Can advanced endoscopic techniques for assessment of mucosal inflammation and healing approximate histology in inflammatory bowel disease?

Validation of a new optical diagnosis training module to improve dysplasia characterization in inflammatory bowel disease: a multicenter international study

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) increases risk of dysplasia and colorectal cancer. Advanced endoscopic techniques allow for the detection and characterization of IBD dysplastic lesions, but specialized training is not widely available. We aimed to develop and validate an online training platform to improve the detection and characterization of colonic lesions in IBD: OPtical diagnosis Training to Improve dysplasia Characterization in Inflammatory Bowel Disease (OPTIC-IBD).

METHODS

We designed a web-based learning module that includes surveillance principles, optical diagnostic methods, approach to characterization, and classifications of colonic lesions using still images and videos. We invited gastroenterologists from Canada, Italy, and the United Kingdom with a wide range of experience. Participants reviewed 24 educational videos of IBD colonic lesions, predicted histology, and rated their confidence. The primary endpoint was to improve accuracy in detecting dysplastic lesions after training on the platform. Furthermore, participants were randomized 1:1 to get additional training or not, with a final assessment occurring after 60 days. Diagnostic performance for dysplasia and rater confidence were measured.

RESULTS

A total of 117 participants completed the study and were assessed for the primary endpoint. Diagnostic accuracy improved from 70.8% to 75.0% (P = .002) after training, with the greatest improvements seen in less experienced endoscopists. Improvements in both accuracy and confidence were sustained after 2 months of assessment, although the group randomized to receive additional training did not improve further. Similarly, participants' confidence in characterizing lesions significantly improved between before and after the course (P < .001), and it was sustained after 2 months of assessment.

CONCLUSIONS

The OPTIC-IBD training module demonstrated that an online platform could improve participants' accuracy and confidence in the optical diagnosis of dysplasia in patients with IBD. The training platform can be widely available and improve endoscopic care for people with IBD. (Clinical trial registration number: NCT04924543.).

High-throughput omics technologies in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing intestinal disease. Elucidation of the pathogenic mechanisms of IBD requires high-throughput technologies (HTTs) to effectively obtain and analyze large amounts of data. Recently, HTTs have been widely used in IBD, including genomics, transcriptomics, proteomics, microbiomics, metabolomics and single-cell sequencing. When combined with endoscopy, the application of these technologies can provide an in-depth understanding on the alterations of intestinal microbe diversity and abundance, the abnormalities of signaling pathway-mediated immune responses and functionality, and the evaluation of therapeutic effects, improving the accuracy of early diagnosis and treatment of IBD. This review comprehensively summarizes the development and advancement of HTTs, and also highlights the challenges and future directions of these technologies in IBD research. Although HTTs have made striking breakthrough in IBD, more standardized methods and large-scale dataset processing are still needed to achieve the goal of personalized medicine.

Present and future of endoscopy precision for inflammatory bowel disease

Several advanced imaging techniques are now available for endoscopists managing inflammatory bowel disease (IBD) patients. These tools, including dye-based and virtual chromoendoscopy, probe-based confocal laser endomicroscopy and endocytoscopy, are increasingly innovative applications in clinical practice. They allow for a more in-depth and refined evaluation of the mucosal and vascular bowel surface, getting closer to histology. They have demonstrated a remarkable ability in assessing intestinal inflammation, histologic remission, and predicting relapse and favorable long-term outcomes. In addition, the future application of molecular endoscopy to predict biological drug responses has yielded preliminary but encouraging results. Furthermore, these techniques are crucial in detecting and characterizing IBD-related dysplasia, assisting endoscopic mucosal resection and submucosal dissection towards a surgery-sparing approach. Artificial intelligence (AI) holds great potential in this promising landscape, as it can provide an objective and reproducible assessment of inflammation and dysplasia. Moreover, it can improve the prediction of outcomes and aid in subsequent therapeutic decision-making. This review aims to summarize the promising role of state-of-the-art advanced endoscopic techniques and related AI-enabled models for managing IBD, paving the way for precision medicine.

