Effect of vedolizumab (anti-α4ß7-integrin) therapy on histological healing and mucosal gene expression in patients with UC.

OBJECTIVE: Lymphocyte recruitment to the inflamed gut is increased in UC. Inhibition of this cell trafficking by vedolizumab (VDZ) was successful in inducing and maintaining remission and in induction of endoscopic mucosal healing. There are no data on histological healing with VDZ. We studied histological changes following VDZ therapy and compared gene expression in patients with UC before and after therapy. DESIGN: Forty-one patients with UC from GEMINI I and LTS were studied before and at three time points (weeks 6/12/52) following VDZ therapy. Colonic biopsies were scored using the Geboes index and correlated with Mayo endoscopic subscore. Gene expression was analysed using Affymetrix gene arrays. RESULTS: Fifty-five per cent of patients achieving endoscopic healing (= Mayo endoscopic subscore 0-1) with VDZ at the studied time points also had histological healing (= Geboes grade 0-1). In most healers, some residual histological changes (eg, disturbed architecture and increased mononuclear cell infiltrate) were still observed, although this was less at week 52. VDZ restored expression of many inflammatory genes in patients with endoscopic healing only at week 52 and not before. In VDZ healers, the expression of many genes remained dysregulated at weeks 6/12/52 compared with controls. CONCLUSIONS: VDZ induces histological healing in >50% of patients with endoscopic healing, with maximal effect at week 52. VDZ also restored, although incompletely, the colonic expression of many immune-related genes in patients with UC achieving endoscopic healing at week 52. However, persistent histological and gene dysregulations did remain even in healers, suggesting that maintenance therapy will be necessary to control the intestinal inflammation. TRIAL REGISTRATION NUMBERS: NCT00783718 and NCT00790933; post-results.

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.

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.

The Modified Mayo Endoscopic Score (MMES): A New Index for the Assessment of Extension and Severity of Endoscopic Activity in Ulcerative Colitis Patients.

BACKGROUND AND AIMS: Current endoscopic activity scores for ulcerative colitis (UC) do not take into account the extent of mucosal inflammation. We have developed a simple endoscopic index for UC that takes into account the severity and distribution of mucosal inflammation. METHODS: In this multicentre trial, UC patients undergoing colonoscopy were prospectively enrolled. For the Modified Score (MS), the sum of Mayo Endoscopic Subscores (MESs) for five colon segments (ascending, transverse, descending, sigmoid and rectum) was calculated. The Extended Modified Score (EMS) was obtained by multiplying the MS by the maximal extent of inflammation. The Modified Mayo Endoscopic Score (MMES) was obtained by dividing the EMS by the number of segments with active inflammation. Colon biopsies were obtained from the rectum and sigmoid, as well as from all inflamed segments, by standard methods. Clinical activity was scored according to the Partial Mayo Score (PMS). Biological activity was scored according to C-reactive protein (CRP) and faecal calprotectin (FC) levels. Histological activity was scored according to the Geboes Score (GS). RESULTS: One hundred and seventy-one UC patients (38% female, median age 47 years, median disease duration 13 years) were included. The MMES correlated significantly with the PMS (r = 0.535), CRP (r = 0.238), FC (r = 0.730) and GS (r = 0.615) (all p < 0.001). Median MMES scores were significantly higher in patients with clinical, biological or histological activity (all p ≤ 0.001) CONCLUSIONS: The MMES is an easy to use endoscopic index for UC that combines the severity analysis of the MES with disease extent, and correlates very well with clinical, biological and histological disease activity.

Infliximab restores the dysfunctional matrix remodeling protein and growth factor gene expression in patients with inflammatory bowel disease.

BACKGROUND: Matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), a disintegrin and metalloprotease with thrombospondin motifs [ADAM(TS)s] and growth factors are involved in inflammation and tissue damage and repair, all occurring in inflammatory bowel disease (IBD). We studied the impact of anti-inflammatory therapy with infliximab on mucosal expression of these tissue remodeling genes in patients with IBD. METHODS: Mucosal gene expression of 23 MMPs, 4 TIMPs, 50 ADAM(TS)s, and 158 growth factors was investigated in 61 patients with IBD before and after the first infliximab therapy and in 12 controls, with microarrays and quantitative RT-PCR. Protein localization, mucosal gelatinase levels, and net gelatinolytic activity were investigated by immunohistochemistry, zymography analysis, and gelatin degradation assay, respectively. RESULTS: In patients with active IBD before infliximab versus controls, gene expression of many MMPs, TIMPs, ADAM(TS)s, and growth factors was upregulated, whereas colonic expression of MMP28 and TGFA and ileal expression of ADAMDEC1 and AGT were downregulated. After controlling inflammation with infliximab, most gene dysregulations observed at baseline were restored in responders. Increased ratio of MMP1/TIMP1 expression at baseline in active IBD was restored in responders with colonic mucosal healing. With immunohistochemistry, protein localization differences of MMP1, MMP3, REG1A, and TIMP1 were shown between active IBD and control mucosa. With zymography analysis and gelatin degradation assay, higher gelatinase levels and net gelatinolytic activity were measured before infliximab and levels normalized after infliximab. CONCLUSIONS: Our data suggest that suppression of inflammation results in the arrest of epithelial damage and subsequent mucosal healing. Therefore, the therapeutic potential of agents targeting MMPs or growth factors as primary therapy seems rather complex.

Correlation between the endoscopic and histologic score in assessing the activity of ulcerative colitis.

