bluuebunny/crossref_metadata_2025_split huggingface dataset:
P039 Regional distribution of TCR Vδ1 and TCR Vδ2 cells in healthy and inflamed mucosa of inflammatory bowel disease
Authors: Tristan E , Carrasco A , Martín-Cardona A , Zabana Y , Aceituno M , Horta D , Andújar X , Salvador I , Loras C , Fernández-Bañares F , Esteve M 
Published: January 2020

Abstract

Background
Vδ1+ and Vδ2+ are TCRγδ lymphocytes of the gut intraepithelial compartment that recognise proteins without help of antigen-presenting cells. Its relevance in inflammatory bowel disease (IBD) is unknown.

Aim
To measure Vδ1+ and Vδ2+ in T-cell subtypes [CD4+, CD8+, double positive (DP,CD4+CD8+), double negative (DN,CD4−CD8−) and CD103+] of healthy and IBD inflammed gut mucosa.

Methods
Twenty-six active IBD patients without immunosuppressants (n = 18 Crohn’s disease (CD), eight ulcerative colitis (UC)) and 10 healthy controls (paired biopsies of ileum, right and left colon) were included. Lymphocytes were analysed with LSRFortessa cytometer. Results expressed as % median (25–75%IQI).

Results
Healthy mucosa: reduction in ileum of total CD3+Vδ1+ due to CD3+CD8+Vδ1+ and CD3+DN_Vδ1+

Conclusion
Reduction of Vδ1+ and Vδ2+, mainly of CD103+, may play a role in IBD pathophysiology by perpetuating inflammation. Increase of CD3+Vδ1+CD4+ in both Ileal CD and UC may compensate this decrease with a selective increase in ‘helper’ function.
P042 Patient perspective on the impact of complex perianal fistulas in Crohn’s disease on quality of life: introducing the concept of the patient survey conducted in Europe
Authors: Spinelli A , Lönnfors S , Avedano L , Bojic D 
Published: January 2020

Abstract

Background
Perianal involvement in Crohn’s disease (CD), including fistulas, ulcers, abscesses, strictures and cancer, can lead to a significant, occasionally debilitating impairment in the patients‘ short- and long-term quality of life (QoL). Perianal fistulae can cause symptoms such as leakage, rectal pain, swelling, pain with bowel movements, and fever, which may significantly affect a patient’s social performance, sexual function and normal life activities. Fistulae are a relatively common CD complication: around 35% of CD patients have at least one fistula, while the majority of CD fistulas are complex. Still, few studies have assessed the impact of complex perianal fistulae (CPF) on the QoL of CD patients from the patient perspective.

Methods
A questionnaire assessing the effect of CPF on the QoL of CD patients was developed by patient representatives and medical experts. It consisted of 43 questions about history and activity of CD and CPF, treatment experiences, self-reported level of being informed about the disease, past and current symptoms, self-reported impact on QoL, emotions related to the disease, impact and restrictions on close relationships and social life, sexual activity, professional life and work absence. The survey was launched online on the European Federation of Crohn’s and ulcerative colitis Associations (EFCCA) website on July 15, 2019 (remains open until December 2019) and shared to national patient associations through the EFCCA network. Both CD patients with and without CPF were invited to participate in order to have a control group of patients for data analysis. The self-selective, anonymous survey was offered in English, French, German, Greek, Hebrew, Italian, Polish, Portuguese, Romanian, Spanish and Slovenian.

Results
On November 20, 2019, there were 788 responses from CD patients with and without CPF. There may have been selection bias as the survey is self-selective, only available online and in a limited amount of languages. Considering the retrospective aspect of some questions, recall bias may also have affected some of the responses. Regardless, the data collected will allow a comparison between CD patients with and without CPF, and between patients in different countries, in important, patient-relevant QoL aspects.

Conclusion
The collected data will be analysed in early 2020. The results will provide valuable insights into the often unspoken burden in the life of CD patients with CPF and potentially help in making treatment decisions for CD patients suffering from CPF.
P062 Dose-dependent differential effects of vedolizumab therapy on adhesion of regulatory and effector T cells
Authors: Becker E , Wiendl M , Schulz-Kuhnt A , Atreya I , Atreya R , Neurath M , Zundler S 
Published: January 2020

Abstract

Background
Vedolizumab has emerged as an important pillar of treatment in inflammatory bowel disease (IBD). However, for unknown reasons, not all patients respond to therapy. Earlier clinical studies suggested decreased response rates in the highest compared with medium dosage groups. Interestingly, vedolizumab has been shown to inhibit the homing of both regulatory (Treg) and effector T (Teff) cells and previous data from our group suggested different effect sizes in both populations. Thus, we hypothesised that the non-linear exposure–efficacy correlation might be explained by dose-dependent differential effects of vedolizumab on Treg and Teff homing. Therefore, we studied functional effects of different vedolizumab exposure levels on Treg and Teff cell trafficking.