Evaluation of Disease Activity in Inflammatory Bowel Disease: Diagnostic Tools in the Assessment of Histological Healing

Inflammatory bowel disease (IBD) comprises two types of chronic intestinal disorders: Crohn's disease and ulcerative colitis. In long-standing ulcerative colitis disease activity, histological persistent inflammation has been linked to an increased risk of relapse, and long-term corticosteroid use, even when endoscopic remission is reached. In Crohn's disease, the discontinuous nature of lesions and transmural inflammation have limited the standardized histological assessment. The current evidence from research proposes that besides clinical and endoscopic healing, the achievement of histological healing constitutes an endpoint to assess disease activity and remission in IBD patients concerning better long-term disease outcomes. Histological alterations may persist even in the absence of endoscopic lesions. For these reasons, new advanced techniques promise to revolutionize the field of IBD by improving the endoscopic and histologic assessment, disease characterization, and ultimately patient care, with an established role in daily practice for objective assessment of lesions. This review outlines the importance of including microscopic evaluation in IBD, highlighting the clinical benefits of a deep state of disease remission using validated diagnostic methods and scoring systems for daily clinical practice.

A virtual chromoendoscopy artificial intelligence system to detect endoscopic and histologic activity/remission and predict clinical outcomes in ulcerative colitis

BACKGROUND

Endoscopic and histological remission (ER, HR) are therapeutic targets in ulcerative colitis (UC). Virtual chromoendoscopy (VCE) improves endoscopic assessment and the prediction of histology; however, interobserver variability limits standardized endoscopic assessment. We aimed to develop an artificial intelligence (AI) tool to distinguish ER/activity, and predict histology and risk of flare from white-light endoscopy (WLE) and VCE videos.

METHODS

1090 endoscopic videos (67 280 frames) from 283 patients were used to develop a convolutional neural network (CNN). UC endoscopic activity was graded by experts using the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) and Paddington International virtual ChromoendoScopy ScOre (PICaSSO). The CNN was trained to distinguish ER/activity on endoscopy videos, and retrained to predict HR/activity, defined according to multiple indices, and predict outcome; CNN and human agreement was measured.

RESULTS

The AI system detected ER (UCEIS ≤ 1) in WLE videos with 72 % sensitivity, 87 % specificity, and an area under the receiver operating characteristic curve (AUROC) of 0.85; for detection of ER in VCE videos (PICaSSO ≤ 3), the sensitivity was 79 %, specificity 95 %, and the AUROC 0.94. The prediction of HR was similar between WLE and VCE videos (accuracies ranging from 80 % to 85 %). The model's stratification of risk of flare was similar to that of physician-assessed endoscopy scores.

CONCLUSIONS

Our system accurately distinguished ER/activity and predicted HR and clinical outcome from colonoscopy videos. This is the first computer model developed to detect inflammation/healing on VCE using the PICaSSO and the first computer tool to provide endoscopic, histologic, and clinical assessment.

New endoscopic tools in inflammatory bowel disease

Endoscopic remission is now considered the ultimate long-term goal for treating inflammatory bowel disease (IBD). Recent advances in endoscopic techniques have progressively added new tools to the armamentarium of endoscopists for a deeper assessment and characterisation of the intestinal mucosa. Virtual Electronic chromoendoscopy is widely available in the endoscopic units, leading to a more accurate evaluation of the vascular and mucosal architecture of the colon, reducing the gap with histology, which is considered a favourable long-term measure. In addition, advanced, sophisticated techniques such as endocytoscope and confocal laser endomicroscopy provide insights into individualised and personalised IBD therapy. Finally, high expectations are placed on the advent of Artificial Intelligence (AI) with promising applications that have the potential to revolutionise IBD diagnosis and management. Here, we discuss state-of-the-art of endoscopic techniques and their applicability to accurate assess endoscopic and histological remission, predict response to therapy and detect, characterise and guide treatment of colonic dysplastic lesions. We are seeing the dawn of a new era wherein the applications of these new endoscopic tools, hand in hand with AI, offer the most incredible opportunity to deliver precision medicine to patients with IBD.

