Validation and Update of the Lémann Index to Measure Cumulative Structural Bowel Damage in Crohn's Disease.

BACKGROUND & AIMS: The Lémann Index is a tool measuring cumulative structural bowel damage in Crohn's disease (CD). We reported on its validation and updating. METHODS: This was an international, multicenter, prospective, cross-sectional observational study. At each center, 10 inclusions, stratified by CD duration and location, were planned. For each patient, the digestive tract was divided into 4 organs, upper tract, small bowel, colon/rectum, anus, and subsequently into segments, explored systematically by magnetic resonance imaging and by endoscopies in relation to disease location. For each segment, investigators retrieved information on previous surgical procedures, identified predefined strictures and penetrating lesions of maximal severity (grades 1-3) at each organ investigational method (gastroenterologist and radiologist for magnetic resonance imaging), provided segmental damage evaluation ranging from 0.0 to 10.0 (complete resection). Organ resection-free cumulative damage evaluation was then calculated from the sum of segmental damages. Then investigators provided a 0-10 global damage evaluation from the 4-organ standardized cumulative damage evaluations. Simple linear regressions of investigator damage evaluations on their corresponding Lémann Index were studied, as well as calibration plots. Finally, updated Lémann Index was derived through multiple linear mixed models applied to combined development and validation samples. RESULTS: In 15 centers, 134 patients were included. Correlation coefficients between investigator damage evaluations and Lémann Indexes were >0.80. When analyzing data in 272 patients from both samples and 27 centers, the unbiased correlation estimates were 0.89, 0,97, 0,94, 0.81, and 0.91 for the 4 organs and globally, and stable when applied to one sample or the other. CONCLUSIONS: The updated Lémann Index is a well-established index to assess cumulative bowel damage in CD that can be used in epidemiological studies and disease modification trials.

Infliximab Exposure Associates With Radiologic Evidence of Healing in Patients With Crohn's Disease.

BACKGROUND & AIMS: Higher infliximab trough levels are associated with clinical and endoscopic remission in patients with Crohn's disease (CD). We investigated pharmacodynamic features of infliximab and radiological healing. METHODS: We performed a substudy of the TAILORIX trial (patients with active luminal CD in Europe, treated with infliximab), analyzing baseline and week 54 magnetic resonance enterography (MRE) data. MREs were scored using the MaRIA score by blinded central readers. Radiologic response and remission were defined, based on MaRIA criteria in all segments, as scores below 11 and 7, respectively. We collected data on infliximab trough levels, biomarkers, and endoscopic findings. Our primary aim was to evaluate pharmacodynamic features associated with radiologic response and remission, based on MRE assessments at baseline and at 54 weeks after initiation of infliximab therapy. RESULTS: We analyzed data from 36 patients (50% female; median age 35.7 years; interquartile age range, 25.6-48.6 years; median disease duration, 1.5 months; interquartile duration range, 0.6-22.4 months). At week 54 of treatment, 36.4% of patients had a radiologic response, 30.3% of patients were in remission, and 71% had endoscopic features of remission. At baseline, there was a correlation between the CD endoscopic index of severity and MaRIA scores (κ = 0.46; P = .008), but we found no correlation at week 54 (κ = 0.06; P = .75). Radiologic remission correlated with infliximab trough level at week 14 (P = .049) when the infliximab trough level cut-off value was set at 7.8 µg/mL (area under the curve, 0.74; 75% sensitivity; 86% specificity; 90% negative predictive value; 57% positive predictive value). Radiologic response correlated with infliximab trough levels at week 14 (P = .048) when the infliximab trough level cut-off value was set at 7.8 µg/mL (area under the curve, 0.73; 70% sensitivity; 90% specificity; 86% negative predictive value; 78% positive predictive value) and with continuous pharmacologic evidence of response (infliximab trough levels above 5.0 µg/mL at all time points) (P = .034). CONCLUSIONS: In a substudy of data from the TAILORIX trial of patients with active luminal CD, we identified a relationship between exposure to infliximab and radiologic evidence of outcomes.

Deep Remission at 1 Year Prevents Progression of Early Crohn's Disease.

