Magnetic resonance enterographic predictors of one-year outcome in ileal and ileocolonic Crohn's disease treated with anti-tumor necrosis factor antibodies

Regulation of intestinal epithelial homeostasis by mesenchymal cells

The gastrointestinal tract harbors diverse microorganisms in the lumen. Epithelial cells segregate the luminal microorganisms from immune cells in the lamina propria by constructing chemical and physical barriers through the production of various factors to prevent excessive immune responses against microbes. Therefore, perturbations of epithelial integrity are linked to the development of gastrointestinal disorders. Several mesenchymal stromal cell populations, including fibroblasts, myofibroblasts, pericytes, and myocytes, contribute to the establishment and maintenance of epithelial homeostasis in the gut through regulation of the self-renewal, proliferation, and differentiation of intestinal stem cells. Recent studies have revealed alterations in the composition of intestinal mesenchymal stromal cells in patients with inflammatory bowel disease and colorectal cancer. A better understanding of the interplay between mesenchymal stromal cells and epithelial cells associated with intestinal health and diseases will facilitate identification of novel biomarkers and therapeutic targets for gastrointestinal disorders. This review summarizes the key findings obtained to date on the mechanisms by which functionally distinct mesenchymal stromal cells regulate epithelial integrity in intestinal health and diseases at different developmental stages.

Risankizumab versus Ustekinumab for Moderate-to-Severe Crohn's Disease

BACKGROUND

The efficacy and safety of risankizumab as compared with ustekinumab in patients with Crohn's disease are unknown.

METHODS

In this phase 3b, multicenter, open-label, randomized, controlled trial with blinded assessment of end points, patients with moderate-to-severe Crohn's disease who had had an inadequate response to anti-tumor necrosis factor (TNF) therapy or unacceptable side effects with such therapy were randomly assigned to receive risankizumab or ustekinumab at standard doses for 48 weeks. The two primary end points, which were tested sequentially, were clinical remission at week 24 (defined as a Crohn's Disease Activity Index score of <150 [range, 0 to 600, with higher scores indicating more severe disease activity]), which was analyzed in the first 50% of patients to complete the week 24 visit, with a noninferiority margin of 10 percentage points; and endoscopic remission at week 48 (defined as a score of ≤4, a decrease of ≥2 points from baseline, and no subscore >1 in any individual variable on the Simple Endoscopic Score for Crohn's Disease [range, 0 to 56, with higher scores indicating more severe disease]), which was analyzed for superiority in 100% of the patients. Safety was assessed in all patients who received at least one dose of risankizumab or ustekinumab.

RESULTS

In the full intention-to-treat population for the efficacy analysis, 230 of 255 patients (90.2%) who received risankizumab and 193 of 265 patients (72.8%) who received ustekinumab completed all the assigned treatments. Both primary end points were met; risankizumab was noninferior to ustekinumab with respect to clinical remission at week 24 (58.6% vs. 39.5%; adjusted difference, 18.4 percentage points; 95% confidence interval [CI], 6.6 to 30.3) and superior to ustekinumab with respect to endoscopic remission at week 48 (31.8% vs. 16.2%; adjusted difference, 15.6 percentage points; 95% CI, 8.4 to 22.9; P<0.001). The incidence of adverse events appeared to be similar in the two groups.

CONCLUSIONS

In this head-to-head clinical trial of risankizumab and ustekinumab involving patients with moderate-to-severe Crohn's disease who had had unacceptable side effects with anti-TNF therapy or an inadequate response to such therapy, risankizumab was noninferior to ustekinumab with respect to clinical remission at week 24 and superior with respect to endoscopic remission at week 48. (Funded by AbbVie; ClinicalTrials.gov number, NCT04524611.).

