Comparison of the Nancy Index With Continuous Geboes Score: Histological Remission and Response in Ulcerative Colitis.

BACKGROUND AND AIMS: Evidence has been supporting that histological activity of ulcerative colitis [UC] has relevance for the prediction of clinical outcomes in UC patients, such as clinical relapse. In this study, we aimed to compare two histological indexes-the continuous Geboes score [GS] and the Nancy index [NI] -regarding their definitions of histological remission and response, and to determine the ability of faecal calprotectin [FC] levels to discriminate between these histological statuses according to the NI. METHODS: A large cohort of UC patients [N = 422] who were previously enrolled in other studies was analysed. RESULTS: GS and NI were shown to be strongly correlated [correlation coefficient: 0.882, p <0.001], indicating high accordance in the classification of patients as having/not having histological remission and response. FC levels moderately correlated with NI regarding these histological statuses [correlation coefficient: 0.481, p <0.001], moderately predicted the absence of remission defined by NI >0 {area under the curve (AUC) 0.667 (95% confidence interval [CI] 0.609-0.724)}, and were good predictors of the absence of histological response defined by NI >1 (AUC 0.825 [95% CI 0.777-0.872]). The optimal FC cut-offs determined to predict the NI-defined histological remission and response were 91 µg/g and 106 µg/g, when maximising the negative predictive value [NPV]. CONCLUSIONS: Due to the higher applicability of the NI, this study encourages the systematic use of this histological index to assess histological remission and response in UC patients.

Comparing the Continuous Geboes Score With the Robarts Histopathology Index: Definitions of Histological Remission and Response and their Relation to Faecal Calprotectin Levels.

BACKGROUND AND AIMS: The histological status of ulcerative colitis [UC] patients in clinical and endoscopic remission has gained space as an important prognostic marker and a key component of disease monitoring. Our main aims were to compare two histological indexes-the continuous Geboes score [GS] and the Robarts Histopathology index [RHI]-regarding their definitions of histological remission and response, and the ability of faecal calprotectin [FC] levels to discriminate between these statuses. METHODS: This was an analysis of three prospective cohorts including 422 patients previously enrolled in other studies. RESULTS: The two continuous scores [GS and RHI] were shown to be significantly correlated [correlation coefficient of 0.806, p < 0.001] and particularly close regarding their definition of histological response: 95% and 88% of all patients classified as having/not having [respectively] histological response according to RHI also did so according to GS. Moreover, median FC levels in patients with histological response were lower than those in patients without histological response [GS: 73.00 vs 525.00, p < 0.001; RHI: 73.50 vs 510.00, p < 0.001]; a similar trend was observed when FC levels of patients in histological remission were compared to those of patients with histological activity [GS: 76.00 vs 228.00, p < 0.001; RHI: 73.50 vs 467.00, p < 0.001]. FC levels allowed us to exclude the absence of histological remission [according to RHI] and absence of histological response [according to RHI and GS], with negative predictive values varying from 82% to 96%. However, optimization of the FC cut-off to exclude the absence of histological remission, as for the continuous GS, falls within values that resemble those of the healthy population. CONCLUSION: The continuous GS and RHI histological scores are strongly correlated in their definitions of histological response. An absence of histological remission could only be excluded at physiological levels of FC.

Fibrogenesis in Chronic DSS Colitis is Not Influenced by Neutralisation of Regulatory T Cells, of Major T Helper Cytokines or Absence of IL-13.

Mechanisms underlying fibrogenesis in chronic colitis are largely unknown. There is an urgent need for clinical markers and identification of targets to prevent, treat and limit intestinal fibrosis. This study investigated the contribution of major T cell cytokines and T regulatory cells (Tregs) to inflammation and fibrosis induced in a model of experimental colitis by oral intake of dextran sodium sulphate (DSS) in wild type and IL-13 knock-out C57Bl/6 mice. Inflammation and fibrosis were scored by macroscopic and histological examination and fibrosis was quantified by hydroxyproline. Numbers of Tregs and IFN-γ+, IL-13+ and IL-17A+ CD4+ T helper (Th) cells in mesenteric lymph nodes increased during chronic DSS administration and mRNA for IFN-γ and IL-17 in the inflamed colon tissue was upregulated. However, antibody-mediated neutralisation of IFN-γ or IL-17A/F in a therapeutic setting had no effect on chronic intestinal inflammation and fibrosis. Antibody-mediated depletion of Tregs did not enhance fibrosis, nor did IL-13 deficiency have an effect on the fibrotic disease. These data argue against an important contribution of Tregs and of the cytokines IFN-γ, IL-13, IL-17A, IL-17F in the induction and/or control of fibrosis in this Crohn's disease like murine model.

