A histopathologic scoring system as a tool for standardized reporting of chronic (ileo)colitis and independent risk assessment for inflammatory bowel disease

Ileal mucus viscoelastic properties differ in Crohn's disease

Crohn's disease (CD) is an inflammatory bowel disease that can affect any part of the gastrointestinal tract, frequently involving the terminal ileum. While colonic mucus alterations in CD patients have been described, terminal ileal mucus and its mechanobiological properties have been neglected. Our study is the first of its kind to decipher the viscoelastic and network properties of ileal mucus. With that aim, oscillatory rheological shear measurements based on an airway mucus protocol that was thoroughly validated for ileal mucus were performed. Our pilot study analyzed terminal ileum mucus from controls (n = 14) and CD patients (n = 14). Mucus network structure was visualized by scanning electron microscopy. Interestingly, a statistically significant increase in viscoelasticity as well as a decrease in mesh size was observed in ileal mucus from CD patients compared to controls. Furthermore, rheological data were analyzed in relation to study participants' clinical characteristics, revealing a noteworthy trend between non-smokers and smokers. In conclusion, this study provides the first data on the viscoelastic properties and structure of human ileal mucus in the healthy state and Crohn's disease, demonstrating significant alterations between groups and highlighting the need for further research on mucus and its effect on the underlying epithelial barrier.

In-Depth Assessment of Endoscopic Remission in Inflammatory Bowel Disease Treated by Anti-TNF or Vedolizumab

BACKGROUND AND AIMS

Confocal endomicroscopy is a technique allowing the in vivo assessment of the superficial layers of the mucosa. Preliminary studies have already suggested its added value in the assessment of endoscopic remission in inflammatory bowel disease. However, most of these studies were performed on patients still having incomplete mucosal healing. Our aim was to disclose persisting endomicroscopic anomalies in patients with full endoscopic remission and to compare them between vedolizumab- and anti-tumor necrosis factor-treated patients.

METHODS

We screened patients with Crohn's disease (CD) or ulcerative colitis (UC) treated for more than 6 months with biologic therapy, and being in steroid-free clinical and biological remission. White light endoscopy and probe-based confocal laser endomicroscopy (pCLE) analysis were performed in the ileum, right colon, transverse colon, left colon, and rectum. Full endoscopic remission was defined by a Mayo endoscopic score of 0 in UC and no remaining ulcer or erosion in CD. Patients were prospectively followed up and clinical relapses were recorded.

RESULTS

Seventy-two CD and UC patients treated by biologic therapy and in clinical and biological remission were screened. A total of 37 were also in full endoscopic remission and were included in our study; 183 intestinal segments were analyzed. We found residual pCLE anomalies in most of the patients. These anomalies were not significantly associated with any demographic or clinical characteristic including the treatment received, nor were they associated with histological parameters, levels of C-reactive protein or fecal calprotectin. Among the 37 patients, 7 (18.9%) relapsed over a median follow-up of 33.7 months. The risk of relapse was not associated with any clinical, biological, histologic, or pCLE feature at baseline.

CONCLUSION

Despite endoscopic, biological, and even histological remission, we found a high prevalence of endomicroscopic abnormalities, which were not different between anti-tumor necrosis factor- and vedolizumab-treated patients. The clinical significance of these anomalies remains to be clarified.

IL-17-driven induction of Paneth cell antimicrobial functions protects the host from microbiota dysbiosis and inflammation in the ileum

Interleukin (IL)-17 protects epithelial barriers by inducing the secretion of antimicrobial peptides. However, the effect of IL-17 on Paneth cells (PCs), the major producers of antimicrobial peptides in the small intestine, is unclear. Here, we show that the targeted ablation of the IL-17 receptor (IL-17R) in PCs disrupts their antimicrobial functions and decreases the frequency of ileal PCs. These changes become more pronounced after colonization with IL-17 inducing segmented filamentous bacteria. Mice with PCs that lack IL-17R show an increased inflammatory transcriptional profile in the ileum along with the severity of experimentally induced ileitis. These changes are associated with a decrease in the diversity of gut microbiota that induces a severe ileum pathology upon transfer to genetically susceptible mice, which can be prevented by the systemic administration of IL-17a/f in microbiota recipients. In an exploratory analysis of a small cohort of pediatric patients with Crohn's disease, we have found that a portion of these patients exhibits a low number of lysozyme-expressing ileal PCs and a high ileitis severity score, resembling the phenotype of mice with IL-17R-deficient PCs. Our study identifies IL-17R-dependent signaling in PCs as an important mechanism that maintains ileal homeostasis through the prevention of dysbiosis.

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.

Meroterpenoid-Rich Ethanoic Extract of Sargassum macrocarpum Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice

Colitis is a colon mucosal disorder characterized by intestinal damage and inflammation. This current study aimed to evaluate the effect of meroterpenoid-rich ethanoic extract of a brown algae, Sargassum macrocarpum (MES) on dextran sulfate sodium (DSS)-induced colitis in mice and explore the possible mechanisms. Mice were given 4% DSS in drinking water for 7 days to induce colitis, followed by 3 days of regular water. MES (12 mg/kg body weight) or celecoxib (10 mg/kg body weight) was administrated orally to mice on a daily basis during these 10 days. Both MES and celecoxib supplementations significantly attenuated DSS-induced weight loss, shortening of colon length, elevated myeloperoxidase activity as well as histomorphological changes of colon. MES and celecoxib reduced the inflammation level of colon tissue, as indicated by its suppression on a panel of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-17, tumor necrosis factor α, and interferon γ, and a group of inflammatory proteins, including intracellular adhesion molecule 1, vascular adhesion molecule 1, matrix metalloproteinase (MMP)-2, MMP-9, MMP-13, and inducible nitric oxidase. In addition, their administration down-regulated pro-inflammatory cytokines in serum. Moreover, the supplementation of MES suppressed the DSS-induced hyperactivation of Akt, JNK, and NF-κB signaling pathways. Taken together, our results demonstrate that MES ameliorates DSS-induced colitis in mice, suggesting that MES may have therapeutic implications for the treatment of colitis.