BACKGROUND & AIMS: We investigated the effects of inducing deep remission in patients with early Crohn's disease (CD). METHODS: We collected follow-up data from 122 patients (mean age, 31.2 ± 11.3 y) with early, moderate to severe CD (median duration, 0.2 years; interquartile range, 0.1-0.5) who participated in the Effect of Tight Control Management on CD (CALM) study, at 31 sites, representing 50% of the original CALM patient population. Fifty percent of patients (n = 61) were randomly assigned to a tight control strategy (increased therapy based on fecal level of calprotectin, serum level of C-reactive protein, and symptoms), and 50% were assigned to conventional management. We categorized patients as those who were vs were not in deep remission (CD endoscopic index of severity scores below 4, with no deep ulcerations or steroid treatment, for 8 or more weeks) at the end of the follow-up period (median, 3.02 years; range, 0.05-6.26 years). The primary outcome was a composite of major adverse outcomes that indicate CD progression during the follow-up period: new internal fistulas or abscesses, strictures, perianal fistulas or abscesses, or hospitalization or surgery for CD. Kaplan-Meier and penalized Cox regression with bootstrapping were used to compare composite rates between patients who achieved or did not achieve remission at the end of the follow-up period. RESULTS: Major adverse outcomes were reported for 34 patients (27.9%) during the follow-up period. Significantly fewer patients in deep remission at the end of the CALM study had major adverse outcomes during the follow-up period (P = .01). When we adjusted for potential confounders, deep remission (adjusted hazard ratio, 0.19; 95% confidence interval, 0.07-0.31) was significantly associated with a lower risk of major adverse outcome. CONCLUSIONS: In an analysis of follow-up data from the CALM study, we associated induction of deep remission in early, moderate to severe CD with decreased risk of disease progression over a median time of 3 years, regardless of tight control or conventional management strategy.

Location but Not Severity of Endoscopic Lesions Influences Endoscopic Remission Rates in Crohn's Disease: A Post Hoc Analysis of TAILORIX.

INTRODUCTION: The impact of severity and location of Crohn's disease (CD) endoscopic ulcers on endoscopic remission in patients treated with antitumor necrosis factor is poorly known. We aimed to describe the endoscopic evolution of CD lesions in a prospective cohort of patients treated with infliximab (IFX) in combo therapy. METHODS: We conducted a post hoc analysis of the TAILORIX randomized controlled trial, which studied biologic-naïve patients with active CD and endoscopic ulcers receiving IFX combo therapy. Ileocolonoscopies were performed at week 0, 12, and 54. Endoscopic healing was defined as the absence of ulcers and complete endoscopic remission as CD Endoscopic Index of Severity (CDEIS) <3. Ileocolonic segments were scored separately for remission by blinded readers. RESULTS: A total of 122 (median disease duration: 7 months) patients were included, corresponding with 379 diseased segments. The median (IQR) CDEIS scores at week 0, 12, and 54 were 9.9 (6.1-14.4), 2.4 (0.2-4.6), and 0.2 (0.0-3.7), respectively. At weeks 12 and 54, the rates of endoscopic healing and complete endoscopic remission were 41% and 61% and 61% and 73%, respectively. Median CDEIS scores were similar among patients with deep ulcers at baseline and those with only superficial ulcers at week 12 and 54. Segmental remission rates were lower both at week 12 and 54 in the ileum compared with colonic segments (P < 0.01 all comparisons) and in the rectum (P = 0.02 and P = 0.03). DISCUSSION: In biologic-naive patients with CD treated with IFX combo therapy, the severity of endoscopic lesions at the baseline did not influence healing rates. Endoscopic remission occurs less frequently in the ileum compared with the colon.

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.

Systematic Review and External Validation of Prediction Models Based on Symptoms and Biomarkers for Identifying Endoscopic Activity in Crohn's Disease.