Comparison of different histological indexes in the assessment of UC activity and their accuracy regarding endoscopic outcomes and faecal calprotectin levels.

OBJECTIVE: Histological remission is being increasingly acknowledged as a therapeutic endpoint in patients with UC. The work hereafter described aimed to evaluate the concordance between three histological classification systems-Geboes Score (GS), Nancy Index (NI) and RobartsHistopathologyIndex (RHI), as well as to evaluate their association with the endoscopic outcomes and the faecal calprotectin (FC) levels. DESIGN: Biopsy samples from 377 patients with UC were blindly evaluated using GS, NI and RHI. The results were compared with the patients' Mayo Endoscopic Score and FC levels. RESULT: GS, NI and RHI have a good concordance concerning the distinction between patients in histological remission or activity. RHI was particularly close to NI, with 100% of all patients classified as being in remission with NI being identified as such with RHI and 100% of all patients classified as having activity with RHI being identified as such with NI. These scores could also predict the Mayo Endoscopic Score and the FC levels, with their sensitivity and specificity levels depending on the chosen cut-offs. Moreover, higher FC levels were statistically associated with the presence of neutrophils in the epithelium, as well as with ulceration or erosion of the intestinal mucosa. CONCLUSIONS: GS, NI and RHI histopathological scoring systems are comparable in what concerns patients' stratification into histological remission/activity. Additionally, FC levels are increased when neutrophils are present in the epithelium and the intestinal mucosa has erosions or ulcers. The presence of neutrophils in the epithelium is, indeed, the main marker of histological activity.

Chromoendoscopy versus narrow band imaging in UC: a prospective randomised controlled trial.

BACKGROUND: Patients with long-standing UC have an increased risk for the development of colonic neoplastic lesions. Chromoendoscopy (CE) has been proven to enhance neoplasia detection while the role of virtual chromoendoscopy (VC) is still to be defined. OBJECTIVE: To compare the performance of CE to VC for the detection of neoplastic lesions in patients with long-standing UC. DESIGN: A multicentre prospective randomised controlled trial. 131 patients with long-standing UC were randomised between CE with methylene blue 0.1% (n=66) or VC with narrow band imaging (NBI) (n=65). Biopsies were taken from visible lesions and surrounding mucosa. No random biopsies were performed. The primary outcome was the difference in total number of neoplastic lesions detected in each group. RESULTS: There was no significant difference between NBI and CE for neoplasia detection. Mean number of neoplastic lesions per colonoscopy was 0.47 for CE and 0.32 for NBI (p=0.992). The neoplasia detection rate was not different between CE (21.2%) and NBI (21.5%) (OR 1.02 (95% CI 0.44 to 2.35, p=0.964). Biopsies from the surrounding mucosa yielded no diagnosis or dysplasia. The per lesion neoplasia detection was 17.4% for CE and 16.3% for NBI (OR 1.09 (95% CI 0.59 to 1.99, p=0.793). The total procedural time was on average 7 min shorter in the NBI group. CONCLUSION: CE and NBI do not differ significantly for detection of colitis-associated neoplasia. Given the longer withdrawal time for CE and easier applicability, NBI may possibly replace classical CE. TRIAL REGISTRATION NUMBER: NCT01882205; Results.

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.

Clinical performance of an infliximab rapid quantification assay.

BACKGROUND: Therapeutic drug monitoring (TDM)-based algorithms can be used to guide infliximab (IFX) adjustments in inflammatory bowel disease (IBD) patients. This study aimed to explore a rapid IFX-quantification test from a clinical perspective. METHODS: This manuscript describes a prospective cohort study involving 110 ulcerative colitis (UC) patients on the maintenance phase of IFX. IFX trough levels were quantified using a rapid quantification assay and a commonly-used reference kit. RESULTS: Irrespective of the assay used to measure IFX, its through levels were statistically different between patients with and without endoscopic remission (Mayo endoscopic score = 0), as well as between patients stratified by their faecal calprotectin (FC) levels. Despite the fact that the two methods correlated well with each other [Spearman's rank correlation coefficient = 0.843, p < 0.001; intraclass correlation coefficients = 0.857, 95% confidence interval (CI): 0.791-0.903], there was a discernible systematic variation; values obtained with the reference kit were on average 2.62 units higher than those obtained with the rapid assay. Notwithstanding, 3 µg/ml was shown to be an acceptable cut-off to assess endoscopic status and inflammatory burden levels using both assays. The percentage of patients that had a positive outcome when the IFX concentration measured by the rapid assay ranked above 3 µg/ml was 88% both for a Mayo endoscopic score ⩽ 1 and for an FC concentration <250 µg/g. CONCLUSIONS: Based on this study, we concluded that using the rapid IFX assessment system with a 3 µg/ml threshold is a reliable alternative to the time-consuming enzyme-linked immunosorbent assays in patients on the maintenance phase of IFX.