Image-Enhanced Endoscopy in the Surveillance of Colitis-Associated Neoplasia

Advances in endoscopic technology have allowed for improved detection and management of dysplasia. These developments have also raised the question of the optimal methods for surveillance. Promising data showed that virtual chromoendoscopy (VCE) is comparable to dye-based chromoendoscopy (DCE). However, the usefulness of DCE and VCE in the surveillance of longstanding inflammatory bowel disease colitis when compared with high-definition white-light endoscopy has been recently questioned. Confocal laser endomicroscopy is a highly innovative endoscopic procedure but is still far from the routine adoption for surveillance. Thus, a personalized approach should guide the most appropriate surveillance strategy.

Mucosal p-STAT1/3 correlates with histologic disease activity in Crohn's disease and is responsive to filgotinib

The validity and relevance of histologic disease activity in Crohn's disease (CD) is unclear, owing to disconnects with endoscopic pathology. Here, we explore relationships between endoscopic, histologic, and molecular activity. This post hoc analysis of the Phase 2 FITZROY trial (NCT02048618) assessed baseline and week 10 (W10) inflammation across matched ileal and colonic segments in CD patients receiving filgotinib 200 mg (n = 42) vs placebo (n = 18). Macroscopic and microscopic disease were assessed by Simple Endoscopic Score for CD ulceration subscore (uSES-CD) and Global Histologic Activity Score activity subscore (aGHAS), respectively. Molecular activity was quantified by phosphorylated signal transducer and activator of transcription (pSTAT)1 and pSTAT3 in epithelium and nonepithelium. Segments were classified as "low" or "high" activity; correlations and concordance were calculated. Logistic regression identified W10 outcome predictors. Overall, 300 segments in 60 patients were assessed. Baseline uSES-CD and aGHAS correlations were 0.72 and 0.53 in colon and ileum, respectively. pSTAT levels had poor-to-moderate concordance with uSES-CD (κ range, 0.11-0.49) but moderate-to-good concordance with aGHAS (0.43-0.77). With filgotinib vs placebo, uSES-CD and aGHAS decreased in significantly more segments with high baseline uSES-CD and aGHAS, and significantly more segments with high baseline pSTAT improved at W10. pSTAT1 was more sensitive to change than uSES-CD and aGHAS. Low baseline pSTAT3 in colon nonepithelium predicted W10 low uSES-CD (P = .044). There was better concordance between histologic and molecular disease activity associated with higher sensitivity to change vs endoscopic severity in ileocolonic CD. Our results suggest histologic activity be included in the assessment of CD inflammatory burden.

Advanced technology for assessment of endoscopic and histological activity in ulcerative colitis: a systematic review and meta-analysis

BACKGROUND

Advanced endoscopic technologies led to significant progress in the definition of endoscopic remission of ulcerative colitis (UC) and correlate better with histological changes, compared with standard endoscopy. However, while studies have assessed the diagnostic accuracy of endoscope technologies individually, there are currently limited data comparing between technologies. As such, the aim of this systematic review was to pool data from the existing literature and compare the correlations between endoscopy and histologic disease activity scores across endoscope technologies.

METHODS

We searched PubMed and Embase until February 2021 for eligible studies reporting the correlation between endoscopy and histology activity scores in UC. Studies were grouped by endoscope technology as standard-definition white light (SD-WLE), high-definition white light (HD-WLE) or electronic virtual chromoendoscopy (VCE) and comparisons made between these groups.

RESULTS

A total of N = 27 studies were identified, of which N = 12 were included in a meta-analysis of correlations between endoscopic and histological activity scores. Combining these studies identified considerable heterogeneity (I ²: 89-93%) and returned a pooled correlation coefficient (ρ) for the SD-WLE group of 0.74, which did not differ significantly from HD-WLE (ρ: 0.65, p = 0.521) or VCE (ρ: 0.70, p = 0.801). In addition, N = 4 studies reported the accuracy of endoscopic activity scores on WLE and VCE to diagnose histological remission. Pooling these found significantly higher accuracy for VCE, compared with WLE [risk ratio: 1.13, 95% confidence interval (CI): 1.07-1.19, p < 0.001].

