Treat to Target: The Role of Histologic Healing in Inflammatory Bowel Diseases: A Systematic Review and Meta-analysis

Lymphocyte subsets for predicting inflammatory bowel disease progression and treatment response: a systematic review

Background

Lymphocytes play a key role in the pathogenesis of inflammatory bowel disease (IBD) and are widely explored as promising prognostic indicators. We aimed to outline the existing evidences on the capability of lymphocyte subpopulations to predict disease progression and treatment response in patients with IBD.

Methods

The protocol for this review was registered in PROSPERO (registration ID: CRD 42022364126). Systematic retrieval was conducted using PubMed, Embase, and Web of Science databases. Original articles on the prognostic value of lymphocyte subsets in IBD published up to April 8, 2023 were eligible for inclusion. The Newcastle-Ottawa Scale was used to evaluate the risk of bias.

Results

Twenty studies were ultimately included: eight evaluated the prediction of disease progression and 12 focused on the prediction of treatment response. According to the Newcastle-Ottawa Scale, three studies were of high quality, 16 were of moderate quality, and only one was of low quality. T-cell subpopulations, including CD4+ T cells, CD8+ T cells, and γδ T cells, are revealed to have prognostic capacity. Transmembrane tumor necrosis factor α-bearing lymphocytes, CD4+ T cells, CD8+ T cells, and Plasma cells are found to have the potential to predict the response to anti-TNFα agents. In contrast memory T cells, CD4+ T cells, and naïve B cells may predict the response to vedolizumab.

Conclusions

This systematic review identified several potential lymphocyte subset-related predictors. If verified in large cohort prospective studies, these findings could aid clinical decision-making.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022364126.

Relationship between histopathological findings, clinical severity and the need for surgery in patients with Crohn's disease

INTRODUCTION

Defining histological variables that make it possible to establish the activity of Crohn's disease (CD) and predict the patients who may present a higher risk of clinical complications and surgical interventions could lead to timely adjustments in medical therapy and elective surgeries that represent a lower risk of complications. The purpose of the study is to determine the relation between the histopathological findings using the Naini and Cortina (N&C) score, the clinical severity, and the indication for surgery in a group of patients with CD.

MATERIALS AND METHODS

Descriptive, retrospective, cross-sectional study of 44 patients diagnosed with CD, treated at the San Vicente Fundación University Hospital in Medellín, Colombia, between 2010 and 2022.

RESULTS

Of the 44 patients, 36 ileum samples and 34 colon samples were obtained. Of the patients with inflammatory behavior, 87.5% did not have surgical intervention (P=.022), a value that remained significant in the ileum subgroup (P=.0058). 91.3% of the patients with ileal involvement did not develop perianal disease (P=.01). Granulomas only occurred in two patients with a colon sample (5.8%). In the histological score of N&C both in the ileum and in the colon, no statistically significant differences were obtained in relation to the surgical outcome (P=.34 and P=.054, respectively).

CONCLUSION

The histological index of N&C was not a predictor in Crohn's disease (CD) related to the surgical outcome.

Artificial intelligence and endo-histo-omics: new dimensions of precision endoscopy and histology in inflammatory bowel disease

Integrating artificial intelligence into inflammatory bowel disease (IBD) has the potential to revolutionise clinical practice and research. Artificial intelligence harnesses advanced algorithms to deliver accurate assessments of IBD endoscopy and histology, offering precise evaluations of disease activity, standardised scoring, and outcome prediction. Furthermore, artificial intelligence offers the potential for a holistic endo-histo-omics approach by interlacing and harmonising endoscopy, histology, and omics data towards precision medicine. The emerging applications of artificial intelligence could pave the way for personalised medicine in IBD, offering patient stratification for the most beneficial therapy with minimal risk. Although artificial intelligence holds promise, challenges remain, including data quality, standardisation, reproducibility, scarcity of randomised controlled trials, clinical implementation, ethical concerns, legal liability, and regulatory issues. The development of standardised guidelines and interdisciplinary collaboration, including policy makers and regulatory agencies, is crucial for addressing these challenges and advancing artificial intelligence in IBD clinical practice and trials.

Endoscopic, Histologic, and Composite Endpoints in Patients With Ulcerative Colitis Treated With Etrasimod

BACKGROUND & AIMS

Histologic remission, a potentially important treatment target in ulcerative colitis (UC), is associated with favorable long-term outcomes. Etrasimod is an oral, once-daily, selective sphingosine 1-phosphate (S1P)1,4,5 receptor modulator for the treatment of moderately to severely active UC. This post-hoc analysis of the ELEVATE UC program evaluated the efficacy of etrasimod according to histologic and composite (histologic/endoscopic/symptomatic) endpoints and examined their prognostic value.

METHODS

Patients with moderately to severely active UC were randomized 2:1 to once-daily oral etrasimod 2 mg or placebo. Histologic and composite endpoints, including disease clearance (endoscopic/histologic/symptomatic remission), were assessed at Weeks 12 (ELEVATE UC 52; ELEVATE UC 12) and 52 (ELEVATE UC 52). Logistic regressions examined associations between baseline and Week 12 histologic/composite endpoints and Week 52 outcomes.

RESULTS

At Weeks 12 and 52, significant improvements with etrasimod vs placebo were observed in histologic/composite outcomes, including endoscopic improvement-histologic remission and disease clearance. The proportion of patients treated with etrasimod achieving clinical remission at Week 52 was higher among those with disease clearance at Week 12 vs those without disease clearance (73.9% [17/23] vs 28.3% [71/251]). Histologic improvement and endoscopic improvement at Week 12 were moderately and strongly associated with clinical remission at Week 52 (odds ratio [OR], 2.37; 95% confidence interval [CI], 1.27-4.41; and OR, 6.36; 95% CI, 3.47-11.64, respectively). Histologic remission and endoscopic improvement at Week 12 were strongly associated with endoscopic improvement-histologic remission at Week 52 (OR, 3.21; 95% CI, 1.70-6.06 and OR, 5.47; 95% CI, 2.89-10.36, respectively).

CONCLUSIONS

Etrasimod was superior to placebo for achievement of stringent histologic and composite endpoints.

CLINICALTRIALS

gov, Number: NCT03945188; ClinicalTrials.gov, Number: NCT03996369.

Histologic Activity From Neoterminal Ileal Biopsies in Patients With Crohn's Disease in Endoscopic Remission is Associated With Postoperative Recurrence

INTRODUCTION

Following ileocolic resection (ICR), the clinical importance and prognostic implications of histologic activity on biopsies in Crohn's disease (CD) patients with endoscopic remission are not well defined. The aim of this study was to determine if histologic activity in patients with endoscopic remission is associated with future risk of endoscopic and/or radiologic postoperative recurrence (POR).

METHODS

In this multicenter retrospective cohort study, adult patients with CD who underwent ICR between 2009 and 2020 with endoscopic biopsies of ileal mucosa from Rutgeerts i0 on index colonoscopy were included. The composite rate of endoscopic (Rutgeerts score ≥i2b) and radiologic (active inflammation on imaging) recurrence was compared in patients with and without histologic activity using a Kaplan-Meier survival analysis. A multivariable Cox proportional hazard regression model including clinically relevant risk factors of POR, postoperative biologic prophylaxis, and histology activity was designed.

RESULTS

A total of 113 patients with i0 disease on index colonoscopy after ICR were included. Of these, 42% had histologic activity. Time to POR was significantly earlier in the histologically active versus normal group ( P = 0.04). After adjusting for clinical risk factors of POR, histologic activity (HR 2.37, 95% CI 1.17-4.79; P = 0.02) and active smoking (HR 2.54, 95% CI 1.02-6.33; P = 0.05) were independently associated with subsequent composite POR risk.

DISCUSSION

In patients with postoperative CD, histologic activity despite complete endoscopic remission is associated with composite, endoscopic, and radiographic recurrence. Further understanding of the role of histologic activity in patients with Rutgeerts i0 disease may provide a novel target to reduce disease recurrence in this population.

How Artificial Intelligence Will Transform Clinical Care, Research, and Trials for Inflammatory Bowel Disease

Artificial intelligence (AI) refers to computer-based methodologies that use data to teach a computer to solve pre-defined tasks; these methods can be applied to identify patterns in large multi-modal data sources. AI applications in inflammatory bowel disease (IBD) includes predicting response to therapy, disease activity scoring of endoscopy, drug discovery, and identifying bowel damage in images. As a complex disease with entangled relationships between genomics, metabolomics, microbiome, and the environment, IBD stands to benefit greatly from methodologies that can handle this complexity. We describe current applications, critical challenges, and propose future directions of AI in IBD.

TNF Promoter Hypomethylation Is Associated With Mucosal Inflammation in IBD and Anti-TNF Response

Background and Aims

Inflammatory bowel diseases (IBDs) are chronic inflammatory conditions influenced heavily by environmental factors. DNA methylation is a form of epigenetic regulation linking environmental stimuli to gene expression changes and inflammation. Here, we investigated how DNA methylation of the tumor necrosis factor (TNF) promoter differs between inflamed and uninflamed mucosa of IBD patients, including anti-TNF responders and nonresponders.

