bluuebunny/crossref_metadata_2025 huggingface dataset:
Standardized cotton swab sampling with nested quantitative polymerase chain reaction is effective for diagnosing ordinary scabies
Authors: Chung Hyun Chul , Chun Eun Ji , Kim Joon Ki , Kim Sang Seok , Kim Chul Woo
Published: January 2023

Background

Low sensitivity of the PCR assay for diagnosing scabies has been noted because of the difficulty in obtaining tissue containing Sarcoptes scabiei DNA.

Aim

To evaluate nested real-time quantitative PCR (nRT-qPCR) with nonexpert-dependent standardized cotton swab sampling (CSW) as a tool for diagnosing scabies.

Methods

All patients underwent dermoscopic and microscopic examination (MS) with scraped sampling (Sc). Patient samples were acquired with a single, dry swab rubbed across the flexor areas of both wrists as well as the eight interdigital spaces and on any suspected scabies lesions. nRT-qPCRs were performed with Sc and CSW samples.

Results

Out of 125 patients with suspected scabies, 120 patients were sampled, and 57 were positive (positive with: MS n = 53; nRT-qPCR with Sc n = 52; nRT-qPCR with CSW n = 46) and 63 were negative for scabies. The sensitivities of these tests were 93.0%, 91.2% and 80.7%, respectively, which were not different statistically (P > 0.05). However, upon subsequent monitoring after treatment, the sensitivity of nRT-qPCR with CSW was only 36.6%, which was significantly lower than 83.0% for MS and 92.7% for nRT-qPCR with Sc (P < 0.001). The obtained sequences showed 97%–100% homology with scabies sequences deposited in GenBank.

Conclusion

CSW with nRT-qPCR shows sensitivity close to MS with scraping performed by experts for diagnosing scabies in an outpatient setting, but not for post-treatment monitoring. CSW with nRT-qPCR may be useful for physicians unfamiliar with a traditional diagnostic method, and for screening an outbreak in community facilities.
OP12 Does early initiation of biologics change the natural history of IBD? a nationwide study from the epi-IIRN
Authors: Focht G , Lujan R , Atia O , Greenfeld S , Kariv R , Loewenberg Weisband Y , Lederman N , Matz E , Dotan I , Turner D
Published: January 2023

Background

Studies have reported conflicting findings regarding the effect of timing of biologics initiation on disease course, often affected by selection and referral biases. In this nationwide cohort study we aimed to explore whether early initiation of biologics is associated with better disease outcomes in CD and UC.

Methods

Data of patients diagnosed with IBD in the epi-IIRN cohort from 2005 to 2020 were retrieved from 4 Israeli Health-Maintenance-Organizations covering 98% of the population.The primary analysis was time to steroid-dependency and IBD-related surgery. To control for confounding by indication in which the severity of disease could account both for the timing of biologics and risk of disease outcomes,we compared treatment strategies using the cloning,censoring and weighting method to emulate a target trial. Inverse probability of treatment weights were fitted per patient to adjust by weighting for time varying confounding and selection bias.Survival probabilities(POS) were estimated and compared at 10 years post diagnosis for each strategy through weighted non-parametric Kaplan-Meier estimators. The 95%CIs for survival probabilities were calculated using non-parametric bootstrap with 500 replicates.

Results

Of the 34,375 patients diagnosed with IBD, 7,452(39%) CD patients and 2,235(15%) UC patients received biologics and included in the analysis. In total,1,139 CD and 206 UC patients received biologics during the first three months after diagnosis,2,108 CD and 450 UC during the 3-12 month period,1,161 CD and 396 UC during 1-2 year period,and 719 CD and 271 UC during 2-3 years post diagnosis. Patients who initiated biologics after 3 years post diagnosis were excluded as they were not considered early biologics initiation.In CD,at 10 years post diagnosis there was a significant but modest decrease in IBD-related surgeries when initiating biologics prior to 3 months compared to the other periods (POS:0-3 months 0.75[CI 0.71- 0.79] vs 2-3 year 0.7[CI 0.66-0.73] ;p<0.05).The same observation with a larger effect, was apparent for steroid-dependency (POS:0-3 months 0.78[CI 0.75-0.82] vs 2-3 year 0.69[CI 0.66-0.71]; p<0.001)(Fig 1). In UC, no significant differences in colectomy rate at 10 years was observed between the treatment periods (POS:0-3 months 0.92[CI 0.87-0.97] vs. 2-3 years 0.94[CI 0.91-0.98];p=0.42). On the other hand, a significant decrease was apparent for steroid-dependency (POS:0-3 months 0.78[CI 0.75-0.82] vs 2-3 year 0.69[CI 0.66-0.71];p<0.001)(Fig 2).

Conclusion

Our study showed a slight advantage to earlier initiation of biologics,as reflected by longer time to IBD-related surgery and steroid-dependency in CD.In UC, the effect of early biologics was minor and was only apparent for steroid dependency in UC.
OP23 Asymptomatic inflammatory bowel disease diagnosed during the colorectal cancer population screening in Catalonia
Authors: Brunet E , Selva A , Bas-Cutrina F , Brujats A , Caballol B , Gomez B , Gonzalez C , Busquets D , Monfort D , Vera D P , Maristany E , Cirera G , Torres G , Castro-Poceiro J , Lopez J , Gonzalez-Gonzalez L , Marquez-Mosquera L , Gallach M , Esteve M , Tremosa G , Torra S , Robles V , Rodríguez-Lago I , Calvet X
Published: January 2023

Background

Background: It has been postulated that early treatment of inflammatory bowel disease (IBD) is associated with a better long-term response. In Catalonia, the early detection program for colorectal cancer (EDPCRC) has been active since 2010, and was extended to the entire Catalan territory in 2015. The aim of this study is to describe the natural history of IBD asymptomatic diagnosed through the EDPCRC in Catalonia.