BACKGROUND & AIMS: Endoscopic healing, an important target of treatment for Crohn's disease (CD), requires ileocolonoscopy, which is costly and burdensome. We investigated whether published noninvasive models (based on symptoms and biomarkers) to evaluate CD activity have sufficient accuracy to replace ileocolonoscopy. METHODS: We performed a systematic review of published noninvasive diagnostic models to evaluate CD activity that used endoscopic features of activity (endoscopic activity) or healing as the reference standard. We externally validated these models for the outcome endoscopic activity (CD endoscopic index of severity scores, ≥3) using data from the a randomized controlled trial investigating tailored treatment with infliximab for active luminal Crohn's disease (TAILORIX) study (346 ileocolonoscopies in 155 patients) and the Utrecht Activity Index (UAI) study (93 ileocolonoscopies in 82 patients). We calculated the area under the receiver operating characteristic curves (AUROCs) for the models using data from these studies, and compared the performance of these models against measurements of fecal calprotectin (FC) and C-reactive protein (CRP). RESULTS: We screened 5303 articles and identified 27 models (from 21 studies) for our analysis. Seven models could be validated externally; in the TAILORIX data set, these models identified patients with endoscopic activity with AUROC values ranging from 0.61 (95% CI, 0.51-0.70) to 0.81 (95% CI, 0.76-0.86). In this data set, the AUROC value for FC concentration was 0.79 (95% CI, 0.74-0.85) and the AUROC value for CRP level was 0.72 (95% CI, 0.66-0.77). The AUROC values for the validation in the UAI data set were similar. In the TAILORIX and/or UAI data set, 4 of the 7 models, as well as the FC and CRP assays, were able to identify patients with endoscopic activity with positive predictive values of 90% or more. Two of the 7 models (but not the FC or CRP values) identified patients without endoscopic activity with a negative predictive value (NPV) of 90% or more, leading to correct prediction of endoscopic healing in 3.2% to 11.3% of all patients. For example, applying the Herranz-Bachiller model (1 of 7 models) at a NPV of 92.1% and a positive predictive value of 91.9% correctly identified 35.7% of all patients in whom ileocolonoscopy could be avoided for expected endoscopic activity or healing but incorrectly identified 3.2% of all patients. Most ileocolonoscopies (66.5% in TAILORIX and 72.6% in the UAI of all ileocolonoscopies) could be avoided correctly based on concentrations of FC of 100 µg/g or less and 250 µg/g or higher. However, using this range of FC concentrations to identify patients who do not require ileocolonoscopy caused 18.7% of all patients in the TAILORIX cohort and 19.8% of all patients in the UAI cohort to be predicted incorrectly to have endoscopic activity or healing. CONCLUSIONS: In a systematic review and external validation of noninvasive models to identify patients with endoscopic activity of CD, we found only 2 of 7 models evaluated to have NPVs of 90% or more, however, leading to correctly predicted EH in only a small proportion of patients. Ileocolonoscopy therefore remains the mainstay to evaluate CD mucosal disease activity and healing.

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.

Monitoring a Combination of Calprotectin and Infliximab Identifies Patients With Mucosal Healing of Crohn's Disease.

BACKGROUND & AIMS: In the TAILORIX trial, no benefit could be shown by infliximab dose escalation based on pharmacokinetic (infliximab serum concentrations) and pharmacodynamic (biomarkers and symptoms) monitoring compared with dose escalation based on symptoms alone in patients with Crohn's disease (CD). We investigated whether integration of pharmacokinetic and pharmacodynamic monitoring can be used to evaluate responses to infliximab induction and maintenance therapy, based on findings from endoscopy. METHODS: We performed a post hoc analysis of patients with CD included in a trial to test the effects of infliximab dose escalation, based on biomarkers and serum concentrations of infliximab, on symptoms (the Study Investigating Tailored Treatment With Infliximab for Active Crohn's Disease trial; n = 122). We analyzed data from this study to determine whether concentrations of biomarkers and serum concentrations of infliximab were associated with endoscopic outcomes (n = 116). The primary end points were endoscopic response (CD endoscopic index of severity decrease ≥50% from baseline), endoscopic remission (CD endoscopic index of severity, <3), and absence of ulcers at weeks 12 and 54 of infliximab treatment. RESULTS: Infliximab trough concentrations greater than 23.1 mg/L at week 2 and greater than 10.0 mg/L at week 6 were associated with endoscopic remission at week 12 (positive predictive values, 72% and 76%; negative predictive values, 65% and 59%, respectively). During maintenance therapy, we found evidence for an exposure-response relationship only after dose escalation; trough concentrations greater than 10.6 mg/L were associated with the absence of ulcers at week 54 (positive predictive value, 49%; negative predictive value, 92%). Low fecal concentrations of calprotectin during therapy were associated with endoscopic response and remission (P < .05). Dose escalations increased trough concentrations of infliximab; persistent increase in fecal concentration of calprotectin, despite dose escalation, was associated with a lack of endoscopic response and remission. A significantly higher proportion of patients with antibodies to infliximab, identified by a drug-tolerant assay, dropped out of the study compared with patients without antibodies (P < .0001). CONCLUSIONS: In a post hoc analysis of data from a trial to test the effects of infliximab dose escalation on symptoms, we found that during maintenance therapy, the combination of fecal concentration of calprotectin and trough concentration of infliximab can guide dose adjustment and increase the chances for endoscopic response and remission. ClinicalTrialsRegister.eu EudraCT no: 2011-003038-14.