CONCLUSION

Activity scores assessed using endoscopy are strongly correlated with activity on histology regardless of endoscopic technology. VCE seems to be more accurate in predicting histological remission than WLE. However, given the heterogeneity between the included studies, head-to-head trials are warranted to confirm these findings.

Endoscopic remission assessed with PICaSSO virtual electronic chromendoscopy accurately predicts clinical outcomes in ulcerative colitis

BACKGROUND AND AIMS

A composite endoscopic-histologic remission is increasingly explored as an important endpoint in ulcerative colitis (UC). We investigated combined endoscopic-histologic remission for predicting clinical outcomes at 12 months compared with endoscopic remission alone using the high definition virtual chromoendoscopy (VCE) Paddington International virtual ChromoendoScopy ScOre (PICaSSO) and histology scores.

METHODS

Ulcerative colitis patients, prospectively enrolled from 11 international centres, underwent VCE with targeted biopsies and followed up for 12 months. Endoscopic activity was assessed by Mayo Endoscopic Score (MES), Ulcerative Colitis Endoscopic Index Severity (UCEIS) followed by VCE-PICaSSO. Robarts Histopathological Index|Robarts Histological index≤3 without neutrophils in mucosa, and Nancy Histological index (NHI)≤ 1 were used to define histologic remission. Combined endoscopic-histologic remission was compared with endoscopic remission alone by Cox proportional hazards model and by two- and three-proportion analysis using pre-specified clinical outcomes.

RESULTS

307 patients were recruited and 302 analysed. There was no difference in survival without specified clinical outcomes between PICaSSO defined endoscopic remission alone and endoscopic plus histologic remission in the rectum (HR 0.42, 95%CI 0.16-1.11 and HR 1.03, 95%CI 0.42-2.52 for Robarts Histological index and NHI respectively) at 12 months. There was however a significant survival advantage without specified clinical outcome events for UCEIS combined with histology compared with UCEIS alone (HR 0.30, 95%CI 0.12-0.75, p = 0.02) at 12 months (but not combined with NHI). For MES there was no advantage for predicting specified clinical outcomes at 12 months for endoscopy alone versus endoscopy plus histology, but there were differences in two and three proportion analysis at 6 months.

CONCLUSION

Endoscopic remission by VCE-PICaSSO alone was similar to combined endoscopic and histologic remission for predicting specified clinical outcomes at 12 months. Larger studies with specific therapeutic interventions are required to further confirm the findings.

Small intestinal sampling capsule for inflammatory bowel disease type detection and management

Although serum and fecal biomarkers (e.g., lactoferrin, and calprotectin) have been used in management and distinction between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), none are proven to be a differential diagnostic tool between Crohn's disease (CD) and ulcerative colitis (UC). The main challenge with laboratory-based biomarkers in the stool test is the inability to indicate the location of the disease/inflammation in the gastrointestinal (GI) tract due to the homogenous nature of the collected fecal sample. For the first time, we have designed and developed a battery-free smart capsule that will allow targeted sampling of inflammatory biomarkers inside the gut lumen of the small intestine. The capsule is designed to provide a simple and non-invasive complementary tool to fecal biomarker analysis to differentiate the type of IBD by pinpointing the site of inflammatory biomarkers secretion (e.g., small or large bowel) throughout the GI tract. The capsule takes advantage of the rapid change from an acidic environment in the stomach to higher pH levels in the small intestine to dissolve a pH-sensitive polymeric coating as a means to activate the sampling process of the capsule within the small intestine. A swelling polyacrylamide hydrogel is placed inside the capsule as a milieu to collect the sampled GI fluid while also providing the required mechanical actuation to close the capsule once the sampling is completed. The hydrogel component along with the collected GI fluid can be easily obtained from the capsule through the screw-cap design for further extraction and analysis. As a proof of concept, the capsule's performance in sampling and extraction of bovine serum albumin (BSA) and calprotectin - a key biomarker of inflammation - was assessed within the physiologically relevant ranges. The ratio of extracted biomarkers relative to that in the initial sampling environment remained constant (∼3%) and independent of the sampling matrix in both in vitro and ex vivo studies. It is believed that the demonstrated technology will provide immediate impact in more effective IBD type differential diagnostic and treatment strategies by providing a non-invasive assessment of inflammation biomarkers profile throughout the digestive tract.