Methods

Methods: Observational, longitudinal and retrospective study of patients with IBD detected in the EDPCRC with a positive faecal immunological test in 21 centers in Catalonia between 2010 and 2019. Data was collected from the clinical histories.

Results

Results: 237 patients were identified; 35 patients had symptoms before endoscopy and were excluded from the study, finally 200 patients were diagnosed with asymptomatic IBD during the EDPCRC; 109 ulcerative colitis (54.5%), 63 Crohn’s disease (31.5%) and 28 unclassifiable colitis (14%). 35.5% were women (n=71) with an average age of 60 years (range 49-79). Of the asymptomatic, 40.5% developed symptoms (n=81), being diarrhea the most frequent (n=45; 55.6%). The median time to first symptom was 368 days. Treatment was prescribed in 74.5% (n=149) of the patients. Mesalazine was the most frequently prescribed drug (n=130). The main reason for prescribing it was endoscopic activity (n=107), followed by the appearance of symptoms (n=39) and the biochemical activity (n=9). Only 19 patients (9.5%) required biological treatment (5 infliximab, 10 adalimumab, 2 vedolizumab and 2 ustekinumab). 4 patients (2%) required surgery.

Conclusion

Conclusion: Less than half of patients diagnosed with IBD at a preclinical stage develop symptoms after the first year of follow-up. Only 9.5% require biological treatment and 2% surgery. Three-quarters of patients are prescribed treatment; the most used was mesalazine.
OP30 Human umbilical cord mesenchymal stem cells derived exosomes alleviate Ulcerative Colitis by inhibiting macrophage ferroptosis via miR-23b-3p/Nrf2 pathway
Authors: Liu L , Zhao J , Ye Y , Feng Z , Wang X , Cao X
Published: January 2023

Background

Human umbilical cord mesenchymal stem cell derived exosomes (HucMSC-Exo) have broad application prospects in treatment of various disease, including ulcerative colitis (UC). Macrophages can trigger intestinal mucosal inflammation thereby participating in the onset and development of UC. As a newly discovered iron-dependent cell death pathway, ferroptosis has also been found accompanied by inflammatory response in recent studies. We speculated that there could be relationship between macrophage ferroptosis and inflammatory response in UC. Furthermore, the role of macrophage ferroptosis in the process of HucMSC-Exo alleviating UC remains undefined. This study aims to explore the therapeutic effect and mechanism of HucMSC-Exo on UC by regulating macrophage ferroptosis.

Methods

The gene expression of ferroptosis-related proteins was assessed in colon samples from healthy controls and UC patients to explore the relationship between ferroptosis and UC. In vivo, colitis was induced by dextran sulfate sodium in mice. HucMSC-Exo was administered intravenously to estimate its curative effect, and its gut homing was evaluated by animal live imaging analysis. In vitro, HucMSC-Exo were cocultured with ferroptosis inducer RSL3-treated bone marrow-derived macrophages (BMDMs), RAW264.7 cell line, followed by examining the effect of HucMSC-Exo. Transfection of microRNA mimics and gene knockdown were used to confirm the role of miR-23b-3p in HucMSC-Exo regulating of macrophage ferroptosis.

Results

Compared with healthy individuals, ferroptosis may be involved in the mucosal inflammation of UC patients. HucMSC-Exo were found to successfully target damaged colon tissues in vivo. HucMSC-Exo treatment significantly improved the pathological damage of colon tissue, increased the expression of glutathione peroxidase 4 (GPX4), while markedly decreasing the levels of iron and lipid ROS, and reducing the secretion of interleukin (IL)-1β and IL-6, and then relieved macrophage ferroptosis to alleviate murine colitis. In vitro experiments showed that HucMSC-Exo could be effectively absorbed by macrophages and rescued RSL3-induced ferroptosis, which was consistent with the effect of ferrostatin-1, a ferroptosis-specifific inhibitor. Mechanismly, HucMSC-exo could inhibit macrophage ferroptosis by delivering its highly expressed miR-23b-3p to activate Nrf2 pathway. Additionally, the protection of HucMSC-exo for UC was attenuated by decreasing the expression of miR-23b-3p or inhibiting Nrf2 pathway.

Conclusion

HucMSC-Exo could activate Nrf2 antioxidant pathway and abrogate macrophage ferroptosis by delivering miR-23b-3p and ultimately ameliorate colitis.
OP31 High fat diet exacerbates colitis through microbial metabolite deoxycholic acids induced-ferroptosis
Authors: Wang C , Gu Y , Cao H
Published: January 2023

Background

High-fat diet (HFD) is closely related to the occurrence and development of IBD, which increases the level of deoxycholic acid (DCA). DCA-treated mice showed pro-inflammatory cell infiltration and colonic inflammation. Ferroptosis, a newly recognized form of cell death characterized by iron overload and the generation of reactive oxygen species (ROS) has recently been observed in colitis. Whether DCA affects ferroptosis and whether it contributes to colitis has not been explored.

Methods

Twenty-four Female C57BL/6 mice were randomly divided into 4 groups: control group, DCA group, DSS group, and DSS plus DCA group. Real-time PCR and Western blotting were used to detect the transcription and protein expression of ferroptosis-related genes. RNA sequencing was used to analyze the changes of differential genes in the intestinal tissue of mice treated with DCA. Transmission electron microscope was employed to observed the changes of intestinal epithelial cell morphology and intracellular mitochondria. Finally, the binding force between DCA and HIF-2α was calculated by molecular dynamics to explore the structural biological basis of the interaction between DCA and HIF-2α, and screen innovative drugs.

