Systemic Human ILC Precursors Provide a Substrate for Tissue ILC Differentiation.

Innate lymphoid cells (ILCs) represent innate versions of T helper and cytotoxic T cells that differentiate from committed ILC precursors (ILCPs). How ILCPs give rise to mature tissue-resident ILCs remains unclear. Here, we identify circulating and tissue ILCPs in humans that fail to express the transcription factors and cytokine outputs of mature ILCs but have these signature loci in an epigenetically poised configuration. Human ILCPs robustly generate all ILC subsets in vitro and in vivo. While human ILCPs express low levels of retinoic acid receptor (RAR)-related orphan receptor C (RORC) transcripts, these cells are found in RORC-deficient patients and retain potential for EOMES+ natural killer (NK) cells, interferon gamma-positive (IFN-γ+) ILC1s, interleukin (IL)-13+ ILC2s, and for IL-22+, but not for IL-17A+ ILC3s. Our results support a model of tissue ILC differentiation ("ILC-poiesis"), whereby diverse ILC subsets are generated in situ from systemically distributed ILCPs in response to local environmental signals.

Interobserver agreement of current and new proposed endoscopic scores for postoperative recurrence in Crohn's disease.

BACKGROUND AND AIMS: The modified Rutgeerts score (mRS) is widely used for the assessment of endoscopic postoperative recurrence (ePOR) in Crohn's disease (CD) after ileocolic resection to guide therapeutic decisions. To improve the validity and prognostic value of this endoscopic assessment, 2 new scores have been proposed. This study assessed the interobserver agreement of the current score (mRS) and the new endoscopic score for ePOR in CD. METHODS: Sixteen Dutch academic and nonacademic inflammatory bowel disease specialists assessed endoscopic videos (n = 71) of postoperative CD patients (n = 66) retrieved from 9 Dutch centers. Each video was assessed for degree of inflammation by 4 gastroenterologists using the mRS and the new proposed endoscopic score: the REMIND score (separate score of anastomosis and neoterminal ileum) and the updated Rutgeerts score (assessment of lesions at the anastomotic line, ileal inlet, ileal body, and neoterminal ileum). In addition, lesions at the ileal body, ileal inlet, neoterminal ileum, and colonic and/or ileal blind loop were separately assessed. Interobserver agreement was assessed by using Fleiss' weighted kappa. RESULTS: Fleiss' weighted kappa for the mRS was .67 (95% confidence interval [CI], .59-.74). The weighted kappa for the REMIND score was .73 (95% CI, .65-.80) for lesions in the neoterminal ileum and .46 (95% CI, .35-.58) for anastomotic lesions. The weighted kappa for the updated Rutgeerts score was .69 (95% CI, .62-.77). The weighted kappa for lesions in the ileal body, ileal inlet, neoterminal ileum, and colonic and ileal blind loop was .61 (95% CI, .49-.73), .63 (95% CI, .54-.72), .61 (95% CI, .49-.74), .83 (95% CI, .62-1.00) and .68 (95% CI, .46-.89), respectively. CONCLUSIONS: The interobserver agreement of the mRS is substantial. Similarly, the interobserver agreement is substantial for the updated Rutgeerts score. According to the REMIND score, the interobserver agreement was substantial for lesions in the neoterminal ileum, although only moderate for anastomotic lesions. Because therapeutic decisions in clinical practice are based on these assessments, and these scores are used as outcome measure in clinical studies, further improvement of the interobserver agreement is essential.

Infliximab desensitization in patients with inflammatory bowel diseases: a safe therapeutic alternative.