Etrolizumab as induction and maintenance therapy for ulcerative colitis in patients previously treated with tumour necrosis factor inhibitors (HICKORY): a phase 3, randomised, controlled trial

BACKGROUND

Etrolizumab is a gut-targeted, anti-β7 integrin, monoclonal antibody. In an earlier phase 2 induction study, etrolizumab significantly improved clinical remission compared with placebo in patients with moderately to severely active ulcerative colitis. We aimed to evaluate the efficacy and safety of etrolizumab in patients with moderately to severely active ulcerative colitis who had been previously treated with anti-tumour necrosis factor (TNF) agents.

METHODS

HICKORY was a multicentre, phase 3, double-blind, placebo-controlled study in adult (18-80 years) patients with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) previously treated with TNF inhibitors. Patients were recruited from 184 treatment centres across 24 countries in North America, South America, Europe, Asia, Oceania, and the Middle East. Patients needed to have an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. In cohort 1, patients received open-label etrolizumab 105 mg every 4 weeks for a 14-week induction period. In cohort 2, patients were randomly assigned (4:1) to receive subcutaneous etrolizumab 105 mg or placebo every 4 weeks for the 14-week induction phase. Patients in either cohort achieving clinical response to etrolizumab induction were eligible for the maintenance phase, in which they were randomly assigned (1:1) to receive subcutaneous etrolizumab 105 mg or placebo every 4 weeks through to week 66. Randomisation was stratified by baseline concomitant treatment with corticosteroids, concomitant treatment with immunosuppressants (induction randomisation only), baseline disease activity, week 14 MCS remission status (maintenance randomisation only), and induction cohort (maintenance randomisation only). All patients and study site personnel were masked to treatment assignment. Primary endpoints were remission (Mayo Clinic total score [MCS] ≤2, with individual subscores of ≤1 and a rectal bleeding subscore of 0) at week 14, and remission at week 66 among patients with a clinical response (MCS with ≥3-point decrease and ≥30% reduction from baseline, plus ≥1 point decrease in rectal bleeding subscore or absolute rectal bleeding score of 0 or 1) at week 14. Efficacy was analysed using a modified intent-to-treat population. Safety analyses included all patients who received at least one dose of study drug during the induction phase. This study is registered at ClinicalTrials.gov, NCT02100696.

FINDINGS

HICKORY was conducted from May 21, 2014, to April 16, 2020, during which time 1081 patients were screened, and 609 deemed eligible for inclusion. 130 patients were included in cohort 1. In cohort 2,479 patients were randomly assigned to the induction phase (etrolizumab n=384, placebo n=95). 232 patients were randomly assigned to the maintenance phase (etrolizumab to etrolizumab n=117, etrolizumab to placebo n=115). At week 14, 71 (18·5%) of 384 patients in the etrolizumab group and six (6·3%) of 95 patients in the placebo group achieved the primary induction endpoint of remission (p=0·0033). No significant difference between etrolizumab and placebo was observed for the primary maintenance endpoint of remission at week 66 among patients with a clinical response at week 14 (27 [24·1%] of 112 vs 23 [20·2%] of 114; p=0·50). Four patients in the etrolizumab group reported treatment-related adverse events leading to treatment discontinuation. The proportion of patients reporting at least adverse event was similar between treatment groups for induction (etrolizumab 253 [66%] of 384; placebo 63 [66%] of 95) and maintenance (etrolizumab to etrolizumab 98 [88%] of 112; etrolizumab to placebo 97 [85%] of 114). The most common adverse event in both groups was ulcerative colitis flare. Most adverse events were mild or moderate. During induction, the most common serious adverse event was ulcerative colitis flare (etrolizumab ten [3%] of 384; placebo: two [2%] of 95). During maintenance, the most common serious adverse event in the etrolizumab to etrolizumab group was appendicitis (two [2%] of 112) and the most common serious adverse events in the etrolizumab to placebo group were ulcerative colitis flare (two [2%] of 114) and anaemia (two [2%] of 114).