Results

We found that DCA exacerbated the disease activity index, histological damage and cell death in mice with colitis. In vivo, ferroptosis KEGG pathway was enriched by RNA sequencing in colonic tissues. DCA treatment significantly induced ferroptosis in DSS-induced mice, as evidenced by iron overload, ROS and MDA production, accompanied by decreased expression of GPX4 and increased expression of ACSL4. Transmission electron microscopy also confirmed the occurrence of ferroptosis in colonic tissues. In vitro, DCA induced ferroptosis were also observed in IEC-6 cells and Caco-2 cells under the combined treatment of Lipopolysaccharide (LPS). Interestingly, RNA sequencing revealed that the expression levels of the apical iron divalent metal transporter-1 (DMT1) were significantly upregulated in DCA treated-mice with colitis. DMT1 is a direct target gene of hypoxia inducible factor (HIF)-2α. We also found that DCA could increase the level of DMT1 and HIF-2α in the intestinal epithelial cell lines. Pharmacological inhibition of HIF-2α significantly inhibited the expression of DMT1 and blocked the promotion of ferroptosis by DCA. These data provide a mechanistic basis for the widely reported link between ferroptosis and colitis risk.

Conclusion

Taken together, these findings suggest that DCA aggravates colitis through the induction of ferroptosis in the HIF2α-DMT1 signaling pathway and provides a new perspective for UC prevention in the future.
OP38 Modulation of the septin cytoskeleton ameliorates intestinal fibrogenesis
Authors: Naydenov N , Le T H N , Lechuga Villarauz S , Elias M , West G , Czarnecki D , Plesec T , Ivanov A , Rieder F
Published: January 2023

Background

Fibrosis-induced intestinal strictures leading to obstruction are a common and serious complication of Crohn’s disease (CD) with currently no available specific anti-fibrotic therapies. Cytoskeletal dynamics in mesenchymal cells are associated with organ fibrogenesis. Septin filaments are a novel cytoskeletal element, but the functional role of septins in regulating intestinal inflammation and fibrosis remain unknown. We examined the involvement of the septin cytoskeleton in modulating fibrogenic signaling in intestinal fibrogenesis in vitro and in vivo.

Methods

Expression of different septins in human intestinal resection tissues, primary human intestinal myofibroblasts (HIMF) and immortalized colonic myofibroblast (CCD 18co cells) were examined by real-time PCR and immunoblotting. Functional inhibition of the septin cytoskeleton was achieved using siRNA for septin 7 and the cell-permeable small molecule forchlorfenuron (FCF). Migration and proliferation of HIMF were examined by wound healing and thymidine incorporation assays, respectively. Levels of secreted cytokines were measured using cytometric bead array. Roles of septins in the development intestinal fibrosis in vivo was studied using a chronic DSS colitis model in mice with administration of FCF or vehicle.

Results

All septin genes were expressed in intestinal tissues with a predominant expression of septin 7. Pro-fibrotic transforming growth factor-β1 (TGFβ1) triggered HIMF activation manifested by the increased production of ECM proteins such as fibronectin and collagen 1 and enhanced expression of the myofibroblast markers α-smooth muscle actin, L-caldesmon and tropomyosin. Septin 7 knockdown resulted in loss of other septin proteins thereby disrupting the entire septin cytoskeleton. Either pharmacological, or genetic disruption of the septin cytoskeleton reversed the effect of TGFβ1 by attenuating production of ECM proteins and reducing expression of myofibroblast markers. Interestingly, these effects were only found on protein level and were not due to changes in gene expression, suggesting inhibition of their expression at a post-transcriptional level. Moreover, pharmacological or genetic disruptions of the septin cytoskeleton resulted in reduced migration, and attenuated cytokine secretion by activated myofibroblasts. FCF administration did not affect intestinal inflammation, but decreased the fibrosis score during chronic DSS colitis in mice.

Conclusion

Our data highlights the septin cytoskeleton as a novel regulator of intestinal myofibroblast activation and function. This for the first time implicates the cytoskeleton as an active participant in intestinal fibrosis and as a potential novel target for the development of anti-fibrotic therapies in IBD patients.
DOP19 Incidence and initial disease presentation of inflammatory bowel diseases in Denmark: findings from a Copenhagen IBD Inception Cohort Study (IBD Prognosis Study)
Authors: Attauabi M , Madsen G R , Wewer A V , Bendtsen F , Jakobsen C , Dorn-Rasmussen M , Malham M , Theede K , Bjerrum J T , Boysen T , Seidelin J B , Burisch J
Published: January 2023

Background

The increasing incidence of inflammatory bowel diseases (IBD), encompassing ulcerative colitis (UC), Crohn’s disease (CD), and unclassified IBD (IBD-U), in Denmark requires close surveillance. Therefore, we aimed to investigate their current incidence and initial disease presentation in a population-based inception cohort.

Methods

IBD Prognosis Study is an ongoing prospective population-based inception cohort of patients diagnosed with UC, CD, or IBD-U between May 1st, 2021, and May 1st, 2023, according to the Copenhagen IBD Criteria within the well-defined geographical uptake area of Hvidovre University Hospital and Herlev University Hospital. This area has a catchment population of 1,050,000, corresponding to ~20% of the Danish population. The incidence rate is defined as the number of new cases between May 1st, 2021, and October 31st, 2022, divided by the total number of 100,000 inhabitants covered in included sites per year during the same period. For the incidence calculations, pediatric-onset of IBD was defined as age < 19 years at diagnosis. However, for the clinical description, for the clinical presentation, the cut-off was <18 years.