BACKGROUND: Hypersensitivity reactions (HSR) to the administration of infliximab (IFX) in Inflammatory Bowel Diseases (IBD) patients are not rare and usually lead to drug discontinuation. We report data on safety and effectiveness of desensitization to IFX in patients with previous HSR. METHODS: We conducted a retrospective monocentric observational study. Patients for whom a desensitization protocol to IFX was realized after a previous HSR were included. Anti-drug antibodies (ADA) and IFX trough levels at both inclusion and six months after desensitization were collected. Clinical outcomes, including recurrence of HSR were evaluated. RESULTS: From 2005 to 2020, 27 patients (Crohn's Disease: 26 (96%) were included). Desensitization after HSR was performed after a median time of 10.4 months (2.9-33.1). Nineteen (70%) patients received immunosuppressants at time of desensitization. Eight (30%) patients presented HSR at first (n = 2), second (n = 4) or third (n = 2) IFX perfusion after desensitization. None led to intensive care unit transfer or death. Thirteen (48%) had clinical response at 6 months and 8 (29%) were still under IFX treatment two years after desensitization. IFX trough levels and ADA were available for 14 patients at time of desensitization. Most patients (12 out of 14) had ADA at a high level. At 6 months, among the 7 patients with long term response to IFX, 4 presented a decrease of ADA titers and 2 had a significant trough level of IFX. CONCLUSION: IFX desensitization in patients with IBD is a safe therapeutic alternative and represents a potential option for patients refractory to multiple biologics.What is already known? Hypersensitivity reactions to the administration of infliximab is frequent. Occurrence of hypersensitivity reaction, either immediate or delayed, usually leads to permanent drug discontinuation.What is new here? Infliximab desensitization is well tolerated with no hypersensitivity reaction recurrence in 70% of patients. Clinical success at 6 months was of 48% and around a third of patients remained under infliximab therapy two years after desensitization. Antidrug antibodies decreased and infliximab trough levels increased in these patients showing the impact of desensitization on immunogenicity.How can this study help patient care? Infliximab desensitization represents a potential option for patients refractory to multiple biologics who presented hypersensitivity reaction to the drug.

Distinct blood protein profiles associated with the risk of short-term and mid/long-term clinical relapse in patients with Crohn's disease stopping infliximab: when the remission state hides different types of residual disease activity.

OBJECTIVE: Despite being in sustained and stable remission, patients with Crohn's disease (CD) stopping anti-tumour necrosis factor α (TNFα) show a high rate of relapse (~50% within 2 years). Characterising non-invasively the biological profiles of those patients is needed to better guide the decision of anti-TNFα withdrawal. DESIGN: Ninety-two immune-related proteins were measured by proximity extension assay in serum of patients with CD (n=102) in sustained steroid-free remission and stopping anti-TNFα (infliximab). As previously shown, a stratification based on time to clinical relapse was used to characterise the distinct biological profiles of relapsers (short-term relapsers: <6 months vs mid/long-term relapsers: >6 months). Associations between protein levels and time to clinical relapse were determined by univariable Cox model. RESULTS: The risk (HR) of mid/long-term clinical relapse was specifically associated with a high serum level of proteins mainly expressed in lymphocytes (LAG3, SH2B3, SIT1; HR: 2.2-4.5; p<0.05), a low serum level of anti-inflammatory effectors (IL-10, HSD11B1; HR: 0.2-0.3; p<0.05) and cellular junction proteins (CDSN, CNTNAP2, CXADR, ITGA11; HR: 0.4; p<0.05). The risk of short-term clinical relapse was specifically associated with a high serum level of pro-inflammatory effectors (IL-6, IL12RB1; HR: 3.5-3.6; p<0.05) and a low or high serum level of proteins mainly expressed in antigen presenting cells (CLEC4A, CLEC4C, CLEC7A, LAMP3; HR: 0.4-4.1; p<0.05). CONCLUSION: We identified distinct blood protein profiles associated with the risk of short-term and mid/long-term clinical relapse in patients with CD stopping infliximab. These findings constitute an advance for the development of non-invasive biomarkers guiding the decision of anti-TNFα withdrawal.

Autologous T cell responses to primary human colorectal cancer spheroids are enhanced by ectonucleotidase inhibition.