INTERPRETATION

HICKORY demonstrated that a significantly higher proportion of patients with moderately to severely active ulcerative colitis who had been previously treated with anti-TNF agent were able to achieve remission at week 14 when treated with etrolizumab compared with placebo; however, there was no significant difference between groups in remission at week 66 among patients with a clinical response at week 14.

FUNDING

F Hoffmann-La Roche.

The endoscopic diagnosis of mucosal healing and deep remission in inflammatory bowel disease

The therapeutic goal in inflammatory bowel disease (IBD) patients has shifted from controlling the clinical activity alone to managing other associated problems. The concept of mucosal healing (MH) and deep remission (DR) are advocated and regarded as new therapeutic goals in IBD. However, the definition of MH still remains controversial. It is unclear whether or not the histological structures or functional factors should be included in the definition of DR in addition to clinical remission and MH. The classifications of white-light imaging (e.g. Mayo endoscopic subscore, UCEIS, CD Endoscopic Index of Severity, simple Endoscopic Score-CD) have been proposed and are now widely used to assess the severity as well as the MH of inflammation in IBD. In ulcerative colitis, magnifying chromoendoscopy has been shown to be useful to assess the MH of inflammation while other types of image-enhanced endoscopy, such as narrow-band imaging, have not. Endocytoscopy and confocal laser endomicroscopy (CLE) are also applied to assess the activity in IBD. These endoscopic procedures can estimate MH with more precision through observing the details of superficial structures, such as crypt openings. In addition, CLE can partially assess the mucosal function by detecting fluorescence leakage. Molecular imaging can possibly detect the molecules associated with inflammation, intestinal regeneration and differentiation, and various functions including the intestinal barrier and mucus secretion. These novel procedures may improve the diagnosis strategy of DR through the assessment of DR-associated factors such as the histological structures and functional factors in the near future.

Ultra-high Magnification Endocytoscopy and Molecular Markers for Defining Endoscopic and Histologic Remission in Ulcerative Colitis-An Exploratory Study to Define Deep Remission

BACKGROUND

Endoscopic and histological remission are both important treatment goals in patients with ulcerative colitis (UC). We aimed to define cellular architecture, expression of molecular markers, and their correlation with endoscopic scores assessed by ultra-high magnification endocytoscopy (ECS) and histological scores.

METHODS

Patients with UC (n = 29) were prospectively recruited. The correlation among ECS score (ECSS), Mayo endoscopic score (MES), and histological scores were determined. Area under curve were plotted to determine the best thresholds for ECSS that predicted histological remission by Robarts (RHI) and Nancy Histological Index (NHI).Soluble analytes relevant to inflammation were measured in serum and mucosal culture supernatants using ProcartaPlex Luminex assays and studied by partial least square discriminant analysis and logistic model. Mucosal RNA sequencing and bioinformatics analysis were performed to define differentially expressed genes/pathways.

RESULTS

Endocytoscope scoring system correlated strongly with RHI (r = 0.89; 95% CI, 0.51-0.98) and NHI (r = 0.86; 95% CI, 0.42-0.98) but correlated poorly with MES (r = 0.28; 95% CI, 0.27-0.70). We identified soluble brain-derived neurotrophic factors (BDNF), macrophage inflammatory proteins (MIP-1 α) and soluble vascular cell adhesion molecule 1 (sVCAM-1) predicted histological remission. Mucosal biopsy cultures also identified sVCAM-1 associated with healed mucosa. RNA-seq analysis identified gene expressions shared between ECSS, RHI, or NHI defined healing. A number of gene expressions and pathways were identified including inflammation and metabolic and tumor suppressors that discriminated healed from nonhealed mucosa.

CONCLUSIONS

Endocytoscopy represents an interesting tool that may sit between endoscopy and histology-but closer to the latter-identifying gene expression markers and pathways that are also identified by histology.