Claudins: Beyond Tight Junctions in Human IBD and Murine Models

Claudins are transmembrane proteins constituting one of three tight junction protein families. In patients with inflammatory bowel disease (IBD), disease activity–dependent changes in expression of certain claudins have been noted, thus making certain claudin family members potential therapy targets. A study was undertaken with the aim of exploring expression of claudins in human disease and two different animal models of IBD: dextrane sulfate sodium–induced colitis and adoptive transfer model of colitis. The expression of sealing claudin-1, claudin-3, claudin-4, and claudin-8, and pore-forming claudin-2 in humans and rodents has been evaluated by immunohistochemistry and quantitative polymerase chain reaction. Claudins were expressed by epithelial and cells of mesodermal origin and were found to be situated at the membrane, within the cytoplasm, or within the nuclei. Claudin expression by human mononuclear cells isolated from lamina propria has been confirmed by Western blot and flow cytometry. The claudin expression pattern in uninflamed and inflamed colon varied between species and murine strains. In IBD and both animal models, diverse alterations in claudin expression by epithelial and inflammatory cells were recorded. Tissue mRNA levels for each studied claudin reflected changes within cell lineage and, at the same time, mirrored the ratio between various cell types. Based on the results of the study, it can be concluded that 1) claudins are not expressed exclusively by epithelial cells, but by certain types of cells of mesodermal origin as well; 2) changes in the claudin mRNA level should be interpreted in the context of overall tissue alterations; and 3) both IBD animal models that were analyzed can be used for investigating claudins as a therapy target, respecting their similarities and differences highlighted in this study.

Histopathological Features in Colonic Biopsies at Diagnosis Predict Long-term Disease Course in Patients with Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease [CD] is characterised by a heterogeneous disease course. Patient stratification at diagnosis using clinical, serological, or genetic markers does not predict disease course sufficiently to facilitate clinical decision making. The current study aimed to investigate the additive predictive value of histopathological features to discriminate between a long-term mild and severe disease course.

METHODS

Diagnostic biopsies from treatment-naïve CD patients with mild or severe disease courses in the first 10 years after diagnosis were reviewed by two gastrointestinal pathologists after developing a standardised form comprising 15 histopathological features. Multivariable logistic regression models were built to identify predictive features and compute receiver operating characteristic [ROC] curves. Models were internally validated using bootstrapping to obtain optimism-corrected performance estimates.

RESULTS

In total, 817 biopsies from 137 patients [64 mild, 73 severe cases] were included. Using clinical baseline characteristics, disease course could only moderately be predicted (area under receiver operating characteristic curve [AUROC]: 0.738 [optimism 0.018], 95% confidence interval [CI] 0.65-0.83, sensitivity 83.6%, specificity 53.1%). When adding histopathological features, in colonic biopsies a combination of [1] basal plasmacytosis, [2] severe lymphocyte infiltration in lamina propria, [3] Paneth cell metaplasia, and [4] absence of ulcers were identified and resulted in significantly better prediction of a severe course (AUROC: 0.883 [optimism 0.033], 95% CI 0.82-0.94, sensitivity 80.4%, specificity 84.2%).

CONCLUSIONS

In this first study investigating the additive predictive value of histopathological features in biopsies at CD diagnosis, we found that certain features of chronic inflammation in colonic biopsies contributed to prediction of a severe disease course, thereby presenting a novel approach to improving stratification and facilitating clinical decision making.

Computed tomography enterography for crohn's disease: correlation between the imaging findings and histopathologic scoring system

OBJECTIVES

The aim of this study was to retrospectively determine if quantitative measurements of computed tomography enterography (CTE) imaging findings correlate with histopathologic scores from biopsy specimens in patients with Crohn's disease (CD).

METHODS

CTE datasets of 34 CD patients (19 male and 15 female) who underwent endoscopy with biopsy within 25 days before or after CTE were retrospectively reviewed. CTE findings of segmental mural hyperenhancement, wall thickening, mural stratification and mesenteric findings were quantitatively measured in the corresponding segment. Histopathologic score of CD was based upon the Naini Cortina scoring system. Correlation between CTE findings and histopathologic scores was assessed using Spearman's rank correlation and logistic or linear regression analysis.

RESULTS

Neutrophilic inflammation contributed the most to the segmental mural hyperenhancement and explained 38.4% of the variance (R² = 0.384, P = 0.006). Moreover, the increased lymphocytes and plasma cells predicted larger lymph node (P = 0.003) and increased attenuation in mesenteric fat (P = 0.022).

CONCLUSIONS

To a certain extent, macroscopic CTE findings may reflect the microscopic histopathologic state in the inflammatory stage of CD, underscoring that establishment of CTE scoring system may potentially provide an objective tool for assessment of disease progression.

Enhanced Expression of miR-34a Enhances Escherichia coli Lipopolysaccharide-Mediated Endometritis by Targeting LGR4 to Activate the NF-κB Pathway

BACKGROUND

Persistent endometritis caused by bacterial infections has lethal effects on the reproductive performance of dairy cattle, which compromises animal welfare and delays or prevents pregnancy. The microRNA (miRNA) miR-34 family plays a pivotal role in the inflammatory process; however, the precise mechanism of miR-34a in endometritis has not been thoroughly elucidated to date.

