Frequency of epithelioid granulomas in colonoscopic biopsy specimens from paediatric and adult patients with Crohn's colitis

Relationship between histopathological findings, clinical severity and the need for surgery in patients with Crohn's disease

INTRODUCTION

Defining histological variables that make it possible to establish the activity of Crohn's disease (CD) and predict the patients who may present a higher risk of clinical complications and surgical interventions could lead to timely adjustments in medical therapy and elective surgeries that represent a lower risk of complications. The purpose of the study is to determine the relation between the histopathological findings using the Naini and Cortina (N&C) score, the clinical severity, and the indication for surgery in a group of patients with CD.

MATERIALS AND METHODS

Descriptive, retrospective, cross-sectional study of 44 patients diagnosed with CD, treated at the San Vicente Fundación University Hospital in Medellín, Colombia, between 2010 and 2022.

RESULTS

Of the 44 patients, 36 ileum samples and 34 colon samples were obtained. Of the patients with inflammatory behavior, 87.5% did not have surgical intervention (P=.022), a value that remained significant in the ileum subgroup (P=.0058). 91.3% of the patients with ileal involvement did not develop perianal disease (P=.01). Granulomas only occurred in two patients with a colon sample (5.8%). In the histological score of N&C both in the ileum and in the colon, no statistically significant differences were obtained in relation to the surgical outcome (P=.34 and P=.054, respectively).

CONCLUSION

The histological index of N&C was not a predictor in Crohn's disease (CD) related to the surgical outcome.

Paediatric Crohn's disease: histologic findings at initial presentation

BACKGROUND

Diagnosing paediatric Crohn's disease (CD) based on histology can present challenges. We evaluate the histological spectrum of treatment-naïve biopsies from children with CD and assess these findings' diagnostic and predictive value.

METHODS

Three cohorts were identified: (1) 137 patients with CD, (2) 116 patients with ulcerative colitis (UC) and (3) 50 patients without inflammatory bowel disease. Biopsies from the gastrointestinal (GI) tract were re-examined for signs of active and chronic inflammation, including lymphocyte-pattern oesophagitis, focal enhancing gastritis and indicators of chronicity. Additionally, granulomas and microgranulomas (defined as clusters of 4-9 epithelioid histiocytes) were evaluated.

RESULTS

Lymphocyte-pattern oesophagitis was observed in 15% of patients (n=20). Moderate-to-severe diffuse gastritis was noted in 50.4% of patients (n=68), while focal enhancing gastritis was identified in 11.1% (n=15). In terminal ileal biopsies, 46.1% exhibited activity and 5.3% showed features of chronicity. Active colitis was present in 73% of patients (n=100), with chronic colitis seen in 11.7% (n=16). Granulomas and microgranulomas were observed in 31.4% (43/137) and 48.9% (67/137) of patients, respectively. Notably, 30.7% (42/137) of patients with microgranulomas were without granulomas. Previously undetected microgranulomas were found in 20 of 27 cases. 2.5% of patients with UC and none of the control cohort showed microgranulomas. Lymphocyte-pattern oesophagitis was associated with an increased need for anti-tumor necrosis factor (TNF) therapy (p=0.007).

CONCLUSIONS

GI microgranulomas, often overlooked, are specific to CD in the proper clinical context. Oesophageal lymphocytosis may predict a need for more aggressive treatment. The study brings to light under-recognised aspects of CD's histological diagnosis, including the oversight of microgranulomas, the high prevalence of diffuse gastritis and low prevalence of focal enhancing gastritis, the frequent absence of terminal ileitis and the infrequent occurrence of chronic colitis.

Definitions of Histological Abnormalities in Inflammatory Bowel Disease: an ECCO Position Paper

Histological assessment of endoscopic biopsies in inflammatory bowel disease [IBD] plays an important role in clinical management, investigative studies, and clinical trials. Scoring schemes consisting of multiple histological items and offering considerable precision are widely available. However, definitions of histological abnormalities are often inconsistent. Furthermore, interobserver variability for their recognition and assessment may be high. The European Crohn's and Colitis Organisation [ECCO] formed an expert panel to explore definitions of histological abnormalities in IBD, with the aim of improving the quality of diagnosis and facilitating development of scoring schemes. The process confirmed that the current definitions often have no evidence base and vary between sources. Using available evidence and expert knowledge, the panel produced a series of ECCO consensus position statements on histological features in IBD.

Detection Rates of Non-Cavitary Epithelioid Cell Granuloma by Gastrointestinal Biopsy in Patients with Treatment-Naïve Crohn's Disease

Introduction

Detecting non-cavitary epithelioid cell granuloma by gastrointestinal biopsy is important in the initial diagnosis of Crohn's disease (CD). In the present study, we aimed to determine the rate of granuloma detection by gastrointestinal biopsy according to the number of biopsies performed.

Methods

The present study included patients newly diagnosed with CD at our hospital between April 2017 and March 2023. During endoscopic examinations, biopsy specimens were taken from affected lesions. Initially, one section per biopsy was examined to detect granuloma. In cases where no granulomas were detected, step sections were additionally prepared and examined. The rate of granuloma detection by gastrointestinal biopsy was retrospectively examined.

Results

A total of 30 patients with a new diagnosis of CD were included in this study. In total, 284 gastrointestinal biopsies were performed in 29 cases. The rate of granuloma detection by gastrointestinal biopsy per case was 58.6% (17 out of 29 cases). The rate of granuloma detection by gastrointestinal biopsy per biopsy was 6.0% (17 out of 284 biopsies) on initial histological examination and 11.6% (33 out of 284 biopsies) following examination of step sections. The rate of granuloma detection was significantly improved by performing histological examination of step sections compared with initial examinations (p < 0.05).

Conclusion

The rate of granuloma detection per biopsy was 11.6%, even after histological examination of step sections. These results indicate that performing multiple intestinal biopsies and assessing for the presence of granuloma using multiple section examinations are required in the initial diagnosis of CD.

"Brunner gland inflammation in Crohn's disease and Celiac disease: Overlapping inflammatory patterns suggest a possible link"

Similar to celiac disease, inflammatory bowel disease frequently manifests in the duodenum. Histopathologic studies focused on mucosal alterations with little attention to submucosal Brunner glands. Recently, several studies have demonstrated overlapping features between Crohn's disease and celiac disease suggesting a putative link. However, histopathologic studies evaluating this possible link are limited, and those that are focused on Brunner glands are lacking. The present study aims to explore whether Crohn's disease and celiac disease display shared or overlapping inflammatory changes in Brunner glands. We performed a retrospective review study over 17-years retrieving duodenal biopsy specimens containing Brunner gland lobules in patients with Crohn's disease, celiac disease, and ulcerative colitis. We found 10 out of 126 duodenal biopsies (8 %) in patients with Crohn's disease and 6 out of 134 (4.5 %) duodenal biopsies in patients with celiac disease sharing inflammatory patterns in duodenal Brunner gland lobules. Both diseases showed interstitial intralobular and interlobular mixed chronic inflammation with variable fibrosis. Focally enhanced active inflammation of Brunner gland lobules was more characteristic of Crohn's disease. Intralobular epithelioid granulomas and multinucleated giant cells were specific to Crohn's disease. Ulcerative colitis patients did not show similar features. The interstitial focally enhanced chronic inflammatory pattern was significantly (p < 0.05) associated with both diseases, while the other inflammatory patterns were not (p > 0.05). This overlapping inflammatory pattern in Brunner glands in patients with Crohn's disease and celiac disease is supportive of the previously reported link between the two diseases. Pathologists should pay more attention to Brunner glands when evaluating duodenal biopsies. Further studies are warranted to validate these observations and their relevance in the pathogenesis of autoinflammatory gastrointestinal diseases.