OBJECTIVE: T cells are major effectors of the antitumoural immune response. Their activation by tumour-associated antigens can unleash their proliferation and cytotoxic functions, leading to tumour cell elimination. However, tumour-related immunosuppressive mechanisms including the overexpression of immune checkpoints like programmed cell death protein-1 (PD-1), are also engaged, promoting immune escape. Current immunotherapies targeting these pathways have demonstrated weak efficacy in colorectal cancer (CRC). It is thus crucial to find new targets for immunotherapy in this cancer type. DESIGN: In a prospective cohort of patients with CRC, we investigated the phenotype of tumour-related and non-tumour related intestinal T cells (n=44), particularly the adenosinergic pathway, correlating with clinical phenotype. An autologous coculture model was developed between patient-derived primary tumour spheroids and their autologous tumour-associated lymphocytes. We used this relevant model to assess the effects of CD39 blockade on the antitumour T cell response. RESULTS: We show the increased expression of CD39, and its co-expression with PD-1, on tumour infiltrating T cells compared with mucosal lymphocytes. CD39 expression was higher in the right colon and early-stage tumours, thus defining a subset of patients potentially responsive to CD39 blockade. Finally, we demonstrate in autologous conditions that CD39 blockade triggers T cell infiltration and tumour spheroid destruction in cocultures. CONCLUSION: In CRC, CD39 is strongly expressed on tumour infiltrating lymphocytes and its inhibition represents a promising therapeutic strategy for treating patients.

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.

Ustekinumab versus adalimumab for induction and maintenance therapy in biologic-naive patients with moderately to severely active Crohn's disease: a multicentre, randomised, double-blind, parallel-group, phase 3b trial.

BACKGROUND: Active-comparator trials are important to inform patient and physician choice. We aimed to evaluate the efficacy and safety of monotherapy with either ustekinumab or adalimumab in biologic-naive patients with moderately to severely active Crohn's disease. METHODS: We conducted a randomised, double-blind, parallel-group, active-comparator, phase 3b trial (SEAVUE) at 121 hospitals or private practices in 18 countries. We included biologic-naive patients aged 18 years or older with moderately to severely active Crohn's disease and a Crohn's Disease Activity Index (CDAI) score of 220-450, who had not responded to or were intolerant to conventional therapy (or were corticosteroid dependent) and had at least one ulcer of any size at baseline endoscopic evaluation. Eligible patients were randomly assigned (1:1; via an interactive web response system) to receive ustekinumab (approximately 6 mg/kg intravenously on day 0, then 90 mg subcutaneously once every 8 weeks) or adalimumab (160 mg on day 0, 80 mg at 2 weeks, then 40 mg once every 2 weeks, subcutaneously) through week 56. Study treatments were administered as monotherapy and without dose modifications. Patients, investigators, and study site personnel were masked to treatment group assignment. The primary endpoint was the proportion of patients who were in clinical remission (CDAI score <150) at week 52 in the intention-to-treat population (ie, all patients who were randomly assigned to a treatment group). This trial is registered with ClinicalTrials.gov, NCT03464136, and EudraCT, 2017-004209-41. FINDINGS: Between June 28, 2018, and Dec 12, 2019, 633 patients were assessed for eligibility and 386 were enrolled and randomly assigned to receive ustekinumab (n=191) or adalimumab (n=195). 29 (15%) of 191 patients in the ustekinumab group and 46 (24%) of 195 in the adalimumab group discontinued study treatment before week 52. There was no significant difference between the ustekinumab and adalimumab groups in the occurrence of the primary endpoint; at week 52, 124 (65%) of 191 patients in the ustekinumab group versus 119 (61%) of 195 in the adalimumab group were in clinical remission (between-group difference 4%, 95% CI -6 to 14; p=0·42). Safety for both groups was consistent with previous reports. Serious infections were reported in four (2%) of 191 patients in the ustekinumab group and five (3%) of 195 in the adalimumab group. No deaths occurred through week 52 of the study. INTERPRETATION: Both ustekinumab and adalimumab monotherapies were highly effective in this population of biologic-naive patients, with no difference in the primary outcome between the drugs. FUNDING: Janssen Scientific Affairs.

