Are endoscopic endpoints reliable in therapeutic trials of ulcerative colitis?

Disease Clearance as a New Outcome in Ulcerative Colitis: a Systematic Review and Expert Consensus

The concept of disease clearance has been proposed as a potential target in ulcerative colitis (UC). We conducted a systematic review to investigate the role of disease clearance, defined as a composite outcome including simultaneous clinical, endoscopic, and histologic remission of disease in the management of patients with UC. Based on the literature data, statements regarding disease clearance were developed and voted on by the members of the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) according to a Delphi methodology. A definition of disease clearance was proposed to standardize its use in clinical practice and clinical trials and to provide practical recommendations for its implementation as a therapeutic target in UC.

Mesalazine granules promote disease clearance in patients with mild-to-moderate ulcerative colitis

BACKGROUND

Over the past decade, treatment targets for ulcerative colitis (UC) have become more stringent, incorporating multiple parameters. Recently, the concept of 'disease clearance'-defined as combined clinical, endoscopic, and histological remission-has been proposed as an ultimate endpoint in treating UC.

OBJECTIVE

To determine the rates of disease clearance in patients with mild-to-moderate UC treated with different doses of mesalazine granules as induction therapy.

METHODS

In a post hoc analysis, data were pooled from four randomised, active-controlled, phase 3 clinical trials in patients with mild-to-moderate UC receiving 8-week induction therapy with mesalazine granules at daily doses of 1.5, 3.0 or 4.5 g. Rates of clinical, endoscopic, and histological remission were determined using stringent criteria and used to calculate rates of the composite endpoints of clinical plus endoscopic remission, endoscopic plus histological remission, and disease clearance (clinical plus endoscopic plus histological remission).

RESULTS

A total of 860 patients were included in the analysis. Among the total population, 20.0% achieved disease clearance with mesalazine granules: 13.1% in patients receiving 1.5 g mesalazine granules/day, 21.8% in those receiving 3.0 g/day and 18.9% in those receiving 4.5 g/day. Among patients with moderate UC, 16.8% achieved disease clearance: 7.1% with 1.5 g/day, 18.8% with 3.0 g/day and 16.2% with 4.5 g/day.

CONCLUSION

Disease clearance, proposed to be predictive of improved long-term outcomes, can be achieved in a clinically meaningful proportion of mild-to-moderate UC patients treated with mesalazine granules. A daily dose of 3.0 g appears optimal to reach this target.

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

BACKGROUND

Endoscopic remission is a recognized therapeutic endpoint in inflammatory bowel disease (IBD; Crohn's disease (CD), ulcerative colitis (UC)). The impact of persistent histologic activity on long-term outcomes is less clear and limited by small studies.

METHODS

We performed a systematic search of PubMed and Embase to identify eligible studies examining the association between histologic activity and relapse in patients with CD or UC in endoscopic remission. Studies were pooled together using random effects meta-analysis per the DerSimonian and Laird inverse variance method. The impact of different histologic scales, cut-offs, and individual features were examined.

FINDINGS

Our meta-analysis included 28 studies contributing 2,806 patients (2677 UC; 129 CD). In UC, histologically active disease was associated with an overall increased risk of relapse (OR, 2.41; 95% CI, 1.91-3.04), with a similar effect noted in the subgroup with endoscopic Mayo endoscopic score of 0 vs 0 or 1. More rigorous Geboes cut-offs demonstrated numerically stronger impact on relapse rates-Geboes <3.1 (OR, 2.40; 95% CI, 1.57-3.65), Geboes <2.1 (OR, 3.91; 95% CI, 2.21-6.91) and Geboes 0 (OR, 7.40; 95% CI, 2.00-18.27). Among individual histologic features, basal plasmacytosis (OR, 1.94), neutrophilic infiltrations (OR, 2.30), mucin depletion (OR, 2.05), and crypt architectural irregularities (OR, 2.22) predicted relapse. There was no association between histologic activity and relapse in CD.

CONCLUSIONS

In patients with UC in endoscopic remission, persistent histologic activity is associated with higher rates of relapse. Greater degree of normalization may have a stronger impact.