Methods
The α4β7 expression on different human T-cell subsets as well as the binding characteristics of vedolizumab to these cells at different exposure levels was analysed via flow cytometry. Functional effects of different vedolizumab concentrations on the adhesion of Tregs and Teffs to mucosal addressin cell adhesion molecule 1 (MAdCAM-1) were analysed using dynamic in vitro adhesion assays, transmigration assays and in vivo homing assays in a humanised mouse model. The in vivo binding of vedolizumab to Tregs and Teffs in patients receiving therapy was quantified and correlated with the corresponding serum levels.

Results
We found a preferential binding of vedolizumab to Tregs at an exposure with 0.4 µg/ml vedolizumab that shifted to a preferential binding to Teffs at an exposure with 10 µg/ml. Further increase of vedolizumab to 50 µg/ml led to equal binding to Tregs and Teffs (Figure 1). Consistently, at 10 µg/ml, dynamic adhesion of Tregs to MAdCAM-1 was increased compared with Teffs, but no difference was noted at 50 µg/ml. Additionally, a higher number of Treg compared with Teff cells were able to transmigrate in a MAdCAM-1-dependent manner at a concentration of 10 µg/ml vedolizumab. Preliminary data from homing experiments in a humanised mouse model and from IBD patients treated with vedolizumab support the notion that differential binding preferences depending on the exposure level can also be observed in vivo.

Conclusion
Our findings support a dose-dependent differential binding of vedolizumab to different T-cell subpopulations and suggest that an optimal ‘window’ of exposure exists, in which effects on Teffs predominate over Tregs. While offering a potential explanation for earlier findings in dose-ranging studies, our data might lay the basis for the establishment of individualised dose optimisation in IBD patients.
P071 Studying the effects of the probiotic bifidobacteria on gut health and intestinal epithelial cells function
Authors: Poletti M , Hautefort I , Treveil A , Demeter A , Rodriguez E , Brion A , Goldson A , Divekar D , Schofield Z , O’Neill I , Lister A , Lipscombe J , Watson A , Macaulay I , Hall L , Korcsmaros T 
Published: January 2020

Abstract

Background
Intestinal homeostasis depends on complex interactions between the microbiota, the intestinal epithelium and the host immune system. Paneth cells play an important role thanks to their release of antimicrobial peptides and their dysfunction has been shown to contribute to Crohn’s disease. The human gut commensal Bifidobacteria has been highlighted as a protective agent in IBD. Whilst the specific modulating factors are largely unidentified, evidence suggests that Bifidobacteria can interact with host intestinal cells. Such interactions can alter host molecular pathways, resulting in a modified intestinal cell function. Understanding these effects is crucial to unravel the potential benefits of bifidobacteria for IBD. In this study, we developed a workflow to investigate the beneficial effects of the probiotic bifidobacteria in modulating gene regulation and function of different intestinal epithelial cells in the gut.

Methods
We gavaged either conventionally raised (SPF) or germ-free mice (n = 5) with Bifidobacterium breve UCC2003 (1–5 × 108 CFU), and sorted intestinal epithelial cell types (Lgr5+ stem cells, Paneth cells and transit-amplifying cells) from the mouse intestinal tissue by flow cytometry using a panel of known antibodies. Each isolated cell population (n = 200) was subsequently profiled by low input RNA sequencing and DNA methylation.

Results
Intracellular lysozyme staining for Paneth cells and initial gene expression data exploration suggests successful separation of the different populations from the mouse intestinal tissue using flow cytometry. Gene expression data were further analysed using network biology approaches to generate cell-type-specific molecular regulatory networks indicating genes regulation by bifidobacteria in each cell types. Overlaying the methylation data will elucidate the role of epigenetics played during this regulation. Together, these networks will improve our understanding of how Bifidobacteria affects these different cells types through communication with precursor stem cells and/or with direct effects on the fully differentiated cells, ultimately impacting their function.

