Single-Cell Analysis of Crohn's Disease Lesions Identifies a Pathogenic Cellular Module Associated with Resistance to Anti-TNF Therapy.

Clinical benefits of cytokine blockade in ileal Crohn's disease (iCD) are limited to a subset of patients. Here, we applied single-cell technologies to iCD lesions to address whether cellular heterogeneity contributes to treatment resistance. We found that a subset of patients expressed a unique cellular module in inflamed tissues that consisted of IgG plasma cells, inflammatory mononuclear phagocytes, activated T cells, and stromal cells, which we named the GIMATS module. Analysis of ligand-receptor interaction pairs identified a distinct network connectivity that likely drives the GIMATS module. Strikingly, the GIMATS module was also present in a subset of patients in four independent iCD cohorts (n = 441), and its presence at diagnosis correlated with failure to achieve durable corticosteroid-free remission upon anti-TNF therapy. These results emphasize the limitations of current diagnostic assays and the potential for single-cell mapping tools to identify novel biomarkers of treatment response and tailored therapeutic opportunities.

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.

Neutralizing Anti-Granulocyte Macrophage-Colony Stimulating Factor Autoantibodies Recognize Post-Translational Glycosylations on Granulocyte Macrophage-Colony Stimulating Factor Years Before Diagnosis and Predict Complicated Crohn's Disease.

BACKGROUND & AIMS: Anti-granulocyte macrophage-colony stimulating factor autoantibodies (aGMAbs) are detected in patients with ileal Crohn's disease (CD). Their induction and mode of action during or before disease are not well understood. We aimed to investigate the underlying mechanisms associated with aGMAb induction, from functional orientation to recognized epitopes, for their impact on intestinal immune homeostasis and use as a predictive biomarker for complicated CD. METHODS: We characterized using enzyme-linked immunosorbent assay naturally occurring aGMAbs in longitudinal serum samples from patients archived before the diagnosis of CD (n = 220) as well as from 400 healthy individuals (matched controls) as part of the US Defense Medical Surveillance System. We used biochemical, cellular, and transcriptional analysis to uncover a mechanism that governs the impaired immune balance in CD mucosa after diagnosis. RESULTS: Neutralizing aGMAbs were found to be specific for post-translational glycosylation on granulocyte macrophage-colony stimulating factor (GM-CSF), detectable years before diagnosis, and associated with complicated CD at presentation. Glycosylation of GM-CSF was altered in patients with CD, and aGMAb affected myeloid homeostasis and promoted group 1 innate lymphoid cells. Perturbations in immune homeostasis preceded the diagnosis in the serum of patients with CD presenting with aGMAb and were detectable in the noninflamed CD mucosa. CONCLUSIONS: Anti-GMAbs predict the diagnosis of complicated CD long before the diagnosis of disease, recognize uniquely glycosylated epitopes, and impair myeloid cell and innate lymphoid cell balance associated with altered intestinal immune homeostasis.

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.

No Difference of Adalimumab Pharmacokinetics When Dosed at 40 mg Every Week or 80 mg Every Other Week in IBD Patients in Clinical Remission After Adalimumab Dose Intensification.