Methods

We obtained mucosal biopsies from 200 participants (133 IBDs and 67 controls) and analyzed TNF promoter methylation using bisulfite sequencing, comparing inflamed with uninflamed segments, in addition to paired inflamed/uninflamed samples from individual patients. We conducted similar analyses on purified intestinal epithelial cells from bowel resections. We also compared TNF methylation levels of inflamed and uninflamed mucosa from a separate cohort of 15 anti-TNF responders and 17 nonresponders. Finally, we sequenced DNA methyltransferase genes to identify rare variants in IBD patients and functionally tested them using rescue experiments in a zebrafish genetic model of DNA methylation deficiency.

Results

TNF promoter methylation levels were decreased in inflamed mucosa of IBD patients and correlated with disease severity. Isolated intestinal epithelial cells from inflamed tissue showed proportional decreases in TNF methylation. Anti-TNF nonresponders showed lower levels of TNF methylation than responders in uninflamed mucosa. Our sequencing analysis revealed 2 missense variants in DNA methyltransferase 1, 1 of which had reduced function in vivo.

Conclusion

Our study reveals an association of TNF promoter hypomethylation with mucosal inflammation, suggesting that IBD patients may be particularly sensitive to inflammatory environmental insults affecting DNA methylation. Together, our analyses indicate that TNF promoter methylation analysis may aid in the characterization of IBD status and evaluation of anti-TNF therapy response.

Development and validation of a novel criterion of histologic healing in ulcerative colitis defined by inflammatory cell enumeration in lamina propria mucosa: A multicenter retrospective cohort in China

BACKGROUND

Histological healing is closely associated with improved long-term clinical outcomes and lowered relapses in patients with ulcerative colitis (UC). Here, we developed a novel diagnostic criterion for assessing histological healing in UC patients.

METHODS

We conducted a retrospective cohort study in UC patients, whose treatment was iteratively optimized to achieve mucosal healing at Shanghai Tenth People's Hospital of Tongji University from January 2017 to May 2022. We identified an inflammatory cell enumeration index (ICEI) for assessing histological healing based on the proportions of eosinophils, CD177 + neutrophils, and CD40L + T cells in the colonic lamina propria under high power field (HPF), and the outcomes (risks of symptomatic relapses) of achieving histological remission vs . persistent histological inflammation using Kaplan-Meier curves. Intrareader reliability and inter-reader reliability were evaluated by each reader. The relationships to the changes in the Nancy index and the Geboes score were also assessed for responsiveness. The ICEI was further validated in a new cohort of UC patients from other nine university hospitals.

RESULTS

We developed an ICEI for clinical diagnosis of histological healing, i.e., Y = 1.701X 1 + 0.758X 2 + 1.347X 3 - 7.745 (X 1 , X 2 , and X 3 represent the proportions of CD177 + neutrophils, eosinophils, and CD40L + T cells, respectively, in the colonic lamina propria under HPF). The receiver operating characteristics curve (ROC) analysis revealed that Y <-0.391 was the cutoff value for the diagnosis of histological healing and that an area under the curve (AUC) was 0.942 (95% confidence interval [CI]: 0.905-0.979) with a sensitivity of 92.5% and a specificity of 83.6% ( P  <0.001). The intraclass correlation coefficient (ICC) for the intrareader reliability was 0.855 (95% CI: 0.781-0.909), and ICEI had good inter-reader reliability of 0.832 (95% CI: 0.748-0.894). During an 18-month follow-up, patients with histological healing had a substantially better outcome compared with those with unachieved histological healing ( P  <0.001) using ICEI. During a 12-month follow-up from other nine hospitals, patients with histological healing also had a lower risk of relapse than patients with unachieved histological healing.

CONCLUSIONS

ICEI can be used to predict histological healing and identify patients with a risk of relapse 12 months and 18 months after clinical therapy. Therefore, ICEI provides a promising, simplified approach to monitor histological healing and to predict the prognosis of UC.

REGISTRATION

Chinese Clinical Trial Registry, No. ChiCTR2300077792.

Histologic Remission in Inflammatory Bowel Disease and Female Fertility: A Nationwide Study

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) is linked to reduced female fertility, but it is unclear how fertility rates vary by histologic disease activity.

METHODS

Nationwide IBD cohort of Swedish women aged 15 to 44 years. We examined fertility rates during periods with vs without histologic inflammation (n = 21,046; follow-up, 1990-2016) and during periods with vs without clinical activity (IBD-related hospitalization, surgery, or treatment escalation) (n = 24,995; follow-up, 2006-2020). Accounting for sociodemographics and comorbidities, we used Poisson regression to estimate adjusted fertility rate ratios (aFRRs) for live births conceived during 12-month periods of histologic inflammation (vs histologic remission) and 3-month periods of clinically active IBD (vs quiescent IBD).

RESULTS

During periods with vs without histologic inflammation, there were 6.35 (95% confidence interval [CI], 5.98-6.73) and 7.09 (95% CI, 6.48-7.70) live births conceived per 100 person-years of follow-up, respectively, or 1 fewer child per 14 women with 10 years of histologic inflammation (aFRR, 0.90; 95% CI, 0.81-1.00). In women with histologic inflammation, fertility was similarly reduced in ulcerative colitis (UC) (aFRR, 0.89 [95% CI, 0.78-1.02]) and Crohn's disease (CD) (aFRR, 0.86 [95% CI, 0.72-1.04]). Clinical IBD activity was associated with an aFRR of 0.76 (95% CI, 0.72-0.79) or 1 fewer child per 6 women with 10 years of clinical activity. Fertility was reduced in clinically active UC (aFRR, 0.75 [95% CI, 0.70-0.81]) and CD (aFRR, 0.76 [95% CI, 0.70-0.82]). Finally, among women with clinically quiescent IBD, histologic inflammation (vs histologic remission) was associated with reduced fertility (aFRR, 0.85 [95% CI, 0.73-0.98]).

CONCLUSIONS

An association between histologic and clinical activity and reduced female fertility in CD and UC was found. Notably, histologic inflammation was also linked to reduced fertility in women with clinically quiescent IBD.

Histological Disease Activity as Predictor of Clinical Relapse, Hospitalization, and Surgery in Inflammatory Bowel Disease: Systematic Review and Meta-Analysis

BACKGROUND

The clinical impact of histological remission on short- and long-term clinical outcomes in patients with inflammatory bowel disease (IBD) is not well established. We assessed risk of clinical relapse, hospitalization, and need for surgery in patients achieving histological remission in comparison with active histological disease.

METHODS

A systematic review was conducted using MEDLINE, Scopus, Cochrane CENTRAL, EMBASE, and conference abstracts from inception to November 2022. Our main outcome was the rate of clinical relapse in patients with IBD who reached histological remission vs patients with active histological disease. Secondary outcomes were clinical complications of IBD such as hospitalization and need for surgery. The endpoints were investigated at 2 time points, 6 to 12 months (short term) and >12 months (long term).

RESULTS

Short-term outcome analysis showed that the risk of clinical relapse was significantly higher in ulcerative colitis patients with active histological disease in comparison with patients at histological remission (risk ratio [RR], 2.41; 95% confidence interval [CI], 1.69-3.44; P < .01). The risk of hospitalization in ulcerative colitis patients was not significant among the 2 groups (RR, 4.22; 95% CI, 0.91-19.62; P = .07). Long-term outcome analysis demonstrated that the risk of clinical relapse (RR, 2.07; 95% CI, 1.55-2.76; P < .01), need for surgery (RR, 3.14; 95% CI, 1.53-6.45; P < .01), and hospitalization (RR, 2.52; 95% CI, 1.59-4.00; P < .01) was significantly higher in patients with active histological disease.

CONCLUSIONS

Histological remission in IBD represents an important therapeutic goal that is not yet routinely pursued in clinical practice. In our study, patients who achieved histological remission have more favorable outcomes than those with active histological disease in ulcerative colitis.

Tofacitinib real-world experience in ulcerative colitis in Finland (FinTofUC): a retrospective non-interventional multicenter patient chart data study

OBJECTIVES

The aim was to define the effectiveness of tofacitinib and to characterize the patient population receiving tofacitinib in a real-world cohort clinical setting for ulcerative colitis (UC) in Finland.

METHODS

This is a retrospective non-interventional multicenter patient chart data study conducted in 23 Finnish Inflammatory Bowel Disease (IBD) centers. Baseline demographic and clinical data, clinical remission, steroid-free remission rate and time to tofacitinib discontinuation, colectomy or UC-related hospitalization were studied.

RESULTS

The study included 252 UC patients of which 69% were male. Most patients had extensive disease (71%) and were bio-experienced (81%). Tofacitinib demonstrated positive treatment outcomes with clinical response, clinical remission, and steroid-free clinical remission at one year in 33%, 34% and 31% of patients, respectively. Moreover, 64% of patients in pMayo remission at week 16 from the start of tofacitinib were still in remission at one year. Only no or mild disease activity compared to moderate activity at baseline was associated with a higher probability of achieving remission according to pMayo at six months, p = .008. Hospitalizations and/or colectomies during the study period (before treatment discontinuation/end of follow-up) were low (n = 24), with less than 5 colectomies.

CONCLUSIONS

In this real-world cohort, including a majority of bio-experienced UC patients, tofacitinib was effective in achieving steroid-free clinical remission in a third of the population at one year. A majority of patients in remission at week 16 were also in remission at one year. Results are in line with earlier published real-world studies. Registration: ClinicalTrials.gov NCT05082428.