Conclusion
In the future, we aim to use a similar workflow using two-dimensional human-derived organoids monolayers co-cultured with bifidobacteria to investigate the effects on host intestinal epithelial cell function in a high-throughput and patient-specific manner. This will increase our understanding of the complex role played by host genetics and microbial factors in the pathogenesis of gastrointestinal diseases such as IBD, and hopefully pave the way for translational developments in the prevention these pathologies.
P072 Evaluation of dosing strategies of anti-TNFα monoclonal antibodies using pharmacokinetic modelling and simulation
Authors: Démaris A , Grišić A M , Huisinga W , Walter R , Kloft C 
Published: January 2020

Abstract

Background
Anti-TNFα monoclonal antibodies (mAbs) are a well-established treatment for patients with Crohn’s disease (CD). However, subtherapeutic concentrations of mAbs have been related to a loss of response during the first year of therapy1. Therefore, an appropriate dosing strategy is crucial to prevent the underexposure of mAbs for those patients. The aim of our study was to assess the impact of different dosing strategies (fixed dose or body size descriptor adapted) on drug exposure and the target concentration attainment for two different anti-TNFα mAbs: infliximab (IFX, body weight (BW)-based dosing) and certolizumab pegol (CZP, fixed dosing). For this purpose, a comprehensive pharmacokinetic (PK) simulation study was performed.

Methods
A virtual population of 1000 clinically representative CD patients was generated based on the distribution of CD patient characteristics from an in-house clinical database (n = 116). Seven dosing regimens were investigated: fixed dose and per BW, lean BW (LBW), body surface area, height, body mass index and fat-free mass. The individual body size-adjusted doses were calculated from patient generated body size descriptor values. Then, using published PK models for IFX and CZP in CD patients2,3, for each patient, 1000 concentration–time profiles were simulated to consider the typical profile of a specific patient as well as the range of possible individual profiles due to unexplained PK variability across patients. For each dosing strategy, the variability in maximum and minimum mAb concentrations (Cmax and Cmin, respectively), area under the concentration-time curve (AUC) and the per cent of patients reaching target concentration were assessed during maintenance therapy.

Results
For IFX and CZP, Cmin showed the highest variability between patients (CV ≈110% and CV ≈80%, respectively) with a similar extent across all dosing strategies. For IFX, the per cent of patients reaching the target (Cmin = 5 µg/ml) was similar across all dosing strategies (~15%). For CZP, the per cent of patients reaching the target average concentration of 17 µg/ml ranged substantially (52–71%), being the highest for LBW-adjusted dosing.

Conclusion
By using a PK simulation approach, different dosing regimen of IFX and CZP revealed the highest variability for Cmin, the most commonly used PK parameter guiding treatment decisions, independent upon dosing regimen. Our results demonstrate similar target attainment with fixed dosing of IFX compared with currently recommended BW-based dosing. For CZP, the current fixed dosing strategy leads to comparable percentage of patients reaching target as the best performing body size-adjusted dosing (66% vs. 71%, respectively).

References
P076 Role of gut microbiota in mediating the effects of thiopurines
Authors: Franzin M , Lucafò M , Lagatolla C , Stocco G , Decorti G 
Published: January 2020

Abstract

Background
A general consensus exists that patients with inflammatory bowel disease (IBD) present compositional changes in the gut microbiota (dysbiosis), including an increase in the abundance of Enterobacteriaceae. Thiopurine drugs are commonly used in the maintenance of remission in IBD. In this context, the purpose of the project is to explore the role of candidate bacterial strains in mediating the effects of thiopurines in vitro.

Methods
Azathioprine (AZA), mercaptopurine (MP) and thioguanine (TG) (400 µM) were incubated in minimal salts medium (M9) in presence or not of E. coli, S. enterica and K. pneumoniae and of their growth phase broths (GPB) for 4 h at 37°C. The viability of NALM6 (B cells) and JURKAT (T cells) exposed to serial dilution of drugs (ranging from 0.2 to 15 μM of AZA, from 0.3 to 20 μM of MP, from 0.08 to 5 μM of TG) previously incubated or not with bacteria and with their GPB was determined by the MTT assay. Absorbance peaks of thiopurines were analysed by UV spectrophotometry. Statistical significance was assessed by two-way ANOVA and Bonferroni’s post-test for MTT tests and by one-way ANOVA for UV spectra.