CORE-IBD: A Multidisciplinary International Consensus Initiative to Develop a Core Outcome Set for Randomized Controlled Trials in Inflammatory Bowel Disease.

BACKGROUND & AIMS: End points to determine the efficacy and safety of medical therapies for Crohn's disease (CD) and ulcerative colitis (UC) are evolving. Given the heterogeneity in current outcome measures, harmonizing end points in a core outcome set for randomized controlled trials is a priority for drug development in inflammatory bowel disease. METHODS: Candidate outcome domains and outcome measures were generated from systematic literature reviews and patient engagement surveys and interviews. An iterative Delphi process was conducted to establish consensus: panelists anonymously voted on items using a 9-point Likert scale, and feedback was incorporated between rounds to refine statements. Consensus meetings were held to ratify the outcome domains and core outcome measures. Stakeholders were recruited internationally, and included gastroenterologists, colorectal surgeons, methodologists, and clinical trialists. RESULTS: A total of 235 patients and 53 experts participated. Patient-reported outcomes, quality of life, endoscopy, biomarkers, and safety were considered core domains; histopathology was an additional domain for UC. In CD, there was consensus to use the 2-item patient-reported outcome (ie, abdominal pain and stool frequency), Crohn's Disease Activity Index, Simple Endoscopic Score for Crohn's Disease, C-reactive protein, fecal calprotectin, and co-primary end points of symptomatic remission and endoscopic response. In UC, there was consensus to use the 9-point Mayo Clinic Score, fecal urgency, Robarts Histopathology Index or Geboes Score, fecal calprotectin, and a composite primary end point including both symptomatic and endoscopic remission. Safety outcomes should be reported using the Medical Dictionary for Regulatory Activities. CONCLUSIONS: This multidisciplinary collaboration involving patients and clinical experts has produced the first core outcome set that can be applied to randomized controlled trials of CD and UC.

Serious immune-related upper gastrointestinal toxicity of immune checkpoint inhibitors: a multicenter case series.

BACKGROUND: Immune checkpoint inhibitors (ICI) improve the prognosis of many cancers but cause immune-related adverse events (IrAEs). Limited data are available on upper gastrointestinal (UGI) IrAEs. We describe the clinical characteristics, prognosis, and efficacy of medical therapy in patients with UGI IrAEs. METHODS: This is a retrospective, multicenter cohort study of patients with UGI symptoms and moderate to severe endoscopic UGI lesions, occurring after ICI. Efficacy of induction medical therapy and at the most recent follow-up was assessed. RESULTS: Forty patients were included; of these, 34 (85%) received anti-PD(L)1, either alone (n = 24) or combined with anti CTLA-4 (n = 10). Eighteen patients (45%) had concomitant enterocolitis. All patients had severe endoscopic lesions (erosions, ulcerations, hemorrhage, or necrotic lesions). Three patients who received an inefficient initial medical treatment had a complicated course: One patient died of enterocolitis, one had a pneumomediastinum, and one developed an ulcerated stricture of the pylorus. Thirty-five patients (88%) were treated with corticosteroids; 28 patients (80%) responded, and 20 (57%) reached clinical remission. Eight patients were treated with infliximab, and six responded (75%). After a median follow-up of 11 months, 36 patients (90%) were in corticosteroid-free clinical remission for their UGI symptoms. Endoscopic lesions persisted in 68% of patients. CONCLUSIONS: ICI cause severe UGI IrAEs, which are associated with enterocolitis in approximately half of the patients. Most patients with UGI IrAEs respond to corticosteroids or infliximab. These data support the recommendation to treat these patients without delay and in the same way as those with enterocolitis.

Steroid-Free Deep Remission at One Year Does Not Prevent Crohn's Disease Progression: Long-Term Data From the TAILORIX Trial.