Results

As of October 31, 2022, a total of 219, 134, and 24 patients with adult-onset UC, CD, and unclassified IBD (IBD-U), respectively, has been included, corresponding to incidence rates of 13.9, 8.5, and 1.5 per 100,000 adults per year. Further, 11, 16, and two patients with pediatric-onset UC, CD, and IBD-U were included, corresponding to 3.6, 6.3, and 0.7 per 100,000 pediatric cases per year. Demographics and initial disease presentation are presented in Tables 1-2, initial disease burden and treatment patterns in Tables 3-4.

Conclusion: The preliminary data from the ongoing prospective population-based cohort, IBD Prognosis Study, indicate that the incidence rates of adult-onset IBD appear stabilized, while that of pediatric-onset CD is increasing, when compared with data from before 2010.1,2

The study is ongoing and includes extensive and continuous examinations, including endoscopy, intestinal ultrasound investigations, magnetic resonance imaging of the small intestine and biliary and pancreatic ducts, patient-reported measures, and biobanking. As such, the cohort is expected to deliver essential knowledge on the mechanisms for the unpredictable course of IBD.3

References:

1. Vind I et al. Am J Gastroenterol. 2006; doi:10.1111/j.1572-0241.2006.00552.x

2. Jakobsen C et al. Inflamm Bowel Dis. 2011; doi:10.1002/ibd.21654

3. Attauabi M et al. BMJ Open. 2022; doi:10.1136/bmjopen-2021-055779
DOP28 Aconitate decarboxylase 1 (ACOD1) represents a crucial regulator of monocyte recruitment, survival and proinflammatory status in intestinal inflammation
Authors: Jones G R , Hegarty L , T'Jonck W , Adams C , Drury B , Byrne A , Ho G T , Bain C
Published: January 2023

Background

Aconitate decarboxylase 1 (ACOD1; also known as IRG-1) is the ubiquitous source of itaconate, which dampens inflammasome activation by preventing HIF1a production of IL-1b and prevents TNF production through NRF2 activation. We reasoned that expression of ACOD1 is an inhibitory pathway within monocytes to curtail their inflammatory function, which could be manipulated in IBD therapy.

Methods

We performed single-cell RNA sequencing of monocytes from colonoscopic biopsies of treatment naïve IBD patients, as well as complementary analysis of DSS treated C57BL/6J (WT) mice, using single-cell protein-mRNA (Primeflow) technologies for validation. To determine the role of ACOD1 in colitis, Acod1–/– mice were administered 2% DSS in drinking water for 6 days (acute colitis) or 4 days followed by 14 day recovery period (inflammation resolution) and assessed the colon myeloid compartment by multi-parameter flow cytometry. This was complemented with competitive bone marrow chimeric mice to assess the intrinsic role of ACOD1 controlling monocyte survival and proinflammatory status. Transcriptional profiling (Nanostring) was used to determine the molecular pathways influenced by ACOD1.

Results

We found that ACOD1/Acod1 represented an evolutionarily conserved of feature of inflammation-associated monocytes, with expression present in mucosal but not blood monocytes. Acod1–/– mice demonstrated increased susceptibility to acute intestinal injury with DSS compared to co-housed WT controls, characterised by increased weight loss and colon shortening with significant accumulation of colonic neutrophils and CD64+Ly6C+ MHC-II+/– monocytes. Consistent with Acod1 limiting inflammasome activation, Acod1–/– monocytes demonstrated significantly greater IL-1b producing capabilities than WT controls.

To assess Acod1 deficient and sufficient haemopoietic cells in in the same environment, we generated competitive bone marrow chimeric mice. Acod1 deficiency conferred a significant advantage to monocyte recruitment to the colon, characterised by a 10fold increase in Ly6C+ MHC-II–colon monocytes in colitis.

Transcriptional profiling of WT and Acod1–/– colonic monocytes revealed significantly greater expression of molecules required for monocyte extravasation, including Sell (CD62L), Icam1, Ccr2 and Itgal (CD11a). In addition, expression of genes indicative of macrophage maturation such as Itgax (CD11c), Cd163 and Cx3cr1 were lower in the context of Acod1 deficiency, suggesting that normal maturation of these cells may be perturbed by loss of Acod1.

Conclusion

ACOD1/Acod1 represents an evolutionarily conserved, monocyte specific immuno-metabolic pathway that acts to limit monocyte recruitment, fate and pro-inflammatory function within the inflamed intestine.
DOP33 Single-cell analysis identifies pathological fibroblasts as a new therapeutic target to prevent intestinal fibrosis in Crohn’s disease.
Authors: Ke B J , Abdurahiman S , Biscu F , Verstockt S , Verstockt B , de Hertogh G , Vermeire S , Matteoli G
Published: January 2023

Background

Recurrent episodes of intestinal inflammation and tissue remodeling progressively result in fibro-stenosis and bowel obstruction in Crohn’s disease (CD). This irreversible end-stage complication is the main indication for surgical intervention but is often associated with postoperative recurrence of inflammation and repeated tissue resection.

Methods

To understand transmural inflammation-induced fibro-stenosis, full-thickness ileum from CD patients (n=10) undergoing ileocecal resection were profiled using single-cell RNA sequencing (scRNA seq) on 10x Genomics platform. Our tissue sampling strategy aimed at recapitulating different disease stages from the same patient including normal ileum, chronic active inflammation and stenotic ileum, allowing a better definition of cell heterogeneity, inter-cellular communication, and tissue organization in CD. Healthy ileum from CRC patients (n=5) undergoing right hemicolectomy were included as external control. Flow cytometry (FACS) was carried out to confirm scRNA seq findings. For functional validation, intestinal fibroblasts were co-cultured with NicheNet-predicted cytokines and FACS-sorted myeloid supernatants. Finally, the chronic dextran sulfate sodium (DSS)-induced colitis model was used to validate the transcription regulation in activated fibroblasts.