Clinical, Endoscopic and Histological Outcomes in Induction of Moderate-to-Severe Ulcerative Colitis: A Systematic Review with Meta-Analysis

BACKGROUND AND AIMS

Interest in histology for ulcerative colitis [UC] has increased recently. This systematic review and meta-analysis aims to assess, for the first time, whether histological outcomes are more informative than endoscopic and clinical outcomes in distinguishing the impact of intervention over placebo in induction trials.

METHODS

MEDLINE, ScienceDirect and Cochrane Central Register of Controlled Trials were searched to identify randomized placebo-controlled trials [RCTs] enrolling moderate-to-severe UC patients. Studies were assessed using the Quality Assessment Tool for Studies with Diverse Designs. We analysed the pooled proportion of patients achieving clinical, endoscopic and histological remission and response after a pharmacological intervention and compared the results with those of placebo-treated patients by using a random-effects model.

RESULTS

From 889 identified records, 13 RCTs were included. The odds ratio [OR] for remission was higher in patients receiving intervention than in those under placebo for clinical (OR 2.13, 95% confidence interval [CI] 1.33-3.43), endoscopic [OR 1.46, 95% CI 0.19-11.18] and histological remission [OR 1.85, 95% CI 1.20-2.84]. Significant differences were observed for all response outcomes [clinical: OR 2.27, 95% CI 1.84-2.85; endoscopic: OR 2.16, 95% CI 1.51-3.10; histological: OR 3.63, 95% CI, 1.41-9.36]. No significant heterogeneity existed; no subgroup effects were found for duration of the induction or histological scale [p > 0.05]. Clinical and histological remission and endoscopic response were concordant in discriminating interventions from placebo.

CONCLUSION

Histological outcomes are informative in trials of moderate-to-severe UC. Further studies analysing histology at the end of induction are needed to confirm its relevance in distinguishing the efficacy of an intervention over placebo in comparison to clinical and endoscopic outcomes and to explore its prognostic value.

'Treat to Target' in Mild to Moderate Ulcerative Colitis: Evidence to Support this Strategy

BACKGROUND

The management of chronic conditions, above all rheumatic disease and diabetes, now incorporates a "treat to target" strategy where treatment aims to achieve objective outcomes. This is applicable in ulcerative colitis (UC) as well. Targets are demonstrated to prevent endorgan dysfunction, specifically bowel damage and its complications, and lastly colorectal cancer. Recently, the scientific community has tried to define further targets beyond those currently recommended, namely mucosal healing and clinical remission. Studies that prospectively investigated this approach in UC are scanty and a treat-to-target (T2T) algorithm is not routinely used in daily clinical practice.

OBJECTIVE

We aim to review current evidence on T2T in UC and discuss its adoption in routine clinical practice as well as in clinical trials.

METHODS

A PubMed search was conducted in February 2020 to identify published papers investigating targets' achievement rates in UC.

RESULTS

Different targets can be achieved through approved drugs for mild to moderate UC; histological remission is emerging as a robust target with respect to long-term outcomes.

CONCLUSION

Further studies to compare a T2T strategy with the traditional care are needed, particularly in the mild to moderate spectrum of disease.

Relationship Between Combined Histologic and Endoscopic Endpoints and Efficacy of Ustekinumab Treatment in Patients With Ulcerative Colitis

BACKGROUND & AIMS

Ustekinumab induces and maintains histologic improvement in patients with ulcerative colitis (UC). The clinical relevance of this endpoint alone, and in combination with endoscopic improvement, is unknown.

METHODS

Histologic disease activity was evaluated in 2630 colonic biopsy samples from patients with UC treated in the UNIFI phase 3 UC clinical studies of ustekinumab. We evaluated associations between histologic improvement (defined as the composite of neutrophil infiltration in less than 5% of crypts and no crypt destruction, erosions, ulcerations, or granulation tissue) and clinical endpoints at the end of induction (week 8 and 16) and maintenance (week 44) periods. We assessed the validity of a combined histologic and endoscopic (Mayo endoscopy subscore, 0 or 1) improvement endpoint, which we called histo-endoscopic mucosal healing (or histo-endoscopic mucosal improvement).