Effectiveness of vedolizumab and ustekinumab as second biologic agent in achieving target outcomes in tumor necrosis factor antagonists experienced patients with inflammatory bowel disease (enroll-ex study)

Background: About a third of patients with inflammatory bowel disease (IBD) do not respond to anti-tumor necrosis factor (anti-TNF) therapy. In our study, we evaluated the effectiveness of vedolizumab and ustekinumab in achieving clinical and endoscopic outcomes in anti-TNF-experienced patients with IBD. Methods: We conducted a retrospective cohort study. Electronic medical records of patients with moderate to severe IBD, who were previously received anti-TNF therapies, were reviewed and evaluated retrospectively in a gastroenterology center. Outcomes of patients treated with ustekinumab or vedolizumab after failing one anti-TNF agent were evaluated. The primary outcomes were the percentage of hospitalization, surgery, mucosal healing and steroid-free remission. Mucosal healing was defined as a Mayo endoscopic score of 0 or 1 in ulcerative colitis (UC) and an SES-CD score of less than 3 in Crohn's disease (CD). Outcomes were quantified using descriptive analysis. Results: A total of 207 (130 CD: 77 UC) patients with IBD who had previously received one anti-TNF agent were included in the study. Of the total cohort, 62 (30.0%) patients were receiving vedolizumab, and 145 (70.0%) patients were on ustekinumab. 101 (77.6%) patients with CD who failed one anti-TNF therapy were on ustekinumab. Of these patients, 26 (19.7%) patients were hospitalized, and 12 (11.9%) patients had IBD-related surgery. 16 (16.1%) patients had at least one corticosteroid course. 60 (59.0%) patients with CD on ustekinumab achieved mucosal healing. 29 (22.3%) patients with CD who failed one anti-TNF therapy were receiving vedolizumab. Of those, 7 (25%) patients were hospitalized, and 11 (37.9%) patients had IBD-related surgery. 15 (51.0%) patients achieved mucosal healing. 44 (57.1%) patients with UC who failed one anti-TNF therapy were on ustekinumab. Of these 6 (14.1%) patients were hospitalized, 3 (7.0%) patients had IBD-related surgery and 13 (30%) patients had at least 1 corticosteroid course. 25 (57.0%) patients achieved mucosal healing. 33 (42.8%) patients with UC who failed one anti-TNF therapy were receiving vedolizumab. Of those, 6 (18.6%) patients were hospitalized, and 16 (49.6%) patients had at least 1 corticosteroid course. 17 (53.2%) patients achieved mucosal healing. Conclusion: Ustekinumab and vedolizumab were both effective in achieving clinical outcomes in patients with IBD after failing an anti-TNF agent. However, patients receiving ustekinumab had numerically higher percentages of reaching target outcomes than patients receiving vedolizumab. A prospective head-to-head trial is warranted to confirm these findings.

Predicting Treatment Response in Inflammatory Bowel Diseases: Cross-Sectional Imaging Markers

Therapeutic options for inflammatory bowel diseases (IBD) have largely expanded in the last decades, both in Crohn's disease and ulcerative colitis, including multiple biological drugs targeting different inflammation pathways. However, choosing the best treatment and timing for each patient is still an undeniable challenge for IBD physicians due to the marked heterogeneity among patients and disease behavior. Therefore, early prediction of the response to biological drugs becomes of utmost importance, allowing prompt optimization of therapeutic strategies and thus paving the way towards precision medicine. In such a context, researchers have recently focused on cross-sectional imaging techniques (intestinal ultrasound, computed tomography, and magnetic resonance enterography) in order to identify predictive markers of response or non-response to biologic therapies. In this review, we aim to summarize data about imaging factors that may early predict disease behavior during biological treatment, potentially helping to define more precise and patient-tailored strategies.

Primary Failure to an Anti-TNF Agent in Inflammatory Bowel Disease: Switch (to a Second Anti-TNF Agent) or Swap (for Another Mechanism of Action)?

BACKGROUND

About a third of patients with inflammatory bowel disease do not respond to anti-tumour necrosis factor (anti-TNF) therapy, which is challenging.

AIM

To review the current data on the two main strategies when facing primary non-response to an anti-TNF agent in inflammatory bowel disease: changing to a second anti-TNF (switching) or to a drug with another mechanisms of action (swapping).

METHODS

We performed a bibliographic search to identify studies reporting on efficacy of any biologic treatment after primary anti-TNF non-response.