METHODS

In this study, the endometrium of cows diagnosed with endometritis was harvested for bacterial culture and Gram staining to evaluate bacterial contamination of the uterus. Based on this, a bovine endometrial epithelial cell (BEND) inflammation model and a mouse model stimulated with lipopolysaccharide (LPS) in vitro and in vivo were constructed. Cell viability was assessed by CCK-8, trypan blue staining, and flow cytometry. H&E was applied to histopathological analysis. Immunohistochemical, immunofluorescence, qRT-PCR, and western blot assays were performed to measure the mRNA and protein expression of relevant genes. Online databases, plasmid construction, and dual-luciferase reporter gene assays were used to predict and validate the interaction between miR-34a and its target gene LGR4. Finally, mice were injected vaginally with a local antagomir to validate the role of miR-34a in murine uterine inflammation.

RESULTS

In this study, we observed that Gram-negative bacteria, represented by Escherichia coli, are the predominant pathogenic agents responsible for the recurrent occurrence of endometritis in dairy cows. Further, miR-34a was found to repress the expression of LGR4 by targeting the 3' untranslated region (3'UTR) of LGR4. miR-34a was upregulated in bovine uterine tissues and bovine endometrial epithelial cells stimulated with LPS. miR-34a induced the release of the proinflammatory cytokines IL-1β, IL-6, and TNF-α by activating the phosphorylation of NF-κB p65. Furthermore, IL-1β upregulated miR-34a transcription and downregulated LGR4 expression in an IL-1β-dependent manner.

CONCLUSIONS

Taken together, our study confirmed that miR-34a is regulated by IL-1β and suppresses the level of the LGR4 3'UTR, which in turn exacerbates the inflammatory response. Thus, the knockdown of miR-34a might be a new direction for the treatment of endometritis.

Ileal or Colonic Histologic Activity Is Not Associated With Clinical Relapse in Patients With Crohn's Disease in Endoscopic Remission

BACKGROUND & AIMS

Goals of treatment for Crohn's disease (CD) are clinical and endoscopic remission. It is not clear whether histologic markers of healing associate with endoscopic remission in patients with CD.

METHODS

We identified patients with CD from a single institutional registry, and collected data from 129 patients (46.5% female; mean age 25 y; mean CD duration 14.5 y) who underwent colonoscopy evaluation and had simple endoscopic scores for CD below 3 (the definition of endoscopic remission). Histologic signs of CD activity were graded in 192 biopsies (90 ileum and 102 colon), and disease was classified as active (presence of crypt destruction, neutrophils, erosions or ulcerations), quiescent (presence of architectural distortion and chronic inflammatory infiltrate), or normal histology (none of these). The primary outcome was clinical relapse within 2 y (dose escalation, change in therapy, need for systemic steroids, or CD-related hospitalization or surgery). We performed multivariable regression adjusting for relevant confounders to examine the independent predictive value of histologic activity.

RESULTS

Within 2 y of endoscopic evaluation, 42 patients (32.6%) had a clinical relapse. There were no significant differences in proportions of patients with active ileal CD (23.8%), quiescent CD (28.6%), or normal histology (37%) between those who relapsed and those remaining in remission (P = .43). There were no significant differences in proportions of relapses among patients with active colonic disease (38.1%), quiescent disease (35.0%), or normal histology (27.9%, P = .73). A linear regression analysis found no association between histologic features of active disease in ileal histology biopsies and symptom scores (Harvey Bradshaw index and simple inflammatory bowel disease questionnaire scores).

CONCLUSIONS

In an analysis of biopsies from patients with CD who had achieved clinical and endoscopic remission, histologic remission was not associated with clinical relapse within 2 years.

Expression of Cyr61 is associated with clinical course in patients with Crohn's disease

Backgrounds

Cysteine-rich angiogenic inducer 61 (Cyr61) is emerging as an important regulator of tissue homeostasis and wound repair. We aim to explore the colonic mucosal expression of Cyr61 and analyze the association between Cyr61 expression and clinical course in patients with Crohn’s disease (CD).

Methods

Endoscopic samples were identified from 83 CD patients with and 372 controls by searching pathological reports. Among them, age- and sex- matched 43 of each group by a propensity score were selected to compare Cyr61 expression by immunohistochemistry (IHC). IHC scores for Cyr61 expression of CD patients were divided into tertiles to evaluate the association with clinical course. We also measured the level of mRNA for Cyr 61 and proinflammatory genes in inflamed and noninflamed colonic mucosal lesions from CD patients.

Results

The mean IHC scores for Cyr61 expression was higher in CD patients (86.5) than in controls (46.1, P < 0.001). In CD patients, the mean IHC scores for Cyr61 expression (68.3) was lower in patients with clinical recurrence than in patients without recurrence (92.2, P = 0.01). Cyr61 mRNA levels in inflamed mucosa were twofold higher than those in non-inflamed lesion (P > 0.05) and the mRNA levels of IL-6 and TLR-4 in inflamed mucosa were significantly higher than those in non-inflamed mucosa in CD patients (all P < 0.05). When CD patients were stratified into tertile groups according to IHC scores for Cyr61 expression, clinical recurrence rates tended to be lower in patients with high Cyr61 expression (P for trend = 0.02). Compared with tertile 1 of Cyr61 expression, tertile 3 of Cyr 61 expression was associated with reduced risk of clinical recurrence (OR 0.43, 95% CI 0.20–0.92) after adjustment for age, sex and CD activity index at the time of colonoscopy in CD patients (P = 0.03).

Conclusions

Cyr61 mucosal expression in CD patients was inversely associated with clinical course. Future study need to be considered to evaluate whether Cyr 61 may play a role in activating inflammatory responses and contributing to wound healing and tissue repair in patients with CD.