Inhibition of gelatinase B/MMP-9 does not attenuate colitis in murine models of inflammatory bowel disease.

One third of patients with inflammatory bowel disease (IBD) inadequately respond to anti-TNF treatment and preclinical data suggest that matrix metalloproteinase-9 (MMP-9) is a novel therapeutic target. Here we show that IBD clinical and histopathological parameters found in wild type mice challenged with three different models of colitis, acute and chronic dextran sodium sulphate (DSS), and acute 2,4,6-trinitrobenzenesulfonic acid-induced colitis are not attenuated in MMP-9 knockout mice. We find similar colonic gene expression profiles in wild type and MMP-9 knockout mice in control and acute DSS conditions with the exception of eleven genes involved in antimicrobial response during colitis. Parameters of chronic colitis are similar in wild type and MMP-9 knockout mice. Pharmacological inhibition of MMP-9 with bio-active peptides does not improve DSS colitis. We suggest that MMP-9 upregulation is a consequence rather than a cause of intestinal inflammation and we question whether MMP-9 represents a disease target in IBD.

Treatment of Intestinal Fibrosis in Experimental Inflammatory Bowel Disease by the Pleiotropic Actions of a Local Rho Kinase Inhibitor.

BACKGROUND: Intestinal fibrosis resulting in (sub)obstruction is a common complication of Crohn's disease (CD). Rho kinases (ROCKs) play multiple roles in TGFß-induced myofibroblast activation that could be therapeutic targets. Because systemic ROCK inhibition causes cardiovascular side effects, we evaluated the effects of a locally acting ROCK inhibitor (AMA0825) on intestinal fibrosis. METHODS: Fibrosis was assessed in mouse models using dextran sulfate sodium (DSS) and adoptive T-cell transfer. The in vitro and ex vivo effects of AMA0825 were studied in different cell types and in CD biopsy cultures. RESULTS: ROCK is expressed in fibroblastic, epithelial, endothelial, and muscle cells of the human intestinal tract and is activated in inflamed and fibrotic tissue. Prophylactic treatment with AMA0825 inhibited myofibroblast accumulation, expression of pro-fibrotic factors, and accumulation of fibrotic tissue without affecting clinical disease activity and histologic inflammation in 2 models of fibrosis. ROCK inhibition reversed established fibrosis in a chronic DSS model and impeded ex vivo pro-fibrotic protein secretion from stenotic CD biopsies. AMA0825 reduced TGFß1-induced activation of myocardin-related transcription factor (MRTF) and p38 mitogen-activated protein kinase (MAPK), down-regulating matrix metalloproteinases, collagen, and IL6 secretion from fibroblasts. In these cells, ROCK inhibition potentiated autophagy, which was required for the observed reduction in collagen and IL6 production. AMA0825 did not affect pro-inflammatory cytokine secretion from other ROCK-positive cell types, corroborating the selective in vivo effect on fibrosis. CONCLUSIONS: Local ROCK inhibition prevents and reverses intestinal fibrosis by diminishing MRTF and p38 MAPK activation and increasing autophagy in fibroblasts. Overall, our results show that local ROCK inhibition is promising for counteracting fibrosis as an add-on therapy for CD.

Calprotectin and the Magnitude of Antibodies to Infliximab in Clinically-stable Ulcerative Colitis Patients are More Relevant Than Infliximab Trough Levels and Pharmacokinetics for Therapeutic Escalation.