The detection rate of granulomas differs between intestinal segments and lesions in Chinese patients with Crohn's disease

BACKGROUND

Crohn's disease (CD) is characterized by non-caseating intestinal granulomas. However, the reported detection rate of granulomas on endoscopy is low. This study aimed to analyze the differences in the detection rate of granulomas in different intestinal segments and lesions in Chinese patients with CD to improve the detection rate of granulomas in clinical practice.

PATIENTS AND METHODS

113 patients with CD were analyzed retrospectively. Patients were divided into two groups: those with (n = 51) and without granulomas (n = 62) on endoscopic biopsies. Clinical information was collected from the medical records, including age; erythrocyte sedimentation rate (ESR); C-reactive protein (CRP), albumin, and hemoglobin (Hb) levels; platelet count; disease course; sex; smoking history; related operation history; Montreal classification; and lesion location, size, and shape.

RESULTS

The detection rates of granulomas in different lesion shapes were significantly different (P < 0.001), with those of longitudinal ulcers and circular ulcers being higher than those of erosion and irregular ulcers. We also found that the detection rates of granulomas in ascending colon and sigmoid colon were relatively higher than other segments of the intestine, however, the difference was not statistically significant (P = 0.716). Additionally, age, sex, smoking history, Montreal classification, related surgical history, disease course, and serum biochemical indicators (ESR; platelet count; and CRP, albumin, and Hb levels) were not significantly different between the two groups.

CONCLUSIONS

The detection rate of granulomas in patients with CD is related to the morphology of the intestinal lesions. Meanwhile, lesion location may be correlated with the detection rate of granulomas.

Diagnosis and Monitoring of Ulcerative Colitis

Ulcerative colitis is one of the two main subtypes of inflammatory bowel disease, along with Crohn's disease. Understanding the clinical and endoscopic features of ulcerative colitis is critical in achieving a timely diagnosis. An initial evaluation includes assessing clinical symptoms, inflammatory markers, endoscopic findings, and determination of the presence or absence of extraintestinal manifestations. Initial disease management should consider disease severity at the time of diagnosis as well as prognostication, or the determination of risk factors present with a high likelihood of severe disease in the future. Once appropriate therapy has been initiated, ongoing monitoring is crucial, which may include repeated clinical assessments over time, measuring noninvasive markers of inflammation, and endoscopic and histologic reevaluation. An important aspect of disease monitoring in ulcerative colitis is dysplasia surveillance; there are many patient-specific risk factors which influence surveillance strategies. Utilizing appropriate surveillance techniques is necessary for early detection of dysplasia and colorectal neoplasia.

Histopathological assessment of the microscopic activity in inflammatory bowel diseases: What are we looking for?

Advances in diagnostics of inflammatory bowel diseases (IBD) and improved treatment strategies allowed the establishment of new therapeutic endpoints. Currently, it is desirable not only to cease clinical symptoms, but mainly to achieve endoscopic remission, a macroscopic normalization of the bowel mucosa. However, up to one-third of IBD patients in remission exhibit persisting microscopic activity of the disease. The evidence suggests a better predictive value of histology for the development of clinical complications such as clinical relapse, surgical intervention, need for therapy escalation, or development of colorectal cancer. The proper assessment of microscopic inflammatory activity thus became an important part of the overall histopathological evaluation of colonic biopsies and many histopathological scoring indices have been established. Nonetheless, a majority of them have not been validated and no scoring index became a part of the routine bioptic practice. This review summarizes a predictive value of microscopic disease activity assessment for the subsequent clinical course of IBD, describes the most commonly used scoring indices for Crohn's disease and ulcerative colitis, and comments on current limitations and unresolved issues.

Tools for the Diagnosis and Management of Crohn's Disease

Numerous tools have emerged over recent decades to aid in the increasingly complex management of patients with Crohn's disease (CD) beyond endoscopy, including video capsule endoscopy, magnetic resonance enterography, computed tomography enterography, a variety of biomarkers, and even wearable biosensors and smartphone applications. These tools have allowed for a more sophisticated and less invasive complementary approach to the evaluation of disease activity and treatment response in patients with CD. This article details the characteristics, practical application, and limitations of these various modalities and discusses how updated guidelines are now incorporating many of them into a treat-to-target strategy.

Microgranulomas at Diagnosis Are Associated With Need for Antitumor Necrosis Factor Escalation in Pediatric Crohn Disease

INTRODUCTION

Granulomas are a pathologic hallmark of Crohn disease (CD) although they are found in only a subset of patients. Well-formed granulomas are associated with an aggressive phenotype although it is unknown if microgranulomas confer a similar phenotype. This study sought to define the incidence of microgranulomas in pediatric CD and compare the clinical course with cases with granulomas and those without granulomatous inflammation.

METHODS

We performed a single-center, retrospective study of pediatric CD patients who had at least 3 years of follow-up. initial diagnostic biopsies were systematically re-examined by a gastrointestinal pathologist. A priori definitions of granuloma (10+ histiocytes) and microgranuloma (4-9 histiocytes) were used. Disease outcomes of hospitalization, development of complicated disease behavior, perianal disease, and the use of anti-tumor necrosis factor (anti-TNF) therapy were assessed by Kaplan-Meier survival plots.

RESULTS

This study included 138 subjects with an average follow-up of 4.6 years. Granulomas were seen in 38 of 138 subjects (27.5%) and an additional 38 subjects (27.5%) had at least 1 microgranuloma (in the absence of granulomas). Escalation to anti-TNF therapy was higher in CD with granulomas (P  = 0.001) and microgranulomas (P  = 0.0001) compared with those without granulomatous inflammation.

CONCLUSIONS

A significant subset of pediatric CD patients have microgranulomas (in the absence of well-defined granulomas). Children with CD who have microgranulomas are escalated to anti-TNF therapy more frequently than those without granulomatous inflammation (and at a similar rate to those with granulomas). Pathologists should have a low threshold to report microgranulomas as they may help to predict disease behavior.

Granulomas in Diagnostic Biopsies Associated With High Risk of Crohn's Complications-But May Be Preventable

BACKGROUND

Granulomatous intestinal inflammation may be associated with aggressive Crohn's disease (CD) behavior. However, this has not been confirmed, and it is unknown if associated disease complications are preventable.

METHODS

This is a retrospective cohort of patients younger than 21 years at CD diagnosis (November 1, 2005 to November 11, 2015). Clinical information was abstracted, including dates of starting medications and the timing of perianal fistula or stricture development, if any. Diagnostic pathology reports were reviewed, and a subset of biopsy slides were evaluated by a blinded pathologist. Patients were excluded if perianal fistula or stricture developed within 30 days after CD diagnosis. Medications were included in analyses only if started >90 days before development of perianal fistula or stricture.

RESULTS

In total, 198 patients were included. Half (54%) had granulomas at diagnosis. Granulomas were associated with a greater than 3-fold increased risk of perianal fistula (hazard ration [HR] = 3.24; 95% confidence interval CI], 1.40-7.48). Immunomodulator and anti-tumor necrosis factor-α (anti-TNF) therapy were associated with 90% (HR, = 0.10; 95% CI, 0.03-0.42) and 98% (HR, = 0.02; 95% CI, 0.01-0.10) reduced risk of perianal fistula, respectively. Patients with granulomatous inflammation preferentially responded to anti-TNF therapy with reduced risk of perianal fistula. The presence of granulomas was not associated with risk of stricture. Immunomodulator and anti-TNF therapy were associated with 96% (HR, = 0.04; 95% CI, 0.01-0.22) and 94% (HR, = 0.06; 95% CI, 0.02-0.20) reduced risk of stricture, respectively.