INTRODUCTION: The pharmacokinetic equivalence of dose intensification with adalimumab (ADA) 80 mg every other week (EOW) compared to weekly 40 mg has only been supported by modeling systems. AIM OF THE STUDY: To compare the trough levels of ADA (TLA) and the occurrence of anti-ADA antibodies (AAA) between these two treatment regimens. PATIENTS AND METHODS: This was a prospective study including all consecutive patients with inflammatory bowel disease (IBD) who had reached a longstanding and deep remission under treatment with ADA 40 mg once a week. In these patients, the ADA regimen was changed from 40 mg/week to 80 mg EOW. TLA and AAA levels using a drug-tolerant assay were monitored before and ten weeks after from the change in the ADA regimen and the results compared by a Wilcoxon paired test. RESULTS: Sixty-two patients (60% CD, mean age 35 years) were included. Before and ten weeks after the changes of ADA regimen, the median TLA were (6.9 µg/mL versus 7.0 µg/mL, respectively; P = 0.34) and the AAA levels (3.4 µg/ml-eq versus 3.0 µg/ml-eq, respectively; P = 0.25.) were quite similar. Likewise, quartiles of TLA (Kendall test r = 0.91; P < 0.001) and AAA (r = 0.78; P < 0.001) did not differ before and after ADA regimen. When stratifying all the patients into 4 groups based on drug/antibody levels (immunogenic, subtherapeutic, therapeutic, or supratherapeutic), no patient needed for returning to the previous weekly regimen. In terms of acceptability, more than 60% of patients preferred an injection EOW compared once a week. CONCLUSIONS: In IBD patients who achieved a deep clinical remission under ADA 40 mg once a week, the pharmacokinetic of ADA was similar when ADA regimen was changed to 80 mg EOW. Given the patient's preference for the latter regimen, a modification of injection regimen should be systematically proposed.

Low Levels of Fecal Calprotectin 3 Months After Surgery Predict Subsequent Endoscopic Postoperative Remission in Crohn's Disease.

BACKGROUND/AIMS: In Crohn's disease (CD) few data are available on the usefulness of monitoring fecal calprotectin (FC) in the early postoperative setting. We assessed prospectively the accuracy of FC measured 3 months after surgery to predict the risk of endoscopic postoperative recurrence (POR) within 1 year after resection. METHODS: In 55 consecutive CD patients who had undergone ileocolonic resection samples were collected 3 months after surgery for measuring serum CRP and FC. Endoscopic POR was assessed by ileocolonoscopy within 6-12 months (median 7 months). Receiver operating characteristic (ROC) curves were generated to assess accuracy of the markers, to determine the best threshold and to calculate sensitivity, specificity, positive and negative predictive values. RESULTS: In contrast with median CRP levels, median FC concentrations measured 3 months after surgery were significantly higher in patients who later experienced endoscopic POR (Rutgeerts ≥ i2) compared with those who stayed in endoscopic remission within the following 6-12 months (205 µg/g IQR [106-721] vs. 103 µg/g IQR [60-219], p = 0.008). Area under the ROC curve for FC was 0.71. The best cutoff value of FC to identify patients in subsequent endoscopic remission 3 months after surgery was 65 µg/g (96% sensitivity, 31% specificity, 50% positive and 91% negative predictive values). In multivariate analysis, FC < 65 µg/g at 3 months was the only factor associated with subsequent endoscopic remission. CONCLUSION: FC measured 3 months after surgery below 65 µg/g is an accurate marker to identify CD patients who will later stay in endoscopic remission within 1 year after resection.

Addition of azathioprine to the switch of anti-TNF in patients with IBD in clinical relapse with undetectable anti-TNF trough levels and antidrug antibodies: a prospective randomised trial.

OBJECTIVES: In patients with IBD experiencing an immune-mediated loss of response (LOR) to antitumour necrosis factor (anti-TNF), algorithms recommend a switch of anti-TNF without immunosuppressive drug. The aim of our study was to compare in these patients two strategies: either switch to a second anti-TNF alone or with addition of azathioprine (AZA). After randomisation outcomes (time to clinical and pharmacokinetic failure) were compared between the two groups during a 2-year follow-up period. DESIGN: Consecutive IBD patients in immune-mediated LOR to a first optimised anti-TNF given in monotherapy were randomised to receive either AZA or nothing with induction by a second anti-TNF in both arms. Clinical failure was defined for Crohn's disease (CD) as a Harvey-Bradshaw index ≥5 associated with a faecal calprotectin level >250 µg/g stool and for UC as a Mayo score >5 with endoscopic subscore >1 or as the occurrence of adverse events requiring to stop treatment. Unfavourable pharmacokinetics of the second anti-TNF were defined by the appearance of undetectable trough levels of anti-TNF with high antibodies (drug-sensitive assay) or by that of antibodies (drug-tolerant assay). RESULTS: Ninety patients (48 CDs) were included, and 45 of them received AZA after randomisation. The second anti-TNF was adalimumab or infliximab in 40 and 50 patients, respectively. Rates of clinical failure and occurrence of unfavourable pharmacokinetics were higher in monotherapy compared with combination therapy (p<0.001; median time of clinical failure since randomisation 18 vs >24 months). At 24 months, survival rates without clinical failure and without appearance of unfavourable pharmacokinetics were respectively 22 versus 77% and 22% versus 78% (p<0.001 for both) in monotherapy versus combination therapy. Only the use of combination therapy was associated with favourable outcomes after anti-TNF switch. CONCLUSION: In case of immune-mediated LOR to a first anti-TNF, AZA should be associated with the second anti-TNF. TRIAL REGISTRATION NUMBER: 03580876.