Histological scores in inflammatory bowel disease

The role of histology in inflammatory bowel disease (IBD) has not yet been well defined. Endoscopic mucosal healing has been proposed as a predictor of the clinical course of IBD and it is indeed considered one of the main therapeutic targets. However, it does not necessarily imply histological healing. Histological remission has been reported to be associated with a better clinical outcome than endoscopic remission only in IBD patients. These observations support the view that histology plays a role as a potential therapeutic target in Crohn's disease and ulcerative colitis. Histological scores being able to quantify the degree of microscopic activity are needed for this purpose. In the era of biologics, indication for proper treatment may benefit from the assessment of clinical and endoscopic activity, as well as histological scores. Such scores may allow us to quantify the microscopic mucosal response to treatment and to define complete healing in IBD. A validated histological score in IBD may lead to the definition of microscopic activity in clinical practice, trials and investigational settings. Several attempts to develop such scores have been reported, but few are currently used and none is applied worldwide in clinical practice. The present review summarizes the main histological scores currently used for assessing IBD activity.

Assessment of disease activity in inflammatory bowel diseases: Non-invasive biomarkers and endoscopic scores

Inflammatory bowel diseases (IBD) comprise two major forms: Crohn's disease and ulcerative colitis. The diagnosis of IBD is based on clinical symptoms combined with results found in endoscopic and radiological examinations. In addition, the discovery of biomarkers has significantly improved the diagnosis and management of IBD. Several potential genetic, serological, fecal, microbial, histological and immunological biomarkers have been proposed for IBD, and they have been evaluated for clinical routine and clinical trials. Ileocolonoscopy, especially with biopsy collection, has been considered the standard method to diagnose IBD and to assess clinical activity of the disease, but it is limited to the colon and terminal ileum and is considered invasive. For this reason, non-invasive biomarkers are necessary for this type of chronic inflammatory disease, which affects mostly young individuals, as they are expected to have a long follow-up.

Enhanced therapeutic efficacy of a novel colon-specific nanosystem loading emodin on DSS-induced experimental colitis

BACKGROUND

Ulcerative colitis (UC) is an intricate enteric disease with a rising incidence that is closely related to mucosa-barrier destruction, gut dysbacteriosis, and immune disorders. Emodin (1,3,8-trihydroxy-6-methyl-9,10-anthraquinone, EMO) is a natural anthraquinone derivative that occurs in many Polygonaceae plants. Its multiple pharmacological effects, including antioxidant, immune-suppressive, and anti-bacteria activities, make it a promising treatment option for UC. However, its poor solubility, extensive absorption, and metabolism in the upper gastrointestinal tract may compromise its anti-colitis effects.

PURPOSE

EMO was loaded in a colon-targeted delivery system using multifunctional biomedical materials and the enhanced anti-colitis effect involving mucosa reconstruction was investigated in this study.

METHODS

EMO-loaded Poly (DL-lactide-co-glycolide)/Eudragit^Ⓡ S100/montmorillonite nanoparticles (EMO/PSM NPs) were prepared by a versatile single-step assembly approach. The colon-specific release behavior was characterized in vitro and in vivo, and the anti-colitis effect was evaluated in dextran sulfate sodium (DSS)-induced acute colitis in mice by weight loss, disease activity index (DAI) score, colon length, histological changes, and colitis biomarkers. The integrity of the intestinal mucosal barrier was evaluated through transwell co-culture model in vitro and serum zonulin-related tight junctions and mucin2 (MUC2) in vivo.

RESULTS

EMO/PSM NPs with a desirable hydrodynamic diameter (~ 235 nm) and negative zeta potential (~ -31 mV) could prevent the premature drug release (< 4% in the first 6 h in vitro) in the upper gastrointestinal tract (GIT) and boost retention in the lower GIT and inflamed colon mucosa in vivo. Compared to free EMO-treatment of different doses in UC mice, the NPs could enhance the remedial efficacy of EMO in DAI decline, histological remission, and regulation of colitis indicators, such as myeloperoxidase (MPO), nitric oxide (NO), and glutathione (GSH). The inflammatory factors including induced nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-1β were suppressed by EMO/PSM NPs at both mRNA and protein levels. The obtained NPs could also promote the regeneration of the mucosal barrier via reduced fluorescein isothiocyanate (FITC)-dextran leakage in the transwell co-culture model and decreased serum zonulin levels, which was demonstrated to be associated with the upregulated tight junctions (TJs)-related proteins (claudin-2, occludin, and zo-1) and MUC2 at mRNA level. Moreover, the NPs could contribute to attenuating the liver injury caused by free EMO under excessive immune inflammation.

CONCLUSION

Our results demonstrated that EMO/PSM NPs could specifically release EMO in the diseased colon, and effectively enhance the anti-colitis effects of EMO related to intestinal barrier improvement. It can be considered as a novel potential alternative for oral colon-targeted UC therapy by increasing therapeutic efficacy and reducing side-effects.

Histologic Healing Is More Strongly Associated with Clinical Outcomes in Ileal Crohn's Disease than Endoscopic Healing

BACKGROUND & AIMS

Deep remission, based on clinical remission and evidence of healing during endoscopic evaluation, are goals of medical treatments for Crohn's disease (CD). We investigated whether histologic healing is associated with outcomes of patients with CD ileitis.

METHODS

We performed a retrospective study of 101 patients with CD (52% male) isolated to the terminal ileum who had a colonoscopy between September 2005 and June 2015. Our analysis included patients in clinical remission at colonoscopy who had biopsies collected from colon and ileum. The ileum was evaluated for endoscopic healing (no ulceration) and histologic evidence of healing (no active inflammation, erosions, ulceration, or neutrophil infiltration). We compared times of clinical relapse-free survival, medication escalation, corticosteroid use, or hospitalization secondary to disease activity between patients with and without histological and endoscopic healing, followed for a median 21 months. We identified factors associated with survival using Kaplan Meier analysis and Cox proportional hazard model.