RESULTS

The efficacy of a second anti-TNF is lower when the reason to withdraw the first one is primary failure. Nevertheless, switching to another anti-TNF even after primary failure may still be effective in some patients. Both vedolizumab and ustekinumab have generally been shown to be less effective in anti-TNF exposed patients. However, despite primary anti-TNF failure, patients may respond to vedolizumab or ustekinumab in a limited but considerable number of cases. The cause for swapping (primary vs. secondary anti-TNF failure) seems to have limited effect on vedolizumab efficacy. Primary anti-TNF non-response seems to be a clearer predictor of treatment failure for ustekinumab. Unfortunately, the two main strategies to treat specifically a patient with primary non-response to an anti-TNF agent-switching to a second anti-TNF or swapping for vedolizumab/ustekinumab-have not been properly compared.

CONCLUSION

The data reviewed in the present study clearly emphasise the imperative need to carry out head-to-head randomised trials in patients exposed to anti-TNF agents in general, and specifically in those with primary non-response to these agents.

Efficacy of drug and endoscopic treatment of Crohn's disease strictures: A systematic review

BACKGROUND AND AIMS

Strictures are the commonest complication in Crohn's disease. Surgery and endoscopic dilation are the mainstays of treatment, while drug therapy has often been considered contraindicated. The benefit of nonsurgical treatments, particularly drug and endoscopic therapy, need to be defined.

METHODS

Ovid MEDLINE, Embase, Emcare, PsycINFO, CINAHL and the Cochrane Library (inception until August 30, 2019) were searched. Studies with ≥ 10 patients with Crohn's disease strictures, reporting on outcomes following medication or endoscopic treatment, were included.

RESULTS

Of 3480 records, 85 studies met inclusion criteria and formed the basis of this analysis. Twenty-five studies assessed drug therapy; none were randomized trials. Despite study heterogeneity anti-tumor necrosis factor (TNF) therapy appeared effective, with 50% of patients avoiding surgery after 4 years of follow up. No other drug therapy was of demonstrable benefit. Sixty studies assessed endoscopic therapy including 56 on endoscopic balloon dilation, two assessed needle knife stricturotomy, and two stent insertion. Dilation was equally effective for de novo and anastomotic strictures ≤ 5 cm in length, with most studies reporting a subsequent surgical rate of 30% to 50%. Repeat dilation was required in approximately half of all patients.

CONCLUSIONS

Anti-TNF drug therapy and endoscopic balloon dilation are effective strategies for avoiding surgery in patients with stricturing Crohn's disease. Additional endoscopic therapies require further evaluation. Early data suggest that combining these therapies may provide greater benefit than individual therapies. Optimization of current drug and endoscopic therapy, and the incorporation of newer therapies, are needed for stricturing Crohn's disease.

Earlier Anti-Tumor Necrosis Factor Therapy of Crohn's Disease Correlates with Slower Progression of Bowel Damage

INTRODUCTION

Crohn's disease (CD) follows a relapsing and remitting course incurring cumulative bowel damage over time. The question of whether or not the timing of the initiating biologic therapy affects long-term disease progression remains unanswered. Herein, we calculated rates of change in the Lémann index-which quantifies accumulated bowel damage-as a function of the time between the disease onset and initiation of biologic therapy. We aimed to explore the impact of the earlier introduction of biologics on the rate of progression of long-term cumulative bowel damage.

METHODS

Medical records of CD patients treated during 2009-2014 at The Mount Sinai Hospital were queried. Inclusion criteria were two comprehensive assessments allowing calculation of the index at t₁ and t₂: two time-points ≥ 1 year apart. Patients with biologics introduced before or within 3 months at inclusion (t₁) were defined as Bio-pre-t₁ and those who did not as Bio-post-t₁. The rate of disease progression was calculated as the change in the index per year during t₁-t₂.

RESULTS

A total of 88 patients were studied: 58 Bio-pre-t₁ and 30 Bio-post-t₁. Among the 58 Bio-pre-t₁ cases, damage progressed in 29 (50%), regressed in 20 (34.5%), and stabilized in 9 (15.5%). Median time to initiation of biologics among patients whose index improved was nominally shorter compared to that in patients whose index progressed (8 vs. 15 years). Earlier introduction of biologics tended to correlate with the slower rate of progression (ρ = 0.241; p = 0.069).

CONCLUSIONS

Earlier introduction of biologics tended to correlate with the slower progression of bowel damage in CD, reflected by the reduced rate of Lémann index progression.

Magnetic resonance imaging and Crohn’s disease endoscopic index of severity: Correlations and concordance

AIM

To examine the correlation between magnetic resonance imaging (MRI) and endoscopic index of severity (CDEIS) in patients with Crohn’s disease (CD).