Postoperative Endoscopic Recurrence on the Neoterminal Ileum But Not on the Anastomosis Is Mainly Driving Long-Term Outcomes in Crohn's Disease.

INTRODUCTION: Early ileocolonoscopy within the first year after surgery is the gold standard to evaluate recurrence after ileocolonic resection for Crohn's disease (CD). The aim of the study was to evaluate the association between the presence and severity of anastomotic and ileal lesions at early postoperative ileocolonoscopy and long-term outcomes. METHODS: The REMIND group conducted a prospective multicenter study. Patients operated for ileal or ileocolonic CD were included. An ileocolonoscopy was performed 6 months after surgery. An endoscopic score describing separately the anastomotic and ileal lesions was built. Clinical relapse was defined by the CD-related symptoms, confirmed by imaging, endoscopy or therapeutic intensification; CD-related complications; or subsequent surgery. RESULTS: Among 225 included patients, long-term follow-up was available in 193 (median follow-up: 3.82 years [interquartile range: 2.56-5.41]). Median clinical recurrence-free survival was 47.6 months. Clinical recurrence-free survival was significantly shorter in patients with ileal lesions at early postoperative endoscopy whatever their severity was (I(1) or I(2,3,4)) as compared to patients without ileal lesions (I(0)) (I(0) vs I(2,3,4): P = 0.0003; I(0) vs I(1): P = 0.0008 and I(1) vs I(2,3,4): P = 0.43). Patients with exclusively ileal lesions (A(0)I(1,2,3,4)) had poorer clinical long-term outcomes than patients with exclusively anastomotic lesions (A(1,2,3)I(0)) (P = 0.009). DISCUSSION: A score describing separately the anastomotic and ileal lesions might be more appropriate to define postoperative endoscopic recurrence. Our data suggest that patients with ileal lesions, including mild ones (I(1)), could beneficiate from treatment step-up to improve long-term outcomes.

Concentrations of Ustekinumab During Induction Therapy Associate With Remission in Patients With Crohn's Disease.

Ustekinumab is approved for treatment of Crohn's disease (CD).1,2 Few data are available to assess the usefulness of monitoring inflammatory biomarkers and therapeutic drug monitoring to predict response to ustekinumab. We conducted a prospective study to assess the relationships between these parameters and the clinical outcome at week 16 in active CD patients receiving ustekinumab.

Usefulness of confocal laser endomicroscopy for predicting postoperative recurrence in patients with Crohn's disease: a pilot study.

