The universal effects of low-dose interleukin-2 across 13 autoimmune diseases in a basket clinical trial.

BACKGROUND: A Tregs insufficiency is central to autoimmune and inflammatory diseases pathophysiology and low dose interleukin-2 (IL-2LD) can specifically activate Tregs. OBJECTIVE: To assess IL-2LD therapeutic potential and select diseases for further clinical development, we performed an open-label, phase 2a, disease-finding, "basket trial" involving patients with one of 13 different autoimmune diseases. METHODS: 81 patients treated with IL-2LD (1 million IU/day) for 5 days, followed by fortnightly injections. The first 48 patients received diluted Proleukin®, while the subsequent 33 received ready-to-use ILT-101®. The primary endpoint was the change in Tregs at day-8 compared to baseline. Key secondary endpoints included clinical efficacy assessments using the Clinical Global Impression (CGI) scale, disease-specific scores, and EuroQL-5D-5L. RESULTS: Our study unveiled a universal and significant expansion and activation of Tregs, without concomitant Teffs activation, across all 13 autoimmune diseases. Both Proleukin® and ready-to-use ILT-101® demonstrated identical effects on Tregs. CGI scores reflecting activity, severity, and efficacy were significantly reduced in the overall patient population. Disease-specific clinical scores improved in five of the six disease cohorts with at least six patients, namely ankylosing spondylitis, systemic lupus erythematosus, Behçet's disease, Sjögren's syndrome, and systemic sclerosis. Urticaria was the only severe adverse event related to treatment. CONCLUSION: IL-2LD was well-tolerated, exhibiting specific Treg activation and clinical improvements across the 13 autoimmune diseases. CLINICAL IMPLICATION: Tregs stimulation by IL-2LD is a promising therapeutic strategy and IL-2LD holds considerable promise for integration into combinatorial therapeutic approaches.

Gut dysbiosis in Crohn's disease: Never so close to solving the chicken-and-egg enigma: Commentary to "Gut microbiome composition is associated with future onset of Crohn's disease in healthy first-degree relatives, by Raygoza Garay JA et al., Gastroenterology 2023".

Crohn's disease (CD) is a chronic disease of the digestive tract whose pathogenesis remains not fully understood. Several studies have implicated the gut microbiota as a key player in the onset of gut inflammation. However, most of the data is based on case-control studies comparing patients with established disease with controls, usually healthy individuals. The study by Raygoza Garay and colleagues shows for the first time that changes in the composition of the gut microbiota precede CD onset by up to five years. The authors developed a microbiome risk score using a machine-learning model that included bacterial composition and clinical variables from a large cohort of healthy first-degree relatives of patients with CD. This study provides strong evidence that the alterations of the gut microbiota is causal in CD pathogenesis and suggest that early intervention targeting it may be an appropriate preventive strategy.

Lymphoma In Patients With Inflammatory Bowel Disease: A Multicenter Collaborative Study Between Getaid And Lysa.

BACKGROUND: IBD is associated with an increased risk of developing lymphoma. Although recent data clarifies lymphoma epidemiology in IBD patients, clinical and pathological characteristics of lymphoma occurring in IBD remain ill-known. METHODS: Patients with IBD and lymphoma were retrospectively identified in the framework of a national collaborative study including the Groupe d'Étude Thérapeutique des Affections Inflammatoires du Tube Digestif (GETAID) and the Lymphoma Study Association (LYSA). We characterized clinical and prognostic features for the 3 most frequent lymphoma subtypes occurring in IBD. We performed a multicentric case-control study. Controls (lymphoma de novo) were matched (5:1) to cases on gender, age at diagnosis, lymphoma subtype, year of diagnosis, IPI/FLIPI indexes. Overall survival (OS) and progression free survival were compared between cases and controls. RESULTS: 133 IBD patients with lymphoma were included (males = 62.4 %, median age at lymphoma diagnosis = 49 years in males ; 42 in females). Most had Crohn's disease (73.7 %) and were exposed to thiopurines (59.4 %). The most frequent lymphoma subtypes were diffuse large B cell lymphoma (DLBCL, 45.1 %), Hodgkin lymphoma (HL, 18.8 %), and follicular lymphoma (FL, 10.5 %). When matched with 365 controls, prognosis was improved in IBD patients with DLBCL compared to controls (p = 0.0064, hazard ratio = 0.36) or similar (HL and FL). CONCLUSION: Lymphomas occurring in IBD patients do not seem to have a worse outcome than in patients without IBD. Due to the scarcity of this situation, those patients should be managed in expert centers.