Efficacy of Tumor Necrosis Factor Antagonist Treatment in Patients With Refractory Ulcerative Proctitis.

BACKGROUND & AIMS: It is a challenge to manage patients with ulcerative proctitis (UP) refractory to standard therapy. We investigated the effectiveness of tumor necrosis factor (TNF) antagonists in a large cohort of patients with refractory UP. METHODS: We conducted a nationwide retrospective cohort study of 104 consecutive patients with active UP refractory to conventional therapies, treated at 1 of 15 centers in France or 1 center in Belgium (the GETAID cohort). Patients received at least 1 injection of anti-TNF (infliximab, adalimumab, golimumab) from October 2006 through February 2017. Clinical response was defined as significant improvement in UC-related symptoms, and remission as complete disappearance of UC-related symptoms, each determined by treating physicians. We collected demographic, clinical, and treatment data. The median duration of follow-up was 24 months (interquartile range, 13-51 months). The primary outcome was clinical response of UP to anti-TNF treatment. RESULTS: Overall, 80 patients (77%) had a clinical response to anti-TNF therapy and 52 patients (50%) achieved clinical remission. Extra-intestinal manifestations (odds ratio OR, 0.24; 95% CI, 0.08-0.7), ongoing treatment with topical steroids (OR, 0.14; 95% CI, 0.03-0.73), and ongoing treatment with topical 5-aminosalycilates (OR, 0.21; 95% CI, 0.07-0.62) were significantly associated with the absence of clinical remission. Sixty percent (38/63) of the patients who had endoscopic assessment during follow up had mucosal healing. Among the overall population (n = 104), the cumulative probabilities of sustained clinical remission were 87.6% ± 3.4% at 1 year and 74.7% ± 4.8% at 2 years. CONCLUSIONS: In a retrospective study of 104 patients with refractory UP, anti-TNF therapy induced clinical remission in 50% and mucosal healing in 60%. About two thirds of the patients were still receiving anti-TNF therapy at 2 years.

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.

Ustekinumab for Perianal Crohn's Disease: The BioLAP Multicenter Study From the GETAID.

INTRODUCTION: New therapeutic options for patients with Crohn's disease (CD) with perianal lesions failing anti-tumor necrosis factor (TNF) agents are needed. We aimed to assess the effectiveness of ustekinumab in perianal CD (pCD) and predictors of clinical success in a real-life multicenter cohort. METHODS: We conducted a national multicenter retrospective cohort study in patients with either active or inactive pCD who received ustekinumab. In patients with active pCD at treatment initiation, the success of ustekinumab was defined by clinical success at 6 months assessed by the physician's judgment without additional medical or surgical treatment for pCD. Univariate and multivariable logistic regression analyses were performed to identify predictors of success. In patients with inactive pCD at ustekinumab initiation, the pCD recurrence-free survival was calculated using the Kaplan-Meier method. RESULTS: Two hundred seven patients were included, the mean age was 37.7 years, the mean duration of CD was 14.3 years, and the mean number of prior perianal surgeries was 2.8. Two hundred five (99%) patients had previously been exposed to at least 1 anti-TNF and 58 (28%) to vedolizumab. The median follow-up time was 48 weeks; 56/207 (27%) patients discontinued therapy after a median time of 43 weeks. In patients with active pCD, success was reached in 57/148 (38.5%) patients. Among patients with setons at initiation, 29/88 (33%) had a successful removal. The absence of optimization was associated with treatment success (P = 0.044, odds ratio 2.74; 95% confidence interval: 0.96-7.82). In multivariable analysis, the number of prior anti-TNF agents (≥3) was borderline significant (P = 0.056, odds ratio 0.4; 95% confidence interval: 0.15-1.08). In patients with inactive pCD at initiation, the probability of recurrence-free survival was 86.2% and 75.1% at weeks 26 and 52, respectively. DISCUSSION: Ustekinumab appears as a potential effective therapeutic option in perianal refractory CD. Further prospective studies are warranted.