CONCLUSIONS

Granulomas are associated with increased risk of perianal fistula but not stricture. Steroid sparing therapies seem to reduce the risk of both perianal fistula and stricture. For those with granulomas, anti-TNF-α therapy greatly reduced the risk of perianal fistula development, whereas immunomodulators did not.

Pattern-based Histologic Approach in Very Early Onset IBD: Main Features and Differential Diagnosis

Very early onset inflammatory bowel disease (VEO-IBD) is a clinical umbrella classification composed of IBD-like diseases encompassing both classic IBD (Crohn's disease and ulcerative colitis) and monogenic disorder, both arising before 6 years of age. VEO-IBD patients present significant clinical differences from IBD occurring in older children and in adults, including more severe disease, often unresponsive to conventional IBD therapy and a greater proportion of cases featuring an underlying genetic alteration. Histologic findings of gastrointestinal biopsies can show an IBD-like pattern (both Crohn's disease-like and ulcerative colitis-like pattern), an apoptotic-like and enterocolitis-like pattern. Findings of specific morphologic alterations, such as villous blunting, apoptosis, dense eosinophilic infiltrates, lack of plasma cells and severe glandular atrophy, can suggest a monogenic disorder. Moreover, individuals with monogenic disorders may develop significant problems such as primary immunodeficiency, impacting treatment options. Finally, IBD histology in childhood can differ from that in older patients and adults. This complexity makes a differential diagnosis between IBD and other pediatric diseases involving the gastrointestinal tract difficult, especially considering that histologic features can be similar between different diseases. Without an appropriate diagnosis, the clinical course of VEO-IBD has greater potential for escalated treatment regimens involving extensive surgery and more intensive medical therapies rather than specific therapy directed toward the underlying defect. For these reasons, a pattern-based histologic approach correlated with clinical and laboratory findings with a multidisciplinary approach is fundamental to reach a correct diagnosis in an adequate clinical context.

Histologic Diagnosis of Inflammatory Bowel Diseases

Inflammatory bowel disease, including ulcerative colitis and Crohn disease, is an idiopathic chronic inflammatory condition of the gastrointestinal tract. Since neither the clinical manifestations nor the morphologic features of inflammatory bowel disease are pathognomonic alone, the differential diagnosis to consider is relatively broad, and it relies on the synthesis of clinical, endoscopic, and microscopic features. Long-held histologic diagnostic principles include recognizing structural and inflammatory features of chronicity, that is, architectural distortion, basal plasmacytosis, and expansion of the lamina propria lymphoplasmacytic infiltrate. In addition, evaluation of the neutrophilic inflammation and related crypt and epithelial destruction is essential to gauge the activity of the disease. Nevertheless, these features can be difficult to confirm in special settings, including at the inception of the disease or in partially treated cases. This review will explore the classic morphologic features of ulcerative colitis and Crohn disease, followed by a detailed discussion of atypical and diagnostically challenging presentations and a brief review of the clinical aspects necessary for the daily practice of pathologists.

ECCO Topical Review Optimising Reporting in Surgery, Endoscopy, and Histopathology

BACKGROUND AND AIMS

Diagnosis and management of inflammatory bowel diseases [IBD] requires a lifelong multidisciplinary approach. The quality of medical reporting is crucial in this context. The present topical review addresses the need for optimised reporting in endoscopy, surgery, and histopathology.

METHODS

A consensus expert panel consisting of gastroenterologists, surgeons, and pathologists, convened by the European Crohn's and Colitis Organisation, performed a systematic literature review. The following topics were covered: in endoscopy: [i] general IBD endoscopy; [ii] disease activity and surveillance; [iii] endoscopy treatment in IBD; in surgery: [iv] medical history with surgical relevance, surgical indication, and strategy; [v] operative approach; [vi] intraoperative disease description; [vii] operative steps; in pathology: [viii] macroscopic assessment and interpretation of resection specimens; [ix] IBD histology, including biopsies, surgical resections, and neoplasia; [x] IBD histology conclusion and report. Statements were developed using a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥ 80% of participants agreed on a recommendation.

RESULTS

Thirty practice positions established a standard terminology for optimal reporting in endoscopy, surgery, and histopathology. Assessment of disease activity, surveillance recommendations, advice to surgeons for operative indication and strategies, including margins and extent of resection, and diagnostic criteria of IBD, as well as guidance for the interpretation of dysplasia and cancer, were handled. A standardised report including a core set of items to include in each specialty report, was defined.

CONCLUSIONS

Interdisciplinary high-quality care requires thorough and standardised reporting across specialties. This topical review offers an actionable framework and practice recommendations to optimise reporting in endoscopy, surgery, and histopathology.

Gastric metaplasia of the duodenal mucosa in Crohn's disease: novel histological and endoscopic findings

Background and study aims  Upper gastrointestinal endoscopy and biopsy are useful for differential diagnosis of Crohn's disease (CD) of the large intestine and ulcerative colitis (UC). We aimed to identify novel histopathological and endoscopic findings in the upper gastrointestinal tract in patients with CD who did not have Helicobacter pylori infection. Patients and methods  Upper gastrointestinal endoscopy was performed on patients with CD and UC. Mucosal lesions detected were subsequently observed using magnifying endoscopy with narrow-band imaging (M-NBI), following which biopsy was performed. When no mucosal lesion was detected on conventional endoscopy, M-NBI and biopsy were performed on four sites: the gastric body, gastric antrum, duodenal bulb, and second portion of the duodenum. Results  The prevalences of gastric metaplasia (GM) were 48 % (24/50) and 16 % (8/50) in the CD and UC groups, showing a significant difference ( P  = 0.001). In 23 of 24 patients with histologically proven GM in the CD group, mucosal lesions were detected using conventional white-light imaging (C-WLI). In 22 of 24 patients with histologically proven GM in the CD group, disappearance of normal villous structure and the presence of curved marginal crypt epithelium were noted using magnifying endoscopic findings characteristic of GM (M-GM). A combination of C-WLI and M-NBI yielded a significantly increased specificity ( P  = 0.004) and accuracy ( P  = 0.039). Conclusions  The prevalence of GM in the duodenal mucosa was significantly higher in patients with CD than in controls. The identified endoscopic findings may be useful as novel indicators for the histological diagnosis of GM in the duodenum.

Evidence-based clinical practice guidelines for inflammatory bowel disease 2020

Inflammatory bowel disease (IBD) is a general term for chronic or remitting/relapsing inflammatory diseases of the intestinal tract and generally refers to ulcerative colitis (UC) and Crohn's disease (CD). Since 1950, the number of patients with IBD in Japan has been increasing. The etiology of IBD remains unclear; however, recent research data indicate that the pathophysiology of IBD involves abnormalities in disease susceptibility genes, environmental factors and intestinal bacteria. The elucidation of the mechanism of IBD has facilitated therapeutic development. UC and CD display heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management depends on the understanding and tailoring of evidence-based interventions by physicians. In 2020, seventeen IBD experts of the Japanese Society of Gastroenterology revised the previous guidelines for IBD management published in 2016. This English version was produced and modified based on the existing updated guidelines in Japanese. The Clinical Questions (CQs) of the previous guidelines were completely revised and categorized as follows: Background Questions (BQs), CQs, and Future Research Questions (FRQs). The guideline was composed of a total of 69 questions: 39 BQs, 15 CQs, and 15 FRQs. The overall quality of the evidence for each CQ was determined by assessing it with reference to the Grading of Recommendations Assessment, Development and Evaluation approach, and the strength of the recommendation was determined by the Delphi consensus process. Comprehensive up-to-date guidance for on-site physicians is provided regarding indications for proceeding with the diagnosis and treatment.