BACKGROUND AND AIMS: Confocal laser endomicroscopy (CLE) has been shown to predict relapse in inflammatory bowel disease, but its value in the detection of postoperative recurrence in Crohn's disease (CD) is unknown. The aims of this pilot study performed in patients with CD after ileocolonic resection were to compare the macroscopic appearance of the neoterminal ileum, according to the endoscopic Rutgeerts score, with the microscopic findings provided by CLE 6 to 12 months after surgery and to assess the predictive values of CLE-generated parameters for predicting further recurrence in patients with postoperative endoscopic remission. METHODS: In 25 consecutive patients with CD within 6 to 12 months of surgery, the neoterminal ileum was examined by standard white-light endoscopy (Rutgeerts scale) followed by CLE (Watson grade). Only patients without endoscopic recurrence (Rutgeerts i0 and i1) were then followed endoscopically and clinically (median follow-up 38 months). RESULTS: At the time of the first postoperative colonoscopy, 18 patients (72%) were in endoscopic remission, and 7 (28%) experienced an endoscopic recurrence (Rutgeerts ≥i2). The Rutgeerts score was significantly correlated with the Watson score (ρ = 0 .73; P < .0001). The Watson scores at baseline were significantly higher in patients with further endoscopic recurrence (median 2.0; interquartile range [IQR] 1.5-2.0) than in those with endoscopic remission (median 1.0; IQR 1.0-1.0; P = .032) and were significantly higher in patients with clinical relapse (medium 2.0, IQR 2.0-2.0) compared with those in clinical remission (median 1.0; IQR 1.0-1.0; P = .036). CONCLUSIONS: CLE could be useful in monitoring patients with CD after intestinal resection. Further studies with a larger population are necessary to confirm these preliminary results.

Intestinal dendritic cell licensing through Toll-like receptor 4 is required for oral tolerance in allergic contact dermatitis.

BACKGROUND: Induction of oral tolerance to haptens is an efficient way to prevent allergic contact dermatitis (ACD) in mice. Toll-like receptor (TLR)-mediated sensing of the microbiota contributes to gut homeostasis, yet whether it contributes to induction of oral tolerance has not been documented. OBJECTIVE: We examined whether oral tolerance to the contact sensitizer 2,4-dinitro-fluorobenzene (DNFB) depends on microbiota/TLRs and evaluated the role of TLR4 on the tolerogenic function of intestinal dendritic cells (DCs). METHODS: Oral tolerance was induced by DNFB gavage in germ-free and mice deficient in several TLRs. Tolerance was assessed by means of suppression of contact hypersensitivity and hapten-specific IFN-γ-producing effector T cells. The tolerogenic function of intestinal DCs was tested by adoptive transfer experiments, ex vivo hapten presentation, and forkhead box p3 regulatory T-cell conversion. RESULTS: Oral tolerance induced by DNFB gavage was impaired in germ-free mice and TLR4-deficient mice. Bone marrow chimeras revealed that TLR4 expression on hematopoietic cells was necessary for oral tolerance induction. TLR4 appeared to be essential for the ability of intestinal dendritic cells from DNFB-fed mice to inhibit ACD on adoptive transfer. Indeed, TLR4 conditioned the in vivo mobilization to mesenteric lymph nodes of intestinal migratory CD103+ DCs carrying oral DNFB, especially the CD103+CD11b+ DC subset expressing the vitamin A-converting enzyme retinaldehyde dehydrogenase and specialized in forkhead box p3-positive regulatory T-cell conversion. CONCLUSIONS: Our data demonstrate that TLR4 conditions induction of oral tolerance to DNFB through licensing tolerogenic gut DCs. Oral biotherapy with TLR4 ligands might be useful to potentiate oral tolerance to haptens and alleviate ACD in human subjects.

Efficacy and Safety of Infliximab Tolerance Induction in Patients with Inflammatory Bowel Diseases who Experienced Acute Infusion Reactions.

BACKGROUND AND AIMS: One of the reasons for the failure of infliximab (IFX) is immediate hypersensitivity reactions (IHR). We aimed to report the efficacy and safety of a tolerance induction protocol in inflammatory bowel diseases (IBD) patients who had previously experienced IHR during IFX infusions. PATIENTS AND METHODS: We reported all cases of IBD patients who had previously experienced IHR due to IFX and who were submitted to a standardized protocol of tolerance induction to IFX from 2010 to 2015. RESULTS: IHR occurred in a majority of patients (69%) during the first 3 infusions and for half of them after a period of IFX withdrawn. Skin prick tests were negative and only 2 intradermal tests were positive. Basophil activation tests and antidrug antibody measurements were performed in 8 out of 16 patients and were positive in 3 and 4 patients respectively. Induction of tolerance was successful in 69% of patients and IFX was pursued with clinical efficacy > 1 year in 7 patients (44%). Allergologic investigations were not predictive of tolerance induction success. CONCLUSION: A majority of IHR to IFX infusions occurred during the beginning or restarting of treatment and was related to a nonallergic hypersensitivity. Induction of tolerance to IFX is feasible and effective and may safely allow retreatment of IFX in almost 70% of IBD patients.