METHODS

This was a retrospective study of 104 patients with CD that were treated at the Ruijin Hospital between March 2015 and May 2016. Among them, 61 patients with active CD were evaluated before/after treatment. MRI and endoscopy were performed within 7 d. CDEIS was evaluated. MRI parameters included MaRIA scores, total relative contrast enhancement (tRCE), arterial RCE (aRCE), portal RCE (pRCE), delay phase RCE (dRCE), and apparent diffusion coefficient. The correlation and concordance between multiple MRI findings and CDEIS changes before and after CD treatment were examined.

RESULTS

Among the 104 patients, 61 patients were classified as active CD and 43 patients as inactive CD. Gender, age, disease duration, and disease location were not significantly different between the two groups (all P > 0.05). CRP levels were higher in the active group than in the inactive group (25.12 ± 4.12 vs 5.14 ± 0.98 mg/L, P < 0.001). Before treatment, the correlations between CDEIS and MaRIAs in all patients were r = 0.772 for tRCE, r = 0.754 for aRCE, r = 0.738 for pRCE, and r = 0.712 for dRCE (all MaRIAs, P < 0.001), followed by MRI single indexes. Among the active CD patients, 44 cases were remitted to inactive CD after treatment. The correlations between CDEIS and MaRIAs were r = 0.712 for aRCE, r = 0.705 for tRCE, r = 0.685 for pRCE, and r = 0.634 for dRCE (all MaRIAs, P < 0.001).

CONCLUSION

Arterial MaRIA should be an indicator for CD follow-up and dynamic assessment. CD treatment assessment was not completely concordant between CDEIS and MRI.

Findings of Retrograde Contrast Study Through Double-balloon Enteroscopy Predict the Risk of Bowel Resections in Patients with Crohn's Disease with Small Bowel Stenosis

BACKGROUND

Patients with Crohn's disease (CD) with small bowel strictures are at risk of surgery. Double-balloon enteroscopy (DBE) can evaluate the status of the small intestine, and retrograde contrast through the scope enables the surgeon to obtain information beyond the reach of the scope. This study aimed to examine whether a retrograde contrast study through DBE could be used as a predictor of subsequent surgery in patients with CD with small intestinal strictures.

METHODS

The findings of DBE with retrograde contrast in 48 patients CD with small bowel strictures were examined.

RESULTS

Of the 48 patients, 14 (29%) underwent surgery for small intestinal strictures during a median observation period of 2.4 years (interquartile range: 1.4-3.7 yr). According to the results of the multivariate analysis, a maximum length of strictures ≥20 mm and the ratio of the maximum diameter of prestenotic dilations to the diameter of the normal small intestine ≥1.4 were independent risk factors of surgery for small intestinal strictures (risk ratio = 7.6 [95% confidence interval, 1.8-42.0], P = 0.006; and risk ratio = 52.0 [95% confidence interval, 3.5-2485.1], P = 0.002, respectively). The latter predicted subsequent surgery with 92% sensitivity and 88% specificity. Cumulative surgery-free rates were discriminated significantly according to the presence or absence of these 2 risk factors (log-rank test: P < 0.001).

CONCLUSIONS

Findings of retrograde contrast through DBE are helpful to predict risk of surgery in patients with CD with small intestinal strictures.

Prediction of complicated disease course for children newly diagnosed with Crohn's disease: a multicentre inception cohort study

BACKGROUND

Stricturing and penetrating complications account for substantial morbidity and health-care costs in paediatric and adult onset Crohn's disease. Validated models to predict risk for complications are not available, and the effect of treatment on risk is unknown.

METHODS

We did a prospective inception cohort study of paediatric patients with newly diagnosed Crohn's disease at 28 sites in the USA and Canada. Genotypes, antimicrobial serologies, ileal gene expression, and ileal, rectal, and faecal microbiota were assessed. A competing-risk model for disease complications was derived and validated in independent groups. Propensity-score matching tested the effect of anti-tumour necrosis factor α (TNFα) therapy exposure within 90 days of diagnosis on complication risk.