RESULTS

At ileo-colonoscopy, 63% of patients had endoscopic healing and 55% had histologic evidence of healing. The level of agreement between endoscopic and histologic activity was fair (62%, K = 0.2250, P = .0064). Forty-two patients had clinical relapse, 45 had medication escalation, 30 required corticosteroids, and 17 were hospitalized (3 required surgery). On multivariate analysis, only histologic healing was associated with decreased risk of clinical relapse (hazard ratio [HR], 2.05; 95% CI, 1.07-3.94; P = .031), medication escalation (HR, 2.17; 95% CI, 1.2-3.96; P = .011), and corticosteroid use (HR, 2.44; 95% CI, 1.17-5.09; P = .018). No factors were associated with hospitalization.

CONCLUSIONS

In patients with ileal CD in clinical remission, histologic healing but not endoscopic healing is associated with decreased risk of clinical relapse, medication escalation, or corticosteroid use.

Systematic Review: Histological Scoring of Strictures in Crohn's Disease

BACKGROUND AND AIMS

In Crohn's disease, many patients develop a stricture, which can due to inflammation, fibrosis and muscular changes or all at the same time. Determining the predominant component has therapeutic consequences but remains challenging. To develop imaging techniques that assess the nature of a stricture, a gold standard is needed and histopathology is considered as such. This paper provides an overview of published histological scoring systems for strictures in Crohn's disease.

METHODS

A systematic literature review according to PRISMA guidelines was performed of histological scoring indices that assessed whether a stricture was inflammation-predominant or fibrosis-predominant. Multiple libraries were searched from inception to December 2018. Two reviewers independently assessed abstracts and full-texts.

RESULTS

Sixteen articles were identified as suitable for this systematic review. A large number of parameters were reported. Extent of neutrophil infiltration and extent of fibrosis in the bowel wall were most frequently described to reflect severity of inflammation and fibrosis, respectively. Among the 16 studies, only two described a numerical scoring system for the inflammatory and fibrotic component separately. Smooth muscle changes were scored in a minority of studies.

CONCLUSIONS

Multiple scoring systems have been developed. There was large heterogeneity in scoring per parameter and construction of numerical scoring systems. Therefore, we feel that none of the systems is suitable to be used as gold standard. We offer an overview of histological parameters that could be incorporated in a future histological scoring index for strictures.

Accuracy of Oral 67Gallium Citrate Scintigraphy in assessment of inflammatory activity of Crohn's disease

AIM

The main goal in Crohn´s disease (CD) is a sustained suppression of inflammatory activity associated with mucosa healing in endoscopic evaluation. During clinical routine, there are small numbers of good markers to monitor inflammatory activity under treatment. We postulated that Oral ⁶⁷Gallium Citrate Scintigraphy is able to mark inflammatory disease in mucosa and deep inflammation in CD, when used in oral form.

OBJECTIVE

Measure the accuracy of Oral ⁶⁷Gallium Citrate Scintigraphy in intestinal inflammatory activity of Crohn´s disease.

PATIENTS AND METHODS

In a prospective consecutive cross-sectional study from January 2018 to June 2019, the ileocolonic region of 32 patients with CD were studied by dividing into four regions of interest (ROI) from the ileum to the rectum. A total of 128 intestinal segments were analyzed in cluster data. Accuracy values of Oral ⁶⁷Gallium Scintigraphy and colonoscopy tests were evaluated with the histological reference test. Values of the respective receiver operating characteristic (ROC) curves were obtained  and compared. The reliability between the tests was evaluated by Kappa statistical with the segment-level analyses using variance adjustments. All statistical analyses were performed with a test significance level of 0.05.

RESULTS

The study population included 32 patients with CD (10 men, 22 women; average age 39 years). Disease time was five years on average. Anti-TNFs treatment was found in 71%. The most found phenotype of the Montreal classification was L3. Differences in ROC curves for colonoscopy (0.94) and Oral ⁶⁷Ga Scintigraphy (0.96) did not show significant value (p = 0.32). The sensitivity of scintigraphy to detect intestinal inflammatory activity in CD was 64%, specificity of 96% and accuracy of 84%. A high agreement was found between oral scintigraphy and histological measurements with kappa = 0.64.

CONCLUSIONS

Oral ⁶⁷Ga Scintigraphy had similar accuracy and agreement compared to colonoscopy in the identification of inflammatory activity in Crohn´s Disease. This new approach may be useful and less invasive for long term follow-ups.

The Role of Histology in Determining Disease Activity, Treatment, and Prognosis: Are We There yet?

Histologic activity in inflammatory bowel disease is associated with an increased risk of clinical relapse, surgery, hospitalizations, and disease-associated dysplasia independent of clinical or endoscopic activity. Several histologic scoring systems exist to capture disease activity. However, none has been validated to assess prognosis or response to therapy and there is no universally accepted definition of histologic healing or remission. Although histologic healing is not a current recommended target for treatment, it may be a more sensitive marker of disease activity. Future studies are needed to determine standardized definitions of disease activity, healing, and evaluating normalization of histology as clinical trial outcomes.

Correlation between endoscopic and histological validated scoring indices in Crohn's disease

BACKGROUND

It is of crucial importance to evaluate disease activity by means of endoscopy and histopathology in Crohn's disease (CD). Nonetheless, correlation between endoscopic and histological validated indices has not been verified.

AIMS

We aim to correlate the Simple Endoscopic Score for Crohns disease (SES-CD) with two validated widely used histological indices in patients with established CD.