A Perioperative Clinical Pathway Can Dramatically Reduce Failure-to-rescue Rates After Cytoreductive Surgery for Peritoneal Carcinomatosis: A Retrospective Study of 666 Consecutive Cytoreductions.

OBJECTIVE: To determine whether a perioperative, standardized clinical pathway could impact the failure-to-rescue rate after cytoreductive surgery (CRS) for peritoneal carcinomatosis (PC) in a tertiary center. SUMMARY OF BACKGROUND DATA: Morbidity and mortality remain significant after CRS for PC. Clinical pathways have been associated with better outcomes after surgery. The failure-to-rescue rate is a useful metric for evaluating quality in surgery. MATERIALS AND METHODS: This study included 666 patients that received CRS for PC between 2009 and 2014. Starting in 2012, a standardized perioperative clinical pathway was introduced, which focused on patient selection, nutrition, renal protection, pain management, prevention, and early detection of complications. Complications were evaluated with the National Cancer Institute's Common Terminology Criteria for Adverse Events. We used multivariate analyses to evaluate clinicopathological and perioperative factors for associations with major complications and failure-to-rescue. Complication rates were compared before and after the clinical pathway implementation. RESULTS: Major complications occurred in 341 patients (51%), leading to 15 deaths. The complication rate was similar before and after clinical pathway introduction (54.75% vs 48.9%, respectively; P = 0.138). Only prolonged surgery (longer than 240 mins) was independently associated with major complications. The failure-to-rescue rate was 4.4% for the entire period, but it significantly decreased after introducing the clinical pathway (9.02% vs 1.02%; P < 0.001). On multivariate analysis, only renal complications were associated with the failure-to-rescue. CONCLUSION: Morbidity after CRS remains significant, but standardized management facilitated a reduction in the failure-to-rescue rate and improved the quality of care. Specific effort should be dedicated to preventing postoperative renal failure.

Mouse and Human Liver Contain Immunoglobulin A-Secreting Cells Originating From Peyer's Patches and Directed Against Intestinal Antigens.

BACKGROUND & AIMS: The liver receives blood from the gastrointestinal tract through the portal vein, and thereby is exposed continuously to dietary antigens and commensal bacteria. Alcoholic liver disease (ALD) is associated with intestinal dysbiosis, increased intestinal permeability, release of microbes into the portal circulation, and increased serum levels and liver deposits of IgA. We characterized B-cell production of IgA in livers of mice at homeostasis, after oral immunization, in a mouse model of ALD and in human liver samples. METHODS: We performed studies with Balb/c and C57BL/6-Ly5.1 mice, as well as transgenic mice (quasimonoclonal, activation-induced [cytidine] deaminase-Cre-tamoxifen-dependent estrogen receptor 2 [ERT2], Blimp-1-green fluorescent protein [GFP]). C57BL/6-Ly5.1 mice were fed chronic plus binge ethanol to create a model of ALD. Some mice also were given repeated injections of FTY720, which prevents egress of IgA-secreting cells from Peyer's patches. We obtained nontumor liver tissues from patients with colorectal carcinoma undergoing surgery for liver metastases or hepatocellular carcinoma. B cells were isolated from mouse and human liver tissues and analyzed by flow cytometry and enzyme-linked ImmunoSpot (ELISpot). In wild-type and transgenic mice, we traced newly generated IgA-secreting cells at steady state and after oral immunization with 4-hydroxy-3-nitrophenylacetyl (NP)-Ficoll or cholera toxin. IgA responses were also evaluated in our model of ALD. RESULTS: Livers of control mice contained proliferative plasmablasts that originated from Peyer's patches and produced IgAs reactive to commensal bacteria. After oral immunization with cholera toxin or a thymus-independent antigen, a substantial number of antigen-specific IgA-secreting cells was found in the liver. Mice fed ethanol had features of hepatitis and increased numbers of IgA-secreting cells in liver, compared with mice given control diets, as well as higher levels of serum IgA and IgA deposits in liver sinusoids. Injection of FTY720 during ethanol feeding reduced liver and serum levels of IgA and IgA deposits in liver and prevented liver injury. Human liver tissues contained a significant proportion of IgA-producing plasma cells that shared phenotypic and functional attributes with those from mouse liver, including reactivity to commensal bacteria. CONCLUSIONS: Based on studies of mice and human liver tissues, we found the liver to be a site of IgA production by B cells, derived from gut-associated lymphoid tissues. These IgAs react with commensal bacteria and oral antigens. Livers from mice with ethanol-induced injury contain increased numbers of IgA-secreting cells and have IgA deposits in sinusoids. IgAs in the liver could mediate clearance of gut-derived antigens that arrive through portal circulation at homeostasis and protect these organs from pathogens.