Urbanization associates with restricted gut microbiome diversity and delayed maturation in infants.

Alterations of the microbiome are linked to increasingly common diseases such as obesity, allergy, and inflammatory bowel disease. Post-industrial lifestyles are thought to contribute to the gut microbiome alterations that cause or aggravate these diseases. Comparing communities across the industrialization spectrum can reveal associations between gut microbiome alterations and lifestyle and health, and help pinpoint which specific aspect of the post-industrial lifestyle is linked to microbiome alterations. Here, we compare the gut microbiomes of 60 mother and infant pairs from rural and urban areas of Senegal over two time points. We find that urban mothers, who were more frequently overweight, had different gut microbiome compositions than rural mothers, showing an expansion of Lachnospiraceae and Enterobacter. Urban infants, on the other hand, showed a delayed gut microbiome maturation and a higher susceptibility to infectious diseases. Thus, we identify new microbiome features associated with industrialization, whose association with disease may be further investigated.

Prevalence of and Factors Associated With Extraintestinal Manifestations and Their Remission in Inflammatory Bowel Disease: The EXTRA-Intestinal Manifestation Prospective Study From the Groupe d'Etude Thérapeutique des Affections Inflammatoires du Tube Digestif.

INTRODUCTION: Extraintestinal manifestations (EIMs) of inflammatory bowel disease (IBD) are challenging clinical situation. No prospective study assessed remission risk factors of EIMs. The aim of this study was to prospectively investigate the epidemiology, risk factors of EIM occurrence, and EIM remission in a large IBD cohort. METHODS: We conducted a cross-sectional study in 30 French referral centers. Between May 2021 and June 2021, all consecutive patients attending to hospital appointment were systematically invited to fill out a questionnaire. RESULTS: A total of 1,971 consecutive patients with IBD were analyzed. There were 1,056 women (53.8%), and the median age of patients was 41 years (31-54). The median disease duration was 11 years (1-18). Overall, 544 (27.6%) had at least 1 EIM. In 20.2% of cases, patients had multiple EIMs. The most frequent EIMs were rheumatological (19%) and dermatological (10%) manifestations. Immunosuppressant treatment (odds ratio [OR] = 2.56; P < 0.001) was a risk factor of EIM, while the Montreal A3 classification (OR = 0.61, P = 0.023) and male gender (OR = 0.61, P < 0.001) were associated with a lower risk of EIM occurrence. IBD current clinical remission (OR = 2.42; P < 0.001) and smoking cessation (OR = 2.98; P < 0.001) were associated factors of EIM remission. Conversely, age at IBD diagnosis (OR = 0.98; P < 0.018) was associated with a lower risk of EIM remission. DISCUSSION: One quarter of patients had at least 1 EIM. Beyond factors associated with the presence of EIMs, patients with IBD current clinical remission and smoking cessation are more likely to achieve EIM remission, while increasing age at IBD diagnosis is associated with decreased chance of remission.

Adalimumab in Biologic-naïve Patients With Crohn's Disease After Resolution of an Intra-abdominal Abscess: A Prospective Study From the GETAID.