Histological healing induced by tofacitinib in ulcerative colitis: A multicentre study

BACKGROUND

While the efficacy of tofacitinib to induce and maintain clinical and endoscopic remission is well established in ulcerative colitis (UC), little is known about its efficacy to induce histological remission.

METHODS

We conducted a retrospective multicentric cohort study. UC patients ≥ 16 years treated by tofacitinib in whom histological activity has been evaluated before and after induction were eligible. The primary endpoint was the histological remission at the end of induction, assessed by the Nancy index and the epithelial neutrophilic infiltrate.

RESULTS

A total of 42 patients with UC (93% previously exposed to an anti-TNF and 81% to vedolizumab) were included between July 2018 and April 2022 and were followed for a median duration of 84 weeks [IQR, 35-134]. At the end of induction period (whether prolonged or not), 19% and 24% of patients achieved histological remission, using the Nancy index and the epithelial neutrophilic infiltrate, respectively. Survival without tofacitinib discontinuation was significantly longer in patients without epithelial neutrophilic infiltrate at the end of induction (whether prolonged or not) compared with patients with epithelial neutrophilic infiltrate (p = 0.036).

CONCLUSION

Tofacitinib induced histological remission in one fifth to one quarter of patients with UC who have previously failed anti-TNF or/and vedolizumab after induction (whether prolonged or not).

Artificial intelligence image-based prediction models in IBD exhibit high risk of bias: A systematic review

BACKGROUND

There has been an increase in the development of both machine learning (ML) and deep learning (DL) prediction models in Inflammatory Bowel Disease. We aim in this systematic review to assess the methodological quality and risk of bias of ML and DL IBD image-based prediction studies.

METHODS

We searched three databases, PubMed, Scopus and Embase, to identify ML and DL diagnostic or prognostic predictive models using imaging data in IBD, to Dec 31, 2022. We restricted our search to include studies that primarily used conventional imaging data, were undertaken in human participants, and published in English. Two reviewers independently reviewed the abstracts. The methodological quality of the studies was determined, and risk of bias evaluated using the prediction risk of bias assessment tool (PROBAST).

RESULTS

Forty studies were included, thirty-nine developed diagnostic models. Seven studies utilized ML approaches, six were retrospective and none used multicenter data for model development. Thirty-three studies utilized DL approaches, ten were prospective, and twelve multicenter studies. Overall, all studies demonstrated high risk of bias. ML studies were evaluated in 4 domains all rated as high risk of bias: participants (6/7), predictors (1/7), outcome (3/7), and analysis (7/7), and DL studies evaluated in 3 domains: participants (24/33), outcome (10/33), and analysis (18/33). The majority of image-based studies used colonoscopy images.

CONCLUSION

The risk of bias was high in AI IBD image-based prediction models, owing to insufficient sample size, unreported missingness and lack of an external validation cohort. Models with a high risk of bias are unlikely to be generalizable and suitable for clinical implementation.

TNF promoter hypomethylation is associated with mucosal inflammation in IBD and anti-TNF response

Background and aims

Inflammatory Bowel Diseases (IBD) are chronic inflammatory conditions influenced heavily by environmental factors. DNA methylation is a form of epigenetic regulation linking environmental stimuli to gene expression changes and inflammation. Here, we investigated how DNA methylation of the TNF promoter differs between inflamed and uninflamed mucosa of IBD patients, including anti-TNF responders and non-responders.

Methods

We obtained mucosal biopsies from 200 participants (133 IBD and 67 controls) and analyzed TNF promoter methylation using bisulfite sequencing, comparing inflamed with uninflamed segments, in addition to paired inflamed/uninflamed samples from individual patients. We conducted similar analyses on purified intestinal epithelial cells from bowel resections. We also compared TNF methylation levels of inflamed and uninflamed mucosa from a separate cohort of 15 anti-TNF responders and 17 non-responders. Finally, we sequenced DNA methyltransferase genes to identify rare variants in IBD patients and functionally tested them using rescue experiments in a zebrafish genetic model of DNA methylation deficiency.

Results

TNF promoter methylation levels were decreased in inflamed mucosa of IBD patients and correlated with disease severity. Isolated IECs from inflamed tissue showed proportional decreases in TNF methylation. Anti-TNF non-responders showed lower levels of TNF methylation than responders in uninflamed mucosa. Our sequencing analysis revealed two missense variants in DNMT1, one of which had reduced function in vivo.

Conclusions

Our study reveals an association of TNF promoter hypomethylation with mucosal inflammation, suggesting that IBD patients may be particularly sensitive to inflammatory environmental insults affecting DNA methylation. Together, our analyses indicate that TNF promoter methylation analysis may aid in the characterization of IBD status and evaluation of anti-TNF therapy response.

Defining Comprehensive Disease Control for Use as a Treatment Target for Ulcerative Colitis in Clinical Practice: International Delphi Consensus Recommendations

BACKGROUND AND AIMS

Treatment of ulcerative colitis [UC] requires a patient-centric definition of comprehensive disease control that considers improvements in aspects not typically captured by classical landmark trial endpoints. In an international initiative, we reviewed aspects of UC that affect patients and/or indicate mucosal inflammation, to achieve consensus on which aspects to combine in a definition of comprehensive disease control, using a modified Delphi process.

METHODS

The Delphi panel comprised 12 gastroenterologists and one patient advocate. Two gastroenterologists were elected as chairs and did not vote. To inform statements, we asked 18 patients and the panel members about their experiences of remission and reviewed published literature. Panel members voted on statements anonymously in three rounds, with a live discussion before Round 3. Consensus was met if ≥67% of the panel agreed. Statements without consensus in Rounds 1 and 2 were revised or discarded after Round 3.

RESULTS

The panel agreed to measure individual patient benefit using a definition of comprehensive disease control that combines aspects currently measured in trials [rectal bleeding, stool frequency, disease-related quality of life, endoscopy, histological inflammatory activity, inflammatory biomarkers, and corticosteroid use] with additional patient-reported symptoms [bowel urgency, abdominal pain, extraintestinal manifestations, fatigue, and sleep disturbance]. The panel agreed on scoring systems and thresholds for many aspects.

CONCLUSIONS

Using a robust methodology, we defined comprehensive disease control in UC. Next, we will combine the measurement and scoring of these aspects into a multicomponent tool and will adopt comprehensive disease control as a treatment target in clinical practice and trials.

Treat to target in Crohn's disease: A practical guide for clinicians

A treat-to-target (T2T) approach applies the principles of early intervention and tight disease control to optimise long-term outcomes in Crohn's disease. The Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE)-II guidelines specify short, intermediate, and long-term treatment goals, documenting specific treatment targets to be achieved at each of these timepoints. Scheduled appraisal of Crohn's disease activity against pre-defined treatment targets at these timepoints remains central to determining whether current therapy should be continued or modified. Consensus treatment targets in Crohn's disease comprise combination clinical and patient-reported outcome remission, in conjunction with biomarker normalisation and endoscopic healing. Although the STRIDE-II guidelines endorse the pursuit of endoscopic healing, clinicians must consider that this may not always be appropriate, acceptable, or achievable in all patients. This underscores the need to engage patients at the outset in an effort to personalise care and individualise treatment targets. The use of non-invasive biomarkers such as faecal calprotectin in conjunction with cross-sectional imaging techniques, particularly intestinal ultrasound, holds great promise; as do emerging treatment targets such as transmural healing. Two randomised clinical trials, namely, CALM and STARDUST, have evaluated the efficacy of a T2T approach in achieving endoscopic endpoints in patients with Crohn's disease. Findings from these studies reflect that patient subgroups and Crohn's disease characteristics likely to benefit most from a T2T approach, remain to be clarified. Moreover, outside of clinical trials, data pertaining to the real-world effectiveness of a T2T approach remains scare, highlighting the need for pragmatic real-world studies. Despite the obvious promise of a T2T approach, a lack of guidance to support its integration into real-world clinical practice has the potential to limit its uptake. This highlights the need to describe strategies, processes, and models of care capable of supporting the integration and execution of a T2T approach in real-world clinical practice. Hence, this review seeks to examine the current and emerging literature to provide clinicians with practical guidance on how to incorporate the principles of T2T into routine clinical practice for the management of Crohn's disease.

Histologic assessments in ulcerative colitis: the evidence behind a new endpoint in clinical trials

INTRODUCTION

Treatment goals for ulcerative colitis (UC) are evolving from the achievement of clinical remission to more rigorous goals defined by endoscopic and histologic healing. Achievement of deeper remission targets aims to reduce the risk of colectomy, hospitalizations, and colorectal cancer.

AREAS COVERED

This review covers histologic assessments, histologic remission as a clinical trial endpoint, and the association between histologic disease activity and clinical outcomes. Future directions are also discussed, including the use of advanced imaging and artificial intelligence technologies, as well as potential future treatment targets beyond histologic remission.