Early microscopic findings in preclinical inflammatory bowel disease

BACKGROUND

The immune response involved in the pathogenesis of Inflammatory Bowel Disease (IBD) may be present years before the diagnosis, but the characteristics of the disease during the preclinical period have been scarcely investigated.

AIM

To describe the microscopic findings of preclinical IBD and its relationship with the natural history of the disease.

METHODS

Medical records from all patients with an incidental diagnosis of IBD during a screening colonoscopy were included in this multicentric and retrospective study. We assessed 15 histologic items in the biopsy samples at diagnosis, and the Geboes score was calculated in patients with Ulcerative Colitis (UC). The main outcome was the development of gastrointestinal symptoms during follow-up.

RESULTS

We included 110 patients (79 UC, 24 Crohn's Disease (CD) and 7 with unclassified disease). In UC the most common histologic findings were acute or chronic inflammatory infiltrate and crypt epithelial polymorphs, while in CD we observed acute or chronic neutrophilic infiltrate and epithelial irregularity. Granuloma were only observed in 4% of CD patients. Crypt distortion and the infiltration of neutrophils in the epithelium were associated with a higher risk of developing symptomatic disease.

CONCLUSIONS

Preclinical IBD shows specific microscopic findings and they are associated with the progression to symptomatic disease.

Changes in duodenal CD163-positive cells in dogs with chronic enteropathy after successful treatment

Chronic enteropathy (CE) in dogs is characterized retrospectively per treatment response as food-responsive enteropathy (FRE), antibiotic-responsive enteropathy (ARE), and immunosuppressant-responsive enteropathy (IRE) - the latter most resembling inflammatory bowel disease in people. The aim of this study was to characterize duodenal macrophages (Mϕ) in CE using immunohistochemistry; with calprotectin (CAL) as a marker of early differentiated Mϕ and CD163 expression as a marker for resident Mϕ in the duodenum before and after treatment. Prior to treatment, dogs with FRE and IRE had a lower CD163⁺/CAL⁺ ratio than control dogs (CTRL) in crypts; this increased significantly and normalized compared with CTRL after treatment. Conversely, the CD163⁺/CAL⁺ ratio in dogs with ARE was comparable to that in healthy dogs before and after treatment. In summary, these results suggest that Mϕ play a role in the pathogenesis of CE in FRE and IRE, with a decrease in resident Mϕ and an increase in early differentiated Mϕ, but not in ARE dogs. Mϕ normalize after successful treatment.

Epithelioid Granulomas Associate With Increased Severity and Progression of Crohn's Disease, Based on 6-Year Follow-Up

BACKGROUND & AIMS

Epithelioid granulomas are characteristics of a subset of patients with Crohn's disease (CD), but their significance, with regard to disease progression and severity, is unclear. We investigated the relationship between granulomas and CD severity over a 6-year time period in a large cohort of patients.

METHODS

We performed a retrospective study of patients with CD seen at the Inflammatory Bowel Disease Center at the University of Pittsburgh; data were collected from 2009 through 2014 and patients were assigned to groups with and without histologic evidence of granuloma. Demographic, clinical (including disease activity, quality of life, medication use, and healthcare utilization), and laboratory data were used in association and survival analyses. Differences between groups were evaluated using the Mann-Whitney U-test for continuous variables.

RESULTS

Of 1466 patients with CD, granulomas were identified in 187 (12.8%). In the subset of patients who underwent surgery, 21.0% had granulomas. The presence of granuloma was associated with increased serum levels of c-reactive protein (odds ratio [OR], 2.9; 95% CI, 2.078-4.208; P < .0001), younger mean age at diagnosis (23.6 ± 11.3 years in patients with granulomas vs 27.9 ± 13.3 years in patients without; P = .0005), higher rates of stricturing or penetrating disease phenotype, higher rates of steroid and narcotic use, and higher healthcare utilization. Among patients that underwent surgery, the presence of granulomas was associated with need for repeat surgery during the 6-year observation period (OR, 2.5; 95% CI, 1.54-4.02; P = .0002). Infliximab use was associated with detection of granuloma in a significantly lower proportion of surgical specimens compared to patients who had not been treated with a biologic agent (OR, 0.22; 95 CI, 0.05-0.97; P = .03).

CONCLUSIONS

Epithelioid granulomas develop in less than 13% of patients with CD, and are associated with a more aggressive disease phenotype. Patients who have undergone surgery for CD and have granulomas are at increased risk for repeat surgery within 6 years.

Evidence-based clinical practice guidelines for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disorder involving mainly the intestinal tract, but possibly other gastrointestinal and extraintestinal organs. Although etiology is still uncertain, recent knowledge in pathogenesis has accumulated, and novel diagnostic and therapeutic modalities have become available for clinical use. Therefore, the previous guidelines were urged to be updated. In 2016, the Japanese Society of Gastroenterology revised the previous versions of evidence-based clinical practice guidelines for ulcerative colitis (UC) and Crohn's disease (CD) in Japanese. A total of 59 clinical questions for 9 categories (1. clinical features of IBD; 2. diagnosis; 3. general consideration in treatment; 4. therapeutic interventions for IBD; 5. treatment of UC; 6. treatment of CD; 7. extraintestinal complications; 8. cancer surveillance; 9. IBD in special situation) were selected, and a literature search was performed for the clinical questions with use of the MEDLINE, Cochrane, and Igaku Chuo Zasshi databases. The guidelines were developed with the basic concept of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Recommendations were made using Delphi rounds. This English version was produced and edited based on the existing updated guidelines in Japanese.

Endoscopic and Histological Assessment of Paediatric Inflammatory Bowel Disease Over a 3-Year Follow-up Period

OBJECTIVES

Discrepancies between inflammatory bowel disease (IBD) endoscopic/histological extent are documented at diagnosis. It is unclear whether these differences persist through disease course, with potential impact on categorization and management. We aimed to analyze the progression of disease over a 3-year period.

METHODS

Patients younger than 17 years, diagnosed between 2010 and 2013 at Southampton Children's Hospital and followed-up for 3 years were eligible. Primary outcome was disease extent at diagnosis and follow-up. Data are presented as percentage of patients undergoing endoscopy. Paris classification (PC) and PC using histological, rather than endoscopic disease, were determined.

RESULTS

One hundred and twenty-five patients were included, 66 boys; Crohn's disease (CD) 74, ulcerative colitis (UC) 40, IBD unclassified (IBDU) 11. All had endoscopy at diagnosis. One hundred and two patients underwent ≥1 repeat endoscopies.Disease extent reduced from diagnosis to first follow-up endoscopy for both endoscopic and histological disease extent (CD/UC/IBDU, all P < 0.00006). Histological extent remained greater than endoscopic in CD with significant differences in stomach, ileum, and large bowel at all follow-up points (P =  < 0.045). Endoscopic matched histological extent in UC/IBDU. Applying a modified PC resulted in significant changes for CD (L3 27.4%-53.2%, P = 0.006, L3 + L4A 21%-50%, P = 0.001, and upper gastrointestinal disease 50%-80.6%, P = 0.0006) but not UC. CD height (-0.37 to -0.25) and weight (-1.09 to -0.19) standard deviation scores increased from diagnosis to follow-up.