Results

Using scRNA seq, we identified a specific subset of activated fibroblasts during chronic inflammation and fibrosis. FACS showed increasing FAP+ fibroblasts in both inflamed and stenotic ileum, compared to control ileum and proximal ileum (p<0.01). Computational methods predicting ligand-receptor signaling suggest that fibroblast activation is mostly mediated by myeloid cell-derived inflammatory signals resulting in collagen deposition and tissue fibrosis. Intestinal fibroblasts co-cultured with inflammatory monocyte supernatant and predicted ligands expressed higher protein levels of FAP, COL3A1 and showed signs of EMT transformation. Furthermore, stimulated intestinal fibroblasts secreted higher levels of ECM proteins, including COL1 (p<0.001), and COL3A1 (p<0.005). After inhibiting an EMT-related transcription factor identified in the activated fibroblasts, collagen expression and extracellular matrix accumulation were decreased in fibroblasts. Finally, inhibition of EMT transformation in chronic DSS colitis resulted in reduced ECM deposition, compared to vehicle mouse (p<0.05).

Conclusion

Our findings suggest that inflammatory monocytes mediate local activation of fibroblasts promoting excessive collagen deposition. We furthermore show that targeting activated fibroblasts was able to reduce tissue remodeling and may therefore prevent fibrostenosis in CD.
DOP48 Key Anti-Inflammatory Faecalibacterium prausnitzii is Heterogeneous and Diverse in the East and West and in Health and Crohn’s disease. The ENIGMA study.
Authors: Teh J J , Kang S , Leonard A , Zhang J , Hu J , Hamilton A L , Wilson-O'Brien A , Trakman G L , Lin W , Ching J , Sung J J Y , Yu J , Ng S C , Kamm M A , Morrison M
Published: January 2023

Background

There is insufficient knowledge about the key characteristics of the pathogenic and protective bacteria in inflammatory bowel disease. The ENIGMA study aimed to identify the phylogenetic and functional characteristics of Faecalibacterium prausnitzii, considered a protective “anti-inflammatory” bacterium, in both health and Crohn’s disease in populations in the West (high Crohn’s incidence) and Hong Kong (rapidly increasing Crohn’s incidence).

Methods

Total DNA was extracted from tissue (right colon and terminal ileum) and stool collected from case-control cohorts in Hong Kong (n=51; 30 Crohn’s, 21 controls) and Australia (n=49; 29 Crohn’s, 20 controls). In parallel, the colonic mucosa-associated microbiota (MAM) for each subject was cultured from anaerobically preserved tissue. Shotgun metagenomic sequencing was used to characterise the stool and colonic MAM, augmented with 16S rRNA gene profiling and F. prausnitzii qPCR. The HUMANn3 and/or QIIME2 packages were used for the taxonomic and/or functional characterisation of the datasets. Metagenome-assembled genomes (MAG) were also produced from colonic MAM datasets using the MetaWRAP pipeline, and taxonomy deduced using the Genome Taxonomy Database-Tool kit (GTDB-tk).

Results

F. prausnitzii was detected in all case-control cohorts from Hong Kong and Australia. However, the prevalence was greater for the colonic MAM cultures of the Australian subjects, which provided 24/32 high-quality Faecalibacterium-affiliated MAG. No less than 6 different species-level lineages were predicted by GTDB-tk, and a similar phylogeny predicted using the gene encoding immunomodulatory peptides (mam). Functional features for the MAG from Crohn’s disease and control subjects were compared, and genes involved with histidine, riboflavin, purine and pyrimidine metabolism, pentose phosphate pathway, and oxidoreductases were enriched in the control subject MAG. In contrast, MAG derived from Crohn’s disease subjects possessed more functions putatively assigned to antibiotic resistance mechanisms and other protective functions. Differences were also observed in the carbohydrate-active enzyme profiles of the MAG recovered from Crohn’s disease and control subjects.

Conclusion

The populations of F. prausnitzii recovered from the colonic mucosa associated microbiota are both diverse and vary between Crohn’s disease and control subjects in both countries. The differences include metabolic and physiological characteristics. Therapeutic modification of F. prausnitzii needs to consider phylogenetic and functional characteristics.

The ENIGMA study is supported by a grant from the Leona M. and Harry B. Helmsley Charitable Trust
DOP50 Impact of Inflammatory Bowel Disease associated dysbiosis on bacterial quorum sensing mediated by Acyl-homoserine Lactone in human gut microbiota
Authors: Grellier N , Suzuki M , Brot L , Rodrigues A , Humbert L , Escoubeyrou K , Rainteau D , Grill J P , Lami R , Seksik P
Published: January 2023

Background

Intestinal dysbiosis is a key feature in the pathogenesis of inflammatory bowel diseases (IBD). Bacterial quorum sensing mediated by acyl-homoserine lactones (AHL) might play a role in the dialogue between the gut microbiota and the host. The main objective of our study was to investigate the presence and expression of AHL synthase and receptor genes in the human gut ecosystem during IBD.

Methods

To confirm the presence of AHL in the gut, mass spectrometric detection was performed on stool samples from IBD patients and non-IBD subjects. Then, by an in silico approach, we exploited the open access database: Inflammatory Bowel Disease Multi’omics Database, an American cohort with bacterial metagenomes and metatranscriptomes data of stool samples from non-IBD and IBD subjects. To characterise gut dysbiosis, the most discriminating bacterial species between non-IBD and IBD patients were identified by multivariate analysis and allowed us to define two groups (dysbiosis/non-dysbiosis). The search for AHL synthase (luxI) and receptor (luxR) known homolog genes, was performed using Basic Local Alignment Search Tool (BLAST) from previously assembled gene files (presence/absence) as well as raw data sequencing files (relative abundance and expression).