BACKGROUND & AIMS: The management of intra-abdominal abscesses complicating Crohn's disease (CD) is challenging, and surgery with delayed intestinal resection is often recommended. The aims of this study were to estimate the success rate of adalimumab (ADA) in patients with CD with an intra-abdominal abscess resolved without surgery, and to identify predictive factors for success. METHODS: A multicenter, prospective study was conducted in biologic-naïve patients with CD with resolved intra-abdominal abscess treated with ADA with a 2-year follow-up. The primary endpoint was ADA failure at week (W) 24 defined as a need for steroids after W12, intestinal resection, abscess recurrence, and clinical relapse. Secondary post-hoc endpoint was the long-term success defined as the survival without abscess relapse or intestinal resection at W104. The factors associated with ADA failure at W24 and W104 were identified using a logistic and a Cox regression, respectively. RESULTS: From April 2013 to December 2017, 190 patients from 27 GETAID centers were screened, and 117 were included in the analysis. Fifty-eight patients (50%) were male, and the median age at baseline was 28 years. At W24, 87 patients (74%; 95% confidence interval [CI], 65.5%-82.0%; n = 117) achieved ADA success. Among the 30 patients with ADA failure, 15 underwent surgery. At W104, the survival rate without abscess recurrence or surgery was 72.9% (95% CI, 62.1%-79.8%; n = 109). Abscess drainage was significantly associated with ADA failure at W24 (odds ratio, 4.18; 95% CI, 1.06-16.5; P =0 .043). Disease duration (hazard ratio [HR], 1.32; 95% CI, 1.09-1.59; P = .008), abscess drainage (HR, 5.59; 95% CI, 2.21-14.15; P = .001), and inflammatory changes in mesenteric fat (HR, 0.4; 95% CI, 0.17-0.94; P = .046) were significantly associated with ADA failure at W104. CONCLUSION: Provided that the abscess was carefully managed before initiating medical treatment, this study showed the high efficacy of ADA in the short and long term in biologic-naïve patients with CD complicated by an intra-abdominal abscess. CLINICALTRIALS: gov, Number: NCT02856763.

Risk of SARS-CoV-2 infection in healthcare workers with inflammatory bowel disease: a case-control study.

Background: Whether healthcare workers with inflammatory bowel disease (IBD) are at increased risk of Novel coronavirus disease (COVID-19) due to occupational exposure is unknown. Aim: To assess the risk of COVID-19 in healthcare workers with IBD. Methods: A case control study enrolled 326 healthcare workers with IBD from 17 GETAID centres and matched non-healthcare workers with IBD controls (1:1) for gender, age, disease subtype and year of diagnosis. The study period was year 2020 during the COVID-19 outbreak. Results: In total, 59 COVID-19 were recorded among cases (n = 32) and controls (n = 27), including 2 severe COVID-19 (requiring hospitalization, mechanic ventilation) but no death. No difference was observed between healthcare workers and controls regarding the overall incidence rates of COVID-19 4.9 ± 2.2 vs. 3.8 ± 1.9 per 100 patient-semesters, P = 0.34) and the overall incidence rates of severe COVID-19 (0.6 ± 7.8 vs. 0.3 ± 5.5 per 100 patient-semesters, P = 0.42). In multivariate analysis in the entire study population, COVID-19 was associated with patients with body mass index > 30 kg/m2 (HR = 2.48, 95%CI [1.13-5.44], P = 0.02). Conclusion: Healthcare workers with IBD do not have an increased risk of COVID-19 compared with other patients with IBD.

Rewiring the altered tryptophan metabolism as a novel therapeutic strategy in inflammatory bowel diseases.