CONCLUSIONS

Histological disease is greater than endoscopic extent at diagnosis and during follow-up in CD, although not in UC/IBDU. Classification of disease extent in CD should be based on both endoscopic and histological criteria.

Partial to complete abrogation of the subepithelial macrophage barrier against the gut microbiota in patients with ulcerative colitis and Crohn's colitis

AIMS

The integrity of the band of indigenous macrophages in the subepithelial layer of the lamina propria (SLP) is crucial in preventing the commensal gut microbiota from attacking the host. The breakdown of the SLP macrophage barrier results in microbiota inflow and improper immune responses; this might lead to inflammatory bowel disease (IBD). During inflammation, the SLP macrophage barrier is reinforced by inflammation-elicited macrophages (IEMs), which are derived from blood-circulating monocytes. The aim was to explore the characteristics of the SLP macrophage band in a cohort of biopsies without inflammation, in patients with ulcerative colitis in remission (UCre), and in patients with right-sided Crohn's colitis (RCC).

METHODS AND RESULTS

Endoscopic biopsies were taken from endoscopically normal descending colon in 247 patients; 80 with IBD (27 UCre and 53 RCC), and 167 without IBD [90 had colonic diarrhoea, 63 were enrolled in a colorectal cancer (CRC) surveillance programme, seven had microscopic colitis in remission, and seven had miscellaneous colonic ailments]. Sections showed no inflammatory changes; they were immunostained with CD68. Among patients with UCre and RCC, the SLP band of CD68+ macrophages was fragmented or minute in 59% (47/80) and negative in 9% (7/80). In contrast, only 31% (51/167) of the biopsies from control patients had a fragmented/minute SLP band of CD68+ macrophages, and none had a negative SLP band of CD68+ macrophages (IBD versus controls, P < 0.05).

CONCLUSIONS

The finding that the SLP macrophage barrier was fragmented to totally abrogated in UCre and RCC patients suggests a longlasting defect in the SLP CD68+ macrophage barrier in these patients. The lack of ongoing inflammation in colonic biopsies should rule out the participation of bone marrow-derived IEMs in the abrogation of the SLP macrophage barrier reported here.

Granulomas in the gastrointestinal tract: deciphering the Pandora's box

Granulomas are organised collection of activated histiocytes induced by a persistent antigen stimulus. A wide variety of antigens encountered by the gastrointestinal tract are of this nature and hence the resulting granulomatous inflammation represents a tissue reaction pattern. The potential causes can be broadly classified as infections or non-infectious immune reactions. There is also a group where a cause is never identified. Granulomas may be of varying morphological appearance, most commonly epithelioid, foreign body type, suppurative and necrotizing. This may provide a clue as to the aetiology; however, in most cases, the cause requires further inquiry. Pathologists may need to cut deeper levels to look for foreign material and apply special stains to look for microorganisms. Pathologists also need to be certain that the process is a true granuloma and not a mimic. The site of occurrence in the gastrointestinal tract and the clinical setting is often paramount in establishing the aetiology. For instance, infections are more likely the cause in developing countries or when there is immunosuppression. Similarly, granulomas in the stomach are usually due to Crohn's disease; however, it is only rarely the cause of granulomas isolated to the appendix.

Recent advances in clinical practice: a systematic review of isolated colonic Crohn's disease: the third IBD?

The genetics of isolated colonic Crohn's disease place it approximately midway between Crohn's disease with small intestinal involvement and UC, making a case for considering it as a separate condition. We have therefore systematically reviewed its epidemiology, pathophysiology and treatment. Key findings include a higher incidence in females (65%) and older average age at presentation than Crohn's disease at other sites, a mucosa-associated microbiota between that found in ileal Crohn's disease and UC, no response to mesalazine, but possibly better response to antitumour necrosis factor than Crohn's disease at other sites. Diagnostic distinction from UC is often difficult and also needs to exclude other conditions including ischaemic colitis, segmental colitis associated with diverticular disease and tuberculosis. Future studies, particularly clinical trials, but also historical cohorts, should assess isolated colonic Crohn's disease separately.

Segmental colitis associated with diverticulosis: is it the coexistence of colonic diverticulosis and inflammatory bowel disease?

Segmental colitis associated with diverticulosis (SCAD) is an inflammatory process that affects colonic luminal mucosa in segments that are also affected by diverticulosis. Its prevalence varies between 1.15% and 11.4% amongst those suffering from diverticular disease (DD). Being closely associated with DD, it is slightly commoner in males and usually presents in the sixth decade of life. Although the exact pathogenesis of SCAD is unknown, it is probably heterogeneous and includes mechanisms that also play a part in inflammatory bowel disease (IBD). The clinical presentation is non-specific and similar to that of other pathologies involving the sigmoid colon, and its diagnosis is based on endoscopic findings in correlation with histology. Currently, there are no guidelines for its management, which is usually based on the administration of salicylates and antibiotics, with surgery being reserved for refractory cases. The rarity of SCAD may be multifactorial: whereas milder forms go undiagnosed or are attributed to DD, more severe forms can be misdiagnosed as IBD. This latter distinction is an important one to make, since SCAD and IBD differ as regards their natural history and prognosis, while very often no long-term medications are required in SCAD.

An index with improved diagnostic accuracy for the diagnosis of Crohn's disease derived from the Lennard-Jones criteria

BACKGROUND

The Lennard-Jones criteria are considered the gold standard for diagnosing Crohn's disease (CD) and include the items granuloma, macroscopic discontinuity, transmural inflammation, fibrosis, lymphoid aggregates and discontinuous inflammation on histology. The criteria have never been subjected to a formal validation process.

AIM

To develop a validated and improved diagnostic index based on the items of Lennard-Jones criteria.

METHODS

Included were 328 adult patients with long-standing CD (median disease duration 10 years) from three centres and classified as 'established', 'probable' or 'non-CD' by Lennard-Jones criteria at time of diagnosis. Controls were patients with ulcerative colitis (n = 170). The performance of each of the six diagnostic items of Lennard-Jones criteria was modelled by logistic regression and a new index based on stepwise backward selection and cut-offs was developed. The diagnostic value of the new index was analysed by comparing sensitivity, specificity and accuracy vs. Lennard-Jones criteria.

RESULTS

By Lennard-Jones criteria 49% (n = 162) of CD patients would have been diagnosed as 'non-CD' at time of diagnosis (sensitivity/specificity/accuracy, 'established' CD: 0.34/0.99/0.67; 'probable' CD: 0.51/0.95/0.73). A new index was derived from granuloma, fibrosis, transmural inflammation and macroscopic discontinuity, but excluded lymphoid aggregates and discontinuous inflammation on histology. Our index provided improved diagnostic accuracy for 'established' and 'probable' CD (sensitivity/specificity/accuracy, 'established' CD: 0.45/1/0.72; 'probable' CD: 0.8/0.85/0.82), including the subgroup isolated colonic CD ('probable' CD, new index: 0.73/0.85/0.79; Lennard-Jones criteria: 0.43/0.95/0.69).

CONCLUSION

We developed an index based on items of Lennard-Jones criteria providing improved diagnostic accuracy for the differential diagnosis between CD and UC.

Endoscopic Versus Histological Disease Extent at Presentation of Paediatric Inflammatory Bowel Disease

OBJECTIVES

The Paris classification (PC) of paediatric inflammatory bowel disease categorises disease extent and therefore affects treatment decisions. Histological (microscopic) disease extent is not incorporated, and endoscopic (macroscopic) findings may underrepresent disease extent when compared with histological findings; this study compares disease extent at presentation.