METHODS

The SES-CD at the worst affected area was scored and histological disease activity using Global Histologic Disease Activity Score (GHAS or D'Haens score) and the Naini and Cortina Score (NCS) was scored independently by two pathologists blinded to the clinical information and endoscopic results. Spearman correlation between the SES-CD, GHAS and NCS were performed.

RESULTS

143 patients, 32 with SES-CD scores 0-2, 57 with 3-6, 37 with 7-15, and 17 with ≥16. Correlation coefficients between SES-CD and GHAS were r = 0.86 (95% CI 0.80-0.91, p < 0.001) and between SES-CD and NCS r = 0.85 (95% CI 0.81-0.88, p < 0.001). There was a strong correlation between the two histological indices (r = 0.70, 95% CI 0.59-0.78, p < 0.001). Mucosal healing without histological disease activity was most correlated with SES-CD score 0 or 1.

CONCLUSIONS

The SES-CD strongly correlates with both GHAS and NCS. The SES-CD of 0 to 1 best represents histological remission that correlates with quiescent disease activity.

What is the role of histopathology in the evaluation of disease activity in Crohn's disease?

Assessment of disease activity is essential for developing and determining appropriate therapy in patients with Crohn's disease. Currently, clinical and endoscopic treatment targets have been proposed, whereas histologic assessment of disease activity is not recommended in expert guidelines. Histologic assessment of disease activity has emerged as an important tool in ulcerative colitis as persistent histological inflammation is associated with clinical relapse, corticosteroid use, hospitalisation, and development of dysplasia. Similar data for Crohn's disease is limited but emerging literature suggests that histologic evaluation of disease activity may have value. This review summarizes the recent literature regarding histologic evaluation of disease activity in Crohn's disease. Correlation between histologic, endoscopic, and other markers of disease activity are discussed. Histologic scoring systems in Crohn's disease are described and practical guidance is provided to gastroenterologists and pathologists on how to report and interpret histologic data.

Eosinophilic colitis and colonic eosinophilia

PURPOSE OF REVIEW

Eosinophilic colitis is a rare condition, with a prevalence rate in the USA of 2-3/100 000 persons (0.003%), but diagnosed in 0.1% of biopsies in those colonoscoped for diarrhoea. Secondary colonic eosinophilia is more common and associated with systemic, colonic and infectious diseases. In this review, the latest advances in diagnosis, treatment and prognosis are summarized and discussed.

RECENT FINDINGS

What constitutes a 'normal' count of eosinophils is poorly documented but there are recent studies that establish normal colonic eosinophil ranges as well as distinguishing histological and clinical findings in primary eosinophilic colitis and secondary colonic eosinophilia in children and adults. Primary eosinophilic colitis is rare, relatively straightforward to diagnose, but may be difficult to treat. Colonic eosinophilia may be overt in parasite infection and connective tissue disease. More subtle, secondary colonic eosinophilia is a useful biomarker for gastrointestinal diseases, such as inflammatory bowel disease, colonic spirochaetosis and collagenous colitis, but the eosinophilia may more often be overlooked. A limited number of drugs are also known to cause left sided colonic eosinophilia such as clopidogrel, ibuprofen and oestroprogestinic agents.

SUMMARY

Advances in our understanding of primary eosinophilic colitis and secondary colonic eosinophilia is progressing and if present, colonic eosinophilia should point the clinician and pathologist to a list of differential diagnoses worth considering to direct optimal management.

Histopathological Features of Inflammatory Bowel Disease are Associated With Different CD4+ T Cell Subsets in Colonic Mucosal Lamina Propria

BACKGROUND

Inflammatory bowel disease [IBD] results particularly from an aberrance of CD4+ helper and regulatory T cells and comprises histopathologically chronic active enterocolitis with features reflecting both activity and chronicity of mucosal inflammation. The exact immunological-histological correlation in IBD is not understood.

METHODS

We studied the correlation between colonic mucosal CD4+ T cell subsets [Th1, Th2, Th17, Th22 and Treg] and mucosal histological changes in ulcerative colitis [UC] and Crohn's disease [CD]. CD4+ T cell subtyping and enumeration were achieved by flow cytometry. Histological features were categorized and assessed semi-quantitatively using three validated histological scoring schemes [ECAP, RHI and D'Haens]. Correlations between prevalence [%] of CD4+ T cell subsets and histological scores were analysed.

RESULTS

Treg cells were correlated with ECAP category A [activity] as well as RHI scores. Treg cell were increased particularly in mucosa with severe neutrophilic infiltration in the cryptal/surface epithelium and in lamina propria, and with basal plasmacytosis. Th17 cells were also increased in cases with extensive neutrophil infiltrate in lamina propria, whereas RORc+ cells were increased in cases with severe lymphoplasmacytic infiltration in lamina propria. In both UC and CD, mucosa with marked crypt architectural alteration had increased IL-22+ and Th22 cells. UC with Paneth cell metaplasia had higher Th17 cells. CD with granuloma had increased IL-22+ and IL-22+IFN-γ+ cells.

CONCLUSIONS

The Treg subset appears to be associated with the overall severity of IBD histopathology, particularly with active inflammation. Th17 is also associated with activity. By contrast, IL-22+ cells are associated with chronicity and granuloma formation in CD.

Increase in chromogranin A- and serotonin-positive cells in pouch mucosa of patients with ulcerative colitis undergoing proctocolectomy

BACKGROUND

Inflammatory bowel disease (IBD) is associated with neuroendocrine cell hyperplasia.

AIMS

We investigated neuroendocrine cells in J-pouches of patients with ulcerative colitis undergoing restorative proctocolectomy and ileal pouch-anal anastomosis.