BACKGROUND & AIMS: Crohn's disease (CD) patients included in the Tailored Treatment With Infliximab for Active Crohn's Disease (TAILORIX) trial started infliximab in combination with an immunosuppressant for 1 year. The aim of the present study was to determine the long-term disease course beyond the study period. METHODS: We compared the outcomes of patients who did or did not reach the primary end point of the TAILORIX trial, defined as sustained corticosteroid-free clinical remission from weeks 22 through 54, with no ulcers on ileocolonoscopy at week 54. The primary outcome of this follow-up study was the progression-free survival of CD defined by anal or major abdominal surgery, CD-related hospitalization, or the need for a new systemic CD treatment. RESULTS: The 95 patients (median disease duration, 4.5 mo; interquartile range, 1.0-56.6 mo) analyzed, including 45 (47%) who achieved the primary end point, were followed up for a median duration of 64.2 months (interquartile range, 57.6-69.9 mo) after the end of the study period. There was no significant difference in CD progression-free survival at 1, 3, and 5 years between patients who achieved the TAILORIX primary end point and patients who did not (P = .64). No difference was observed between both groups for each component of CD progression: anal surgery, major abdominal surgery, CD-related hospitalization, or the need for a new systemic CD treatment. CONCLUSIONS: Achieving a sustained clinical remission off steroids with complete endoscopic remission in this cohort of 95 patients with early CD was not associated with less disease progression. Prospective trials to define the therapeutic goals that change the natural history of CD and prevent complications are needed.

IOIBD Recommendations for Clinical Trials in Ulcerative Proctitis: The PROCTRIAL Consensus.

BACKGROUND & AIMS: Clinical trials evaluating biologics and small molecules in patients with ulcerative colitis are predominantly excluding ulcerative proctitis. The objective of the Definition and endpoints for ulcerative PROCtitis in clinical TRIALs initiative was to develop consensus statements for definitions, inclusion criteria, and endpoints for the evaluation of ulcerative proctitis in adults. METHODS: Thirty-five international experts held a consensus meeting to define ulcerative proctitis, and the endpoints to use in clinical trials. Based on a systematic review of the literature, statements were generated, discussed, and approved by the working group participants using a modified Delphi method. Consensus was defined as at least 75% agreement among voters. RESULTS: The group agreed that the diagnosis of ulcerative proctitis should be made by ileocolonoscopy and confirmed by histopathology, with the exclusion of infections, drug-induced causes, radiation, trauma, and Crohn's disease. Ulcerative proctitis was defined as macroscopic extent of lesions limited to 15 cm distance from the anal verge in adults. Primary and secondary endpoints were identified to capture response of ulcerative proctitis to therapy. A combined clinical and endoscopic primary endpoint for the evaluation of ulcerative proctitis disease activity was proposed. Secondary endpoints that should be evaluated include endoscopic remission, histologic remission, mucosal healing, histologic endoscopic mucosal improvement, disability, fecal incontinence, urgency, constipation, and health-related quality of life. CONCLUSIONS: In response to the need for guidance on the design of clinical trials in patients with ulcerative proctitis, the Definition and end points for ulcerative PROCtitis in clinical TRIALs consensus provides recommendations on the definition and endpoints for ulcerative proctitis clinical trials.

Efficacy and Safety of Infliximab Retreatment in Crohn's Disease: A Multicentre, Prospective, Observational Cohort (REGAIN) Study from the GETAID.