Association Between Low Trough Levels of Vedolizumab During Induction Therapy for Inflammatory Bowel Diseases and Need for Additional Doses Within 6 Months.

BACKGROUND & AIMS: We investigated whether serum trough levels of vedolizumab, a humanized monoclonal antibody against integrin α4ß7, during the induction phase of treatment can determine whether patients will need additional doses (optimization of therapy) within the first 6 months. METHODS: We conducted an observational study of 47 consecutive patients with Crohn's disease (CD; n = 31) or ulcerative colitis (UC; n = 16) who had not responded to 2 previous treatment regimens with antagonists of tumor necrosis factor and were starting therapy with vedolizumab at 2 hospitals in France, from June 2014 through April 2016. All patients were given a 300-mg infusion of vedolizumab at the start of the study, Week 2, Week 6, and then every 8 weeks; patients were also given corticosteroids during the first 4-6 weeks. Patients not in remission at Week 6 were given additional doses of vedolizumab at Week 10 and then every 4 weeks (extended therapy or optimization). Remission at Week 6 of treatment was defined as CD activity score below 150 points for patients with CD and a partial Mayo Clinic score of <3 points, without concomitant corticosteroids, for patients with UC. Blood samples were collected each week and serum levels of vedolizumab and antibodies against vedolizumab were measured using an enzyme-linked immunosorbent assay. Median trough levels of vedolizumab and interquartile ranges were compared using the nonparametric Mann-Whitney test. The primary objective was to determine whether trough levels of vedolizumab measured during the first 6 weeks of induction therapy associated with the need for extended treatment within the first 6 months. RESULTS: Based on response to therapy at Week 6, extended treatment was required for 30 of the 47 patients (23 patients with CD and 7 patients with UC). At Week 2, trough levels of vedolizumab for patients selected for extended treatment were 23.0 µg/mL (interquartile range, 14.0-37.0 µg/mL), compared with 42.5 µg/mL in patients who did not receive extended treatment (interquartile range, 33.5-50.7; P = .15). At Week 6, trough levels of vedolizumab <18.5 µg/mL were associated with need for extended therapy (100% positive predictive value, 46.2%; negative predictive value; area under the receiver operating characteristic curve, 0.72) within the first 6 months. Among patients who required extended treatment at Week 10, all of those with trough levels of vedolizumab <19.0 µg/mL at Week 6 had achieved clinical remission 4 weeks later (secondary responders). CONCLUSIONS: In a prospective study of patients with CD or UC receiving induction therapy with vedolizumab, low trough levels of vedolizumab at Week 6 (<19.0 µg/mL) are associated with need for additional doses (given at Week 10 and then every 4 weeks). All patients receiving these additional doses achieved a clinical response 4 weeks later.

Plasmacytoid dendritic cells are dispensable for noninfectious intestinal IgA responses in vivo.