Endoscopic and Histologic Predictors of Outcomes in Pediatric Ulcerative Colitis-Caveat Emptor

The impact of endoscopic and histological mucosal healing on outcomes in adult settings is impressive. Despite many clinical parallels, pediatric ulcerative colitis (UC) is set apart from adult disease in several respects. Many frequently used indices are not fully validated, especially in pediatric settings, and consensus on precise definitions in clinical settings are lacking. Endoscopic mucosal healing is an acceptable long-term treatment goal in pediatrics, but not histologic normalization. Early prediction of disease course in UC may allow treatment stratification of patients according to risks of relapse, acute severe colitis, and colectomy. Putative endoscopic and histologic predictors of poor clinical outcomes in adults have not held true in pediatric settings, including baseline endoscopic extent, endoscopic severity, and specific histologic characteristics which are less prevalent in pediatrics at diagnosis. In this mini-review we appraise predictive endoscopic and histologic factors in pediatric UC with reference to relapse, severe colitis, and colectomy risks. We recommend that clinicians routinely use endoscopic and histologic sores to improve the quality of clinical and research practice. The review summarizes differences between adult and pediatric prediction data, advises special consideration of those with primary sclerosing cholangitis, and suggests areas for future study in this field.

Incremental Benefit of Achieving Endoscopic and Histologic Remission in Patients With Ulcerative Colitis: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Clinical remission, defined by a composite of patient reported outcomes and Mayo endoscopy subscore (MES) 0 or 1 is a recommended treatment target in patients with ulcerative colitis (UC). We estimated whether incorporating more rigorous remission definitions, of endoscopic remission (MES 0) and histologic remission, affects risk of relapse.

METHODS

Through a systematic review, we identified cohort studies in adults with UC in clinical remission that reported a minimum 12-month risk of clinical relapse, based on MES (0 vs 1) and/or histologic disease activity, in patients with endoscopic remission. Using random effects meta-analysis, we calculated relative and absolute risk of clinical relapse in patients with UC achieving different treatment targets.

RESULTS

In a meta-analysis of 17 studies that included 2608 patients with UC in clinical remission, compared to patients achieving MES 1, patients achieving MES 0 had a 52% lower risk of clinical relapse (relative risk, 0.48; 95% CI, 0.37-0.62). The median 12-month risk of clinical relapse in patients with MES 1 was 28.7%; the estimated annual risk of clinical relapse in patients with MES 0 was 13.7% (95% CI, 10.6-17.9). In a meta-analysis of 10 studies in patients in endoscopic remission (MES 0), patients who achieved histologic remission had a 63% lower risk of clinical relapse vs patients with persistent histologic activity (relative risk, 0.37; 95% CI, 0.24-0.56). Estimated annual risk of clinical relapse in who achieved achieving histologic remission was 5.0% (95% CI, 3.3-7.7).

CONCLUSIONS

In a systematic review and meta-analysis of patients with UC in clinical remission, we observed that patients achieving more rigorous treatment endpoints (endoscopic and histologic remission) have a substantially lower risk of clinical relapse compared with patients achieving clinical remission.

The emerging role of histologic disease activity assessment in ulcerative colitis

BACKGROUND AND AIMS

Assessment of disease activity is essential for developing and determining appropriate therapy in patients with ulcerative colitis (UC). Validated clinical and endoscopic scoring systems have been established to accurately define disease activity. Clinical and endoscopic treatment targets have also been proposed, with gastroenterologists encouraged to optimize medical therapy to achieve these targets. Recently, histology has been recognized as an important prognostic factor and potential treatment target in patients with UC.

METHODS

This review summarizes the recent literature regarding histologic scoring indices in UC and offers practical guidance to gastroenterologists on how to interpret histologic data.

RESULTS

Substantial evidence indicates that histology accurately predicts clinical relapse, hospitalization, corticosteroid use, and development of dysplasia. Furthermore, compared with endoscopy, findings suggest that histology may be more predictive of these outcomes. Because microscopic disease activity can persist in the absence of clinical or endoscopic disease activity, histology may be the ideal marker of inflammation. Standardized definitions of histologic response and remission and a biopsy procurement protocol are needed to guide clinical decision making. It is recommended that overall assessment of disease severity be determined according to the worst affected biopsy fragment. Crypt architectural distortion, basal plasmacytosis, and neutrophilic activity should be reported. A 5-category classification system based on disease chronicity/activity and basal plasmacytosis is proposed. It is not yet necessary to report on the degree of mucosal eosinophilia or use a validated scoring system, although the latter may aid in determining therapeutic response.