Ustekinumab Serum Trough Levels May Identify Suboptimal Responders to Ustekinumab in Crohn's Disease.

INTRODUCTION: The aim of this study was to evaluate the association between serum ustekinumab (UST) trough levels and response to induction and maintenance UST treatment in refractory Crohn's Disease (CD) patients. METHODS: We performed a prospective study including CD patients who received UST from September 2015 to January 2017. Patients received 90 mg of UST subcutaneously at weeks 0, 4, and 12, then every 8 weeks. Two cohorts of patients were analyzed: an induction cohort and a maintenance cohort. We evaluated clinical, biological, and imaging/endoscopic response to UST treatment. UST trough levels and anti-UST antibodies were dosed at weeks 12 and 28 in the induction cohort, and at a single time point in the maintenance cohort. RESULTS: Forty-nine patients were enrolled in the maintenance cohort. Mean concentrations of UST were 1.88 ± 1.40 µg/mL. UST trough levels were not significantly different in patients with or without clinical, biological, or imaging/endoscopic responses to UST treatment (p > 0.11). Twenty-three consecutive patients were included in the induction cohort. At week 12, mean UST concentrations were 1.45 ± 1.15 µg/mL. Patients with a biological response to UST treatment had significant higher serum UST trough concentration (median 1.72 µg/mL) than non-responders (median 0.56 µg/mL, p = 0.02). A UST trough level ≥ 1.10 µg/mL at week 12 was associated with a biological response to UST treatment at 6 months. CONCLUSION: UST trough levels were associated with a biological response at the end of the induction phase. In patients with low levels of UST, optimization treatment may be necessary to obtain a sustained response.

Radiological Response Is Associated with Better Outcomes and Should Be Considered a Therapeutic Target in Crohn's Disease.

BACKGROUND: The aim of the study was to identify factors associated with a radiological response and to assess the impact of radiological improvement in long-term outcomes in small bowel (SB) Crohn's disease (CD) patients. METHODS: We performed a retrospective study from June 2011 to June 2017 in the tertiary center, Claude Huriez Hospital in Lille, France. All SB CD patients, who underwent two magnetic resonance enterographies (MRE) 3-12 months apart, with at least 1-year follow-up after the second MRE, were included. Signs of radiological inflammation were identified by two expert radiologists in CD. Patients were classified as radiological responders (RR) and non-responders (NR). Hospitalization rates, adjustment of treatment, and surgical or endoscopic interventions were assessed and compared between RR and NR. Factors associated with a radiological response were also studied using the Cox model. RESULTS: One hundred and fifteen SB CD patients were included with a median follow-up of 17 months (IQR 11.6-28.3). There were 54 (47%) RR and 61 (53%) NR. The risk of surgical or endoscopic intervention was higher in NR than RR (p = 0.04), and the median delay until a surgical or endoscopic intervention was shorter in NR (p = 0.04). Multifocal disease, a hypersignal on diffusion-weighted or dynamic contrast-enhanced imaging, a stricture, or a fistula was significantly associated with a decreased probability of a radiological response (p < 0.05). CONCLUSION: This study shows that a radiological response is associated with a decreased risk of surgical or endoscopic intervention and should be considered as a therapeutic target in CD patients.

T cell clonal expansions in ileal Crohn's disease are associated with smoking behaviour and postoperative recurrence.