Although infliximab (IFX) is an efficient therapy for ulcerative colitis (UC) patients, a considerably high rate of therapeutic failures still occurs. This study aimed at a better understanding of IFX pharmacokinetics and pharmacodynamics among clinically-asymptomatic UC patients. This was a multicentric and prospective study involving 65 UC patients in the maintenance phase of IFX therapy. There were no significant differences between patients with positive and negative clinical, endoscopic and histological outcomes concerning their IFX trough levels (TLs), area under the IFX concentration vs. time curve (AUC), clearance and antibodies to infliximab (ATI) levels. However, the need to undergo therapeutic escalation later in disease development was significantly associated with higher ATI levels (2.62µg/mL vs. 1.15µg/mL, p=0.028). Moreover, and after adjusting for disease severity, the HR (hazard ratio) for therapeutic escalation was significantly decreased for patients with an ATI concentration below 3µg/mL (HR=0.119, p=0.010), and increased for patients with fecal calprotectin (FC) level above 250µg/g (HR=9.309, p=0.018). In clinically-stable UC patients, IFX pharmacokinetic features cannot predict therapeutic response on a short-term basis. However, high levels of ATIs or FC may be indicative of a future therapeutic escalation.

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 Guyatt's 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.

A Simplified Geboes Score for Ulcerative Colitis.

BACKGROUND AND AIMS: The original Geboes Score [OGS] is the most commonly used histological score in ulcerative colitis [UC], but rather complicated to use in daily clinical practice. The aim of this study was to develop a Simplified Geboes Score [SGS] and to compare it with the OGS in patients newly diagnosed with UC. METHODS: All patients diagnosed with UC at a tertiary referral centre between 2005 and 2010, who had serial colonoscopies with biopsies, were retrospectively included. The 5-year endoscopic/histological evolution after diagnosis was recorded. Histological activity was scored by an experienced inflammatory bowel disease pathologist and three trained readers using the OGS and also the new SGS that only includes variables linked to active inflammatory disease. The correlation between endoscopic and histological activity and the histological inter-observer agreement were measured. RESULTS: A total of 528 slides from 339 colonoscopies of 103 UC patients were reviewed. Forty [12%] colonoscopies presented Mayo 0, 74 [22%] Mayo 1, 107 [31%] Mayo 2 and 118 [35%] Mayo 3. Active microscopic disease [≥ 3.1 in both scores] was described in 10/40 [25%] patients who were in complete endoscopic remission [Mayo 0], and 62/74 [84%] with mild endoscopic lesions [Mayo 1]. The correlation analysis between endoscopy and OGS/SGS did not show significant differences between the histological scores. The inter-observer agreement was moderate for all the grades of the SGS. CONCLUSIONS: The assessments of histological activity based on the OGS and the SGS were comparable in newly diagnosed active UC patients. Further prospective validation should now be done to replace the OGS with the SGS.

Accuracy of Faecal Calprotectin and Neutrophil Gelatinase B-associated Lipocalin in Evaluating Subclinical Inflammation in UlceRaTIVE Colitis-the ACERTIVE study.

BACKGROUND AND AIMS: Mucosal healing and histological remission are different targets for patients with ulcerative colitis, but both rely on an invasive endoscopic procedure. This study aimed to assess faecal calprotectin and neutrophil gelatinase B-associated lipocalin as biomarkers for disease activity in asymptomatic ulcerative colitis patients. METHODS: This was a multicentric cross-sectional study including 371 patients, who were classified according to their endoscopic and histological scores. These results were evaluated alongside the faecal levels of both biomarkers. RESULTS: Macroscopic lesions [i.e. endoscopic Mayo score ≥1] were present in 28% of the patients, and 9% had active disease according to fht Ulcerative Colitis Endoscopic Index of Severity. Moreover, 21% presented with histological inflammation according to the Geboes index, whereas 15% and 5% presented with focal and diffuse basal plasmacytosis, respectively. The faecal levels of calprotectin and neutrophil gelatinase B-associated lipocalin were statistically higher for patients with endoscopic lesions and histological activity. A receiver operating characteristic-based analysis revealed that both biomarkers were able to indicate mucosal healing and histological remission with an acceptable probability, and cut-off levels of 150-250 µg/g for faecal calprotectin and 12 µg/g for neutrophil gelatinase B-associated lipocalin were proposed. CONCLUSIONS: Faecal calprotectin and neutrophil gelatinase B-associated lipocalin levels are a valuable addition for assessment of disease activity in asymptomatic ulcerative colitis patients. Biological levels of the analysed biomarkers below the proposed thresholds can rule out the presence of macroscopic and microscopic lesions with a probability of 75-93%. However, caution should be applied whenever interpreting positive results, as these biomarkers present consistently low positive predictive values.

Characterisation of Mucosal Healing with Adalimumab Treatment in Patients with Moderately to Severely Active Crohn's Disease: Results from the EXTEND Trial.