METHODS

Data were obtained of patients <17 years of age diagnosed with inflammatory bowel disease from 2010 to 2013 at University Hospital Southampton. Data are presented as percentage of patients undergoing endoscopy. PC was performed alongside a modified PC by histological disease location.

RESULTS

A total of 172 patients were identified (median age at diagnosis 13.5 years, 115 boys); Crohn disease (CD) 107, ulcerative colitis (UC) 50, inflammatory bowel disease unclassified (IBDU) 15; 159 had undergone upper gastrointestinal (GI) endoscopy, 163 had undergone lower GI endoscopy. Histological disease was more extensive at all points for CD, UC, and IBDU. CD--endoscopic ileal disease in 49% of patients compared with histological disease in 71.3%. Comparing PC--a 10% increase in L3 disease (ileocolonic), a 24% increase in L3 + L4a disease (ileocolonic plus upper GI), and a 27% increase in all of the upper GI involvement if histological disease extent was used. UC--the most common disease location was the rectum (endoscopic 91.5% vs histological 93.6%) and descending colon (endoscopic 89.4% vs histological 95.7%). Comparing PC--a 19% increase in E4 disease (pancolitis) if histological disease extent was used.

CONCLUSIONS

These data confirm that histological disease extent is greater than endoscopic disease extent. This should be considered when the PC is used. Further study is needed to elucidate which classification would better predict disease outcome.

A Bamboo Joint-Like Appearance is a Characteristic Finding in the Upper Gastrointestinal Tract of Crohn's Disease Patients: A Case-Control Study

The clinical importance of Crohn's disease (CD)-specific lesions in the upper gastrointestinal tract (upper GIT) has not been sufficiently established. The aim of this case-control study is to investigate the characteristic findings of CD in the upper GIT. In 2740 patients who underwent gastroduodenoscopy at Asahikawa Medical University between April 2011 and December 2012, 81 CD patients, 81 gender- and age-matched non-IBD patients, and 66 ulcerative colitis (UC) patients were investigated in the present study. (1) The diagnostic ability and odds ratio of each endoscopic finding (a bamboo joint-like appearance in the cardia, erosions, and/or ulcers in the antrum, notched signs, and erosions and/or ulcers in the duodenum) were compared between the CD and non-IBD patients or UC patients. (2) The interobserver agreement of the diagnosis based on the endoscopic findings was evaluated by 3 experienced and 3 less-experienced endoscopists. The incidence of detecting a bamboo joint-like appearance, notched signs, and erosions and/or ulcers in the duodenum was significantly higher in the CD patients than in the non-IBD and UC patients. In addition, the diagnostic ability and odds ratio of a bamboo joint-like appearance for CD were higher than those for the other findings. Kendall's coefficients of concordance in the group of experienced and less-experienced endoscopists were relatively high for a bamboo joint-like appearance (0.748 and 0.692, respectively). A cardiac bamboo joint-like appearance is a useful finding for identifying high-risk groups of CD patients using only gastroduodenoscopy.

Clinical Implications of Noncaseating Granulomas on Histology in Patients with Ileal Pouches

BACKGROUND

Granulomas are occasionally detected on biopsy specimen of the ileal pouch and their clinical implications are not clear. The aim of this study was to evaluate clinical implications of noncaseating granuloma on histology in patients with ileal pouches.

METHODS

All eligible patients with confirmed noncaseating granulomas on histology of the biopsy specimens of the pouch body, afferent limb, or cuff in our prospectively maintained Pouch Registry between 2002 and 2014 were evaluated. Demographic and clinical factors were analyzed. The disease course of those patients was evaluated.

RESULTS

Of 1564 patients in the Registry, 42 met the criteria and were included. The median duration from the pouch construction to the last visit was 9 years (range, 2-28 yr). Twenty-eight patients (66.7%) developed clinical Crohn's disease (CD) of the pouch, whereas 14 (33.3%) were classified as having histologic CD of the pouch. Six patients (21.4%) in the clinical CD of the pouch group and 4 (28.6%) in the histologic CD of the pouch group had granulomas on more than 1 endoscopy. Postoperative biological therapy was administered more in the clinical CD group than in the histologic CD group (39.3% versus 0%, P = 0.007). Pouch-related fistulae and presacral sinus were verified more in clinical CD group than the histologic CD group. However, Kaplan-Meier plot showed comparable pouch survival between clinical CD and histologic CD groups.

CONCLUSIONS

In our current study, one-third of the patients with noncaseating pouch granulomas did not develop clinical CD of the pouch. With proper medical therapy, long-term pouch outcomes appeared to be similar in those patients with clinical CD or histologic CD of the pouch.

Significance of the epithelioid granuloma in biopsies of Crohn's colitis

BACKGROUND

The relevance of granulomas in biopsy specimens from patients with Crohn's disease is largely unknown. Most previous studies have been performed on small samples and have produced conflicting results. This study was designed to compare the demographic, clinical, and histopathologic characteristics of a large cohort of documented patients with Crohn's disease with and without epithelioid granulomas.

METHODS

Data of all patients with Crohn's disease were extracted from a computerized database of 1.3 million subjects who underwent colonoscopy and had their biopsy specimens diagnosed by a single group of gastrointestinal pathologists. The influence of age, gender, patient symptoms, and histopathologic finding on the presence of granuloma was analyzed.

RESULTS

There were 10,456 patients with Crohn's disease: 952 (9%) patients harbored granulomas (cases) and 9504 (91%) patients (controls) had none. Cases were significantly younger than controls: 42.4 ± 17.9 versus 48.0 ± 16.4 years (P < 0.0001). Cases presented with more symptoms than controls (odds ratio, 95% confidence interval): diarrhea (2.29, 2.28-2.31), anemia (2.06, 2.02-2.10), vomiting (2.13, 2.07-2.19), abdominal pain (1.75, 1.72-1.78), hematochezia (1.97, 1.94-2.00), and weight loss (3.94, 3.93-3.94). In a multivariate logistic regression analysis, younger age, presence of chronic active colitis, and symptoms of weight loss remained independent statistically significant predictors for the presence of granulomas.

CONCLUSIONS

In colonic biopsies from patients with Crohn's disease, granulomas constitute a rare finding. Presence of granulomas is associated with younger patient age, more severe histopathologic expression of the underlying disease, and more clinical symptoms.

Systematic review: histological remission in inflammatory bowel disease. Is 'complete' remission the new treatment paradigm? An IOIBD initiative

BACKGROUND AND AIMS

Advances in the medical management of inflammatory bowel disease (IBD) have altered treatment targets. Endoscopic mucosal healing is associated with better outcomes in IBD, though less is known about the significance of achieving histological remission. Our aim was to perform a systematic review to investigate whether histological or 'complete' remission constitutes a further therapeutic target in IBD.

METHODS

A bibliographic search was performed on the 1st of October 2013 and subsequently on the 1st of March 2014 of online databases (OVID SP MEDLINE, OVID EMBASE, National Pubmed Central Medline, Cochrane Library, ISI, conference abstracts), using MeSH terms and key words: ("inflammatory bowel diseases" OR "crohn disease" OR "ulcerative colitis" OR "colitis") AND ("mucosal healing" OR "histological healing" OR "pathological healing" OR "histological scoring" OR "pathological scoring").

RESULTS

The search returned 2951 articles. 120 articles were cited in the final analysis. There is no validated definition of histological remission in IBD. There are 22 different histological scoring systems for IBD, none of which are fully validated. Microscopic inflammation persists in 16-100% of cases of endoscopically quiescent disease. There is evidence that histological remission may predict risk of complications in ulcerative colitis beyond endoscopic mucosal healing, though data are scarce in Crohn's disease.