BACKGROUND: In routine practice, scoring of activity and severity of ulcerative colitis is based on combined clinical and endoscopic assessment. Histology also allows sensitive scoring of ulcerative colitis activity. The correlation between endoscopy and histology has not been investigated thoroughly. It is still unknown how well they correlate and whether scoring both endoscopy and histology better reflects the true disease activity than each of the methods separately. METHODS: Two hundred and sixty-three biopsy sets from 131 known patients with ulcerative colitis were reviewed by an experienced gastrointestinal pathologist and scored using the Geboes and Riley histologic scoring systems. Endoscopic scoring had been performed previously by inflammatory bowel disease specialists using the Mayo endoscopic subscore. Bidirectional comparison of the Mayo endoscopic subscore with the full and converted histologic scores was then performed. RESULTS: We found a statistically significant overall correlation between the Mayo endoscopic subscore and the histologic scores (highest correlation: Kendall's τ = 0.482, P < 0.0001). Although a very high concordance was found for inactive and severely active disease, a high diversity was detected between these extremes. For example, endoscopic mildly active disease (Mayo 1) was distributed over all different histologic grades (37%, grade 0; 21%, grade 1; 28%, grade 2; and 14%, grade 3). CONCLUSIONS: Both extremes of the histologic and endoscopic activity scores neatly correlate, but important misclassifications exist for mild disease. Microscopy may detect more severe disease than endoscopically suspected, possibly altering the clinical follow-up scheme. We also infer from our results that histologic scoring should be used in addition to endoscopy when scoring disease activity for clinical trials.

Prognostic value of serologic and histologic markers on clinical relapse in ulcerative colitis patients with mucosal healing.

OBJECTIVES: Endoscopic mucosal healing is a key endpoint for the treatment of ulcerative colitis (UC). The role of microscopic activity in predicting disease relapse has not been fully assessed. We aimed to investigate the predictive role of serologic and histologic markers on disease relapse in UC patients with endoscopically inactive disease. METHODS: Adult UC patients with endoscopically inactive disease (Mayo 0) and a 12-month follow-up between 2008 and 2011 were retrospectively included. An expert pathologist evaluated all colonic biopsies for histologic activity (Geboes score) and the presence of basal plasmacytosis. Blood samples collected around the time of endoscopy were analyzed. Disease relapse, defined as a clinical Mayo score ≥3, was documented during follow-up. RESULTS: The study cohort consisted of 75 patients (53% men, median age 47 years). Despite normal endoscopy, histology showed inflammatory activity with a Geboes score ≥3.1 in 40% and basal plasmacytosis in 21% of patients. At 12 months, clinical relapse was observed in 20% (n=15) of patients. Presence of basal plasmacytosis (P=0.007) and a Geboes score ≥3.1 (P=0.007) were predictive of disease relapse. Using multivariate analysis, the presence of basal plasmacytosis was predictive of clinical relapse (odds ratio (OR) 5.13 (95% confidence interval (CI): 1.32-19.99), P=0.019), whereas the use of biologicals at endoscopy favored remission (OR 0.24 (95% CI: 0.05-1.01), P=0.052). CONCLUSIONS: We demonstrated that the presence of basal plasmacytosis predicts UC clinical relapse in patients with complete mucosal healing. We recommend closer follow-up and optimization of medical therapy in patients with basal plasmacytosis.

Genetic variants in autophagy-related genes and granuloma formation in a cohort of surgically treated Crohn's disease patients.

BACKGROUND AND AIMS: Granulomas are a characteristic microscopic finding in Crohn's disease. Their clinical significance is controversial and their pathogenesis is unknown, but impaired processing of bacterial components has been suggested. Autophagy is a fundamental process involved in the elimination of intracellular bacteria. Genetic variants in autophagy genes IRGM and ATG16L1 have been associated with susceptibility to Crohn's disease. We therefore investigated whether variants in autophagy genes contribute to granuloma formation. METHODS: Surgical specimens from 464 clinically well-documented Crohn's patients were reviewed and scored for the presence and distribution of granulomas. All patients were genotyped for the CD-associated SNPs in ATG16L1 and IRGM as well as for 77 haplotype tagging SNPs in 13 additional autophagy genes. RESULTS: Granulomas were found in 75% of the patients. Their frequency increased with more distal involvement of the GI tract. Granuloma positive patients were significantly younger at the time of diagnosis and surgery, and were more likely to smoke. We identified associations between granulomas and autophagy gene variants ATG4A (rs5973822), FNBP1L (rs17109951) and ATG4D (rs7248026; rs2304165; rs10439163). CONCLUSION: These findings suggest that granuloma formation is a marker of a more aggressive disease course, and that variants in autophagy genes ATG4A, ATG2A, FNBP1L and ATG4D, may contribute to granuloma formation.

Assessment of the microbiota in microdissected tissues of Crohn's disease patients.

The microbiota of the gastrointestinal tract is frequently mentioned as one of the key players in the etiopathogenesis of Crohn's disease (CD). Four hypotheses have been suggested: the single, still unknown bacterial pathogen, an abnormal overall composition of the bowel microbiota ("dysbiosis"), an abnormal immunological reaction to an essentially normally composed microbiota, and increased bacterial translocation. We propose that laser capture microdissection of selected microscopic structures, followed by broad-range 16S rRNA gene sequencing, is an excellent method to assess spatiotemporal alterations in the composition of the bowel microbiota in CD. Using this approach, we demonstrated significant changes of the composition, abundance, and location of the gut microbiome in this disease. Some of these abnormal findings persisted even after macroscopic mucosal healing. Further investigations along these lines may lead to a better understanding of the possible involvement of the bowel bacteria in the development of clinical Crohn's disease.