BACKGROUND AND AIMS: Mucosal healing [MH] is an important goal for patients with Crohn's disease [CD], yet is incompletely characterised. We investigated whether MH differed by segments across the colon and ileum in patients who received adalimumab maintenance treatment in the EXTEND study. METHODS: In this double-blind study in adults with moderate to severe ileocolonic CD and mucosal ulceration, all patients received adalimumab induction [Week 0, 160 mg; Week 2, 80 mg]. At Week 4, patients were randomised to 40 mg adalimumab or placebo every other week until Week 52. In this post-hoc analysis, MH was assessed by CD Endoscopic Index of Severity [CDEIS], Simple Endoscopic Score for CD [SES-CD], and Colonic and Ileal Global Histologic Disease Activity Scores [CGHAS/IGHAS]. RESULTS: Baseline endoscopic severity was similar across segments. At Week 52, mean changes in CDEIS surface involved and ulcerated surface were -68.5% to -90.6% in the rectum, sigmoid/left colon, and transverse colon compared with -22.3% to -50.0% in the right colon and ileum. Favourable shifts by Week 52 in ulcer size and ulcerated surfaces per SES-CD were more pronounced in the rectum, sigmoid/left colon, and transverse colon vs the right colon and ileum. At Week 52, CGHAS and IGHAS healing was more common in the colon [28.3%] vs the ileum [21.2%]. CONCLUSIONS: This analysis suggests differing propensities of the ileocolonic segments to heal endoscopically during adalimumab treatment. In the sigmoid/left and transverse colon, higher MH rates may be achieved, compared with the ileum, in patients with moderate to severe CD.

Submucosal Plexitis as a Predictive Factor for Postoperative Endoscopic Recurrence in Patients with Crohn's Disease Undergoing a Resection with Ileocolonic Anastomosis: Results from a Prospective Single-centre Study.

AIM: Ileocolonoscopy allows early detection of recurrence after surgical resection for Crohn's disease [CD]. Plexitis, defined as presence of inflammatory cells in or around enteric ganglia or nerve bundles, in the proximal surgical margin has been associated with an increased overall recurrence risk. We investigated prospectively whether plexitis can predict endoscopic recurrence [ER] in a consecutive cohort of CD patients undergoing ileocolonic resection. METHODS: All CD patients undergoing ileocolonic resection in our institution between October 2009 and December 2012 were eligible for this study. Clinical data were obtained prospectively from the patients' files, and biopsies from the proximal surgical margins were analysed immunohistochemically for inflammation at the myenteric and submucosal plexus [lymphocytes, mast cells, eosinophils]. The degree of plexitis was correlated with the presence of ER at 6 months, defined as a modified Rutgeerts' score of ≥ i2b. Multivariate models were developed and tested to predict posterior probability of ER. RESULTS: A total of 74 patients were included. Six months after ileocolonic resection, 50% showed ER. Known risk factors such as penetrating disease, previous resections, and active smoking, showed no relation with ER. On the other hand, submucosal lymphocytic plexitis was associated with ER [p = 0.020]. The predictive value of lymphocytic cell count increased with more extensive biopsy sampling and with application of immunohistochemistry. CONCLUSIONS: Submucosal lymphocytic plexitis in the proximal surgical margin was significantly related with a higher risk for ER after ileocolonic resection. These data support development of a postoperative prevention trial with vedolizumab, which may block lymphocytic trafficking in the postoperative bowel.

Genetic Deletion of Tissue Inhibitor of Metalloproteinase-1/TIMP-1 Alters Inflammation and Attenuates Fibrosis in Dextran Sodium Sulphate-induced Murine Models of Colitis.

BACKGROUND AND AIMS: Increased levels of tissue inhibitor of metalloproteinase-1 [TIMP-1] have been detected in both inflammatory and fibrotic lesions in Crohn's disease. In a murine model of chronic inflammation, fibrosis was associated with an increase in TIMP-1 and inhibition of matrix metalloproteinase [MMP]-mediated degradation. We investigated the effect of TIMP-1 deficiency in acute and chronic murine models of colitis. METHODS: Colitis was induced via oral administration of dextran sodium sulphate [DSS] to B6.129S4-Timp1tm1Pds/J knock-out [KO] and C57BL/6J wild-type [WT] mice. Levels of inflammation and fibrosis were assessed and gelatin zymographies and gene expression microarrays were performed. RESULTS: Compared with WT mice, TIMP-1 KO mice had higher inflammatory parameters after acute DSS administration and developed less fibrosis after chronic DSS administration. MMP-2 levels were increased in WT versus TIMP-1 KO mice with acute colitis, whereas a trend for higher proMMP-9 levels was observed in WT versus TIMP-1 KO mice with chronic colitis. In control conditions, several immune-related genes [e.g Ido1, Cldn8] were differentially expressed between young TIMP-1 KO and WT mice, but to a lesser extent between older TIMP-1 KO and WT mice. In response to DSS, the gene expression pattern was significantly different between young TIMP-1 KO and WT mice, whereas it was similar in older TIMP-1 KO and WT mice. CONCLUSIONS: TIMP-1 deficiency leads to differential expression of immune-related genes and to attenuated development of fibrosis. Unravelling the role of TIMP-1 in intestinal remodelling is necessary to develop more effective and more targeted therapeutic strategies for intestinal fibrosis.

