Binding to membrane proximal regions of checkpoint receptors, together with Fc interactions with receptors on opposing cells, can contribute to tight immune synapse formation between the immune cell and antigen presenting cell. This has been proposed to improve potency of agonistic signaling by excluding phosphatases such as CD45 from the immune synapse and promoting receptor clustering. Optimization of these characteristics results in improved agonism and depletion, with the potential for restoration of immune balance and broader clinical outcomes. Rosnilimab was engineered to leverage these important characteristics. It is a PD-1 agonist IgG1 antibody designed to optimize inhibitory signaling through the PD-1 receptor and to deplete PD-1high pathogenic T cells. Rosnilimab is in Phase 2 clinical development for UC and rheumatoid arthritis.

Methods

Mutations to surface exposed regions of the PD-1 extracellular domain were made and surface plasmon resonance was used to infer the epitopes of PD-1 agonist molecules from resulting changes to binding. Membrane proximal and distal binding antibodies were studied in in vitro functional assays to assess T cell proliferation and antibody-dependent cellular toxicity.

Results

Epitopes of agonistic antibodies were mapped to locations on the PD-1 receptor. The membrane proximal binding epitope of rosnilimab was confirmed and binding epitopes for other reference antibodies (ref) were identified. Rosnilimab and a membrane distally binding antibody (ref 1) were selected for comparison in functional assays. Rosnilimab demonstrated greater reduction of T cell proliferation and depletion of PD-1+ T cells compared to ref 1, consistent with the hypothesis that membrane proximal binding improves agonistic activity and target cell depletion.

Conclusion

By targeting and leveraging inhibitory immune regulatory mechanisms to modulate the pathogenic T cells driving disease, there is an opportunity to dampen the inflammatory cycle and restore immune balance via agonism. Rosnilimab binds to a membrane proximal region of the PD-1 receptor, resulting in potent reduction of T cell proliferation and depletion of PD-1high T cells. These mechanistic data, translational in vivo and in vitro data, robust Phase 1 healthy volunteer data, and unmet needs in UC provide rationale for an ongoing global Phase 2 study of rosnilimab in UC (NCT06127043).
P169 Circulating eNAMPT predicts anti-TNF response in IBD patients: possible place in therapy of anti-eNAMPT antibody
Authors: Travelli C , Cascetta G , colombo G , Alessi A , Caputo E , Lenti M V , Pasini A , Porta C , Ribaldone D , Pastorelli L , Di Sabatino A , Genazzani A , Caviglia G P , Stocco G
Published: January 2024

Background

extracellular Nicotinamide phosphoribosyltrasferase (eNAMPT) is a cytokine with paracrine and autocrine effects on different cell types. Importantly, eNAMPT levels are increased in patients suffering of Inflammatory Bowel Diseases (IBD). Biologic drugs have been found effective in many IBD patients; however, a large proportion of patients with severe disease fail to achieve remission due to lack of drug response, loss of response, drug intolerance, or severe side effects that require cessation of therapy. Therefore, there is a clinical need for predictive response biomarkers as well as for new therapeutic strategies.

Methods

First, we investigated the expression of NAMPT in biopsies, in stools and the secretion of eNAMPT in serum in four cohorts of IBD patients. Second, we investigated if circulating eNAMPT levels correlate with the clinical response to biologics (infliximab, adalimumab, ustekinumab, vedolizumab). Clinical response is defined as a reduction of >2 points in HBI (for CD) and in pMAYO (for UC) from baseline. Third, we have developed a monoclonal anti-eNAMPT antibody and we have evaluated its preclinical efficacy in acute and chronic preclinical models of IBD.

Results

We have determined the levels of circulating eNAMPT in three cohorts of patients that were not controlled by DMARDs and were treated with infliximab (IFX, cohort 1 and 3) or adalimumab (ADA, cohort 2). Notably, we confirmed a pronounced variability through the cohorts, identifying a group of patients with eNAMPT serum levels comparable with healthy adult populations and a group that showed elevated levels of eNAMPT. Performing a ROC curve analysis, a cutoff of 4.5 ng/ml can be extrapolated to discriminate these two populations.