METHODS

Sections from pouch biopsies of 17 patients and ileal biopsies of 17 active IBD patients and 16 controls were processed by immunohistochemistry for chromogranin A (CgA) and serotonin. Mucosal tryptophan hydroxylase (TpH)-1 and serotonin-selective reuptake transporter (SERT) transcripts were measured by quantitative RT-PCR. TpH-1 and SERT transcripts were detected in pouch biopsies cultured with infliximab or its isotype control, while interleukin (IL)-6 and IL-8 were measured in biopsy supernatants.

RESULTS

A significant increase in CgA-positive cells and serotonin-positive cells was observed in both pouch and IBD ileum compared to control ileum. Significantly raised transcripts of TpH-1, but not SERT, were found in IBD ileum in comparison to control ileum, with no significant difference between pouch and IBD ileum. Infliximab had no influence on ex vivo pouch expression of TpH-1 and SERT, nor on the production of IL-6 and IL-8.

CONCLUSION

We here demonstrated neuroendocrine cell hyperplasia in pouch mucosa. Further studies are needed to clarify the pathophysiological implication of this finding.

Histologic scoring indices for evaluation of disease activity in Crohn's disease

BACKGROUND

Histologic assessment of mucosal disease activity has been increasingly used in clinical trials of treatment for Crohn's disease. However, the operating properties of the currently existing histologic scoring indices remain unclear.

OBJECTIVES

A systematic review was undertaken to evaluate the development and operating characteristics of available histologic disease activity indices in Crohn's disease.

SEARCH METHODS

Electronic searches of MEDLINE, EMBASE, PubMed, and the Cochrane Library (CENTRAL) databases from inception to 20 July 2016 were supplemented by manual reviews of bibliographies and abstracts submitted to major gastroenterology meetings (Digestive Disease Week, United European Gastroenterology Week, European Crohn's and Colitis Organisation).

SELECTION CRITERIA

Any study design (e.g. randomised controlled trial, cohort study, case series) that evaluated a histologic disease activity index in patients with Crohn's disease was considered for inclusion. Study participants included adult patients (> 16 years), diagnosed with Crohn's disease using conventional clinical, radiographic or endoscopic criteria.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed the titles and abstracts of the studies identified from the literature search. The full text of potentially relevant citations were reviewed for inclusion and the study investigators were contacted as needed for clarification. Any disagreements regarding study eligibility were resolved by discussion and consensus with a third author.Two authors independently extracted and recorded data using a standard form. The following data were recorded from each eligible study: number of patients enrolled; number of patients per treatment arm; patient characteristics: age and gender distribution; description of histologic disease activity index utilized; and outcomes such as content validity, construct validity, criterion validity, responsiveness, intra-rater reliability, inter-rater reliability, and feasibility.

MAIN RESULTS

Sixteen reports of 14 studies describing 14 different numerical histological indices fulfilled the inclusion criteria.Inter-rater reliability was assessed in one study. For the Naini and Cortina Score, estimates of correlation were 'almost perfect', ranging from r = 0.94 to 0.96. The methodological quality of this study with respect to reliability was 'good'.With respect to validity, correlation estimates between various histological scoring systems and Crohn's disease activity as measured by objective markers of inflammation (including C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin and fecal lactoferrin); endoscopic disease activity scores; clinical disease activity scores; and quality of life questionnaires were reported. Comparisons between histologic scoring indices and endoscopic scoring indices ranged from no correlation to 'substantial' (r = 0.779). The methodological quality of the studies that explored validity ranged form 'poor' to 'good'.Responsiveness data were available in seven studies. After subjects were administered a treatment of known efficacy, statistically significant change in the index score was demonstrated in five studies with respect to six indices. Two studies failed to indicate whether there was statistically significant change in the index score post-treatment. With regard to methodological quality, six of the studies were rated as 'poor' and one of the studies was rated as 'fair'.Feasibility was assessed by one study. The Naini and Cortina Score was shown to be simple to use and feasible for every given case.

AUTHORS' CONCLUSIONS

Currently there is no fully validated histological scoring index for evaluation of Crohn's disease activity. Development of a validated histological scoring index for Crohn's disease is a clinical and research priority.

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.

Protease-activated Receptor 1 Plays a Proinflammatory Role in Colitis by Promoting Th17-related Immunity

BACKGROUND

Proteolytic cleavage of protease-activated receptor 1 (PAR1) can result in potent downstream regulatory effects on inflammation. Although PAR1 is expressed throughout the gastrointestinal tract and activating proteases are increased in inflammatory bowel disease, the effect of PAR1 activation on colitis remains poorly understood, and has not previously been studied in pediatric disease.

METHODS

Expression of PAR1 and inflammatory cytokines in colonic biopsies from pediatric patients with Crohn's disease exhibiting active moderate to severe colitis was measured by quantitative PCR. The functional relevance of these clinical data was further studied in a mouse model of Citrobacter rodentium-induced colitis.

RESULTS

PAR1 expression was significantly upregulated in the inflamed colons of pediatric patients with Crohn's disease, with expression levels directly correlating to disease severity. In patients with severe colitis, PAR1 expression uniquely correlated with Th17-related (IL17A, IL22, and IL23A) cytokines. Infection of PAR1-deficient (PAR1) and wildtype mice with colitogenic C. rodentium revealed that disease severity and colonic pathology were strongly attenuated in mice lacking PAR1. Furthermore, Th17-type immune response was completely abolished in the colons of infected PAR1 but not wildtype mice. Finally, PAR1 was shown to be essential for secretion of the Th17-driving cytokine IL-23 by C. rodentium-stimulated macrophages.

CONCLUSIONS

This study demonstrates a strong link between PAR1 expression, Th17-type immunity, and disease severity in both pediatric patients with Crohn's disease and C. rodentium-induced colitis in mice. The data presented suggest PAR1 exerts a proinflammatory role in colitis in both humans and mice by promoting a Th17-type immune response, potentially by supporting the production of IL-23.

