Lisa M. Shackelton

A prospective cohort study to determine the relationship between serum infliximab concentration and efficacy in patients with luminal Crohn's disease

Patients with Crohns disease (CD) may experience disease relapse on maintenance infliximab. Anti‐drug antibodies likely contribute to loss of response, and serum infliximab levels likely correlate with efficacy.

Histologic evaluation of ulcerative colitis: a systematic review of disease activity indices.

Background:Ulcerative colitis (UC) is an idiopathic inflammatory disorder. Currently, the main goals of treatment are to induce and maintain clinical and/or endoscopic remission. However, evidence indicates that persistent disease activity on colonic biopsies in the setting of clinical or endoscopic remission is an independent predictor of poor outcomes. A number of previous studies have proposed histologic indices for use in specific trials of UC. The aim of this study was to systematically review the existing histological indices for UC and assess their potential use in both patient management and clinical trials. Methods:We performed a systematic review of histological indices evaluating disease activity in UC. MEDLINE (Ovid), EMBASE (Ovid), PubMed, the Cochrane Library (CENTRAL), and Digestive Diseases Week (DDW) abstracts of randomized and/or controlled trials clinical trials were searched from inception to February 2013 for applicable studies. Data from these studies were reviewed and analyzed. Results:After systematically applying inclusion criteria, we identified 108 scientific articles including 88 clinical studies and 21 related clinical reviews. Eighteen indices of histological activity in UC were identified and reviewed. Conclusions:Although multiple histological scoring indices for assessment of UC disease activity currently exist, none of these instruments were developed using a formal validation process and their operating properties remain poorly understood. Future studies are needed to address this deficiency.

Development and validation of a histological index for UC

Objective Although the Geboes score (GS) and modified Riley score (MRS) are commonly used to evaluate histological disease activity in UC, their operating properties are unknown. Accordingly, we developed an alternative instrument. Design Four pathologists scored 48 UC colon biopsies using the GS, MRS and a visual analogue scale global rating. Intra-rater and inter-rater reliability for each index and individual index items were measured using intraclass correlation coefficients (ICCs). Items with high reliability were used to develop the Robarts histopathology index (RHI). The responsiveness/validity of the RHI and multiple histological, endoscopic and clinical outcome measures were evaluated by analyses of change scores, standardised effect size (SES) and Guyatts responsiveness statistic (GRS) using data from a clinical trial of an effective therapy. Results Inter-rater ICCs (95% CIs) for the total GS and MRS scores were 0.79 (0.63 to 0.87) and 0.80 (0.69 to 0.87). The correlation estimates between change scores in RHI and change score in GS and MRS were 0.75 (0.67 to 0.82) and 0.84 (0.79 to 0.88), respectively. The SES and GRS estimates for GS, MRS and RHI were: 1.87 (1.54 to 2.20) and 1.23 (0.97 to 1.50), 1.29 (1.02 to 1.56) and 0.88 (0.65 to 1.12), and 1.05 (0.79 to 1.30) and 0.88 (0.64 to 1.12), respectively. Conclusions The RHI is a new histopathological index with favourable operating properties.

Reproducibility of histological assessments of disease activity in UC.

Objective Histopathology is potentially an important outcome measure in UC. Multiple histological disease activity (HA) indices, including the Geboes score (GS) and modified Riley score (MRS), have been developed; however, the operating properties of these instruments are not clearly defined. We assessed the reproducibility of existing measures of HA. Design Five experienced pathologists with GI pathology fellowship training and expertise in IBD evaluated, on three separate occasions at least two weeks apart, 49 UC colon biopsies and scored the GS, MRS and a global rating of histological severity using a 100 mm visual analogue scale (VAS). The reproducibility of each grading system and for individual instrument items was quantified by estimates of intraclass correlation coefficients (ICCs) based on two-way random effects models. Uncertainty of estimates was quantified by 95% two-sided CIs obtained using the non-parametric cluster bootstrap method. Biopsies responsible for the greatest disagreement based on the ICC estimates were identified. A consensus process was used to determine the most common sources of measurement disagreement. Recommendations for minimising disagreement were subsequently generated. Results Intrarater ICCs (95% CIs) for the total GS, MRS and VAS scores were 0.82 (0.73 to 0.88), 0.71 (0.63 to 0.80) and 0.79 (0.72 to 0.85), respectively. Corresponding inter-rater ICCs were substantially lower: 0.56 (0.39 to 0.67), 0.48 (0.35 to 0.66) and 0.61 (0.47 to 0.72). Correlation between the GS and VAS was 0.62 and between the MRS and VAS was 0.61. Conclusions Although ‘substantial’ to ‘almost perfect’ ICCs for intrarater agreement were found in the assessment of HA in UC, ICCs for inter-rater agreement were considerably lower. According to the consensus process results, standardisation of item definitions and modification of the existing indices is required to create an optimal UC histological instrument.