INTRODUCTION: The objective of this study was to describe the efficacy and safety of infliximab (IFX) reintroduction in Crohn's disease (CD) after stopping for loss of response or intolerance. METHODS: We conducted a prospective multicenter observational cohort study including adult patients with clinically (CD Activity Index >150) and objectively active luminal CD in whom IFX was reintroduced after at least 6 months of discontinuation. The reasons for the initial discontinuation could be a secondary loss of response or IFX intolerance. The reintroduction schedule included 3 IFX infusions at weeks 0, 4, and 8, after a systematic premedication. The primary end point was the efficacy of IFX retreatment at week 26 defined by a CD Activity Index of <150 in the absence of IFX discontinuation or use of corticosteroids, surgery, or other biologic. RESULTS: At week 26, 24 patients (35%) among the 69 analyzed reached the primary end point. No significant difference was observed between rates of clinical remission at week 26 in patients with prior LOR (n = 48) and those with IFX intolerance (n = 21) (35% and 33%, P = 0.87, respectively). Thirty-two acute infusion reactions were recorded in 27 patients, leading to withdrawal of IFX in 20 patients. No pharmacokinetic characteristic at baseline but detection of positive anti-drug antibodies at week 4 was predictive of IFX failure or infusion reaction at week 26. DISCUSSION: In this first prospective cohort study, IFX retreatment was safe and effective in one-third of the patients with CD, regardless the reason of prior discontinuation. Early detection of anti-drug antibodies can predict subsequent IFX reintroduction failure and infusion reactions.

Comparative real-world effectiveness of vedolizumab and ustekinumab for patients with ulcerative colitis: a GETAID multicentre cohort study.

INTRODUCTION: There are currently no comparative data on the efficacy and safety of vedolizumab and ustekinumab in ulcerative colitis (UC) after anti-TNF therapy fails. METHODS: We retrieved the full datasets of two observational, multicentre, retrospective studies of patients with UC for whom anti-TNF therapy failed and the patients were then treated with either vedolizumab or ustekinumab. The outcomes included steroid-free clinical remission, clinical remission, treatment persistence, colectomy, hospitalization, and serious and infectious adverse events. Propensity scores weighted comparison was applied. RESULTS: In total, 121 patients were included in the vedolizumab group and 97 were included in the ustekinumab group. At week 14 and week 52, in the weighted cohort, no difference was found between vedolizumab and ustekinumab for steroid-free clinical remission (OR = 0.55 [0.21-1.41], p = .21 and 0.94 [0.40-2.22], p = .89, respectively). There was no difference between vedolizumab and ustekinumab for secondary outcomes such as clinical remission, hospitalization, UC-related surgery, treatment persistence and serious and infectious adverse events. CONCLUSION: In patients with UC for whom anti-TNF therapy failed, no difference was found between vedolizumab and ustekinumab after propensity scores weighted comparison. Further studies are required to determine predictive factors of the efficacy of both biological agents.

Evolution of Endoscopic Lesions in Steroid-Refractory Acute Severe Ulcerative Colitis Responding to Infliximab or Cyclosporine.

BACKGROUND/AIMS: Few data on the evolution of endoscopic findings are available in patients with acute severe ulcerative colitis (ASUC). The aim of this study was to describe this evolution in a prospective cohort. METHODS: Patients admitted for a steroid-refractory ASUC and included in a randomized trial comparing infliximab and cyclosporine were eligible if they achieved steroid-free clinical remission at day 98. Flexible sigmoidoscopies were performed at baseline, days 7, 42 and 98. Ulcerative colitis endoscopic index of severity (UCEIS) and its sub-scores - vascular pattern, bleeding and ulceration/erosion - were post-hoc calculated. Global endoscopic remission was defined by a UCEIS of 0, and partial endoscopic remission by any UCEIS sub-score of 0. RESULTS: Among the 55 patients analyzed (29 infliximab and 26 cyclosporine), 49 (83%) had UCEIS ≥6 at baseline at baseline. Partial endoscopic remission rates were higher for bleeding than for vascular pattern and for ulcerations/erosions at day 7 (20% vs. 4% and 5% (n = 55); p = .004 and p=.04), for bleeding and ulceration/erosion than for vascular pattern at day 42 [63% and 65% vs. 33% (n=54); p<.001 for both] and at day 98 [78% and 92% vs. 56% (n = 50); p = .007 and p < .001]. Global endoscopic remission rates at day 98 were higher in patients treated with infliximab than with cyclosporine [73% vs. 25% (n = 26 and 24); p < .001]. CONCLUSION: In steroid-refractory ASUC patients responding to a second-line medical therapy, endoscopic remission process started with bleeding remission and was not achieved in half the patients at day 98 for vascular pattern. Infliximab provided a higher endoscopic remission rate than cyclosporine at day 98.