EXPERT OPINION

Histologic assessments are used for their sensitivity in measuring mucosal inflammatory changes in UC. Due to correlation with disease activity, histologic assessments may support clinical decision-making regarding treatment decisions as such assessments can be associated with rates of clinical relapse, hospitalization, colectomy, and neoplasia. While histologic remission is limited by varying definitions and multiple histologic indices, work is ongoing to create a consensus on the use of histologic assessments in clinical trials. As research advances, aspirational targets beyond histologic remission, such as molecular healing and disease clearance, are being explored.

Neutrophil-only Histological Assessment of Ulcerative Colitis Correlates with Endoscopic Activity and Predicts Long-term Outcomes in a Multicentre Study

BACKGROUNDS AND AIMS

Absence of neutrophils is the minimum standard to consider histological remission of ulcerative colitis [UC]. The PICaSSO Histological Remission Index [PHRI] is a new simple index for UC, based only on the detection of neutrophils. We evaluate PHRI's correlation with endoscopy and its prognostic value compared with other established indices.

METHODS

Consecutive patients with UC underwent colonoscopy at two referral centres [Birmingham, UK, and Milan, Italy,] and were followed up for 2 years. Correlation between histology (PHRI, Nancy [NHI], and Robarts [RHI] indexes) and endoscopy (Mayo Endoscopic Score [MES], Ulcerative Colitis Endoscopic Index of Severity [UCEIS], and PICaSSO index) was calculated as Spearman coefficients. Diagnostic performance of endoscopy was assessed with receiver operating characteristic [ROC] curves and outcome stratification with Kaplan-Meier curves.

RESULTS

A total of 192 patients with UC was enrolled, representing all grades of endoscopic severity. Correlation between histology and endoscopy did not differ significantly when using PHRI instead of NHI or RHI. In particular, PHRI's correlation with MES, UCEIS, and PICaSSO was 0.745, 0.718, and 0.694, respectively. Endoscopically-assessed remission reflected the absence of neutrophils [PHRI = 0] with areas under the ROC curve of 0.905, 0.906, and 0.877 for MES, UCEIS, and PICaSSO, respectively. The hazard ratio for disease flare between patients in histological activity/remission was statistically similar [p >0.05] across indexes [2.752, 2.706, and 2.871 for RHI, NHI, and PHRI, respectively].

CONCLUSION

PHRI correlates with endoscopy and stratifies risk of relapse similarly to RHI and NHI. Neutrophil-only assessment of UC is a simple yet viable alternative to established histological scores.

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.

Healing of the epithelial barrier in the ileum is superior to endoscopic and histologic remission for predicting major adverse outcomes in ulcerative colitis

Background

Achieving endoscopic remission is a key therapeutic goal in patients with ulcerative colitis (UC) that is associated with favorable long-term disease outcomes. Here, we prospectively compared the predictive value of endoscopic and/or histologic remission against ileal barrier healing for predicting long-term disease behavior in a large cohort of UC patients in clinical remission.

Methods

At baseline, UC patients in clinical remission underwent ileocolonoscopy with assessment of ileal barrier function by confocal endomicroscopy. Endoscopic and histologic disease activity and ileal barrier healing were scored using validated scores. During subsequent follow-up (FU), patients were closely monitored for clinical disease activity and occurrence of major adverse outcomes (MAO) defined as the following: disease relapse; UC-related hospitalization; UC-related surgery; necessity for initiation or dose escalation of systemic steroids, immunosuppressants, small molecules or biological therapy.

Results

Of the 73 UC patients included, 67% experienced MAO during a mean FU of 25 months. The probability of MAO-free survival was significantly higher in UC patients with endoscopic and/or histologic remission compared to patients with endoscopically and/or histologically active disease. Ileal barrier healing on endomicroscopy was highly accurate for predicting the further course of UC and outcompeted endoscopic and histologic remission for predicting MAO-free survival.

Conclusion

Ileal barrier healing in clinically remittent UC patients can accurately predict future MAO development and is superior in its predictive capabilities than endoscopic and histologic remission. Ileal barrier healing therefore represents a novel and superior surrogate parameter for stratification of UC patients according to their risk for development of complicated disease behavior.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/NCT05157750, identifier NCT05157750.

Additional information obtained from mucosal biopsies is limited after pan-enteric capsule endoscopy in patients with suspected Crohn's disease

Background and study aims Pan-enteric capsule endoscopy (CE) is an emerging alternative to ileo-colonoscopy for diagnosing Crohn's disease (CD). However, CE does not offer the opportunity to take biopsies to support the diagnosis. This study examined the additional information obtained with mucosal biopsies and the feasibility of CE as a single diagnostic procedure. Patients and methods This retrospective study was based on a prospective, blind multicenter trial in which patients with suspected CD were examined with ileo-colonoscopy plus segmental biopsies and CE. Histopathological findings were compared to the result of CE. Results A total of 107 patients with a complete CE were included in the analysis. CE was consistent with CD in 44 patients (41.1%) and ulcerative colitis in 10 patients (9.3%). Histopathology confirmed the result of CE in 39.3% of patients and added new diagnostic information in 6.5% of patients. A CE consistent with CD was histologically confirmed in 20.5% of patients. Biopsies most often showed non-specific inflammation (61.4%). Only one patient with a normal CE had a specific histological diagnosis (microscopic colitis). Biopsies altered the diagnosis of ulcerative colitis to CD in two patients, and in two patients with a normal CE, biopsies showed CD or ulcerative colitis. In one patient with lymphoma in the terminal ileum and cecum, CE was misinterpreted as CD. Conclusions In patients with suspected CD and an evident result of CE, the additional information obtained from biopsies is limited, and CE as a single diagnostic procedure might be feasible in selected patients. Biopsies are warranted, however, in patients with an atypical endoscopic appearance or suspected malignancy.

Histologic Inflammation can Predict Future Clinical Relapse in Ulcerative Colitis Patients in Endoscopic Remission

Background

In ulcerative colitis (UC), endoscopic improvement, defined as a Mayo Endoscopic Score (MES) of 0 or 1, is a target of treatment. The aim of our study was to evaluate the risk of clinical relapse between patients with an MES of 0 or 1 and determine if histologic activity using the Robarts Histopathologic Index (RHI) was predictive of clinical relapse.

Methods

UC patients with an MES score of 0 or 1, no prior colectomy, and at least 1 year of outpatient follow-up after colonoscopy were included. Demographic, clinical characteristics, and clinical relapse were retrospectively collected. Biopsy specimens were read by a gastrointestinal pathologist. Primary outcome was defined as a composite of relapse requiring change in medical therapy, new steroid use, UC-related hospitalization, and/or colectomy.

Results

Four hundred and forty-five UC patients were identified. Ninety-five percent of patients with MES 0 were in histologic remission by the RHI whereas only 35% of patients with MES 1 were in histologic remission. Twenty-six percent of patients experienced a clinical relapse; patients with MES 1 or RHI > 3 were significantly more likely to relapse (P < .01) compared to patients with MES 0 or RHI ≤ 3. When patients were stratified into 4 groups (MES 0, RHI ≤ 3; MES 0, RHI > 3; MES 1, RHI ≤ 3; MES 1, RHI > 3) and adjusted for age and sex, RHI > 3 was predictive of relapse (P = .008).

Conclusions

UC patients with endoscopic improvement have a high rate of clinical relapse over time. Histologic activity is a predictor of clinical relapse.

Utility of a rapid assay for prostaglandin E-major urinary metabolite as a biomarker in pediatric ulcerative colitis

Prostaglandin E-major urinary metabolite (PGE-MUM) is a urinary biomarker reflecting ulcerative colitis (UC) activity. This prospective observational study aimed to evaluate the usefulness of PGE-MUM via rapid chemiluminescent enzyme immunoassay in detecting endoscopic remission (ER) and histologic remission (HR) in pediatric UC (6-16 years) in comparison with fecal calprotectin (FCP). ER and HR were defined as Mayo endoscopic score (MES) of 0 and Matts' histological grades (Matts) of 1 or 2, respectively. A total of 104 UC and 39 functional gastrointestinal disorder (FGID) were analyzed. PGE-MUM levels were significantly higher in the UC group than in the FGID group (P < 0.001). FCP levels were significantly elevated in the group without ER and HR than in the group with ER and HR (P < 0.001 and P = 0.001), whereas PGE-MUM levels were significantly higher in the group without ER compared to the group with ER (P < 0.001). No significant differences were noted in the AUCs for PGE-MUM and FCP in detecting ER and HR. Although PGE-MUM was inferior to FCP for the detection of HR, it might have the potential for application as a biomarker of endoscopic activity in pediatric UC owing to its noninvasive and rapid method.

Inflammatory Bowel Diseases: Does One Histological Score Fit All?

Mucosal healing (MH) is the main treatment target in ulcerative colitis (UC) and Crohn's disease, and it is defined by the combination of complete endoscopic and histologic remission. The complete resolution of mucosal inflammation should be confirmed by histology but its assessment is not always univocal. Neutrophil infiltration represents the unique histological marker in discriminating the active vs. quiescent phases of the disease, together with crypt injuries (cryptitis and crypt abscesses), erosions, and ulcerations. On the contrary, basal plasmacytosis is not indicative of activity or the remission of inflammatory bowel diseases (IBDs) but instead represents a diagnostic clue, mostly at the onset. Several histological scoring systems have been developed to assess grade severity, particularly for UC. However, most are complex and/or subjective. The aim of this review was to summarize available scores, their characteristics and limitations, and to present the advantages of a simplified mucosa healing scheme (SHMHS) based on neutrophils and their distribution in the gut mucosa. Finally, we overview future developments including artificial intelligence models for standardization of disease assessments and novel molecular markers of inflammation with potential application in diagnostic practice.