Results

Mass spectrometry confirmed a higher concentration of AHL molecules in healthy subjects than in relapsing IBD. Regarding in silico analysis, 103 subjects were selected including 50 with Crohn’s disease (CD), 27 with ulcerative colitis (UC), and 26 non-IBD subjects. No luxI-like synthase genes were retrieved by BLAST searches. However, several homologs of receptor genes were identified: sdiA gene from Escherichia coli (7/103 patients) and luxR-like homologs from Bacteroides fragilis and Bacteroides dorei present in all patients. According to disease, only one luxR-like gene from Bacteroides dorei was under-expressed in IBD patients (p = 0.02) compared to non-IBD, especially in CD (p = 0.02) (Figure 1). In dysbiosis situation, one luxR receptor gene from Bacteroides fragilis appeared to be over-expressed (p = 0.04) compared to non-dysbiotic patients (Figure 2).

Conclusion

Through this computational approach, AHL-synthesising bacteria have not been found. However, the expression of quorum sensing receptor genes appears to be modulated by IBD-associated gut dysbiosis. The role of LuxR receptors, especially in Bacteroides species, should be investigated to understand its impact on gut microbiota (Figure 3). Targeting LuxR receptors of bacterial quorum sensing might represent a new approach to modulate the gut microbiota in IBD.
DOP65 T-cell derived TGFβ1 remodels the rectum mesenchyme in Crohn’s Disease patients with perianal fistulizing disease
Authors: Gudiño V , Cho J W , Corraliza A M , Caballol B , Garrido-Trigo A , Masamunt M C , Ordás I , Ricart E , Hemberg M , Panés J , Salas A
Published: January 2023

Background

Perianal fistulizing disease (PFD) is a complication occurring in about 20% of Crohn’s Disease (CD) patients. It consists of the formation of new epithelised tracks connecting the intestine with the outer perianal region, which dramatically worsens a patient’s quality of life. The mechanisms driving fistula formation have not been elucidated and therefore, there are currently no specific treatments for PFD.

Methods

We collected rectum biopsies of CD patients with and without PFD in the absence of rectal inflammation (CD and CD+PFD), and with active rectal inflammation (CDinf and CD+PFDinf) (Fig.1). Rectal tissue samples were processed for RT-qPCR, or histologic analysis, and single-cell RNA sequencing (scRNAseq) for each patient.

Results

Differential expression gene (DEG) analysis of CD4+ and CD8+ T cells comparing CD vs CD+PFD and CDinf vs CD+PFDinf patients, respectively, revealed increased expression of TGFB1 in patients with fistulae. To investigate the main cellular subsets TGFB1 was interacting with, we performed ligand-receptor interaction analysis using CellphoneDB, which indicated that T-cell derived TGFB1 was primary interacting with the stromal compartment (Fig.2). 365 DEG were found in lamina propria (LP) fibroblasts of CD+PFD compared to CD, including TGFβ1-inducible genes such as TFPI2, SERPINE2 and MMPs 1 and 3. These changes were validated by bulk RT-qPCR, underscoring their potential use as PFD biomarkers (Fig.3). Moreover, we also identified a signature of elastin fibre assembly genes dysregulated in CD+PFD fibroblasts, suggesting molecular changes in the formation of elastin fibres in these patients. To determine whether the differentiation of fibroblasts was altered in the context of PFD, we conducted trajectory analysis using RNA velocity. Whilst fibroblasts in CD patients preferentially differentiate towards myofibroblasts, patients with PFD are biased towards LP fibroblasts, indicating an overall structural rearrangement of the mesenchyme in the rectum of patients with PFD, regardless of their inflammatory status (Fig.4). Importantly, analysis of an independent scRNAseq dataset of CD and ulcerative colitis (UC) patients showed higher expression of TGFB1 in T cells of active CD compared to active UC patients, suggesting that these alterations are already present in CD patients before the onset of a fistulizing phenotype and might potentially contribute to explain the absence of PFD in UC patients.

Conclusion

Based on these results, we suggest that the rectum of patients suffering from PFD present cellular and transcriptomic differences compared to CD patients without PFD. These changes are inflammation independent and point towards the TGFβ pathway as the main driver of this complication.
DOP69 Glycans as an actor in the microbiome-immune response crosstalk.
Authors: Rodrigues C , Gaifem J , Pereira M , Lavelle A , Colombel J F , Sokol H , Pinho S
Published: January 2023

Background

The perturbation of the symbiotic relationship between microbes and the intestinal immune system contributes to Inflammatory Bowel Disease (IBD) development even years before diagnosis. However, the causes underlying the loss of gut microbial equilibrium (dysbiosis) associated with inflammation still remain unknow. The host glycocalyx (repertoire of glycans/sugar-chains at the surface of gut mucosa) constitutes a major biological interface between gut mucosa and microorganisms1. In this study we aimed to evaluate whether and how an altered host glycome perturbs microbiome composition associated with dysbiosis and initiation of intestinal inflammation.

Methods

We have modulated the glycosylation profile at the level of gut mucosa using specific glycoengineered mouse models (KO) that exhibit specific alterations (deficiencies) in glycosylation composition. Colitis was induced using DSS and microbiome analysis was performed by 16S rDNA sequencing both in WT and KO mice. The mucosa glyco-immunoprofile was characterized.

Results

We first demonstrated in different glycoengineered mice that changes in the composition of glycans at gut mucosa resulted in dysbiosis characterized by a significant decrease in beneficial members of the Firmicutes phylum compared with WT mice. These mice with deficiency in mucosa glycosylation exhibited a higher susceptibility to colitis2. Then, and to determine the causal effect of mucosa glycosylation-induced microbiota modulation, we co-housed KO and WT mice. After 5 weeks of cohousing with WT mice, the KO mice exhibited a much less severe colitis and an increased proportion of bacteria from Firmicutes phylum compared to single housed KO mice. Inferred metagenomics analysis further revealed an alteration of the glycosylation biosynthetic pathway that was apparently shared and gained upon co-housing the KO mice with WT. The analysis of colonic inflammatory infiltrate from cohoused KO mice showed an increased expression of IL17 and IL22 production in gut mucosa, at baseline and before DSS. This pinpoints a potential protective effect of the enhancement of glycosylation biosynthesis (through microbiome sharing with WT) for preventing dysbiosis and dysregulation of gut immune response.