OBJECTIVE: The extent to which tryptophan (Trp) metabolism alterations explain or influence the outcome of inflammatory bowel diseases (IBDs) is still unclear. However, several Trp metabolism end-products are essential to intestinal homeostasis. Here, we investigated the role of metabolites from the kynurenine pathway. DESIGN: Targeted quantitative metabolomics was performed in two large human IBD cohorts (1069 patients with IBD). Dextran sodium sulphate-induced colitis experiments in mice were used to evaluate effects of identified metabolites. In vitro, ex vivo and in vivo experiments were used to decipher mechanisms involved. Effects on energy metabolism were evaluated by different methods including Single Cell mEtabolism by profiling Translation inHibition. RESULTS: In mice and humans, intestinal inflammation severity negatively correlates with the amount of xanthurenic (XANA) and kynurenic (KYNA) acids. Supplementation with XANA or KYNA decreases colitis severity through effects on intestinal epithelial cells and T cells, involving Aryl hydrocarbon Receptor (AhR) activation and the rewiring of cellular energy metabolism. Furthermore, direct modulation of the endogenous tryptophan metabolism, using the recombinant enzyme aminoadipate aminotransferase (AADAT), responsible for the generation of XANA and KYNA, was protective in rodent colitis models. CONCLUSION: Our study identified a new mechanism linking Trp metabolism to intestinal inflammation and IBD. Bringing back XANA and KYNA has protective effects involving AhR and the rewiring of the energy metabolism in intestinal epithelial cells and CD4+ T cells. This study paves the way for new therapeutic strategies aiming at pharmacologically correcting its alterations in IBD by manipulating the endogenous metabolic pathway with AADAT.

Role of adherent and invasive Escherichia coli in Crohn's disease: lessons from the postoperative recurrence model.

OBJECTIVE: We used the postoperative recurrence model to better understand the role of adherent and invasive Escherichia coli (AIEC) bacteria in Crohn's disease (CD), taking advantage of a well-characterised postoperative cohort. DESIGN: From a prospective, multicentre cohort of operated patients with CD, AIEC identification was performed within the surgical specimen (M0) (N=181 patients) and the neoterminal ileum (n=119 patients/181) during colonoscopy performed 6 months after surgery (M6). Endoscopic postoperative recurrence was graded using Rutgeerts' index. The mucosa-associated microbiota was analysed by 16S sequencing at M0 and M6. Relative risks or ORs were adjusted on potential confounders. RESULTS: AIEC prevalence was twofold higher within the neoterminal ileum at M6 (30.3%) than within the surgical specimen (14.9%) (p<0.001). AIEC within the neoterminal ileum at M6 was associated with higher rate of early ileal lesions (i1) (41.6% vs 17.1%; aRR 3.49 (95% CI 1.01 to 12.04), p=0.048) or ileal lesions (i2b+i3) (38.2% vs 17.1%; aRR 3.45 (95% CI 1.06 to 11.30), p=0.040) compared with no lesion (i0). AIEC within the surgical specimen was predictive of higher risk of i2b-endoscopic postoperative recurrence (POR) (aOR 2.54 (95% CI 1.01 to 6.44), p=0.049) and severe endoscopic POR (aOR 3.36 (95% CI 1.25 to 9.06), p=0.017). While only 5.0% (6/119) of the patients were AIEC-positive at both M0 and M6, 43.7% (52/119), patients with history of positive test for AIEC (M0 or M6) had higher risk of ileal endoscopic POR (aOR 2.32 (95% CI 1.01 to 5.39), p=0.048)), i2b-endoscopic postoperative recurrence (aOR 2.41 (95% CI 1.01 to 5.74); p=0.048) and severe endoscopic postoperative (aOR=3.84 (95% CI 1.32 to 11.18), p=0.013). AIEC colonisation was associated with a specific microbiota signature including increased abundance of Ruminococcus gnavus. CONCLUSION: Based on the postoperative recurrence model, our data support the idea that AIEC are involved in the early steps of ileal CD. TRIAL REGISTRATION NUMBER: NCT03458195.

Impact of IBD-Associated Dysbiosis on Bacterial Quorum Sensing Mediated by Acyl-Homoserine Lactone in Human Gut Microbiota.