Quantitative Phase Imaging Using Digital Holographic Microscopy to Assess the Degree of Intestinal Inflammation in Patients with Ulcerative Colitis

Ulcerative colitis (UC) is characterized by chronic inflammation of the colorectum. Histological remission has emerged as a potential future treatment goal; however, the histopathological assessment of intestinal inflammation in UC remains challenging with a multitude of available scoring systems and the need for a pathologist with expertise in inflammatory bowel disease (IBD). In previous studies, quantitative phase imaging (QPI) including digital holographic microscopy (DHM) was successfully applied as an objective method for stain-free quantification of the degree of inflammation in tissue sections. Here, we evaluated the application of DHM for the quantitative assessment of histopathological inflammation in patients with UC. In our study, endoscopically obtained colonic and rectal mucosal biopsy samples from 21 patients with UC were analyzed by capturing DHM-based QPI images that were subsequently evaluated using the subepithelial refractive index (RI). The retrieved RI data were correlated with established histological scoring systems including the Nancy index (NI) as well as with endoscopic and clinical findings. As a primary endpoint, we found a significant correlation between the DHM-based retrieved RI and the NI (R² = 0.251, p < 0.001). Furthermore, RI values correlated with the Mayo endoscopic subscore (MES; R² = 0.176, p < 0.001). An area under the receiver operating characteristics (ROC) curve of 0.820 confirms the subepithelial RI as a reliable parameter to distinguish biopsies with histologically active UC from biopsies without evidence of active disease as determined by conventional histopathological examination. An RI higher than 1.3488 was found to be the most sensitive and specific cut-off value to identify histologically active UC (sensitivity of 84% and specificity of 72%). In conclusion, our data demonstrate DHM to be a reliable tool for the quantitative assessment of mucosal inflammation in patients with UC.

Artificial Intelligence Enables Quantitative Assessment of Ulcerative Colitis Histology

Ulcerative colitis is a chronic inflammatory bowel disease that is characterized by a relapsing and remitting course. Assessment of disease activity critically informs treatment decisions. In addition to endoscopic remission, histologic remission is emerging as a treatment target and a key factor in the evaluation of disease activity and therapeutic efficacy. However, manual pathologist evaluation is semiquantitative and limited in granularity. Machine learning approaches are increasingly being developed to aid pathologists in accurate and reproducible scoring of histology, enabling precise quantitation of clinically relevant features. Here, we report the development and validation of convolutional neural network models that quantify histologic features pertinent to ulcerative colitis disease activity, directly from hematoxylin and eosin-stained whole slide images. Tissue and cell model predictions were used to generate quantitative human-interpretable features to fully characterize the histology samples. Tissue and cell predictions showed comparable agreement to pathologist annotations, and the extracted slide-level human-interpretable features demonstrated strong correlations with disease severity and pathologist-assigned Nancy histological index scores. Moreover, using a random forest classifier based on 13 human-interpretable features derived from the tissue and cell models, we were able to accurately predict Nancy histological index scores, with a weighted kappa (κ = 0.91) and Spearman correlation (⍴ = 0.89, P < .001) when compared with pathologist consensus Nancy histological index scores. We were also able to predict histologic remission, based on the absence of neutrophil extravasation, with a high accuracy of 0.97. This work demonstrates the potential of computer vision to enable a standardized and robust assessment of ulcerative colitis histopathology for translational research and improved evaluation of disease activity and prognosis.

Recent Advances in the Optimization of Anti-TNF Treatment in Patients with Inflammatory Bowel Disease

Despite the evolution in inflammatory bowel disease (IBD) management during the last 20 years owing to the advent of new advanced therapies, anti-TNF agents still remain the cornerstone of therapy for both Crohn's disease and ulcerative colitis. However, this does not only secure favorable outcomes for patients considering the progressive disease character and the high likelihood of primary or secondary loss of response. Therefore, trying to reach a better treatment approach and maximize the benefits anti-TNF agents offer, optimization strategies should be examined. It has been indicated that optimizing treatment with anti-TNF enhances drug efficacy and has been associated with improved disease outcomes and a complication-free disease course. From this perspective, we aim to provide an overview of currently available data and recent advances in the practices of anti-TNF treatment optimization. Special focus has been given to the role of therapeutic drug monitoring (TDM), as well as the utility of combining anti-TNF with an immunomodulator and the treat-to-target approach.

Comparative study between histochemical mucus volume, histopathological findings, and endocytoscopic scores in patients with ulcerative colitis

Ulcerative colitis (UC) causes a reduction in goblet cells. However, there have been few reports on the relationship between endoscopic and pathological findings and mucus volume. In this study, we quantitatively evaluated histochemical colonic mucus volume by fixing biopsied tissue sections taken from patients with UC in Carnoy's solution and compared it with endoscopic and pathological findings to determine whether there is a correlation between them. Observational study. A single-center, university hospital in Japan. Twenty-seven patients with UC (male/female, 16/11; mean age, 48.4 years; disease median duration, 9 years) were included in the study. The colonic mucosa of the most inflamed area and the surrounding less inflamed area were evaluated separately by local MES and endocytoscopic (EC) classification. Two biopsies were taken from each area; one was fixed with formalin for histopathological evaluation, and the other was fixed with Carnoy's solution for the quantitative evaluation of mucus via histochemical Periodic Acid Schiff and Alcian Blue staining. The relative mucus volume was significantly reduced in the local MES 1-3 groups, with worsening findings in EC-A/B/C and in groups with severe mucosal inflammation, crypt abscess, and severe reduction in goblet cells. The severity of inflammatory findings in UC by EC classification correlated with the relative mucus volume suggesting functional mucosal healing. We found a correlation between the colonic mucus volume and endoscopic and histopathological findings in patients with UC, and a stepwise correlation with disease severity, particularly in EC classification.

AGA Clinical Practice Guideline on the Role of Biomarkers for the Management of Ulcerative Colitis

BACKGROUND & AIMS

Biomarkers are used frequently for noninvasive monitoring and treatment decision making in the management of patients with ulcerative colitis (UC). This American Gastroenterological Association (AGA) guideline is intended to support practitioners in decisions about the use of biomarkers for the management of UC.

METHODS

A multidisciplinary panel of content experts and guideline methodologists used the Grading of Recommendations Assessment, Development and Evaluation framework to prioritize clinical questions, identify patient-centered outcomes, and conduct an evidence synthesis on the clinical performance of serum C-reactive protein (CRP), fecal calprotectin, and fecal lactoferrin as biomarkers of disease activity in patients with established UC in symptomatic remission or with active symptoms. The guideline panel used the Evidence-to-Decision framework to develop recommendations for the use of biomarkers for monitoring and management of UC and provided implementation considerations for clinical practice.

RESULTS

The guideline panel made 7 conditional recommendations. In patients with UC in symptomatic remission, the panel suggests the use of a biomarker- and symptom-based monitoring strategy over a symptom-based monitoring strategy. For patients in symptomatic remission, the panel suggests using fecal calprotectin <150 μg/g, normal fecal lactoferrin, and/or normal CRP to rule out active inflammation and avoid routine endoscopic assessment of disease. In patients with UC with moderate to severe symptoms, the panel suggests using fecal calprotectin >150 μg/g, elevated fecal lactoferrin, or elevated CRP to inform treatment decisions and avoid routine endoscopic assessment of disease. However, in patients in symptomatic remission but elevated biomarkers, and in patients with moderate to severe symptoms with normal biomarkers, the panel suggests endoscopic assessment of disease to inform treatment decisions. In patients with UC with mild symptoms, the panel suggests endoscopic assessment of disease activity to inform treatment decisions. The panel identified the use of a biomarker-based monitoring strategy over an endoscopy-based monitoring strategy as a knowledge gap. The panel also proposed key implementation considerations for optimal use of biomarkers, and identified areas for future research.

CONCLUSIONS

In patients with UC, noninvasive biomarkers, including fecal calprotectin, fecal lactoferrin, and serum CRP can inform disease monitoring and management.

Intestinal Barrier Healing Is Superior to Endoscopic and Histologic Remission for Predicting Major Adverse Outcomes in Inflammatory Bowel Disease: The Prospective ERIca Trial

BACKGROUND & AIMS

Endoscopic and histologic remission have emerged as key therapeutic goals in the management of inflammatory bowel diseases (IBD) that are associated with favorable long-term disease outcomes. Here, we prospectively compared the predictive value of barrier healing with endoscopic and histologic remission for predicting long-term disease behavior in a large cohort of patients with IBD in clinical remission.

METHODS

At baseline, patients with IBD in clinical remission underwent ileocolonoscopy with assessment of intestinal barrier function by confocal endomicroscopy. Endoscopic and histologic disease activity, as well as barrier healing, was prospectively assessed along established scores. During subsequent follow-up, patients were closely monitored for clinical disease activity and the occurrence of major adverse outcomes (MAOs): disease flares, IBD-related hospitalization or surgery, and initiation or dose escalation of systemic steroids, immunosuppressants, small molecules, or biological therapy.