Intestinal DCs orchestrate gut immune homeostasis by dampening proinflammatory T-cell responses and inducing anti-inflammatory IgA responses. Although no specific DC subset has been strictly assigned so far to govern IgA response, some candidate subsets emerge. In particular, plasmacytoid DCs (pDCs), which notoriously promote anti-viral immunity and T-cell tolerance to innocuous antigens (Ags), contribute to IgA induction in response to intestinal viral infection and promote T-cell-independent IgA responses in vitro. Here, using two transgenic mouse models, we show that neither short-term nor long-term pDC depletion alters IgA class switch recombination in Peyer's patches and frequency of IgA plasma cells in intestinal mucosa at steady state, even in the absence of T-cell help. In addition, pDCs are dispensable for induction of intestinal IgA plasma cells in response to oral immunization with T-cell-dependent or T-cell-independent Ags, and are not required for proliferation and IgA switch of Ag-specific B cells in GALT. These results show that pDCs are dispensable for noninfectious IgA responses, and suggest that various DC subsets may play redundant roles in the control of intestinal IgA responses.

Postoperative Complications after Ileocecal Resection in Crohn's Disease: A Prospective Study From the REMIND Group.

OBJECTIVES: We sought to determine the frequency of and risk factors for early (30-day) postoperative complications after ileocecal resection in a well-characterized, prospective cohort of Crohn's disease patients. METHODS: The REMIND group performed a nationwide study in 9 French university medical centers. Clinical-, biological-, surgical-, and treatment-related data on the 3 months before surgery were collected prospectively. Patients operated on between 1 September 2010 and 30 August 2014 were included. RESULTS: A total of 209 patients were included. The indication for ileocecal resection was stricturing disease in 109 (52%) cases, penetrating complications in 88 (42%), and medication-refractory inflammatory disease in 12 (6%). A two-stage procedure was performed in 33 (16%) patients. There were no postoperative deaths. Forty-three (21%) patients (23% of the patients with a one-stage procedure vs. 9% of those with a two-stage procedure, P=0.28) experienced a total of 54 early postoperative complications after a median time interval of 5 days (interquartile range, 4-12): intra-abdominal septic complications (n=38), extra-intestinal infections (n=10), and hemorrhage (n=6). Eighteen complications (33%) were severe (Dindo-Clavien III-IV). Reoperation was necessary in 14 (7%) patients, and secondary stomy was performed in 8 (4.5%). In a multivariate analysis, corticosteroid treatment in the 4 weeks before surgery was significantly associated with an elevated postoperative complication rate (odds ratio (95% confidence interval)=2.69 (1.15-6.29); P=0.022). Neither preoperative exposure to anti-tumor necrosis factor (TNF) agents (n=93, 44%) nor trough serum anti-TNF levels were significant risk factors for postoperative complications. CONCLUSIONS: In this large, nationwide, prospective cohort, postoperative complications were observed after 21% of the ileocecal resections. Corticosteroid treatment in the 4 weeks before surgery was significantly associated with an elevated postoperative complication rate. In contrast, preoperative anti-TNF therapy (regardless of the serum level or the time interval between last administration and surgery) was not associated with an elevated risk of postoperative complications.

Isolated ileitis associated with primary sclerosing cholangitis in three patients with Crohn's disease.

BACKGROUND: Primary sclerosing cholangitis (PSC) is associated with ulcerative colitis and extensive colonic involvement or ileocolitis in Crohn's disease (CD). To our knowledge, no specific report of isolated ileitis associated with PSC in CD patients has been published in CD patients. AIM AND METHODS: We report three cases of patients with isolated Crohn's ileitis associated with PSC and in whom colonic inflammation was never documented. RESULTS: Patients were followed up 10-23 years and each patient underwent 6-7 ileocolonoscopies: inflammation was located only in the terminal ileum, which was confirmed on surgical specimens in two patients. Small-duct PSC led to diagnosis of CD ileitis in one patient, while small and large-ducts PSC were evidenced after CD diagnosis in the other 2. PSC were regularly followed for 9-10 years. CONCLUSIONS: Our three cases of PSC with isolated CD ileitis and long-term follow-up without any sign of colonic involvement argue against the concept that colonic mucosal inflammation is critical for the pathogenesis of PSC in inflammatory bowel disease.