Intestinal dysbiosis is a key feature in the pathogenesis of inflammatory bowel disease (IBD). Acyl-homoserine lactones (AHL) are bacterial quorum-sensing metabolites that may play a role in the changes in host cells-gut microbiota interaction observed during IBD. The objective of our study was to investigate the presence and expression of AHL synthases and receptor genes in the human gut ecosystem during IBD. We used an in silico approach, applied to the Inflammatory Bowel Disease Multi'omics Database comprising bacterial metagenomic and metatranscriptomic data from stools of patients with Crohn's disease (CD) (n = 50), ulcerative colitis (UC) (n = 27) and non-IBD controls (n = 26). No known putative AHL synthase gene was identified; however, several putative luxR receptors were observed. Regarding the expression of these receptor genes, the luxR gene from Bacteroides dorei was under-expressed in IBD patients (p = 0.02) compared to non-IBD patients, especially in CD patients (p = 0.02). In the dysbiosis situation, one luxR receptor gene from Bacteroides fragilis appeared to be over-expressed (p = 0.04) compared to that of non-dysbiotic patients. Targeting LuxR receptors of bacterial quorum sensing might represent a new approach to modulate the gut microbiota in IBD.

Loss of primary cilia promotes inflammation and carcinogenesis.

Primary cilia (PC) are important signaling hubs, and we here explored their role in colonic pathology. In the colon, PC are mostly present on fibroblasts, and exposure of mice to either chemically induced colitis-associated colon carcinogenesis (CAC) or dextran sodium sulfate (DSS)-induced acute colitis decreases PC numbers. We generated conditional knockout mice with reduced numbers of PC on colonic fibroblasts. These mice show increased susceptibility to CAC, as well as DSS-induced colitis. Secretome and immunohistochemical analyses of DSS-treated mice display an elevated production of the proinflammatory cytokine IL-6 in PC-deficient colons. An inflammatory environment diminishes PC presence in primary fibroblast cultures, which is triggered by IL-6 as identified by RNA-seq analysis together with blocking experiments. These findings suggest an activation loop between IL-6 production and PC loss. An analysis of PC presence on biopsies of patients with ulcerative colitis or colorectal cancer (CRC) reveals decreased numbers of PC on colonic fibroblasts in pathological compared with surrounding normal tissue. Taken together, we provide evidence that a decrease in colonic PC numbers promotes colitis and CRC.

3-oxo-C12:2-HSL, quorum sensing molecule from human intestinal microbiota, inhibits pro-inflammatory pathways in immune cells via bitter taste receptors.

In the gut ecosystem, microorganisms regulate group behaviour and interplay with the host via a molecular system called quorum sensing (QS). The QS molecule 3-oxo-C12:2-HSL, first identified in human gut microbiota, exerts anti-inflammatory effects and could play a role in inflammatory bowel diseases where dysbiosis has been described. Our aim was to identify which signalling pathways are involved in this effect. We observed that 3-oxo-C12:2-HSL decreases expression of pro-inflammatory cytokines such as Interleukine-1ß (- 35%) and Tumor Necrosis Factor-α (TNFα) (- 40%) by stimulated immune RAW264.7 cells and decreased TNF secretion by stimulated PBMC in a dose-dependent manner, between 25 to 100 µM. Transcriptomic analysis of RAW264.7 cells exposed to 3-oxo-C12:2-HSL, in a pro-inflammatory context, highlighted JAK-STAT, NF-κB and TFN signalling pathways and we confirmed that 3-oxo-C12:2-HSL inhibited JAK1 and STAT1 phosphorylation. We also showed through a screening assay that 3-oxo-C12:2-HSL interacted with several human bitter taste receptors. Its anti-inflammatory effect involved TAS2R38 as shown by pharmacologic inhibition and led to an increase in intracellular calcium levels. We thus unravelled the involvement of several cellular pathways in the anti-inflammatory effects exerted by the QS molecule 3-oxo-C12:2-HSL.