Noteworthy, 100% patients with levels of eNAMPT below 4.5 ng/ml were responsive to infliximab/adalimumab. In contrast, anti-TNF therapy failed either at 14 or 22 weeks in some patients with high circulating levels of eNAMPT, indicating that high systemic eNAMPT might be associated with an increased risk of resistance to anti-TNF therapy. Notably, we found also that eNAMPT levels in stools of IBD patients are elevated compared to healthy subjects.

Then, we have developed and validated a candidate monoclonal antibody (called C269) which bind to eNAMPT, block is cytokine activity and reduces IBD symptoms, immune infiltrate and fibrosis in DSS and DNBS models.

Conclusion

Our data demonstrate that eNAMPT serum levels correlate with the clinical response to anti-TNF therapies suggesting that eNAMPT is not a simple by- stander of IBD, and that local and serum eNAMPT could be define as a biomarker to define the responsiveness to biologics. Notably, its neutralization might be a pharmacological strategy worth investigating.
P173 Characterization of the gut microbiota and the colonic immune response in acute severe ulcerative colitis : the multi-omics ITAC project
Authors: Riviere P , Dallmann-Sauer M , Enaud R , Bessissow T , Treton X , Uzzan M , Poullenot F , Zerbib F , Laharie D , Schurr E
Published: January 2024

Background

Limited understanding exists regarding the pathogenesis of acute severe ulcerative colitis (UC). Microorganisms are proposed as potential triggers due to the resemblances to infectious colitis and the essential role played by gut microbiota in UC-related inflammation. Our aim was to identify microbiome elements and host factors associated with acute severe UC.

Methods

This was a prospective study across three referral centers comparing two UC patient groups: acute severe hospitalized UC (as per Truelove and Witts criteria) and non-severe UC. We analyzed gut microbiota using 16S rRNA gene sequencing and conducted single-cell RNA-Seq on rectal biopsies in a subgroup of patients to uncover cellular subtypes and pathways involved in mucosal inflammation. We utilized whole blood RNA-Seq to investigate the host pathways involved in mediating systemic inflammation.

Results

Forty-one patients (23 (56%) female, median (interquartile range IQR) age 42 (34 – 57) years were included: 19 with acute severe UC and 22 with non-severe UC. Compared to patients with non-severe UC, those with acute severe UC displayed distinct gut microbiota with reduced diversity, increased Proteobacteria (Escherichia/Shigella genus), and decreased Lachnospiraceae and Ruminococcaceae. In severe cases (n=4 - 13,047 cells), single-cell RNA-Seq analysis of rectal biopsies revealed distinctive patterns compared to non-severe cases (n=5 - 18,433 cells): plasmablasts showed an altered transcriptomic profile with heightened IgG expression, and there was an expanded cluster of interleukin (IL) 26 expressing T cell population. Innate immune cells exhibited a pro-inflammatory profile marked by increased expression of the IL1B gene. In blood samples, we observed no distinct differentiation of transcriptomic profiles between severe and non-severe cases.

Conclusion

Our multi-omics study reveals key cellular and bacterial components in acute severe UC pathogenesis. We identified Proteobacteria, especially Escherichia coli as a potential pathobiont in acute severe UC. At the colonic level, we observed an increased IgG/IgA ratio, while both T cells and innate immune cells indicated a pro-Th17 mucosal environment. Enhanced systemic inflammation in acute severe UC was not reflected by specific changes in immune circulating cells. These insights may pave the way for future research focusing on microbiome modulation, interventions targeting plasmablasts, or nuanced inhibition of the Th17/IL-23 axis in acute severe UC.
P186 Comparative Analysis of Clinical Phenotypes and Pathogenic Features between Late-Onset and Infantile-Onset Monogenic Inflammatory Bowel Disease
Authors: Xiao F , Liu H , Xu J , Shen Y , Liao J
Published: January 2024

Background

Previous research on monogenic IBD (m-IBD) has mainly focused on very-early-onset IBD (VEO-IBD) and Montreal classification A1 type IBD patients. In non-A1 type (age > 16y) late-onset IBD patients, some individuals also exhibit IBD manifestations due to monogenic mutations. Here we systematically review the literature, using infantile-onset monogenic IBD patients as a control, to explore the genetic characteristics, clinical presentations, and treatment strategies of late-onset monogenic IBD.