RESULTS

The final analysis included 181 patients, 100 with Crohn's disease [CD] and 81 with ulcerative colitis (UC). During a mean follow-up of 35 (CD) and 25 (UC) months, 73% of patients with CD and 69% of patients with UC experienced at least 1 MAO. The probability of MAO-free survival was significantly higher in patients with IBD with endoscopic remission compared with endoscopically active disease. In addition, histologic remission predicted MAO-free survival in patients with UC but not CD. Barrier healing on endomicroscopy was superior to endoscopic and histologic remission for predicting MAO-free survival in both UC and CD.

CONCLUSIONS

Barrier healing is associated with decreased risk of disease progression in patients with clinically remittent IBD, with superior predictive performance compared with endoscopic and histologic remission. Analysis of barrier function might be considered as a future treatment target in clinical trials.

CLINICALTRIALS

gov number, NCT05157750.

Histologic Activity in an Endoscopically Normal-Appearing Pouch Predicts Future Risk of Pouchitis in Patients With Ulcerative Colitis

INTRODUCTION

The impact of histologic inflammation on subsequent risk of acute pouchitis in patients with ulcerative colitis (UC) has not been robustly examined.

METHODS

We examined the association between histologic inflammation in endoscopically normal-appearing ileal pouches in patients with UC with subsequent risk of antibiotic-responsive acute pouchitis.

RESULTS

Among 163 study patients, 53% had histologic inflammation in an endoscopically normal-appearing ileal pouch. Histologic inflammation in the pouch was associated with an increased risk of pouchitis (24.1% vs 6.8%, adjusted odds ratio 4.41, 95% confidence interval 1.48-13.20).

DISCUSSION

Histologic inflammation in an endoscopically normal pouch was associated with an increased risk of acute pouchitis.

Endocytoscopy for assessing histologic inflammation in ulcerative colitis: development and prospective validation of the ELECT (ErLangen Endocytoscopy in ColiTis) score (with videos)

BACKGROUND AND AIMS

Apart from endoscopic healing as an established treatment goal in patients with inflammatory bowel disease (IBD), histologic remission is an emerging endpoint that might even better predict disease outcome, especially in ulcerative colitis (UC). Within this study, we aimed to evaluate whether endocytoscopy (EC) as an in vivo contact microscopy technology can accurately assess histologic inflammation and predict the further course of disease in UC patients.

METHODS

Initially, a new and intuitive EC score reflecting the entire spectrum of microscopic disease activity in UC was consensually developed. Subsequently, this score was independently validated in 46 patients with UC who underwent close-meshed follow-up during which major adverse outcomes (MAOs; defined as disease flare, IBD-related hospitalization, IBD-related surgery, necessity for initiation or escalation therapy) were recorded. Results of EC grading of inflammatory activity were compared against 2 validated histologic scores in UC. Diagnostic performance of endoscopic remission under white-light endoscopy (Mayo Endoscopic Score and Ulcerative Colitis Endoscopic Index of Severity), EC, and histology were compared for the prediction of MAOs.

RESULTS

Endocytoscopic assessment of inflammatory activity in UC based on the newly developed ErLangen Endocytoscopy in ColiTis score showed strong correlation with histopathologic scoring (Robarts Histopathology Index, r = .70; Nancy Histologic Index, r = .73) and was superior to white-light endoscopy for grading of microscopic disease activity, with a sensitivity of 88%, specificity of 95.2%, and area under the curve of .916. Furthermore, EC exhibited a high interobserver agreement for in vivo grading of microscopic inflammation and was comparably accurate as histopathology for forecasting the occurrence of MAOs in UC.

CONCLUSIONS

Endocytoscopic grading of inflammatory activity along a newly developed scoring system enabled real-time histology in UC patients and better predicted clinical outcome in UC patients than endoscopic remission.

Effectiveness and Safety Profiles of Biological Therapies in Inflammatory Bowel Disease: Real Life Data from an Active Pharmacovigilance Project

Post-marketing surveillance is essential to evaluate the risk/benefit profile of drugs; however, pharmacovigilance studies comparing persistence and safety of biologic therapies in patients with inflammatory bowel disease (IBD) are scant. The aim of this study was to prospectively investigate persistence together with safety profiles of biologics in a cohort of patients diagnosed with Crohn's Disease (CD) or ulcerative colitis (UC) followed by the IBD unit of Messina and treated with infliximab (IFX), adalimumab (ADA), golimumab (GOL), vedolizumab (VED), and ustekinumab (UST) from 2017 through 2021. Descriptive and treatment persistence analyses with predictors for discontinuation and occurrence of adverse drug reactions (ADRs) were performed. A total of 675 IBD patients were enrolled. A higher persistence rate was noted for UST and ADA in the first year (83.8% and 83.1%, respectively) and for IFX in the fifth year of treatment (58.1%). GOL, VED, and UST-all used as second/third-line therapies-seemed to have a higher risk of non-persistence than IFX (in order HR: 2.19; CI 95%: 1.33-3.61, 1.45; 1.04-2.04, 2.25; 1.25-4.07) as well as switchers and those who had at least one ADR (18.1; 13.22-24.68 and 1.55; 1.20-1.99, respectively). The reported ADRs, which were generally mild-moderate, were largely known. However, real-world data should be implemented to further study undetected safety concerns, including risk of malignancy.

Deep learning-based automated quantification of goblet cell mucus using histological images as a predictor of clinical relapse of ulcerative colitis with endoscopic remission

BACKGROUND

Mucin depletion is one of the histological indicators of clinical relapse among patients with ulcerative colitis (UC). Mucin depletion is evaluated semiquantitatively by pathologists using histological images. Therefore, the interobserver concordance is not extremely high, and an objective evaluation method is needed. This study was conducted to demonstrate that our automated quantitative method using a deep learning-based model is useful in predicting the prognosis of patients with UC.

METHODS

Deep learning-based models were trained to detect goblet cell mucus area from whole slide images of biopsy specimens. This study involved 114 patients with UC in endoscopic remission with a partial Mayo score of ≤ 1. Biopsy specimens were collected during colonoscopy, and the ratio of goblet cell mucus area to the epithelial cell and goblet cell mucus area was calculated as goblet cell ratio (GCR). The follow-up time was 12 months, and the primary outcome was the relapse rate. Clinical relapse was defined as partial Mayo score of ≥ 3.

RESULTS

Sixteen patients (14%) experienced clinical relapse. In the relapsed group, the GCRs of specimens obtained from the cecum, ascending colon, and rectum were significantly lower than those of specimens in the relapse-free group (p = 0.010, p = 0.027, p < 0.01). In the rectum, patients with a GCR of ≤ 12% had a significantly higher relapse rate than those with a GCR of > 12% (45% [10/22] vs. 6.5% [6/92]; p < 0.01).

CONCLUSIONS

Quantifying goblet cell mucus areas using a deep learning-based model is useful in predicting the clinical relapse in patients with UC in clinical and endoscopic remission.

Histologic Evaluation Using the Robarts Histopathology Index in Patients With Ulcerative Colitis in Deep Remission and the Association of Histologic Remission With Risk of Relapse

BACKGROUND

This study prospectively evaluated the risk of relapse according to the status of histologic activity in patients with ulcerative colitis (UC) who achieved deep remission.

METHODS

Patients with UC in clinical remission (partial Mayo score ≤1) and endoscopic remission (ulcerative colitis endoscopic index of severity ≤1) were enrolled. Rectal biopsies were performed in patients, and histologic remission was defined as a Robarts histopathology index of ≤3. Receiver-operating characteristic curve analysis was conducted to determine fecal calprotectin cutoff values for histologic remission. The cumulative risk of relapse was evaluated using the Cox proportional hazards model.

RESULTS

Among the 187 patients enrolled, 82 (43.9%) achieved histologic remission. The best cutoff value of fecal calprotectin for predicting histologic remission was 80 mg/kg (area under the curve of 0.646, sensitivity of 74%, and specificity of 61%). Among 142 patients who were followed up for >3 months, 56 (39.4%) showed clinical relapse during a median of 42 weeks. The risk of relapse was lower in patients with histologic remission than in those with histologic activity (P = .026). In multivariable analysis, histologic remission (hazard ratio [HR], 0.551; 95% confidence interval [CI], 0.316-0.958; P = .035), elevated C-reactive protein levels (HR, 3.652; 95% CI, 1.400-9.526; P = .008), and history of steroid use (HR, 2.398; 95% CI, 1.196-4.808; P = .014) were significantly associated with clinical relapse.

CONCLUSIONS

In patients with UC who achieved clinical and endoscopic remission, histologic remission was independently associated with a lower risk of clinical relapse.

Harnessing the Vnn1 pantetheinase pathway boosts short chain fatty acids production and mucosal protection in colitis

OBJECTIVE

In the management of patients with IBD, there is a need to identify prognostic markers and druggable biological pathways to improve mucosal repair and probe the efficacy of tumour necrosis factor alpha biologics. Vnn1 is a pantetheinase that degrades pantetheine to pantothenate (vitamin B₅, a precursor of coenzyme A (CoA) biosynthesis) and cysteamine. Vnn1 is overexpressed by inflamed colonocytes. We investigated its contribution to the tolerance of the intestinal mucosa to colitis-induced injury.