Deciphering the Metal Speciation in Low-Molecular-Weight Complexes by IMS-MS: Application to the Detection of Manganese Superoxide Dismutase Mimics in Cell Lysates.

The detection and quantification of exogenous metal complexes are crucial to understanding their activity in intricate biological media. MnII complexes are difficult to detect and quantify because of low association constants, and high lability. The superoxide dismutase (SOD) mimic (or mimetic) labelled Mn1 is based on a 1,2-di-aminoethane functionalized with imidazole and phenolate and has good intrinsic anti-superoxide, antioxidant and anti-inflammatory activities in lipopolysaccharide (LPS)-activated intestinal epithelial HT29-MD2 cells, similar to that of its propylated analogue labelled Mn1P. Ion mobility spectrometry-mass spectrometry (IMS-MS) is a powerful technique for separating low molecular weight (LMW) metal complexes and can even separate complexes with the same ligand but bound to different divalent metal cations with similar ionic radii. We demonstrated the intracellular presence of the Mn1 and Mn1P complexes, at least partly intact, in lysates of cells incubated with the complexes and estimated the intracellular Mn1P concentration using a Co-13 C6 analogue.

Fecal microbiota and bile acids in IBD patients undergoing screening for colorectal cancer.

Due to the potential role of the gut microbiota and bile acids in the pathogenesis of both inflammatory bowel disease (IBD) and sporadic colorectal cancer, we aimed to determine whether these factors were associated with colorectal cancer in IBD patients. 215 IBD patients and 51 non-IBD control subjects were enrolled from 10 French IBD centers between September 2011 and July 2018. Fecal samples were processed for bacterial 16S rRNA gene sequencing and bile acid profiling. Demographic, clinical, endoscopic, and histological outcomes were recorded. Characteristics of IBD patients included: median age: 41.6 (IQR 22); disease duration 13.2 (13.1); 47% female; 21.9% primary sclerosing cholangitis; 109 patients with Crohn's disease (CD); 106 patients with ulcerative colitis (UC). The prevalence of cancer was 2.8% (6/215: 1 CD; 5 UC), high-grade dysplasia 3.7% (8/215) and low-grade dysplasia 7.9% (17/215). Lachnospira was decreased in IBD patients with cancer, while Agathobacter was decreased and Escherichia-Shigella increased in UC patients with any neoplasia. Bile acids were not associated with cancer or neoplasia. Unsupervised clustering identified three gut microbiota clusters in IBD patients associated with bile acid composition and clinical features, including a higher risk of neoplasia in UC in two clusters when compared to the third (relative risk (RR) 4.07 (95% CI 1.6-10.3, P < .01) and 3.56 (95% CI 1.4-9.2, P < .01)). In this multicentre observational study, a limited number of taxa were associated with neoplasia and exploratory microbiota clusters co-associated with clinical features, including neoplasia risk in UC. Given the very small number of cancers, the robustness of these findings will require assessment and validation in future studies.

Prevalence of anti-TNF contraindications in Crohn's disease: A cross-sectional survey from the GETAID.

BACKGROUND: The exact rate of contraindications to anti-TNF therapy and physician perspectives on treatment choices facing to anti-TNF contraindication, are poorly reported. METHODS: A two-week cross-sectional study was conducted in 31 centres. Physicians completed a questionnaire for a total of 1,314 consecutive outpatients with Crohn's disease, assessing each patient's potential contraindications to anti-TNF therapy, the choice of alternative therapy to anti-TNFs, and their preference in an unrestricted reimbursement setting. RESULTS: Among the 1,293 responses to the first item, 148 (11.5%) reported 32 absolute contraindications (2.5%) and 116 relative contraindications (9.0%) to anti-TNF therapy. When asked about their preference of alternative therapies in those cases with contraindications to anti-TNF, physicians chose ustekinumab and vedolizumab, 75.6% and 23.9%, respectively. In multivariable analysis, the choice of vedolizumab was the preferred choice for patients aged > 60 years with the L2 phenotype and the absence of perianal lesions. In a hypothetical setting of unrestricted reimbursement, anti-TNFs remained physicians' preferred first-line biological therapy choice for 78.2%. CONCLUSION: Anti-TNF contraindications occurred in up to 11.5% of patients with Crohn's disease. Physicians' choices for alternative therapy to anti-TNF relied on ustekinumab in 75.6% and vedolizumab in 23.9% of these cases. This choice was driven mainly by phenotypical criteria and age.