Methods

Based on the onset age of IBD, m-IBD was categorized into infantile-onset (IO, <2 years) and late-onset (LO, >16 years as non-A1 type based on Montreal classification) groups. A systematic review was conducted to analyze the gastrointestinal (GI) clinical features of detailed cases published from January 1990 to June 2023 and to summarize the correlation between genetic pathogenesis and onset ages.

Results

512 m-IBD cases (398 IO and 114 LO) associated with 87 genes were included. Of these genes, 25 out of 87 genes were found to cause both IO and LO conditions. Crohn’s disease (CD) was the predominant type of IBD, account for 42.2% of IO and 44.7% of LO cases. Difficult-to-treat IBD patients showed similar rates (17.4% for IO and 13.0% for LO). However, infantile-onset cases were predominantly associated with complex perianal disease (13.5%), while late-onset cases were linked to postoperative recurrence following surgical resections (10.6%). Anti-inflammatory medicine and biologics were the main strategies, but in infantile-onset (IO) cases, immunosuppressants (57.9%), parenteral nutrition (26.8%), gastroenterostomy (20.2%), and HSCT (24.6%) were more frequently utilized compared to late-onset (LO) cases, where intestinal resection (37.8%) was more prevalent. Homozygosity was the predominant zygosity type (39.9% in IO and 39.3% in LO), while heterozygosity was more prevalent in LO cases (28.9%) compared to IO cases (13.3%) (p<0.05). Most of the genes associated with median onset ages of IBD before 2 years were causative genes for primary immunodeficiency (PID), whereas significantly lower rate of PID genes mutation was found in LO cases (26/27, 96.3% vs. 6/11, 54.5%, p= 0.005).

Conclusion

m-IBD patients predominantly present with CD, ulceration and atypical pathology, colon involvement, and difficult to treat regardless of onset ages, but vary in terms of family history, GI symptoms, location of the lesion, polyps and villous atrophy, type of complications, treatment options, and type of Difficult-to- treat IBD.
P188 Cumulative inflammatory burden as a risk factor for colorectal neoplasia in inflammatory bowel disease patients with primary sclerosing cholangitis: a multi-center case-control study
Authors: Van Lierop L , Derks M E W , te Groen M , Tran C D , Lytvyak E , Dijkstra G , Montano-Loza A J , Hoentjen F
Published: January 2024

Background

Inflammatory bowel disease (IBD) patients with concomitant primary sclerosing cholangitis (PSC-IBD) have a 25-year cumulative risk of up to 50% to develop colorectal neoplasia (CRN). Mucosal inflammation is an important driver of CRN, but it is unknown whether this also applies to PSC-IBD patients. We aimed to assess the impact of chronic mucosal inflammation per colonic segment on CRN risk in PSC-IBD patients.

Methods

This is a multi-center case-control study including cases with PSC-IBD and CRN and controls with PSC-IBD without CRN. Subjects were included from 8 medical centers in Canada and the Netherlands. Exclusion criteria were a CRN diagnosis prior to IBD or PSC diagnosis, familial CRC syndromes, and <2 available colonoscopy reports. Data was collected on demographics, IBD and PSC disease characteristics, CRN lesions, and endoscopy reports between 1977 and 2023. Pan-colonic and segmental (right colon, transverse colon, left colon, rectum) endoscopic cumulative inflammatory burden scores were calculated as the sum of (mean) endoscopic inflammation severity between colonoscopies x length of the surveillance interval until index procedure. The index procedure was the colonoscopy during which CRN was detected (cases) or randomly selected and matched for disease duration (controls). The primary outcome was a CRN diagnosis, secondary outcomes were CRN grade and location, time to CRN (Kaplan-Meier curve), pan-colonic cumulative inflammatory burden, cumulative inflammatory burden per colonic segment harboring CRN, and colonic surgery.

Results

We included 335 PSC-IBD patients (224 UC, 101 CD) with a median follow-up of 8 years (IQR: 5.0-14.0) and 6 endoscopies (IQR: 4.0-8.0). Median disease duration was 19.5 years for IBD (IQR: 11.0-26.0) and 13 years for PSC (IQR: 7.0-19.0). Advanced neoplasia (HGD or CRC) was found in 35 out of 102 cases (34%). Fifty-six (55%) cases were diagnosed with > 1 lesion, and 43 (42%) had ≥ 1 right-sided lesion. Median time to index CRN was 17 years (IQR: 8.0-24.0). Sixty-six patients underwent (sub)total colectomy or proctocolectomy, including 49 (74%) due to CRN diagnosis. There was no difference in pan-colonic cumulative inflammatory burden scores (mean scores: 4.7 (cases) and 3.7 (controls); P=0.21, 95%-CI: -2.52-.56) and segmental scores (mean scores: 4.9 (cases) and 4.1 (controls); P=0.27, 95%-CI: -2.29-.65) between cases and controls. Mortality was 13% (n=45.)