Levels of Fecal Calprotectin Are Associated With the Severity of Postoperative Endoscopic Recurrence in Asymptomatic Patients With Crohn's Disease.

OBJECTIVES: Fecal calprotectin (fCal) is widely used as marker of gut inflammation and is strongly associated with the severity of endoscopic lesions in Crohn's disease (CD). We analyzed the relationships between levels of fCal and high-sensitivity C-reactive protein (hsCRP) and the presence and severity of postoperative endoscopic recurrence in asymptomatic CD patients (Harvey-Bradshaw index≤3). METHODS: Blood and fecal samples were collected in consecutive asymptomatic CD patients (Harvey-Bradshaw index 0.85 ± 0.19, mean ± s.e.m.) who had undergone an ileocolonic resection. hsCRP and fCal were measured and a routine ileocolonoscopy was performed within 18 months (median 7 months) from resection, to detect endoscopic recurrence according to the Rutgeerts score. RESULTS: Eighty-six patients were included in this prospective multicenter observational cohort. fCal concentrations differed significantly in patients with endoscopic recurrence when compared with those in endoscopic remission (mean ± s.e.m.: 473 ± 78 µg/g vs. 115 ± 18 µg/g; P<0.0001). The area under the receiver operating characteristic (ROC) curve to discriminate between patients in endoscopic remission and recurrence was 0.86 for fCal and lower for hsCRP (0.70). The best cutoff point for fCal to distinguish between endoscopic remission and recurrence was 100 µg/g as determined by the ROC curve, and its sensitivity, specificity, positive and negative predictive values (NPVs), as well as overall accuracy were 95%, 54%, 69%, 93%, and 77%, respectively. CONCLUSION: Measurement of fCal concentrations is a promising and useful tool for monitoring asymptomatic CD patients after ileocolonic resection. Taking into account the high NPV of fCal, a threshold below 100 µg/g could avoid systematic ileocolonoscopies in 30% of patients from this population.

GRECCAR 8: impact on survival of the primary tumor resection in rectal cancer with unresectable synchronous metastasis: a randomized multicentre study.

BACKGROUND: A majority of patients with rectal cancer and metastasis are not eligible to curative treatment because of an extensive and unresectable metastatic disease. Primary tumor resection is still debated in this situation. Rectal surgery treats or prevents the symptoms and avoids the risk of acute complications related to the primary tumor. Several studies on colorectal cancers seem to show interesting results in terms of survival in favor to the resection of the primary tumor. To date, no randomized trial or even a prospective study has assessed the impact of primary tumor resection on overall survival in patients with colorectal cancer with unresectable metastasis. All published studies were retrospective and included colon and rectal cancers. Rectal cancer is associated with specific problems related to the rectal surgery. Surgery is more complex, and may be source of more morbidity and postoperative functional dysfunctions (stoma, digestive, sexual, urinary) than colic surgery. On the other hand, symptoms related to the progression of rectal tumor are often very disabling: pain, rectal syndrome. METHODS/DESIGN: GRECCAR 8 is a multicentre randomized open-label controlled trial aimed to evaluate the impact on survival of the primary tumor resection in rectal cancer with unresectable synchronous metastasis. Patients must undergo upfront systemic chemotherapy for at least 4 courses before inclusion. Patients with progressive metastatic disease during upfront chemotherapy will be excluded from the study. Patients will be randomly assigned in a 1:1 ratio to Arm A: primary tumor resection followed by systemic chemotherapy versus Arm B: systemic chemotherapy alone. Primary endpoint will be overall survival measured from the date of randomization to the date of death or to the end of follow-up (2 years). Secondary endpoints will include progression-free survival, quality of life, toxicity of chemotherapy, response of the primary tumor and metastatic disease to chemotherapy, postoperative morbidity and mortality, rate of patient not eligible for postoperative chemotherapy (arm A), primary tumor related complications and rate of emergency surgery (arm B). The number of patients needed is 290. TRIAL REGISTRATION: ClinicalTrial.gov: NCT02314182.