Inertness of Superoxide Dismutase Mimics Mn(II) Complexes Based on an Open-Chain Ligand, Bioactivity, and Detection in Intestinal Epithelial Cells.

Oxidative stress is known to play a major role in the pathogenesis of inflammatory bowel diseases (IBDs), and, in particular, superoxide dismutase (SODs) defenses were shown to be weakened in patients suffering from IBDs. SOD mimics, also called SOD mimetics, as low-molecular-weight complexes reproducing the activity of SOD, constitute promising antioxidant catalytic metallodrugs in the context of IBDs. A Mn(II) complex SOD mimic (Mn1) based on an open-chain diaminoethane ligand exerting antioxidant and anti-inflammatory effects on an intestinal epithelial cellular model was shown to experience metal exchanges between the manganese center and metal ions present in the biological environment (such as Zn(II)) to some degrees. As the resulting complexes (mainly Zn(II)) were shown to be inactive, improving the kinetic inertness of Mn(II) complexes based on open-chain ligands is key to improve their bioactivity in a cellular context. We report here the study of three new Mn(II) complexes resulting from Mn1 functionalization with a cyclohexyl and/or a propyl group meant to limit, respectively, (a) metal exchanges and (b) deprotonation of an amine from the 1,2-diaminoethane central scaffold. The new manganese-based SOD mimics display a higher intrinsic SOD activity and also improved kinetic inertness in metal ion exchange processes (with Zn(II), Cu(II), Ni(II), and Co(II)). They were shown to provide anti-inflammatory and antioxidant effects in cells at lower doses than Mn1 (down to 10 µM). This improvement was due to their higher inertness against metal-assisted dissociation and not to different cellular overall accumulations. Based on its higher inertness, the SOD mimic containing both the propyl and the cyclohexyl moieties was suitable for intracellular detection and quantification by mass spectrometry, quantification, that was achieved by using a 13C-labeled Co-based analog of the SOD mimics as an external heavy standard.

Impact of the Ileal Microbiota on Surgical Site Infections in Crohn's Disease: A Nationwide Prospective Cohort.

BACKGROUND AND AIMS: Surgery is performed in 50-70% of Crohn's disease [CD] patients, and its main risk is surgical site infection [SSI]. The microbiota has been extensively assessed in CD but not as a potential risk factor for septic morbidity. The objective of this study was to assess the impact of the gut microbiota on SSI in CD. METHODS: We used the multicentric REMIND prospective cohort to identify all patients who experienced SSI after ileocolonic resection for CD, defined as any postoperative local septic complication within 90 days after surgery: wound abscess, intra-abdominal collection, anastomotic leakage or enterocutaneous fistula. The mucosa-associated microbiota of the ileal resection specimen was analysed by 16S gene sequencing in 149 patients. The variable selection and prediction were performed with random forests [R package VSURF] on clinical and microbiotal data. The criterion of performance that we considered was the area under the Receiver Operating Characteristic [ROC] curve [AUC]. RESULTS: SSI occurred in 24 patients [16.1%], including 15 patients [10.1%] with major morbidity. There were no significant differences between patients with or without SSI regarding alpha and beta diversity. The top selected variables for the prediction of SSI were all microbiota-related. The maximum AUC [0.796] was obtained with a model including 14 genera, but an AUC of 0.78 had already been obtained with a model including only six genera [Hungatella, Epulopiscium, Fusobacterium, Ruminococcaceae_ucg_009, Actinomyces and Ralstonia]. CONCLUSION: The gut microbiota has the potential to predict SSI after ileocolonic resection for CD. It might play a role in this frequent postoperative complication.