Conclusion

In this large multi-center cohort study, the risk for CRN-associated colectomy in PSC-IBD was high, while pan-colonic and segmental cumulative inflammatory burden scores were not associated with CRN risk.
P192 Personalizing treatment for predicting response to infliximab in children with Crohn’s disease using proteomic biomarkers
Authors: Winter H , Baldassano R N , Pfeffkorn M D , Wali P , Verstraete S G , Picoraro J A , Washek M A , Kumar N , Mortan W , Havard- Jr M , Blystone L , Trombler B , Pursley C , Lin X , Dillon S T , Gu X , Otu H H , Ngo L , Libermann T A
Published: January 2024

Background

Identifying minimally invasive diagnostic biomarkers that predict and monitor response to TNF inhibitors would enable treatment to be personalized and increase knowledge of the biological pathways associated with response or lack thereof.

Methods

Children and adolescents with Crohn’s disease who started treatment with infliximab (IFX) were enrolled in a prospective, multi-center (n=6) trial to identify biomarkers that predict response to IFX. Electronic case report forms were prepared by Studytrax (Macon, GA). Subjects <18 years of age were diagnosed with Crohn’s disease using standard clinical/pathologic criteria. Clinical evaluation and serum samples were obtained prior to initiation of IFX, after induction (dose 4), at six months, and after one year or at the time of treatment withdrawal. There were 119 subjects enrolled and 102 subjects completed induction. Non-responders (n=15) were defined prior to the 4th infusion as having a PCDAI > 10, an elevated Physician Global Assessment (PGA) or requiring dose escalation or medication change. Responders at the 4th infusions were either in remission (PUCAI ≤ 10) or were described as quiescent by PGA. Using the 7k SomaScan (SomaLogic; Boulder, CO) proteomics platform, quantitative protein profiles were generated from banked pre-treatment (V1) and after the three-dose induction (V2) to identify candidate protein biomarkers predictive of therapeutic response. Associations between the 7,310 proteins detected with SomaScan and response to IFX were assessed using t test. Response predictor models were developed using linear regression with backward selection. We report our preliminary findings from a discovery cohort of 56 subjects who completed induction.

Results

There were 15/56 (27%) non-responders and 41/56 (73%) responders at V2 after IFX induction. SomaScan analysis of the 56 individuals identified sets of differentially expressed proteins discriminating between non-responders and responders at both V1 and V2 and also defined protein signatures that changed from V1 to V2 for responders and non-responders, respectively. Strikingly, only responders demonstrated significant decreases in pro-inflammatory pathways at V2 compared to V1, thereby correlating well with anticipated reduced inflammation in responders. A 6-protein linear regression model performed with an AUC of 0.99 for predicting IFX response at pre-treatment V1.

Conclusion

In a discovery cohort from a multicenter, prospective trial of children and adolescents treated with infliximab, a comprehensive proteomics platform was able to identify serum proteins that are highly associated with response to infliximab and accurately predict response prior to treatment.
P197 Exploring diet categorisations and their influence on flare prediction in IBD, using Sparse Group LASSO
Authors: Stevens C L , Adriaans G M C , Spooren C E G M , Peters V , Pierik M J , Dijkstra G , Almeida R J , Jonkers D M A E , Campmans-Kuijpers M J E
Published: January 2024

Background

Diet is an important environmental factor that may affect flare occurrence in inflammatory bowel disease (IBD), but analyses are hindered by its complexity. Different a priori and a posteriori dietary assessment tools can be used, such as dietary quality scores and dietary pattern analyses. The Sparse Group LASSO (SGL) might be a novel method combining an a priori and an a posteriori approach. In this study, we aim to explore the SGL method to study whether different food categorisations, representing different dietary patterns, can predict flares in patients with IBD.