Histological Outcomes and Predictive Value of Faecal Markers in Moderately to Severely Active Ulcerative Colitis Patients Receiving Infliximab.

BACKGROUND AND AIMS: Histological healing has emerged as a promising therapeutic goal in ulcerative colitis. This is especially important in the context of biological therapies. The objectives of the present study were to investigate the ability of infliximab to induce histological remission in ulcerative colitis [UC] patients and to explore the utility of faecal calprotectin and lactoferrin in predicting histological activity. METHODS: Multi-centre, single-cohort, open-label, 52-week trial including moderately to severely biological-naïve UC patients receiving intravenous infliximab [5mg/kg]. The primary outcome was the proportion of patients with histological remission [Geboes index ≤ 3.0] after 8 weeks of treatment, scored by two independent pathologists. RESULTS: Twenty patients were included. The rate of histological remission increased from 5% at baseline to 15% and 35% at Week 8 and Week 52, respectively. At Week 8, 40% of patients were in clinical remission [Mayo ≤ 2] and 45% achieved mucosal healing [Mayo endoscopy subscore 0-1]. At Week 52, 25% of patients had clinical, endoscopic and histological remission. Faecal calprotectin and lactoferrin showed the highest correlation with histological activity at Week 8 (area under the curve [AUC] 94%, p = 0.017; and 96%, p = 0.013, respectively) and both markers revealed an excellent positive predictive value for this outcome at this time point [100%, p = 0.017; and 94%, p = 0.013, respectively]. CONCLUSIONS: Infliximab was able to induce histological remission. There was a good agreement between histology and faecal biomarkers. Faecal calprotectin and lactoferrin were good predictors of histological remission. Our data support inclusion of histology as a treatment target complementary to endoscopy in clinical trials when evaluating therapeutic response in UC.

Contemporary methods for the diagnosis and treatment of microscopic colitis.

Microscopic colitis is a common cause of chronic diarrhea. It is characterized by non-bloody watery diarrhea with macroscopically normal colonic mucosa. Its specific histological characteristics confirm the diagnosis. Two distinct histological forms can be identified, namely, collagenous colitis and lymphocytic colitis. In collagenous colitis, a thick colonic subepithelial collagenous deposit can be observed, whereas in lymphocytic colitis, a pronounced intraepithelial lymphocytic inflammation in the absence of a thickened collagen band can be identified. Microscopic colitis occurs more frequently in elderly females and its etiology is believed to be multifactorial, although smoking and consumption of several drugs have been identified as risks factors for the development of the disease. The treatment is based on avoiding the risks factors and administration of oral budesonide.

Delivery of a mucin domain enriched in cysteine residues strengthens the intestinal mucous barrier.

A weakening of the gut mucous barrier permits an increase in the access of intestinal luminal contents to the epithelial cells, which will trigger the inflammatory response. In inflammatory bowel diseases, there is an inappropriate and ongoing activation of the immune system, possibly because the intestinal mucus is less protective against the endogenous microflora. General strategies aimed at improving the protection of the intestinal epithelium are still missing. We generated a transgenic mouse that secreted a molecule consisting of 12 consecutive copies of a mucin domain into its intestinal mucus, which is believed to modify the mucus layer by establishing reversible interactions. We showed that the mucus gel was more robust and that mucin O-glycosylation was altered. Notably, the gut epithelium of transgenic mice housed a greater abundance of beneficial Lactobacillus spp. These modifications were associated with a reduced susceptibility of transgenic mice to chemically induced colitis. Furthermore, transgenic mice cleared faster Citrobacter rodentium bacteria which were orally given and mice were more protected against bacterial translocation induced by gavage with adherent-invasive Escherichia coli. Our data show that delivering the mucin CYS domain into the gut lumen strengthens the intestinal mucus blanket which is impaired in inflammatory bowel diseases.