Long-term efficacy of fibrin glue injection for perianal fistulas in patients with Crohn's disease.

AIM: The treatment of perianal fistulas in Crohn's disease remains challenging. Fibrin glue injection has previously shown short-term efficacy in a randomized controlled trial. No long-term data are available to assess the benefit of this treatment. METHODS: This retrospective multicentre study included all patients with drained fistulas treated by at least one fibrin glue injection between January 2004 and June 2015 in three tertiary French centres. The primary end-point was the rate of complete clinical remission at 1 year after injection defined by the closure of all fistula tracts with no need for iterative anal surgery or for optimization of immunosuppressants and/or biologics. RESULTS: In all, 119 patients (median age 33 years, complex fistulas 65%, median previous anal surgery two, median Harvey Bradshaw score 3, immunosuppressants exposure 50%, anti-tumor necrosis factor exposure 60% with median time of administration of 1.1 year) were analysed with a median follow-up of 18.3 months. The complete clinical remission rate at 1 year was 45.4%. The primary end-point was achieved in 63% of the cases in the combination therapy group and 37% in other patients. The only predictor of complete clinical remission at 1 year was combination therapy at the time of injection (P = 0.01). The rate of early reintervention after glue injection was 2.5%. The cumulative incidence of iterative anal surgery and ostomy in the whole population was 54% and 5.6% respectively at 5 years. CONCLUSION: An adjunct of fibrin glue to conventional medical therapy may be an effective and safe treatment for perianal fistulas in patients with Crohn's disease.

Mitochondrial impairment drives intestinal stem cell transition into dysfunctional Paneth cells predicting Crohn's disease recurrence.

OBJECTIVE: Reduced Paneth cell (PC) numbers are observed in inflammatory bowel diseases and impaired PC function contributes to the ileal pathogenesis of Crohn's disease (CD). PCs reside in proximity to Lgr5+ intestinal stem cells (ISC) and mitochondria are critical for ISC-renewal and differentiation. Here, we characterise ISC and PC appearance under inflammatory conditions and describe the role of mitochondrial function for ISC niche-maintenance. DESIGN: Ileal tissue samples from patients with CD, mouse models for mitochondrial dysfunction (Hsp60Δ/ΔISC) and CD-like ileitis (TNFΔARE), and intestinal organoids were used to characterise PCs and ISCs in relation to mitochondrial function. RESULTS: In patients with CD and TNFΔARE mice, inflammation correlated with reduced numbers of Lysozyme-positive granules in PCs and decreased Lgr5 expression in crypt regions. Disease-associated changes in PC and ISC appearance persisted in non-inflamed tissue regions of patients with CD and predicted the risk of disease recurrence after surgical resection. ISC-specific deletion of Hsp60 and inhibition of mitochondrial respiration linked mitochondrial function to the aberrant PC phenotype. Consistent with reduced stemness in vivo, crypts from inflamed TNFΔARE mice fail to grow into organoids ex vivo. Dichloroacetate-mediated inhibition of glycolysis, forcing cells to shift to mitochondrial respiration, improved ISC niche function and rescued the ability of TNFΔARE mice-derived crypts to form organoids. CONCLUSION: We provide evidence that inflammation-associated mitochondrial dysfunction in the intestinal epithelium triggers a metabolic imbalance, causing reduced stemness and acquisition of a dysfunctional PC phenotype. Blocking glycolysis might be a novel drug target to antagonise PC dysfunction in the pathogenesis of CD.

Prominence of ileal mucosa-associated microbiota to predict postoperative endoscopic recurrence in Crohn's disease.