Computed Tomography and Magnetic Resonance Enterography in Crohn's Disease: Assessment of Radiologic Criteria and Endpoints for Clinical Practice and Trials

Early recognition of Crohn's disease with initiation of disease-modifying therapy has emerged as a prominent inflammatory bowel disease management strategy. Clinical practice and trials have often focused on patient symptoms, and more recently, serologic tests, stool inflammatory markers, and/or endoscopic inflammatory features for study entry criteria, treatment targets, disease activity monitoring, and to assess therapeutic response. Unfortunately, patient symptoms do not correlate well with biological disease activity, and endoscopy potentially misses or underestimates disease extent and severity in small bowel Crohn's disease. Computed tomography enterography and magnetic resonance enterography (MRE) are potential tools to identify and quantify transmural structural damage and disease activity in the small bowel. In this review, we discuss the role of computed tomography enterography and MRE in disease management algorithms in clinical practice. We also compare the currently developed MRE-based scoring systems, their strengths and pitfalls, as well as the role for MRE in clinical trials for Crohn's disease.

A seeding-searching-ensemble method for gland segmentation in H&E-stained images

Background

Glands are vital structures found throughout the human body and their structure and function are affected by many diseases. The ability to segment and detect glands among other types of tissues is important for the study of normal and disease processes and helps their analysis and visualization by pathologists in microscopic detail.

Methods

In this paper, we develop a new approach for segmenting and detecting intestinal glands in H&E-stained histology images, which utilizes a set of advanced image processing techniques: graph search, ensemble, feature extraction, and classification. Our method is computationally fast, preserves gland boundaries robustly and detects glands accurately.

Results

We tested the performance of our gland detection and segmentation method by analyzing a dataset of over 1700 glands in digitized high resolution clinical histology images obtained from normal and diseased human intestines. The experimental results show that our method outperforms considerably the state-of-the-art methods for gland segmentation and detection.

Conclusions

Our method can produce high-quality segmentation and detection of non-overlapped glands that obey the natural property of glands in histology tissue images. With accurately detected and segmented glands, quantitative measurement and analysis can be developed for further studies of glands and computer-aided diagnosis.

Balancing the risks and benefits of biologic therapy in inflammatory bowel diseases

INTRODUCTION

The incidence of Inflammatory Bowel Diseases (IBD) is rising and overall epidemiology is changing. Goals of IBD therapy are also fast changing to reflect the concept of mucosal healing. IBD management is increasingly revolving around questions of ideal positioning of biologic therapies.

AREAS COVERED

This paper covers important concepts regarding two classes of biologic medications approved for treatment of IBD in the United States - anti-TNF-α agents and lymphocyte-homing antagonists. Topics covered include drug mechanism of action, pharmacokinetic considerations for the clinician including therapeutic drug monitoring, summary of current evidence of drug efficacy in IBD focusing on randomized, controlled trial data. Additionally, nuanced discussion of medication side-effects and adverse reactions is presented.

EXPERT OPINION

Paradigms of treatment goals in IBD are changing with increasing focus on mucosal healing. Concomitantly, our understanding of important factors that impact drug pharmacokinetic/pharmacodynamics relationships with biologic agents has increased which will help eventually develop personalized algorithms to optimize the efficacy of these agents. Though direct head-to-head comparisons between these agents are lacking, biologic agents can be considered the safest and most effective therapies introduced for IBD.

Converging goals of treatment of inflammatory bowel disease from clinical trials and practice

It is important to have clear goals for treating inflammatory bowel disease in clinical practice and in research. Conventional end points for trials in ulcerative colitis and Crohn's disease have been based on composite indices, such as the Mayo Clinic Score and the Crohn's Disease Activity Index; these indices incorporate symptoms, signs, and findings from laboratory tests and sometimes endoscopic assessments. Although definitions of clinical response and remission have been based on these indices for regulatory purposes, they are difficult to apply to practice because they are complex and not intuitive to clinicians. This has caused a disconnect between clinical trials and practice. Recently, the use of composite indices in trials has been reevaluated in Food and Drug Administration-sponsored Gastroenterology Regulatory Endpoints and the Advancement of Therapeutics workshops due to concerns about the validity of the indices. Alternative measures of outcome and definitions of response are being developed. Patient-reported outcomes are psychometric instruments created and defined by patients to quantify symptoms. A combination of end points, comprising patient-reported outcomes and objective evaluation of inflammation by endoscopy, offers a clinically meaningful and scientifically valid alternative to existing composite indices. Unlike composite indices, response definitions based on endoscopy and patient-reported outcomes can be readily applied in practice. This convergence of outcome assessment in clinical trials and practice could expedite implementation of "treat-to-target" algorithms, in which therapy is progressively intensified until a specific treatment goal is reached. This approach could improve patient care by reducing rates of disease-related complications, surgery, and hospitalization.

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

BACKGROUND

Crohn's 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.

Identifying neutrophils in H&E staining histology tissue images

Identifying neutrophils lays a crucial foundation for diagnosing acute inflammation diseases. But, such computerized methods on the commonly used H&E staining histology tissue images are lacking, due to various inherent difficulties of identifying cells in such image modality and the challenge that a considerable portion of neutrophils do not have a "textbook" appearance. In this paper, we propose a new method for identifying neutrophils in H&E staining histology tissue images. We first segment the cells by applying iterative edge labeling, and then identify neutrophils based on the segmentation results by considering the "context" of each candidate cell constructed by a new Voronoi diagram of clusters of other neutrophils. We obtain good performance compared with two baseline algorithms we constructed, on clinical images collected from patients suspected of having inflammatory bowl diseases.