DESIGN

We performed an RNA sequencing study on colon biopsy samples from patients with IBD stratified according to clinical severity and modalities of treatment. We generated the VIVA mouse transgenic model, which specifically overexpresses Vnn1 on intestinal epithelial cells and explored its susceptibility to colitis. We developed a pharmacological mimicry of Vnn1 overexpression by administration of Vnn1 derivatives.

RESULTS

VNN1 overexpression on colonocytes correlates with IBD severity. VIVA mice are resistant to experimentally induced colitis. The pantetheinase activity of Vnn1 is cytoprotective in colon: it enhances CoA regeneration and metabolic adaptation of colonocytes; it favours microbiota-dependent production of short chain fatty acids and mostly butyrate, shown to regulate mucosal energetics and to be reduced in patients with IBD. This prohealing phenotype is recapitulated by treating control mice with the substrate (pantethine) or the products of pantetheinase activity prior to induction of colitis. In severe IBD, the protection conferred by the high induction of VNN1 might be compromised because its enzymatic activity may be limited by lack of available substrates. In addition, we identify the elevation of indoxyl sulfate in urine as a biomarker of Vnn1 overexpression, also detected in patients with IBD.

CONCLUSION

The induction of Vnn1/VNN1 during colitis in mouse and human is a compensatory mechanism to reinforce the mucosal barrier. Therefore, enhancement of vitamin B₅-driven metabolism should improve mucosal healing and might increase the efficacy of anti-inflammatory therapy.

Histopathological assessment of the microscopic activity in inflammatory bowel diseases: What are we looking for?

Advances in diagnostics of inflammatory bowel diseases (IBD) and improved treatment strategies allowed the establishment of new therapeutic endpoints. Currently, it is desirable not only to cease clinical symptoms, but mainly to achieve endoscopic remission, a macroscopic normalization of the bowel mucosa. However, up to one-third of IBD patients in remission exhibit persisting microscopic activity of the disease. The evidence suggests a better predictive value of histology for the development of clinical complications such as clinical relapse, surgical intervention, need for therapy escalation, or development of colorectal cancer. The proper assessment of microscopic inflammatory activity thus became an important part of the overall histopathological evaluation of colonic biopsies and many histopathological scoring indices have been established. Nonetheless, a majority of them have not been validated and no scoring index became a part of the routine bioptic practice. This review summarizes a predictive value of microscopic disease activity assessment for the subsequent clinical course of IBD, describes the most commonly used scoring indices for Crohn's disease and ulcerative colitis, and comments on current limitations and unresolved issues.

Ulcerative colitis: Impact of early disease clearance on long‐term outcomes ‐ A multicenter cohort study

Background

Clinical remission and endoscopic mucosal healing are the main treatment targets in patients with ulcerative colitis (UC). Recently, the concept of disease clearance has been proposed as a potential target in UC.

Objective

We aimed to evaluate the impact of disease clearance on long‐term outcomes in UC patients.

Methods

A multicenter retrospective cohort study was conducted at the Humanitas Research Hospital‐IRCCS (Italy) and at the Nancy University Hospital (France) between 2014 and 2021. Disease clearance in UC was defined as simultaneous clinical (partial‐Mayo score ≤2), endoscopic (endoscopic‐Mayo score = 0), and histological (Nancy index = 0) remission, and patients were monitored over a long‐time follow‐up (≥12 months), to compare the occurrence of negative outcomes.

Results

A total of 494 patients with UC was included in the study (269, 54.4% males). Disease clearance was present in 109 patients (22.1%) at baseline. Median follow up was 24 months. Patients with disease clearance were associated to a significantly lower risk of UC‐related hospitalization compared with the control group (5.5% vs. 23.1%; p < 0.001) at last observation. Similarly, a lower rate of surgeries was detected in patients with disease clearance at baseline compared with those without (1.8% vs. 10.9%; p = 0.003). The Kaplan Meier curves confirmed that patients with disease clearance at baseline had a lower risk of hospitalization (log‐rank p < 0.0001) and surgery (log‐rank p < 0.00095).

Conclusion

In UC patients with early disease clearance are at significant lower risk for hospitalization and surgery. Disease clearance should be considered as a new composite outcome.

Histological Indices and Risk of Recurrence in Crohn's Disease: A Retrospective Study of a Cohort of Patients in Endoscopic Remission

BACKGROUND

Although histological healing is raising interest in ulcerative colitis to predict recurrence, its meaning in Crohn's disease (CD) remains unknown. We aimed to study the performances of different histological indices to predict recurrence of CD patients with mucosal healing.

METHODS

Crohn's disease patients with mucosal healing diagnosed between 2010 and 2018 were included if there was available clinical and endoscopical data. Nancy Histological index (NHI), Geboes score (GS), Robarts Histopathology index (RHI), Global Histological Disease Activity Score (GHAS), and Inflammatory Bowel Disease-Distribution Chronicity Activity score (IBD-DCA) were independently assessed by 3 pathologists.

RESULTS

Eighty-eight patients were included, of which 28 relapsed (32%) within 30.5 months. All 4 histological indices were associated with recurrence, with significant relapse risk (NHI, odds ratio [OR], 1.67; GHAS, OR, 2.33; RHI, OR, 1.19; GS, OR, 2.09; and IBD-DCA, OR, 2.14). Microscopic activity was significantly associated with relapse only with the IBD-DCA score. Predicting performances of all these scores were poor. Calibration curves indicate that the GHAS and IBD-DCA are the closest to the ideal predicted probability curve and thus could better predict recurrence than the other scores. Interobserver agreement varied from poor for GHAS (k = .39) to good for RHI (k = .68).

CONCLUSIONS

Histological scores are valuable indicators to predict recurrence. Histological assessment of activity seems insufficient to predict CD course with most of the score evaluated, highlighting the need for new indices or adaptation of actual scores to CD specificities.

Impact of thiopurines and tumour necrosis factor antagonists on primary sclerosing cholangitis outcomes in patients with inflammatory bowel disease

BACKGROUND

Patients with primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) are at risk of biliary tract cancer and liver damage (possibly leading to liver transplantation), and are often treated for IBD with thiopurines and/or tumour necrosis factor antagonists (anti-TNF) on a long-term basis.

AIMS

To assess the risk of biliary tract cancer and liver transplantation in patients exposed to thiopurines and/or anti TNF agents in a French nationwide cohort.

METHODS

We performed a population-based study of patients aged 18 years or older with PSC and IBD in the French national health insurance database. Patients were followed from 1 January 2009 to 31 December 2018. The risks of biliary tract cancer and liver transplantation associated with thiopurines and anti-TNF exposure were assessed with marginal structural Cox proportional hazard models, adjusting for baseline demographics and comorbidities, and time-varying medications and PSC activity.

RESULTS

Among the 1929 patients with PSC and IBD included, 37 biliary tract cancers and 83 liver transplantations occurred. Compared with patients not exposed to thiopurines or anti-TNF agents, patients exposed to thiopurines (hazard ratio [HR], 1.05; 95% confidence interval [CI], 0.39-2.82) or anti-TNF agents (HR, 0.59; 95% CI, 0.13-2.80) had no excess risk of biliary tract cancer. Similarly, patients exposed to thiopurines (HR, 0.67; 95% CI, 0.30-1.48) or anti-TNF agents (HR, 0.68; CI, 0.22-2.09) had no excess risk of liver transplantation.

CONCLUSIONS

Patients with PSC and IBD who are exposed to thiopurines or anti-TNF agents are not at excess risk of biliary tract cancer or liver transplantation.

(Re)Appraising Remission in Ulcerative Colitis

As the therapeutic targets in ulcerative colitis (UC) shift from control of symptoms to mucosal healing and prevention of disease complications like disability, colectomy, and cancer, the definition of remission has evolved. The current definition of clinical remission is variable and is determined by the clinical context in which it is being used. This results in skepticism and uncertainty about the true meaning of the term "clinical remission." In this review, the authors reexamine the definition of clinical remission and propose a novel approach to define remission in UC.

Increased Expression of Interleukin-13 Receptor in Ileum Associated With Nonresponse to Adalimumab in Ileal Crohn's Disease

BACKGROUND

The terminal ileum poses a predilection for Crohn's disease (CD) but is less susceptible to undergo healing to treatment with biologics and small molecules. This study aimed to evaluate histologic features associated with endoscopic remission (ER).

METHODS

This is a post hoc analysis of patients with moderately to severely active CD, defined as Crohn's disease activity index 220 to 450, and terminal ileal ulceration treated with antitumor necrosis factor (TNF)-α inhibitor adalimumab from the EXTEND trial. We studied whether baseline total Global Histologic Disease Activity Scores (GHAS), any individual histologic element, and specific immunohistochemical (IHC) markers of chronic inflammation from biopsy specimens were associated with postinduction (week 12) and maintenance (week 52) ER, defined as Simple Endoscopic Score for Crohn's Disease of 0. Multivariable logistic regression models adjusted for confounders were used to assess the relationship between histologic markers and 1-year outcomes.