CONCLUSIONS

Histological remission in IBD represents a target distinct from endoscopic mucosal healing, not yet routinely sought in clinical trials or practice. There remains a need for a standardized and validated histological scoring system and to confirm the prognostic value of histological remission as a treatment target in IBD.

Diagnosis of inflammatory bowel disease: Potential role of molecular biometrics

Accurate diagnosis of predominantly colonic inflammatory bowel disease (IBD) is not possible in 30% of patients. For decades, scientists have worked to find a solution to improve diagnostic accuracy for IBD, encompassing Crohn's colitis and ulcerative colitis. Evaluating protein patterns in surgical pathology colectomy specimens of colonic mucosal and submucosal compartments, individually, has potential for diagnostic medicine by identifying integrally independent, phenotype-specific cellular and molecular characteristics. Mass spectrometry (MS) and imaging (I) MS are analytical technologies that directly measure molecular species in clinical specimens, contributing to the in-depth understanding of biological molecules. The biometric-system complexity and functional diversity is well suited to proteomic and diagnostic studies. The direct analysis of cells and tissues by Matrix-Assisted-Laser Desorption/Ionization (MALDI) MS/IMS has relevant medical diagnostic potential. MALDI-MS/IMS detection generates molecular signatures obtained from specific cell types within tissue sections. Herein discussed is a perspective on the use of MALDI-MS/IMS and bioinformatics technologies for detection of molecular-biometric patterns and identification of differentiating proteins. I also discuss a perspective on the global challenge of transferring technologies to clinical laboratories dealing with IBD issues. The significance of serologic-immunometric advances is also discussed.

Diagnosis of inflammatory bowel disease: Potential role of molecular biometrics

Accurate diagnosis of predominantly colonic inflammatory bowel disease (IBD) is not possible in 30% of patients. For decades, scientists have worked to find a solution to improve diagnostic accuracy for IBD, encompassing Crohn’s colitis and ulcerative colitis. Evaluating protein patterns in surgical pathology colectomy specimens of colonic mucosal and submucosal compartments, individually, has potential for diagnostic medicine by identifying integrally independent, phenotype-specific cellular and molecular characteristics. Mass spectrometry (MS) and imaging (I) MS are analytical technologies that directly measure molecular species in clinical specimens, contributing to the in-depth understanding of biological molecules. The biometric-system complexity and functional diversity is well suited to proteomic and diagnostic studies. The direct analysis of cells and tissues by Matrix-Assisted-Laser Desorption/Ionization (MALDI) MS/IMS has relevant medical diagnostic potential. MALDI-MS/IMS detection generates molecular signatures obtained from specific cell types within tissue sections. Herein discussed is a perspective on the use of MALDI-MS/IMS and bioinformatics technologies for detection of molecular-biometric patterns and identification of differentiating proteins. I also discuss a perspective on the global challenge of transferring technologies to clinical laboratories dealing with IBD issues. The significance of serologic-immunometric advances is also discussed.

ESPGHAN revised porto criteria for the diagnosis of inflammatory bowel disease in children and adolescents

BACKGROUND

The diagnosis of pediatric-onset inflammatory bowel disease (PIBD) can be challenging in choosing the most informative diagnostic tests and correctly classifying PIBD into its different subtypes. Recent advances in our understanding of the natural history and phenotype of PIBD, increasing availability of serological and fecal biomarkers, and the emergence of novel endoscopic and imaging technologies taken together have made the previous Porto criteria for the diagnosis of PIBD obsolete.

METHODS

We aimed to revise the original Porto criteria using an evidence-based approach and consensus process to yield specific practice recommendations for the diagnosis of PIBD. These revised criteria are based on the Paris classification of PIBD and the original Porto criteria while incorporating novel data, such as for serum and fecal biomarkers. A consensus of at least 80% of participants was achieved for all recommendations and the summary algorithm.

RESULTS

The revised criteria depart from existing criteria by defining 2 categories of ulcerative colitis (UC, typical and atypical); atypical phenotypes of UC should be treated as UC. A novel approach based on multiple criteria for diagnosing IBD-unclassified (IBD-U) is proposed. Specifically, these revised criteria recommend upper gastrointestinal endoscopy and ileocolonscopy for all suspected patients with PIBD, with small bowel imaging (unless typical UC after endoscopy and histology) by magnetic resonance enterography or wireless capsule endoscopy.

CONCLUSIONS

These revised Porto criteria for the diagnosis of PIBD have been developed to meet present challenges and developments in PIBD and provide up-to-date guidelines for the definition and diagnosis of the IBD spectrum.

The histopathological approach to inflammatory bowel disease: a practice guide

Inflammatory bowel diseases (IBDs) are lifelong disorders predominantly present in developed countries. In their pathogenesis, an interaction between genetic and environmental factors is involved. This practice guide, prepared on behalf of the European Society of Pathology and the European Crohn's and Colitis Organisation, intends to provide a thorough basis for the histological evaluation of resection specimens and biopsy samples from patients with ulcerative colitis or Crohn's disease. Histopathologically, these diseases are characterised by the extent and the distribution of mucosal architectural abnormality, the cellularity of the lamina propria and the cell types present, but these features frequently overlap. If a definitive diagnosis is not possible, the term indeterminate colitis is used for resection specimens and the term inflammatory bowel disease unclassified for biopsies. Activity of disease is reflected by neutrophil granulocyte infiltration and epithelial damage. The evolution of the histological features that are useful for diagnosis is time- and disease-activity dependent: early disease and long-standing disease show different microscopic aspects. Likewise, the histopathology of childhood-onset IBD is distinctly different from adult-onset IBD. In the differential diagnosis of severe colitis refractory to immunosuppressive therapy, reactivation of latent cytomegalovirus (CMV) infection should be considered and CMV should be tested for in all patients. Finally, patients with longstanding IBD have an increased risk for the development of adenocarcinoma. Dysplasia is the universally used marker of an increased cancer risk, but inter-observer agreement is poor for the categories low-grade dysplasia and indefinite for dysplasia. A diagnosis of dysplasia should not be made by a single pathologist but needs to be confirmed by a pathologist with expertise in gastrointestinal pathology.

Genetic variants synthesize to produce paneth cell phenotypes that define subtypes of Crohn's disease

BACKGROUND & AIMS

Genetic susceptibility loci for Crohn's disease (CD) are numerous, complex, and likely interact with undefined components of the environment. It has been a challenge to link the effects of particular loci to phenotypes of cells associated with pathogenesis of CD, such as Paneth cells. We investigated whether specific phenotypes of Paneth cells associated with particular genetic susceptibility loci can be used to define specific subtypes of CD.

METHODS

We performed a retrospective analysis of 119 resection specimens collected from patients with CD at 2 separate medical centers. Paneth cell phenotypes were classified as normal or abnormal (with disordered, diminished, diffuse, or excluded granule phenotypes) based on lysozyme-positive secretory granule morphology. To uncover the molecular basis of the Paneth cell phenotypes, we developed methods to determine transcriptional profiles from whole-thickness and laser-capture microdissected, formalin-fixed, paraffin-embedded tissue sections.

RESULTS

The proportion of abnormal Paneth cells was associated with the number of CD-associated NOD2 risk alleles. The cumulative number of NOD2 and ATG16L1 risk alleles had an additive effect on the proportion of abnormal Paneth cells. Unsupervised clustering analysis of demographic and Paneth cell data divided patients into 2 principal subgroups, defined by high and low proportions of abnormal Paneth cells. The disordered and diffuse abnormal Paneth cell phenotypes were associated with an altered transcriptional signature of immune system activation. We observed an inverse correlation between abnormal Paneth cells and presence of granuloma. In addition, high proportions of abnormal Paneth cells were associated with shorter time to disease recurrence after surgery.