CONCLUSIONS

Although rarely used to measure inflammation and guide therapy, histologic disease activity is predictive of important clinical outcomes in UC. Randomized controlled trials are needed to determine whether histology should function as a treatment target.

Disease activity and mucosal healing in inflammatory bowel disease: a new role for histopathology?

Histologic evaluation of disease activity in the setting of inflammatory bowel disease is gaining interest within the gastroenterology community. Recent data suggests that histologic measurements of inflammation in ulcerative colitis are more sensitive at detecting disease activity and perform better than endoscopic measurements in predicting clinical outcomes. Histologic measurements are also increasingly used in ulcerative colitis clinical trials to assess response to new therapies. Histologic measurements of disease activity are less well studied in Crohn's disease, but are gaining attention. Current published treatment algorithms in inflammatory bowel disease do not take into consideration histologic activity; however, this may change in the near future. In order for histologic measurements to be included in clinical decision-making, validated, reliable, and responsive histologic scoring systems are needed. In this review, the recent literature on the significance of histologic activity in both ulcerative colitis and Crohn's disease is summarized. Histologic scoring systems are also briefly discussed.

Histological Disease Activity as a Predictor of Clinical Relapse Among Patients With Ulcerative Colitis: Systematic Review and Meta-Analysis

OBJECTIVES

Endoscopic remission in ulcerative colitis (UC) is associated with improved clinical outcomes. We assessed whether histological remission predicts clinical outcomes, estimated the magnitude of effect, and determined whether histological remission provides additional prognostic utility beyond clinical or endoscopic remission.

METHODS

Bibliographic databases were searched for studies in inflammatory bowel disease providing baseline histological status and relation to an outcome of clinical relapse or exacerbation. Our primary analysis compared the proportion of patients with study-defined histological remission vs. the proportion with histological activity who developed clinical relapse/exacerbation. Additional analyses compared the proportion with relapse/exacerbation for the presence vs. absence of different histological features and for histological remission vs. endoscopic remission and clinical remission. A fixed-effect model was used for meta-analysis, with a random-effects model if statistical heterogeneity was present.

RESULTS

Fifteen studies met inclusion criteria. The major methodological shortcoming was lack of blinding of the assessor of clinical relapse/exacerbation to baseline histological status in 13 of the 15 studies. Relapse/exacerbation was less frequent with baseline histological remission vs. histological activity (relative risk (RR)=0.48, 95% confidence interval (CI) 0.39-0.60) and vs. baseline clinical and endoscopic remission (RR=0.81, 95% CI 0.70-0.94). Relapse/exacerbation was also less common in the absence vs. presence of specific histological features: neutrophils in epithelium (RR=0.32, 95% CI 0.23-0.45), neutrophils in lamina propria (RR=0.43, 95% CI 0.32-0.59), crypt abscesses (RR=0.38, 95% CI 0.27-0.54), eosinophils in the lamina propria (RR=0.43, 95% CI 0.21-0.91), and chronic inflammatory cell infiltrate (RR=0.28, 95% CI 0.10-0.75). Histological remission was present in 964 (71%) of the 1360 patients with combined endoscopic and clinical remission at baseline.

CONCLUSIONS

UC patients with histological remission have a significant 52% RR reduction in clinical relapse/exacerbation compared with those with histological activity. Histological remission is also superior to endoscopic and clinical remission in predicting clinical outcomes. As ~30% of patients with endoscopic and clinical remission still have histological activity, addition of histological status as an end point in clinical trials or practice has the potential to improve clinical outcomes.

Endoscopic Disease Activity in Inflammatory Bowel Disease

Endoscopic scoring systems in Crohn’s disease and ulcerative colitis aim to translate the assessment of mucosal disease activity into a quantified value. This value seeks to provide a clear, objective record of the endoscopic mucosal severity, which can then be used to guide medical management decisions. The primary driver of all endoscopic indices, however, is to define a scale of responsiveness for therapeutic endpoints in clinical trials. Mucosal healing now has widespread acceptance as a therapeutic and clinical endpoint, but despite the development of multiple endoscopic scoring systems, the endoscopic definition has yet to be resolved. This review describes recent advances in endoscopic scoring systems for ulcerative colitis (Mayo Clinic endoscopy subscore, UCEIS, and UCCIS among others) and for Crohn’s disease.