Conclusion

In this study, we demonstrate that changes in composition of glycans at the gut mucosa level is associated with dysbiosis and susceptibility to colitis. These results illustrate the relevance of the gut glycome in shaping the gut microbiota, highlighting its role in maintaining a homeostatic crosstalk between the microbiome and host immunity.

This study was funded by ECCO Pioneer Award.

1.Verhelst, Gastroenterology 2020. PMID: 31626754

2.Dias et al PNAS 2018 PMID: 29720442
DOP77 Is durable remission achievable after ileocolic resection for Crohn’s disease ? Long-term results of a prospective multicentric cohort study of the GETAID Chirurgie
Authors: Abdalla S , Benoist S , Maggiori L , Lefevre J , Denost Q , Cotte E , Germain A , Beyer-Berjot L , Desfourneaux V , Rahili A , Duffas J P , Pautrat K , Denet C , Bridoux V , Meurette G , Faucheron J L , Loriau J , Souche F R , Corte H , Zerbib P , Panis Y , Brouquet A ,   GETAID Chirurgie
Published: January 2023

Background

Most of the patients undergoing bowel resection for Crohn’s disease (CD) develop postoperative recurrence requiring medical treatment intensification or surgery. Is there a subgroup of patients for which surgery allows durable remission?

Methods

In this retrospective follow-up study, we collected data from 592 patients undergoing ileocolic resection for CD who were included from 2013 to 2015 in a prospective nation-wide cohort of the GETAID Chirurgie group. Patients with follow-up superior to 36 months were included. Primary outcome was durable remission, defined as the absence of endoscopic recurrence (Rutgeerts ≥i2) and/or absence of medical treatment intensification. Uni- and multivariate analyses of the predictive factors for durable remission were carried out.

Results

Among 268 included patients, 158 (59%) had a B2 stricturing phenotype, 92 (34%) had a B3 penetrating phenotype and 18 (7%) had a non-stricturing non-perforating phenotype (Montreal classification). One hundred and eighty-eight patients (70%) had a primary ileocolic resection. One hundred and sixty-seven patients (66%) had postoperative medical treatment to prevent postoperative recurrence (Table 1). After a median follow-up of 85 (36-104) months, 52 patients (19%) had a durable remission, among which 24 (46%) had no medical treatment and 28 (54%) maintained the same postoperative prophylactic treatment, including anti-TNF therapy in 15 patients (54%) (Table 2). Durable remission rate was significantly increased in B1 phenotype vs B2/B3 (n=7/18 ;39% vs n=45/250; 18%, p=0.030) and in primary ileocolic resection vs redo ileocolic resection (n=43/184 ; 23% vs n=9/80 ; 11%, p=0.023). In multivariate analysis, B1 phenotype was an independent predictive factor for durable remission (OR=3.59, IC95%[1.13-11.37], p=0.030) (Table 3).

Conclusion

These long-term data obtained from a nation-wide prospective cohort are in line with those of a randomised controlled trial (LIR!C) and show that durable remission is obtained in nearly 40% of CD patients with non-stricturing non-penetrating phenotype operated for CD refractory to medical treatment. This important result should be considered when medical treatment intensification versus surgery is discussed in these patients.
P026 Cost per Response/Remission analysis of biologic therapies availables in Argentina for the treatment of Bio-exposed patients with moderate-to-severe active Ulcerative Colitis
Authors: Elgart J , Balderramo S , Calvi G , Kanevsky D , Sánchez Gonzalez Y
Published: January 2023

Background

Response and remission are among the most clinically relevant outcomes for patients treated for ulcerative colitis (UC). The aim of the study is comparing the cost of a sustained clinical response or remission (at 52 weeks’ follow-up) across biologics available in Argentina for the treatment of bio-exposed patients with moderate-to-severe UC.

Methods

Using a model developed in Excel, which combine efficacy event rates (clinical response/remission) and treatment costs, we estimated the cost per response or remission of the following UC treatments: adalimumab (ADA), tofacitinib (TOFA), upadacitinib (UPA), ozanimod, ustekinumab and vedolizumab (VEDO). Event rates were obtained from a published network meta-analysis (NMA) of Phase 3 randomized controlled trials (RCTs) in moderately-to-severely active UC (bio-naïve or bio-exposed patients) for the following efficacy outcomes: Clinical response and Clinical remission per Full Mayo (FM) score. Costs of treatments were estimated based on approved regimens and doses of each drug as well as drug prices obtained from a publicly available list of prices. The cost per event was calculated as treatment cost divided by efficacy rate. For sensitivity, costs per event were also calculated using the 95% credible intervals from the NMA efficacy results. Costs per response/remission are expressed in US-dollars (exchange rate: US$1=AR$152.25, Sept 2022).

Results

Considering the Clinical Response at 52 weeks, the lowest cost per responder therapies were: UPA (induction x maintenance: 45mg QD x 15mg QD) $58.216 [95% CrI $42.854 - $98.094]; UPA (45mg QD x 30mg QD) $79.270 [$62.146 - $121.400]; TOFA (10mg BID x 5mg BID) $109.708 [$65.205-$ 232.217]; and TOFA (10mg BID x 10mg BID) $154.218 [$99.169 -$296.204].