OBJECTIVE: Following ileal resection for Crohn's disease (CD), recurrence is very frequent. Although several clinical risk factors of recurrence have been identified, predicting relapse remains challenging. Performing an ileocolonoscopy within the first year after surgery is currently recommended to assess endoscopic recurrence and to adjust the treatment. We took advantage of a large prospective multicentric cohort to investigate the role of the ileal mucosa-associated microbiota in postoperative endoscopic recurrence. PATIENTS AND METHODS: Ileal mucosa-associated microbiota was analysed by 16S sequencing at the time of surgery and/or of endoscopic evaluation in 201 patients (288 samples in total) prospectively recruited in France. RESULTS: Ileal mucosa-associated microbiota exhibits profound changes following surgery in CD. Compared with non-recurrence setting, endoscopic recurrence is associated with strong changes in ileal mucosa-associated microbiota that are highly reminiscent of those observed generally in ileal CD compared with healthy subjects with a reduction in alpha diversity, an increase in several members of the Proteobacteria phylum and a decrease in several members of the Lachnospiraceae and the Ruminococcaceae families within the Firmicutes phylum. At the time of surgery, we identified several bacterial taxa associated with endoscopic recurrence and that can better predict relapse than usual clinical risk factors. CONCLUSION: Surgery has an important impact on ileal mucosa-associated microbiota. Postoperative endoscopic recurrence is associated with changes in microbiota composition and alpha diversity. The gut microbiota has the potential to predict postoperative evolution and recurrence.

The role of integrins in the pathogenesis of inflammatory bowel disease: Approved and investigational anti-integrin therapies.

Inflammatory bowel disease (IBD) is characterized by uncontrolled inflammation in the gastrointestinal tract. The underlying pathobiology of IBD includes an increase in infiltrating gut-homing lymphocytes. Although lymphocyte homing is typically a tightly regulated and stepwise process involving multiple integrins and adhesion molecules expressed on endothelial cells, the distinct roles of integrin-expressing immune cells is not fully understood in the pathology of IBD. In this review, we detail the involvement of integrins expressed on specific lymphocyte subsets in the pathogenesis of IBD and discuss the current status of approved and investigational integrin-targeted therapies.

Association Between Microscopic Lesions at Ileal Resection Margin and Recurrence After Surgery in Patients With Crohn's Disease.

BACKGROUND AND AIMS: Different types of histologic lesions at the ileal margin, detected by histology, have been associated with increased rates of recurrence after ileocaecal surgery in patients with Crohn's disease (CD). We aimed to characterize histologic features of the ileal margin and to evaluate their association with disease recurrence. METHODS: We collected histologic data from 211 patients with ileal or ileocolonic CD who underwent ileocolonic resections at hospitals in France from September 2010 through December 2016. Ileal margins were analyzed. Early endoscopic recurrence was defined by a Rutgeerts score of i2 or more, 6 months after surgery. We also collected data from 10 adults with healthy ileum who underwent ileocecal resection for colonic tumors (controls). Clinical relapse was defined by CD-related symptoms confirmed by imaging, endoscopy, therapy intensification, CD-related complication, or subsequent surgery. RESULTS: Six months after surgery, 49% of patients had endoscopic recurrence; 5 years after surgery, 57% of patients had clinical relapse. Ileal margins were macroscopically affected in 20.9% of patients. CD transmural lesions at the margin (defined by mucosal ulceration or cryptitis, submucosal fibrosis and lymphoplasmacytic infiltrate of the subserosa) were observed in 13.6% of patients. Endoscopic recurrence was observed in 75% of patients with CD transmural lesions vs 46% of patients without (P =.005). In multivariate analysis, CD transmural lesions at the margin were independently associated with early endoscopic recurrence (OR, 3.83; 95% CI, 1.47-11.05; P =.008) and clinical recurrence (OR 2.04; 95% CI, 1.09-3.99; P =.026). CONCLUSION: In patients with CD, transmural lesions at the ileal margin were associated with an increased risk of post-operative recurrence. Histologic features of the ileal margin should be included in making decisions about post-operative therapy.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (second edition).

These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.