RESULTS

Seventy-one adult patients with CD affecting the ileum were included in this analysis. Both baseline ileal GHAS scores and individual histologic components were not found to be associated with ER at weeks 12 or 52. Increased expression of interleukin-13 receptor (IL-13R) on IHC stains was associated with reduced likelihood of achieving 1-year ER (adjusted odds ratio, 0.06; 95% CI, 0.01-0.92; P = .044). No other biomarker assessed was associated with 1-year ER.

CONCLUSIONS

Ileal histologic disease activity and IHC activation markers of chronic mucosal inflammation were not associated with 1-year ER. However, strong staining for IL-13 receptor in the ileum was associated with reduced odds of 1-year ER using adalimumab. Mucosal cellular disease profiles might pose an opportunity to guide treatment of CD.

ECCO Position on Harmonisation of Crohn's Disease Mucosal Histopathology

In inflammatory bowel disease [IBD], mucosal healing is a major therapeutic target and a reliable predictor of clinical course. However, endoscopic mucosal healing is not synonymous with histological healing, and the additional benefits of including histological remission as a target are unclear. In Crohn´s disease [CD], there are few studies highlighting the value of histological remission as a therapeutic target. Histological activity can persist in CD patients who are in endoscopic remission, and the absence of histological activity may be associated with lower relapse rates. Therefore, standardisation of procedures to evaluate CD histological activity is desirable. Topics that would benefit from standardisation and harmonisation include biopsy procedures, biopsy processing techniques, the content of histological scores, and the definitions of histological remission, histological response, and histological activity. In line with these needs, the European Crohn's and Colitis Organisation [ECCO] assembled a consensus group with the objective of developing position statements on CD histology based on published evidence and expert consensus. There was agreement that definitions of histological remission should include absence of erosion, ulceration, and mucosal neutrophils; that the absence of neutrophilic inflammation is an appropriate histological target in CD; that CD histological scores, such as the Global Histological Disease Activity Score, lack formal validation; and that histological scoring systems for ulcerative colitis, including the Geboes Score, Robarts Histopathology Index, and Nancy Histological Index, can be used for scoring intestinal biopsies in CD patients.

Faecal Myeloperoxidase as a Biomarker of Endoscopic Activity in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD], consisting of Crohn's disease [CD] and ulcerative colitis [UC], is a relapsing-remitting illness. Treat-to-target IBD management strategies require monitoring of gastrointestinal inflammation. This study aimed to investigate faecal myeloperoxidase [fMPO], a neutrophil granule enzyme, as a biomarker of IBD activity.

METHODS

Prospectively recruited participants with IBD, undergoing ileocolonoscopy for disease assessment, provided biological samples and completed symptom questionnaires prior to endoscopy. fMPO, C-reactive protein [CRP], and faecal calprotectin [fCal] were compared with validated endoscopic indices [simple endoscopic score for CD and UC endoscopic index of severity]. Receiver operating characteristic [ROC] curves assessed the performance of fMPO, CRP, and fCal in predicting endoscopic disease activity. Baseline biomarkers were used to predict a composite endpoint of complicated disease at 12 months [need for escalation of biologic/immunomodulator due to relapse, steroid use, IBD-related hospitalisation, and surgery].

RESULTS

A total of 172 participants were recruited [91 female, 100 with CD]. fMPO was significantly correlated with endoscopic activity in both CD [r = 0.53, p < 0.01] and UC [r = 0.63, p < 0.01], and with fCal in all patients with IBD [r = 0.82, p < 0.01]. fMPO was effective in predicting moderate-to-severely active CD [AUROC 0.86, p < 0.01] and UC [AUROC 0.92, p < 0.01]. Individuals with a baseline fMPO > 26 µg/g were significantly more likely to reach the composite outcome at 12 months (hazard ratio [HR] 3.71, 95% confidence interval [CI] 2.07-6.64, p < 0.01).

CONCLUSIONS

Faecal myeloperoxidase is an accurate biomarker of endoscopic activity in IBD and predicted a more complicated IBD course during follow-up.

Reproducibility of the electronic chromoendoscopy PICaSSO score (Paddington International Virtual ChromoendoScopy ScOre) in ulcerative colitis using multiple endoscopic platforms: a prospective multicenter international study (with video)

BACKGROUND AND AIMS

Endoscopic and histologic remission (HR) are key therapeutic targets in the management of ulcerative colitis (UC). The aim of this study was to evaluate the reproducibility of the Paddington International virtual ChromoendoScopy ScOre (PICaSSO), a virtual chromoendoscopy score originally validated by use of the iSCAN platform, with the narrow-band imaging (NBI), linked-color imaging (LCI), and blue-laser imaging (BLI) platforms.

METHODS

We evaluated endoscopic activity using the Mayo Endoscopic Score (MES), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and PICaSSO in 159 UC patients (78 NBI and 81 BLI/LCI) who underwent colonoscopy in 2 tertiary referral centers. HR was defined by the Robarts Histopathology Index (RHI) and the Nancy Histologic Index (NHI). Receiver operating characteristic curves were plotted to evaluate endoscopic scores for the prediction of HR. Intraclass correlation coefficients (ICC) between endoscopists were evaluated.

RESULTS

PICaSSO had an ICC of 0.825 when the NBI and BLI/LCI cohorts were combined, higher than MES and UCEIS. The correlation between PICaSSO and RHI and NHI was 0.83 and 0.79 in the NBI cohort and between 0.63 and 0.65 in LCI/BLI. In the NBI cohort, the accuracy of MES, UCEIS, and PICaSSO was 0.936, 0.897, and 0.808 for HR measured by RHI and 0.897, 0.885, and 0.821 by NHI, respectively. In the BLI/LCI cohort, the accuracy of MES, UCEIS, LCI PICaSSO and BLI PICaSSO was 0.765, 0.778, 0.827, and 0.79 to predict HR with RHI and NHI, respectively.

CONCLUSIONS

The PICaSSO score can be consistently and accurately reproduced with NBI and LCI/BLI and therefore can be applied to all virtual electronic chromoendoscopy platforms.

Targeting IL12/23 in ulcerative colitis: update on the role of ustekinumab

As our comprehension of the pathogenic mechanisms of inflammatory bowel disease (IBD) increases, the therapeutic armamentarium for its treatment can expand, and novel target therapies join the treatment pipeline. Interleukin (IL)-12 and IL23 are two key cytokines responsible for promoting and perpetuating bowel inflammation in IBD. Ustekinumab is a monoclonal antibody directed against the shared p40 subunit of both cytokines, and it was recently approved for the treatment of ulcerative colitis (UC). In the pivotal phase III UNIFI trial, ustekinumab showed a superiority over placebo in both clinical and endoscopic outcomes; furthermore, it was characterized by a favorable safety profile, with a similar rate of adverse events as compared with placebo. Recent evidence from real-life experiences have started accumulating, generally confirming the effectiveness and safety figures emerged from the registration studies. However, most of these observational studies enrolled multirefractory patients; moreover, comparative data with other target therapies are lacking, leaving physicians without clear indications about the appropriate positioning of ustekinumab in the therapeutic pipeline for UC. This review examines the basis of targeting IL12-23 in UC therapy and summarizes the data from both clinical trials and real-life studies, to highlight the main evidence already available and the research gaps that need to be filled for the optimal usage of ustekinumab in UC.

Early Change in Epithelial Neutrophilic Infiltrate Predicts Long-Term Response to Biologics in Ulcerative Colitis

BACKGROUND & AIMS

The prognostic value of histologic scores, grades, and individual histologic subcomponents, alone or in combination with endoscopy, for predicting endoscopic improvement (EI) and histoendoscopic mucosal improvement (HEMI) during maintenance therapy in ulcerative colitis remains uncertain.

METHODS

We performed a post hoc analysis of participants from the VARSITY trial (n = 734 with histology). Receiver operating characteristic and multivariate logistic regression analyses were performed to assess whether baseline and/or week 14 assessments for the Robarts Histopathology Index, Geboes score, individual histologic subcomponents, and baseline disease characteristics, including endoscopic severity and biomarkers, could predict the achievement of EI and HEMI at week 52.

RESULTS

Changes in epithelial neutrophil involvement from baseline to week 14 had the best performance for predicting week 52 EI (area under the curve, 0.83; 95 % confidence interval [CI], 0.74-0.91) and HEMI (area under the curve, 0.85; 95 % CI, 0.76-0.94). On multivariate analyses, improvement of neutrophils in the epithelium was the only histologic parameter associated with increased odds of week 52 EI (odds ratio, 3.63; 95 % CI, 1.45-9.08; P = .0059) and HEMI (odds ratio, 6.88; 95 % CI, 3.29-14.36; P < .0001). Patients with more than 50 % of crypts involved with neutrophils at week 14 were significantly less likely to achieve week 52 HEMI irrespective of week 14 Mayo endoscopic scores (week 14 Mayo endoscopic score of 2-3: 9.9 % vs 22.4 %; P = .001; week 14 Mayo endoscopic score of 0-1: 33 % vs 62.4 %; P = .044).

CONCLUSIONS

Our results on epithelial neutrophilic infiltrate after induction therapy as the only independent predictor for achievement of maintenance EI or HEMI helps clarify the clinical relevance of measuring histologic disease activity in ulcerative colitis. Epithelial neutrophilic infiltrate poses a means to stratify patients according to their likelihood of response to biologic treatment.

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.