Randomised clinical trial: a phase 1, dose-ranging study of the anti-matrix metalloproteinase-9 monoclonal antibody GS-5745 versus placebo for ulcerative colitis

Matrix metalloproteinase‐9 is a proteolytic enzyme whose expression is increased in ulcerative colitis.

Assessment of histologic disease activity in Crohn's disease: a systematic review.

Background:Crohns disease (CD) is an idiopathic, chronic, transmural inflammatory disorder of the gastrointestinal tract. Because mucosal involvement is near-universal, endoscopic healing has emerged as an important aspect in improving outcome. However, resolution of histologic disease activity has potential to convey additional benefit beyond that attained with endoscopic healing alone. Validated scoring systems of histologic disease activity are required to further assess this possibility. The aim of this study was to systematically review the existing histologic disease activity indices (HDAI) for CD and to assess their operating properties and potential use as outcome measures in clinical trials. Methods:MEDLINE (Ovid), EMBASE (Ovid), PubMed, the Cochrane Library (CENTRAL), and Digestive Disease Week (DDW) abstracts were searched from 1981 to April 2013 for applicable studies to identify relevant studies for review and analysis. Results:In total, 3732 citations were screened to obtain 89 articles for inclusion. Sixty-six HDAIs were characterized as either stepwise or numerical instruments. These HDAIs were used for either assessment of response to medical therapy or for comparison with biomarkers or imaging tests. None of the HDAIs identified was developed according to currently accepted methods for developing evaluative instruments, and none have been formally validated. Conclusions:Measurement of histologic disease activity has potential value in CD; however, no validated measures are available. Additional research is needed to develop a methodologically rigorous instrument for use in clinical investigation and potentially for clinical practice.

Review article: dose optimisation of infliximab for acute severe ulcerative colitis

Although optimal medical management of acute severe ulcerative colitis (UC) is ill‐defined, infliximab has become a standard of care. Accumulating evidence suggests an increased rate of infliximab clearance in patients with acute severe UC and a reduced colectomy rate with an intensified infliximab induction regimen.

Systematic Review and Meta-analysis: Placebo Rates in Induction and Maintenance Trials of Ulcerative Colitis

BACKGROUND AND AIMS Minimisation of the placebo responses in randomised controlled trials [RCTs] is essential for efficient evaluation of new interventions. Placebo rates have been high in ulcerative colitis [UC] clinical trials, and factors influencing this are poorly understood. We quantify placebo response and remission rates in UC RCTs and identify trial design factors influencing them. METHODS MEDLINE, EMBASE, and the Cochrane Library were searched from inception through April 2014 for placebo-controlled trials in adult patients with UC of a biological agent, corticosteroid, immunosuppressant, or aminosalicylate. Data were independently doubly extracted. Quality was assessed using the Cochrane risk of bias tool. RESULTS In all, 51 trials [48 induction and 10 maintenance phases] were identified. Placebo response and remission rates were pooled according to random-effects models, and mixed-effects meta-regression models were used to evaluate effects of study-level characteristics on these rates. Pooled estimates of placebo remission and response rates for induction trials were 10% (95% confidence interval [CI] 7-13%) and 33% [95% CI 29-37%], respectively. Corresponding values for maintenance trials were 19% [95% CI 11-30%] and 22% [95% CI 17-28%]. Trials enrolling patients with more active disease confirmed by endoscopy [endoscopy subscore ≥ 2] were associated with lower placebo rates. Conversely, placebo rates increased with increasing trial duration and number of study visits. CONCLUSIONS Objective assessment of greater disease activity at trial entry by endoscopy lowered placebo rates, whereas increasing trial duration and more interactions with healthcare providers increased placebo rates. These findings have important implications for design and conduct of clinical trials.