Identification of Gene Expression Profiles Associated with an Increased Risk of Post-Operative Recurrence in Crohn's Disease.

BACKGROUND AND AIMS: Ileocolonic resection is frequently needed in the course of Crohn's disease [CD] treatment and post-operative recurrence is extremely common. Our main objective was to analyse gene expression in the mucosa of CD patients at the time of surgery and at post-operative endoscopy, in order to identify predictors and mechanisms of early endoscopic recurrence. METHODS: We conducted transcriptome analyses on ileal mucosa samples collected from inflamed sections of the surgical specimens [n = 200], from ileal resection margins [n = 149] and in the neo-terminal ileum 6 months after surgery [n = 122]; these were compared with non-inflammatory bowel disease controls [n = 25]. The primary endpoint was post-operative endoscopic recurrence at 6 months. We applied regression models to identify gene signatures predicting endoscopic recurrence. RESULTS: Chronic inflammation was associated with strong expression of inflammatory genes [IL-6, IL-8, IL-1B] and decreased expression of genes involved in metabolic processes, but with a high inter-individual heterogeneity. Gene signatures associated with early endoscopic recurrence were mainly characterized by upregulation of TNFα, IFNγ, IL23A and IL17A. Pathway analyses showed that upregulation of mitochondrial dysfunction within the inflamed sections and JAK/STAT at the ileal margin were predictive of post-operative recurrence. A combined model integrating these top pathway signatures improved the prediction of endoscopic recurrence [area under the curve of 0.79]. STAT3 phosphorylation at the surgical ileal margin was associated with severe recurrence at 6 months. CONCLUSION: We identified several biological pathways in surgical ileal mucosa specimens associated with an increased risk of disease recurrence. Integration of the JAK/STAT and mitochondrial dysfunction pathways in the clinical model improved the prediction of post-operative recurrence.

Bariatric Surgery in Patients With Inflammatory Bowel Disease: A Case-Control Study from the GETAID.

BACKGROUND: The prevalence of obesity and the number of bariatric surgeries in both the general population and in patients with inflammatory bowel disease (IBD) have increased significantly in recent years. Due to small sample sizes and the lack of adequate controls, no definite conclusions can be drawn from the available studies on the safety and efficacy of bariatric surgery (BS) in patients with IBD. Our aim was to assess safety, weight loss, and deficiencies in patients with IBD and obesity who underwent BS and compare findings to a control group. METHODS: Patients with IBD and a history of BS were retrospectively recruited to centers belonging to the Groupe d'Etude Thérapeutique des Affections Inflammatoires du Tube Digestif (GETAID). Patients were matched 1:2 for age, sex, body mass index (BMI), hospital of surgery, and type of BS with non-IBD patients who underwent BS. Complications, rehospitalizations, weight, and deficiencies after BS were collected in cases and controls. RESULTS: We included 88 procedures in 85 patients (64 Crohn's disease, 20 ulcerative colitis, 1 unclassified IBD) with a mean BMI of 41.6 ± 5.9 kg/m2. Bariatric surgery included Roux-en-Y gastric bypass (n = 3), sleeve gastrectomy (n = 73), and gastric banding (n = 12). Eight (9%) complications were reported, including 4 (5%) requiring surgery. At a mean follow-up of 34 months, mean weight was 88.6 ± 22.4 kg. No difference was observed between cases and controls for postoperative complications (P = .31), proportion of weight loss (P = .27), or postoperative deficiencies (P = .99). CONCLUSIONS: Bariatric surgery is a safe and effective procedure in patients with IBD and obesity; outcomes in this patient group were similar to those observed in a control population.