T cell clonal expansions are present in the inflamed mucosa of patients with Crohn's disease (CD) and may be implicated in postoperative recurrence after ileocolonic resection. METHODS: T cell receptor (TCR) analysis was performed in 57 patients included in a prospective multicentre cohort. Endoscopic recurrence was defined by a Rutgeerts score >i0. DNA and mRNA were extracted from biopsies collected from the surgical specimen and endoscopy, and analysed by high throughput sequencing and microarray, respectively. RESULTS: TCR repertoire in the mucosa of patients with CD displayed diverse clonal expansions. Active smokers at time of surgery had a significantly increased proportion of clonal expansions as compared with non-smokers (25.9%vs17.9%, p=0.02). The percentage of high frequency clones in the surgical specimen was significantly higher in patients with recurrence and correlated with postoperative endoscopic recurrence (area under the curve (AUC) 0.69, 95% CI 0.54 to 0.83). All patients with clonality above 26.8% (18/57) had an endoscopic recurrence. These patients with a high clonality were more frequently smokers than patients with a low clonality (61% vs 23%, p=0.005). The persistence of a similar TCR repertoire at postoperative endoscopy was associated with smoking and disease recurrence. Patients with high clonality showed increased expression of genes associated with CD8 T cells and reduced expression of inflammation-related genes. Expanded clones were found predominantly in the CD8 T cell compartment. CONCLUSION: Clonal T cell expansions are implicated in postoperative endoscopic recurrence. CD patients with increased proportion of clonal T cell expansions in the ileal mucosa represent a subgroup associated with smoking and where pathogenesis appears as T cell driven. TRIAL REGISTRATION NUMBER: NCT03458195.

Treatments for Crohn's Disease-Associated Bowel Damage: A Systematic Review.

BACKGROUND & AIMS: Despite significant advances in the treatment of Crohn's disease (CD), most patients still develop stricturing or penetrating complications that require surgical resections. We performed a systematic review of mechanisms and potential treatments for tissue damage lesions in CD patients. METHODS: We searched the PubMed, MBASE, and Cochrane databases from January 1960 to July 2017 for full-length articles on CD, fibrosis, damage lesions, mesenchymal stem cells, and/or treatment. We also searched published conference abstracts and performed manual searches of all reference lists of relevant articles. RESULTS: Mechanisms of intestinal damage in patients with CD include fibroblast proliferation and migration, activation of stellate cells, recruitment of intestinal or extra-intestinal fibroblast, and cell trans-differentiation. An altered balance of metalloproteinases and tissue inhibitors of metalloproteinases might contribute to fistula formation. Treatment approaches that reduce excessive transforming growth factor beta (TGFB) activation might be effective in treating established intestinal damage. Stem cell therapies have been effective in tissue damage lesions in CD. Particularly, randomized controlled trials have shown local injections of mesenchymal stem cells to heal perianal fistulas. CONCLUSION: In a systematic review of mechanisms and treatments of bowel wall damage in patients with CD, we found a need to test drugs that reduce TGFB and increase healing of transmural damage lesions and to pursue research on local injection of mesenchymal stem cells.

Increasing Infliximab Dose Based on Symptoms, Biomarkers, and Serum Drug Concentrations Does Not Increase Clinical, Endoscopic, and Corticosteroid-Free Remission in Patients With Active Luminal Crohn's Disease.