RESULTS

Histologic improvement was significantly (P < .0001) associated with clinical remission, lower mean disease activity scores, and greater improvement in disease activity at the end of induction and maintenance studies. Ustekinumab induced and maintained significantly higher rates of histologic improvement at induction week 8 and maintenance week 44 than placebo when more stringent definitions of histologic improvement were used. Histologic improvement and endoscopic improvement following induction were associated with 10% to 20% higher rates of histo-endoscopic mucosal healing, clinical remission, and corticosteroid-free remission at week 44 (all P < .05) in patients who received ustekinumab maintenance therapy. At week 44, 61% of patients (56/92) with histo-endoscopic mucosal healing after induction therapy achieved clinical remission, versus 39% of patients (9/23, P = .0983) and 34% of patients (24/71, P = .0009) with endoscopic or histologic improvement alone after induction, respectively.

CONCLUSION

Data from the UNIFI program of ustekinumab in patients with UC treated with ustekinumab indicated the achievement of histo-endoscopic mucosal healing after induction therapy is associated with lower disease activity at the end of maintenance therapy than either histologic or endoscopic improvement alone. ClinicalTrials.gov number: NCT02407236.

Comparison between Diffusion-Weighted Sequences with Selective and Non-Selective Fat Suppression in the Evaluation of Crohn's Disease Activity: Are They Equally Useful?

Background: We compared the efficiency of two MRI diffusion weighted imaging (DWI) techniques: DWI with SPIR (DWI_SPIR) and DWI with STIR (DWI_STIR), to estimate their eligibility for quantitative assessment of Crohn’s disease activity in children and adults. Methods: In inflamed terminal ileum segments (n = 32 in adults, n = 46 in children), Magnetic Resonance Index of Activity (MaRIA) was calculated, ADC values of both DWI techniques were measured, and the corresponding Clermont scores calculated. ADC values of both DWI techniques were compared between both and within each patient group, assessing their mutual correlation. Correlations between MaRIA and the corresponding ADC values, and Clermont scores based on both DWI techniques were estimated. Results: No correlation between ADC of DWI_SPIR and DWI_STIR was observed (rho = 0.27, p = 0.13 in adults, rho = 0.20, p = 0.17 in children). The correlation between MaRIA and Clermont scores was strong in both techniques—in SPIR, rho = 0.93; p < 0.0005 in adults, rho = 0.98, p < 0.0005 in children, and, in STIR, rho = 0.89; p < 0.0005 in adults, rho = 0.95, p < 0.0005 in children. The correlation between ADC and MaRIA was moderate negative for DWI_STIR (rho = 0.93, p < 0.0005 in adults, rho = 0.95, p < 0.0005 in children), but, in DWI_STIR, no correlation between ADC and MaRIA score was observed in adults (rho = −0.001, p = 0.99), whereas children presented low negative correlation (rho = −0.374, p = 0.01). Conclusions: DWI_STIR is not suitable for quantitative assessment of Crohn’s disease activity both in children and adult patients.

Mucosal healing in Crohn's disease: new insights

INTRODUCTION

Traditional management of patients with Crohn's disease includes symptoms and quality of life improvement. With the advent of biological agents, mucosal healing has become an achievable goal, documented through endoscopy. However, due to the transmural nature of inflammation, the prevention of bowel damage should be included in the aims of a targeted therapeutic strategy.

AREAS COVERED

Updated literature has been searched in PubMed from 2008 to 2020. This review focuses on the state of the art in the innovative therapeutic goals in Crohn's disease, also considering still controversial aspects and future research topics in the management of Crohn's disease.

EXPERT OPINION

Although a widely agreed view supports the notion that mucosal healing and bowel damage control may promote beneficial outcomes (i.e. reduction in hospitalization and surgical rates, avoidance of steroids), long-term robust data are still missing. On the other hand, the development of -omics techniques has expanded our knowledge of the pathogenetic mechanism underlying inflammatory bowel disease and opened up new horizons in precision or personalized medicine.