FINDINGS

Between Nov 1, 2008, and June 30, 2012, we enrolled 913 patients, 78 (9%) of whom experienced Crohn's disease complications. The validated competing-risk model included age, race, disease location, and antimicrobial serologies and provided a sensitivity of 66% (95% CI 51-82) and specificity of 63% (55-71), with a negative predictive value of 95% (94-97). Patients who received early anti-TNFα therapy were less likely to have penetrating complications (hazard ratio [HR] 0·30, 95% CI 0·10-0·89; p=0·0296) but not stricturing complication (1·13, 0·51-2·51; 0·76) than were those who did not receive early anti-TNFα therapy. Ruminococcus was implicated in stricturing complications and Veillonella in penetrating complications. Ileal genes controlling extracellular matrix production were upregulated at diagnosis, and this gene signature was associated with stricturing in the risk model (HR 1·70, 95% CI 1·12-2·57; p=0·0120). When this gene signature was included, the model's specificity improved to 71%.

INTERPRETATION

Our findings support the usefulness of risk stratification of paediatric patients with Crohn's disease at diagnosis, and selection of anti-TNFα therapy.

FUNDING

Crohn's and Colitis Foundation of America, Cincinnati Children's Hospital Research Foundation Digestive Health Center.

Findings of ulceration and severe stricture on MRE can predict prognosis of Crohn's disease in patients treated with anti-TNF treatment

BACKGROUND

MR enterography (MRE) is useful for evaluating transmural lesions and extra-intestinal complications of Crohn's disease (CD). The aim of this study was to prospectively evaluate whether MRE could detect severe strictures and inflammatory lesions in patients who lost the responsiveness to anti-TNF treatment and whether MRE could predict prognosis of CD patients with clinical remission.

PATIENTS AND METHODS

MRE were conducted in 50 patients who were treated with infliximab or adalimumab. The main aims of this study were as follows; (1) to compare the rates of CD lesions of the patients with clinical remission and active disease at the baseline and (2) to assess the MRE findings that were predictors of clinical recurrence among patients with clinical remission at the baseline.

RESULTS

The MRE detection rates of markedly increased contrast uptake, severe strictures, and the presence of ulcers were significantly higher in patients with Crohn Disease Activity Index ≥150 than in patients with clinical remission. Over a mean follow-up of 18.2 months, the absence of ulceration (p = 0.001) or severe stricture (p = 0.01) prolonged clinical recurrence among patients with clinical remission at baseline. Expected duration of recurrence significantly prolonged in patients with total magnetic resonance index of activity (MaRIA) <36.3 [29.8 months (95% CI 23.7-35.9)] than in patients with total MaRIA ≥36.3 (13.9 months (95% CI 7.7-20.1). A cut-off value of total MaRIA score of 36.3 had a sensitivity of 75% and specificity of 70% for predicting recurrence.

CONCLUSION

Findings of ulceration and severe stricture on MRE predict prognosis of CD patients who were treated with anti-TNF treatment. MRE might be useful for making treatment decisions in patients who lost the effectiveness of medical treatments.

Optical coherence tomography-guided laser microsurgery for blood coagulation with continuous-wave laser diode

Blood coagulation is the clotting and subsequent dissolution of the clot following repair to the damaged tissue. However, inducing blood coagulation is difficult for some patients with homeostasis dysfunction or during surgery. In this study, we proposed a method to develop an integrated system that combines optical coherence tomography (OCT) and laser microsurgery for blood coagulation. Also, an algorithm for positioning of the treatment location from OCT images was developed. With OCT scanning, 2D/3D OCT images and angiography of tissue can be obtained simultaneously, enabling to noninvasively reconstruct the morphological and microvascular structures for real-time monitoring of changes in biological tissues during laser microsurgery. Instead of high-cost pulsed lasers, continuous-wave laser diodes (CW-LDs) with the central wavelengths of 450 nm and 532 nm are used for blood coagulation, corresponding to higher absorption coefficients of oxyhemoglobin and deoxyhemoglobin. Experimental results showed that the location of laser exposure can be accurately controlled with the proposed approach of imaging-based feedback positioning. Moreover, blood coagulation can be efficiently induced by CW-LDs and the coagulation process can be monitored in real-time with OCT. This technology enables to potentially provide accurate positioning for laser microsurgery and control the laser exposure to avoid extra damage by real-time OCT imaging.