BACKGROUND & AIMS: A combination of infliximab and immunomodulators is the most efficacious treatment for Crohn's disease (CD). Patients have the best outcomes when their serum concentrations of these drugs are above a determined therapeutic threshold. We performed a prospective, randomized trial to determine whether therapeutic drug monitoring (TDM) to maintain serum levels of infliximab above 3 µg/mL produced higher rates of clinical and endoscopic remission than adapting dose based only on symptoms. METHODS: We performed a double-blind trial in which 122 biologic-naïve adult patients with active CD (71 female, median age 29.8 years) received induction treatment with infliximab in combination with an immunosuppressant, from July 2012 through September 2015 at 27 centers in Europe. At week 14 of treatment, patients were randomly assigned (1:1:1) to 3 infliximab maintenance groups: dose increases (2 maximum) in steps of 2.5 mg/kg based on clinical symptoms and biomarker analysis and/or serum infliximab concentrations (dose intensification strategy [DIS]1 group); dose increase from 5 to 10 mg/kg based on the same criteria (DIS2 group); dose increase to 10 mg/kg based on clinical symptoms alone (controls). Patients' CD activity index scores, levels of C-reactive protein, fecal levels of calprotectin, and serum concentrations of infliximab were determined at baseline and at weeks 2, 4, 6, 12, and 14 of treatment, and then every 4 weeks thereafter until week 54. The primary endpoint was sustained corticosteroid-free clinical remission (CD activity index <150) from weeks 22 through 54 with no ulcers at week 54. RESULTS: The primary endpoint was reached by 15 (33%) of 45 patients in the DIS1 group, 10 (27%) of 37 patients in the DIS2 group, and 16 (40%) of 40 patients in the control group (P = .50). CONCLUSIONS: In a prospective randomized exploratory trial of patients with active CD, we found increasing dose of infliximab based on a combination of symptoms, biomarkers, and serum drug concentrations does not lead to corticosteroid-free clinical remission in a larger proportion of patients than increasing dose based on symptoms alone. EUDRACT NUMBER: 2011-003038-14.

Dramatic Increase in Incidence of Ulcerative Colitis and Crohn's Disease (1988-2011): A Population-Based Study of French Adolescents.

OBJECTIVES: Few data are available to describe the changes in incidence of pediatric-onset inflammatory bowel disease (IBD). The aim of this study was to describe changes in incidence and phenotypic presentation of pediatric-onset IBD in northern France during a 24-year period. METHODS: Pediatric-onset IBD (<17 years) was issued from a population-based IBD study in France between 1988 and 2011. Age groups and digestive location were defined according to the Paris classification. RESULTS: 1,350 incident cases were recorded (8.3% of all IBD) including 990 Crohn's disease (CD), 326 ulcerative colitis (UC) and 34 IBD unclassified (IBDU). Median age at diagnosis was similar in CD (14.4 years (Q1=11.8-Q3=16.0)) and UC (14.0 years (11.0-16.0)) and did not change over time. There were significantly more males with CD (females/males=0.82) than UC (females/males=1.25) (P=0.0042). Median time between onset of symptoms and IBD diagnosis was consistently 3 months (1-6). Mean incidence was 4.4/105 for IBD overall (3.2 for CD, 1.1 for UC and 0.1 for IBDU). From 1988-1990 to 2009-2011, a dramatic increase in incidences of both CD and UC were observed in adolescents (10-16 years): for CD from 4.2 to 9.5/105 (+126%; P<0.001) and for UC, from 1.6 to 4.1/105 (+156%; P<0.001). No modification in age or location at diagnosis was observed in either CD or UC. CONCLUSIONS: In this population-based study, CD and UC incidences increased dramatically in adolescents across a 24-year span, suggesting that one or more strong environmental factors may predispose this population to IBD.

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.

Lymphoid Aggregates Remodel Lymphatic Collecting Vessels that Serve Mesenteric Lymph Nodes in Crohn Disease.

Early pathological descriptions of Crohn disease (CD) argued for a potential defect in lymph transport; however, this concept has not been thoroughly investigated. In mice, poor healing in response to infection-induced tissue damage can cause hyperpermeable lymphatic collecting vessels in mesenteric adipose tissue that impair antigen and immune cell access to mesenteric lymph nodes (LNs), which normally sustain appropriate immunity. To investigate whether analogous changes might occur in human intestinal disease, we established a three-dimensional imaging approach to characterize the lymphatic vasculature in mesenteric tissue from controls or patients with CD. In CD specimens, B-cell-rich aggregates resembling tertiary lymphoid organs (TLOs) impinged on lymphatic collecting vessels that enter and exit LNs. In areas of creeping fat, which characterizes inflammation-affected areas of the bowel in CD, we observed B cells and apparent innate lymphoid cells that had invaded the lymphatic vessel wall, suggesting these cells may be mediators of lymphatic remodeling. Although TLOs have been described in many chronic inflammatory states, their anatomical relationship to preestablished LNs has never been revealed. Our data indicate that, at least in the CD-affected mesentery, TLOs are positioned along collecting lymphatic vessels in a manner expected to affect delivery of lymph to LNs.