Likewise considering sustained remission the lowest costs per responder therapies were: UPA (45mg QD x 15mg QD) $64.782 [$42.658 - $136.390]; UPA (45mg QD x 30mg QD) $92.874 [$64.488 - $182.236]; VEDO (300mg x 300mg Q8W) $278.299 [$124.766 - $779.009]; and TOFA (10mg BID x 5mg BID) $305.534 [$126.845 - $904.439]. The cost per responder was consistently lower for upadacitinib compared to all biologic treatments available in Argentina across both clinical measures.

Conclusion

Among therapies for the treatment of bio-exposed patients with moderate-to-severe UC evaluated, upadacitinib have shown the lowest median cost per clinical remission and response from an Argentinian healthcare payer perspective.
P027 Anorectal Motility Disorders in Inflammatory Bowel Disease patients
Authors: Costache R , Dimitriu A , Les A , Gheorghe C
Published: January 2023

Background

In spite of prolonged disease remission of IBD patients, induced by the new biological molecules, a significant number of them suffer from persistent debilitating symptoms with major impact on the quality of life. Frequently, these symptoms are due to post-inflammatory motility changes and misinterpreted as functional disorders. Our aim is to identify and characterize the anorectal motility dysfunction in IBD patients.

Methods

We are conducting an ongoing prospective study started in August 2019, which includes the IBD patients admitted in a Tertiary Gastroenterology Centre in Bucharest, with specific symptoms (anorectal pain, incontinence, difficult defecation). We perform high resolution anorectal manometry using Sandhill Scientific systems, the parameters being analysed using InSIGHT software. The manometric testing comprise measurements of anorectal pressure at rest, during squeeze, simulated evacuation, rectoanal inhibitory reflex (RAIR) and rectal sensory testing, in compliance with International Anorectal Physiology Working Group protocol.

Results

We studied 21 patients (12 patients with Ulcerative Colitis and 9 patients with Crohn’s Disease, 15 females and 6 males, mean age 40 (±11.43) years. Only 23.1% (5 patients) had rectal active involvement. Symptoms were reported by 81.0% (17) patients: pain (57.1%), anal incontinence (94.1%), difficult evacuation (29.4%), urgency (64.7%) and intolerance of rectal therapies (35.3%); rectal inflammation was not correlated with the presence of symptoms in our study group (p= 0.53). Modified manometric parameters were found in 81.0% patients and were associated with previous pelvic surgical interventions (p<0.05); although, the latter does not seem to increase the risk of incontinence (p=0.33). In 61.9% cases the manometric measurements correlated with the symptoms. 85% of the patients with passive incontinence presented lower resting pressure and 57.1% of those with active incontinence were found with lower squeeze pressures. Changes compatible with dyssynergia were detected in 61.9% of the cases. Sensory testing revealed alterations in 46.2% of patients, and RAIR was negative in 33.3% of the cases.

Conclusion

There is a considerable number of patients with anorectal motility changes. Therefore, pelvic floor investigation is an essential tool in the management of IBD patients with anorectal symptoms.
P033 The assessment of serum cytokines at baseline could predict mucosal healing in patients with Crohn’s disease treated with ustekinumab. A prospective study.
Authors: Bertani L , Antonioli L , Fornili M , D’Antongiovanni V , Coppini F , Ceccarelli L , Carmisciano L , Benvenuti L , Mumolo M G , Bottari A , Baglietto L , Bellini M , Fornai M , De Bortoli N , Costa F
Published: January 2023

Background

Ustekinumab (UST) is a monoclonal IgG1 antibody binding the p40 subunit of IL-12 and IL-23. The blockage of the activation of the heterodimer IL-12/IL-23 inhibits the differentiation of Th1 and Th17 cells, reducing the inflammatory cascade typical of Crohn’s disease (CD). Some patients with CD achieve mucosal healing after one year of UST therapy, whereas others experience primary non-response or loss of response. No biomarkers are currently available to predict therapeutic response to UST. The aim of this prospective study was to identify one or more biomarkers able to predict mucosal healing in patients with CD treated with UST.

Methods

We prospectively enrolled all consecutive CD patients treated with UST, following the current guidelines. A blood sample was drawn before UST infusion at week 0 (baseline), 24 and 48, and serum cytokines IL1α, IL-1β, IL-6, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, IL-22, IL-23 and IL-33 were evaluated by a fluorescence assay. At the same timepoints, Fecal Calprotectin (FC) was assessed. A colonoscopy was performed before starting the treatment and at week 48, where therapeutic outcome was evaluated in terms of mucosal healing, defined as a Simple Endoscopic Score for CD <2.

Results

Out of 44 patients enrolled, 22 (50%) achieve mucosal healing at the end of follow up. Baseline IL-23 levels were higher in responders than in non-responders (Mann-Whitney test, p-value<0.001), whereas higher baseline levels of IL-1α are associated with non-response (p=0.03). We also observed a higher probability of mucosal healing in those with lower levels of IL-6 at baseline (p=0.05). A borderline statistically significant association was observed for baseline FC, which values were lower in responders than in non-responders (Mann-Whitney test, p=0.098). No significant differences were observed with regard to the baseline levels of the other cytokines. FC levels decreased over time in responders, whereas its values did not change over time in non-responders (test for the interaction between time and outcome, p<0.001). IL-13 presented a homogenously decreasing time trend regardless the outcomes (test for the association with time and outcome, p=0.019). No significant time trend was observed with regard to the other cytokines.

Conclusion

Baseline serum levels of IL-23, IL-1α and IL-6, as well as the decrease of FC over time, showed a good reliability in predicting therapeutic outcome to UST in CD in terms of mucosal healing. These biomarkers could help clinicians in the perspective of a better management of UST therapy, identifying early the patients with higher probability to respond to the treatment.