Results
In NALM6 cells, the cytotoxic effects of 15 μM of AZA, 2.5 μM of MP and 1.25 μM of TG decreased significantly (p &lt; 0.001) after incubation with K. pneumoniae (respectively 45 ± 2.9%; 34 ± 2.5%% and 21 ± 0.6%) and its GPB (respectively 41 ± 7.7%; 41 ± 5.1% and 27 ± 3.5%) compared with the drugs not previously exposed (respectively 76 ± 2.3%; 69 ± 1.7% and 43 ± 3.8%). In JURKAT cells, the cytotoxic effects of 15 μM of AZA, 2.5 μM of MP and 1.25 μM of TG decreased significantly (p &lt; 0.001) after incubation with K. pneumoniae (respectively 46 ± 2.8%; 38 ± 1.29% and 19 ± 3.3%) and its GPB (respectively 49 ± 9.4%; 38 ± 1.5% and 26 ± 1.5%) in comparison with the drugs not exposed (respectively 75 ± 4.0%; 50 ± 3.5% and 54 ± 4.0%). E. coli and S. enterica did not affect the cytotoxicity of the thiopurines. UV analysis evidenced a reduction of absorbance peaks of AZA (21 ± 0.05%), MP (32 ± 0.015%) and TG (30 ± 0.03%) after incubation with K. pneumoniae but not with its growth phase broth (GPB).

Conclusion
The activity of thiopurines decreased after incubation with both K. pneumoniae and its GPB. UV analysis suggested that the lower cytotoxicity of thiopurines exposed to the bacterial strain is due to the reduction of the concentration of the drugs exposed to K. pneumoniae. Moreover, the reduction of drug availability after the exposure to GPB could be explained with a possible interaction between thiopurines and capsular polysaccharides released by the bacteria.
P077 Metabonomic profiling distinguishes Crohn’s perianal fistulas and idiopathic idiopathic (cryptoglandular) perianal fistulas: possible clues to underlying pathogenesis?
Authors: Adegbola S , Sarafian M , Sahnan K , Tozer P , Ding N , Faiz O , Warusavitarne J , Phillips R , Holmes E , Hart A 
Published: January 2020

Abstract

Background
The reasons why fistulas originate have been explained in idiopathic cases, with the cryptoglandular theory being widely accepted; however, in Crohn ́s disease, it is thought to involve interplay between microbiological, immunological and genetic factors. It remains unclear why fistulas persist. Novel investigative tools in systems biology are improving our understanding of pathogenesis, and one such tool is metabonomic profiling, whereby spectrometry is used to assess metabolic responses of complex systems in health and disease. These changes are mapped using analytical and statistical techniques. To the best our knowledge, these methodologies have not been applied to aid understanding of the pathogenesis of Crohn’s perianal fistula persistence.

Methods
Fistula tissue biopsy was obtained from the fistula tract of 30 patients with idiopathic perianal fistula and 20 patients with Crohn ́s anal fistula. Two analytical platforms were attempted to achieve broad metabolome coverage. Univariate (student t-test) and multivariate statistical data analyses were performed. From the latter principle component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), models were built to find metabolites that could predict tissue samples from patients with either Crohn’s or idiopathic anal fistula. Metabolite putative identification was conducted by matching accurate mass:charge ratio (m/z) measurements of detected chromatographic features to theoretical value from in-house databases and on-line databases and previous publications.

Results
Significant OPLS-DA predictive models (validated with CV-ANOVA p-value &lt;0.05) differentiated metabolites from tissue samples from Crohn’s vs. idiopathic anal fistula patients using both metabonomic profiling platforms (HILIC/lipid profiling). A total of 22 differentiating metabolites were identified from the HILIC profiling and 19 from the lipid profiling analysis. Mapped pathway analysis was performed for metabolites identified using online database searches.

Conclusion
Forty-one differentiating metabolites were discovered belonging to various classes of lipids, amino acids and nucleotides. Pathways involved included amino acid metabolism, phospholipid metabolism and glycerolipid metabolism amongst others. Further work in larger numbers is required to validate these findings as well as cross correlation with microbiome work to understand the impact of host gut interactions in the pathophysiology of Crohn’s and idiopathic perianal fistulas.
P085 Deep profiling of the circulating immune cell landscape in inflammatory bowel disease by mass cytometry
Authors: Horn V , Borek Z , Mantzivi E , Urbicht M , Boesel D , Baumgart S , Sonnenberg E , Lissner D , Siegmund B , Mei H , Hegazy A N 
Published: January 2020

Abstract

Background
A complex interplay of innate and adaptive immune cells maintains intestinal homeostasis. In inflammatory bowel disease (IBD), the fragile balance between regulatory and inflammatory cell subsets breaks down. The latter are recruited to the gut where they sustain intestinal inflammation and lead to tissue destruction. Due to re-circulation and gut-homing processes, the circulating immune cell compartment experiences profound changes that reflect disease activity. Meanwhile, single-cell techniques like mass cytometry have become a powerful technology to shed a light on the heterogeneity and dynamics of immune cells. As obtaining intestinal biopsies from inflamed gut is invasive and poses patients at risk, diagnostics and therapy monitoring from ‘liquid biopsies’ would be a great advance. A deeper understanding of the circulating immune cell landscape in IBD pre- and post-treatment could significantly contribute to IBD patient management by early prediction of therapy response.