Methods

Baseline data on habitual dietary intake and longitudinal data on disease course was collected over a period of 24 months from two cohorts from the Northern and Southern provinces of the Netherlands. Collected food items were classified into 22 food groups. These were further classified into 3 diet categorisations, representing different dietary patterns: model 1. Plant vs animal vs mixed; model 2. Potentially healthy vs neutral vs potentially unhealthy; model 3. Ultra-processed vs not ultra-processed. The SGL parameter ‘lambda’ identifies important groups using a priori group information, while allowing for only a subset of variables within a group to be important predictors.

Results

Of 724 eligible patients, 427 were in remission at baseline and could be included in the SGL analyses. 106 patients (65.1% female, 34% ulcerative colitis, mean age 43.3 ± 14.7 years) developed a flare within 11.2 ± 6.6 months of follow-up. There was a significant higher crude food intake of red meat (p=0.028) and vegetables (p=0.027) in patients who developed a flare compared to those remaining in remission. Prediction models were moderate with AUC varying between 0.425 and 0.542 for model 1, 0.512 and 0.562 for model 2 and 0.451 and 0.612 for model 3 (Table 1). All models showed red meat, legumes and vegetables as the first selected predicting variables. Unexpectedly, legumes and vegetables predicted a higher risk on flares independently of their categorisation. This was robust in our data and confirmed by Kaplan-Meier survival analyses. Notably, clinical confounders sex and kilocalorie intake had the highest predictive values in all 3 models.

Conclusion

Categorisation of the same food groups and food items in different ways influences the predictive value of the SGL method. For the present study, categorising according to ultra-processed and not ultra-processed achieved the best prediction model, though still moderate. The current exploration of the SGL method showed that food might not be the most important predictor of flares in IBD. However, red meat, legumes and vegetables were the most important dietary influencers in these cohorts.
P209 Work productivity and unmet needs of treated ulcerative colitis patients: A Japan National Health and Wellness Survey study
Authors: Kim H , Huang Z , Qin F , Arokianathan F M N , Kamiya Y , Wang D , Hiraoka S
Published: January 2024

Background

Ulcerative colitis (UC), a subset of inflammatory bowel disease (IBD), is a chronic, immune-mediated disease process which causes inflammation and ulceration of the large intestine. In Japan, the annual prevalence of UC in 2014 showed a ten-fold increase in more than 10 years. Despite current treatments, patient-reported disease challenges persist. This study investigated the disease burden and unmet needs of treated UC patients in Japan.

Methods

This cross-sectional, observational study used existing data from the online, self-administered Japan National Health and Wellness Survey conducted in 2017, 2019, and 2021. Respondents were aged ≥18 years, with self-reported UC and had undergone/were on treatment [5-Aminoslicyclic acid (5-ASA), steroids, immunomodulators (IMs), biologics (Bio)/Janus kinase inhibitors (JAKi), or others]. Data pertaining to demographics and clinical characteristics, medication adherence, health-related quality of life (HRQoL), work productivity and activity impairment (WPAI), and indirect cost were collected and analysed.

Results

Among 293 treated UC patients in Japan, most were conventional treatment users (84%) and 29% were living with UC for ≥15 years. Despite active treatment, 91% of patients reported UC as bothersome to a certain degree, 35% reported having moderate-to-severe disease severity post-treatment, and 55% reported ≥1 persisting UC symptom. Treated patients reported EuroQoL-5-dimension visual analogue scale scores of 68. Depression and anxiety were reported in ≥35% of patients and majority (68%) of employed patients reported work productivity impairment. On average, employed UC patients reported 30-40% WPAI on a weekly basis, resulting in a mean indirect cost of 1.12 million Japanese yen (€8,799) per patient annually. Males, moderate-to-severe disease activity, and low treatment adherence (<80%) were associated with increased WPAI (p<0.05). In comparison to 5-ASA users, Bio/JAKi users had the highest work impairment, while steroid and IM users had higher activity impairment (p<0.05).

Conclusion

The overall HRQoL scores were lower than the average Japanese healthy population and the indirect cost due to work productivity impairment was high, equating to approximately 1/5 of the average household income. Those with lower treatment adherence consistently reported the highest work and activity impairment. The findings implicate a high disease burden and unmet needs affecting Japanese UC patients despite currently available treatments, suggesting the importance of a new convenient treatment for optimising UC outcomes. Additionally, workplace accommodations and understanding of employers on UC could assist in improving work productivity of UC patients.