Systematic Review: Disease Activity Indices in Eosinophilic Esophagitis

Objectives:There is no clear consensus regarding the most appropriate measure(s) of eosinophilic esophagitis (EoE) disease activity. We aimed to identify all scoring indices used for the measurement of disease activity in EoE, appraise their operating properties, and discuss their value as outcome measures.Methods:MEDLINE, EMBASE, and CENTRAL (The Cochrane library) were searched from inception to 11 May 2016. Randomized controlled trials (RCTs), cohort, case–control, and cross-sectional studies that reported outcomes to measure EoE disease activity or response to treatment were eligible. Operating properties of histologic, endoscopic, and patient reported/symptomatic and health-related quality of life measures were critically appraised according to guidelines proposed by the United States Food and Drug Administration.Results:Of 4,373 citations, 130 studies were eligible, of which 20 were RCTs. Although no index met all evaluative criteria, we found that: (1) the EoE histologic scoring system (EoEHSS) is the most valid histologic measure; (2) the Endoscopic Reference Score (EREFS) is the most reliable and responsive endoscopy measure; and (3) the Eosinophilic Esophagitis Activity Index (EEsAI) or the Dysphagia Symptoms Questionnaire (DSQ) had superior construct validity and responsiveness in adults. The Pediatric Quality of Life Inventory EoE was the most valid pediatric symptomatic measure.Conclusions:Current evidence supports the use of the EoEHSS and EREFS as measures of histologic and endoscopic EoE disease activity, respectively, and the EEsAI, DSQ, or Pediatric Quality of Life Inventory EoE as measures of adult and pediatric symptoms. Additional research is needed to optimize endpoint configuration to facilitate development of new therapies.

Responsiveness of Endoscopic Indices of Disease Activity for Crohn’s Disease

Objectives:The Crohn’s Disease Endoscopic Index of Severity (CDEIS) and the Simple Endoscopic Score for Crohn’s Disease (SES-CD) are commonly used to assess Crohn’s disease (CD) activity; however neither instrument is fully validated. We evaluated the responsiveness to change of the SES-CD and CDEIS using data from a trial of adalimumab, a drug therapy of known efficacy.Methods:Paired video recordings (N=112) of colonoscopies (baseline and week 8–12) obtained from patients with CD who participated in a trial of adalimumab therapy were reviewed in random order, in duplicate, by four central readers (56 pairs of videos by 2 groups of readers). Responsiveness of the SES-CD and the CDEIS was evaluated by comparing correlations between the observed and pre-specified predictions of change scores for these endoscopic indices with a global endoscopic evaluation of severity (GELS), a patient reported outcome (PRO2), and the Crohn’s disease activity index (CDAI), and by calculation of the standardized effect size, and Guyatt’s Responsiveness statistic (GRS) using 2 definitions of change; (1) treatment assignment and (2) an absolute change in total PRO2 of 50. The potential application of effect size estimates was demonstrated by calculating hypothetical sample sizes for comparing two independent groups. The impact of removing stenosis as an index item and adjusting for the number of segments observed was also assessed.Results:Changes in both endoscopic instruments and the GELS were highly correlated. The SES-CD displayed numerically higher effect sizes for both definitions of change. The standardized effect size and GRS estimates (95% confidence interval) for the SES-CD based on treatment assignment were 0.84 (0.53, 1.15) and 0.79 (0.48, 1.09). Corresponding values for the CDEIS were 0.72 (0.42, 1.02) and 0.75 (0.45, 1.06). The standardized effect size and GRS estimates for the SES-CD based on an absolute change in total PRO2 of 50 points or greater were 0.76 (0.49, 1.02) and 0.93 (0.64, 1.21). Corresponding values for CDEIS were 0.70 (0.44, 0.97), 0.83 (0.55, 1.10). Removal of stenosis as an index item and adjusting for observed segments did not improve responsiveness estimates.Conclusions:Although both the SES-CD and CDEIS are valid measures of endoscopic disease activity that are moderately responsive to changes in endoscopic disease activity, the SES-CD displayed numerically greater responsiveness in this data set.