Methods
Whole blood from 24 IBD patients—including 16 ulcerative colitis (UC) and 6 Crohn’s disease (CD) patients before treatment—and 18 age- and sex-matched healthy donors (HDs) was incubated with proteomic stabiliser and frozen. Upon thawing, cell suspensions were Palladium barcoded, stained with a 37-marker panel and acquired on a Helios mass cytometer. The generated dataset was normalised, de-barcoded and subsequently analysed.

Results
Using dimensionality reduction and neural-network-based algorithms, we faithfully identified different circulating immune subsets in healthy donors and IBD patients. Our preliminary analysis revealed altered myeloid cell populations, like neutrophils and macrophages, in IBD patients. In line with an activation of the innate immune system, we observed a considerable increase in the neutrophil compartment compared with healthy donors. Moreover, patterns of marker expression within different subsets showed substantial differences between healthy donors, CD and UC patients.

Conclusion
Here, we show a mass cytometry panel that identifies the circulating immune cell landscape and shows major differences between healthy donors, CD and UC patients.
P086 Identification of constitutive modifications in plasma cells and B lymphocytes in patients with inflammatory bowel disease
Authors: Marin A C , Fernández-Tomé S , Ortega Moreno L , Martin Dominguez V , Casabona S , Becerro I , Mora-Gutiérrez I , Villacañas-Gil I , Baldan-Martin M , Moreno-Monteagudo J A , Santander C , Chaparro M , Bernardo D , Gisbert J P 
Published: January 2020

Abstract

Background
Plasma cells (PCs) and B lymphocytes (BLs) are a source of immunoglobulins (Ig), being IgA essential for intestinal homeostasis. An unbalanced intestinal Ig production has been described in inflammatory bowel disease (IBD). Nevertheless little is known about the role of mucosal Ig-producing BL and PC in IBD, reason why we decided to study them.

Methods
We included 12 healthy controls -HC-, 10 patients with ulcerative colitis (three active -aUC- and seven quiescent -qUC) and 10 patients with Crohn’s disease (three active -aCD- and seven quiescent -qCD). Disease was located in the distal colon in all patients, although the quiescent ones had no inflammation (endoscopic Mayo = 0; SES-CD = 0–1). Distal colon biopsies were collected together with peripheral blood. Mucus layer and epithelial barrier was removed from the biopsies and lamina propria mononuclear cells were harvested using the ‘walk-out’ protocol. Peripheral blood mononuclear cells were obtained after ficoll centrifugation. In both cases, cells were stained with specific antibodies, acquired in a FACSCanto II cytometer, and analysed with FlowJo. Median percentage of PC and BL (and their subsets) relative to each tissue was calculated and compared using non-parametric statistics, considering statistically significant p &lt; 0.05.

Results
The proportion of plasmablasts, blood-precursors of PC, was higher in the blood of active IBD patients (HC: 0.8%; aUC: 5.3%; aCD: 3.4%). Even though there were no differences in the colonic proportion of PC between the study groups, there was a constitutive lower proportion of IgA-producing PC in IBD, irrespective of its type (UC or CD) or presence of inflammation (HC: 88%; qUC: 55%; aUC: 38%; qCD: 70%; aCD: 44%). Moreover, aCD patients also showed a significantly higher proportion of IgM-producing PC (HC: 6% vs. aCD: 10%), and a higher proportion PC expressing CD19 compared both with HC and qCD (HC: 43%; qCD: 52%; aCD: 74%). The proportion of BL and their subsets did not show differences between the study groups, neither in blood nor in colon. However, in UC patients, some circulating subsets displayed a lower proportion of cells expressing the gut-homing integrin β7: naive BL (HC: 11.5%; qUC: 2.9%; aUC: 0.6%) and IgM memory BL type CD27+ (HC: 43%; qUC: 30%; aUC: 23%) and also CD27- (HC: 32% vs. aUC: 5%).

Conclusion
IBD patients have a diminished percentage of colonic IgA-producing PC, which is irrespective of the type of IBD or the inflammatory status; this reduction could compromise the correct microbiota regulation in IBD. The reduction of the percentage of β7-expressing BL in the blood of UC patients could potentially point to a specific pathogenic mechanism of UC.