CONCLUSIONS

Histologic analysis of Paneth cell phenotypes can be used to divide patients with CD into subgroups with distinct pathognomonic and clinical features.

European consensus on the histopathology of inflammatory bowel disease

The histologic examination of endoscopic biopsies or resection specimens remains a key step in the work-up of affected inflammatory bowel disease (IBD) patients and can be used for diagnosis and differential diagnosis, particularly in the differentiation of UC from CD and other non-IBD related colitides. The introduction of new treatment strategies in inflammatory bowel disease (IBD) interfering with the patients' immune system may result in mucosal healing, making the pathologists aware of the impact of treatment upon diagnostic features. The European Crohn's and Colitis Organisation (ECCO) and the European Society of Pathology (ESP) jointly elaborated a consensus to establish standards for histopathology diagnosis in IBD. The consensus endeavors to address: (i) procedures required for a proper diagnosis, (ii) features which can be used for the analysis of endoscopic biopsies, (iii) features which can be used for the analysis of surgical samples, (iv) criteria for diagnosis and differential diagnosis, and (v) special situations including those inherent to therapy. Questions that were addressed include: how many features should be present for a firm diagnosis? What is the role of histology in patient management, including search for dysplasia? Which features if any, can be used for assessment of disease activity? The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas.

Frequency and characteristics of granulomas in 368 pediatric patients with Crohn’s disease

Introduction: Epitheloid granulomas are one of the best histological criteria for distinguishing Crohn’s disease from other inflammatory bowel diseases. However, the role of granuloma in the pathogenesis and clinical characteristics of Crohn’s disease is unclear. Aim: The aim of the present study was to evaluate the frequency of granulomas and their association with clinical characteristics using the database of the Hungarian Pediatric Inflammatory Bowel Disease Registry. Method: Three hundred and sixty-eight children with Crohn’s disease were registered between January 1st, 2007 and December 31st, 2010. Results: The frequency of granulomas was 31.4% (111/353) at diagnosis. Isolated granuloma in the upper gastrointestinal tract was detected in 2.5% of patients, while those in the terminal ileum was found in 5% of patients. There was no difference in location, behavior and disease activity indexes between patients with and without granulomas. Need for immunomodulators and biological therapy was similar in the two groups in the first year of diagnosis. Conclusions: The frequency of granulomas in this cohort was comparable to the frequency reported in other studies. Interestingly, granulomas in the terminal ileum or upper gastrointestinal tract contributed to the diagnosis of Crohn’s disease in one of 13 children. These data indicate that multiple biopsies from multiple sites are essential for the diagnosis of pediatric Crohn’s disease. Orv. Hetil., 154 (43), 1702–1708.

Challenging question: can we diagnose Crohn's disease without histology?

No single test is diagnostic of Crohn's disease (CD). In the presence of a compatible clinical presentation, diagnosis is by convention confirmed by a combination of imaging, serologic, endoscopic and histologic investigations. This diagnostic recommendation should be maintained, even though histology is often 'compatible with' rather than 'diagnostic of' suspected CD. The importance of histology varies depending on the specific sites of macroscopic disease. Histology is particularly important in distinguishing type of inflammatory bowel disease, when the colon predominantly is involved, and in confirming CD when macroscopic disease is atypically located.

Diarrheal Illness in the Pediatric Population: A Review of Neonatal Enteropathies and Childhood Idiopathic Inflammatory Bowel Disease

In the clinical context of pediatric diarrheal illness, the interpretation of endoscopic mucosal biopsies varies significantly from that in adults. This review outlines these differences by first describing a host of diarrheal illnesses that are nearly exclusive to the pediatric age group. The final portion of this article describes salient pathologic differences between adult and pediatric idiopathic inflammatory bowel disease. The goal of this review is to provide a brief description of each disease process and focus on practical aspects of diagnosis that are applicable for pathologists working in general practice settings.

Histological healing in inflammatory bowel disease: A still unfulfilled promise

Treatment of inflammatory bowel disease (IBD) is traditionally based on several drugs, including salicylates, corticosteroids, and antibiotics; in addition, the therapeutic armamentarium has considerably evolved with the advent of newer, effective therapeutic measures (such as the biological agents) that are able to improve in a considerable manner both the clinical and endoscopic variables. Thus, mucosal healing, at least considered from an endoscopic point of view, is today regarded as the ultimate endpoint for treatment of these conditions. However, it is also increasingly clear that endoscopic healing is not necessarily paralleled by histological healing; There are few doubts that the latter should be considered as a true, objective healing and the ultimate goal to reach when treating patients with IBD. Unfortunately, and surprisingly, only a few, incomplete, and somewhat conflicting data exist on this topic, especially because there is still the need to standardize both histological assessment and the severity grading of these disorders; Issues that have not been yet been resolved for clinical practice and therapeutic trials. Hopefully, with the help of an increased awareness on the clinical researchers’ side, and the availability of dedicated pathologists on the other side, this matter will be effectively faced and resolved in the near future.

Microbiota separation and C-reactive protein elevation in treatment-naïve pediatric granulomatous Crohn disease

OBJECTIVES

In patients with inflammatory bowel diseases (IBDs), the presence of noncaseating mucosal granuloma is sufficient for diagnosing Crohn disease (CD) and may represent a specific immune response or microbial-host interaction. The cause of granulomas in CD is unknown and their association with the intestinal microbiota has not been addressed with high-throughput methodologies.

METHODS

The mucosal microbiota from 3 different pediatric centers was studied with 454 pyrosequencing of the bacterial 16S rRNA gene and the fungal small subunit (SSU) ribosomal region in transverse colonic biopsy specimens from 26 controls and 15 treatment-naïve pediatric CD cases. Mycobacterium avium subspecies paratuberculosis (MAP) was tested with real-time polymerase chain reaction. The correlation of granulomatous inflammation with C-reactive protein was expanded to 86 treatment-naïve CD cases.

RESULTS

The CD microbiota separated from controls by distance-based redundancy analysis (P = 0.035). Mucosal granulomata found in any portion of the intestinal tract associated with an augmented colonic bacterial microbiota divergence (P = 0.013). The granuloma-based microbiota separation persisted even when research center bias was eliminated (P = 0.04). Decreased Roseburia and Ruminococcus in granulomatous CD were important in this separation; however, principal coordinates analysis did not reveal partitioning of the groups. CRP levels >1 mg/dL predicted the presence of mucosal granulomata (odds ratio 28 [6-134.32]; 73% sensitivity, 91% specificity).

CONCLUSIONS

Granulomatous CD associates with microbiota separation and C-reactive protein elevation in treatment-naïve children; however, overall dysbiosis in pediatric CD appears rather limited. Geographical/center bias should be accounted for in future multicenter microbiota studies.

Granulomas in Crohn's disease: does progression through the bowel layers affect presentation or predict recurrence?

AIM

The aim of the study was to correlate the presence and pattern of distribution of granulomas in resected specimens to clinical characteristics and outcome in patients undergoing surgery for Crohn's disease.

METHOD

Patients with Crohn's disease who underwent surgical resection between 2001 and 2007 were identified. Pathology slides were reviewed for the presence, number and location of granulomas in four representative slides from each specimen.

RESULTS

Two-hundred and seven patients were identified. At a mean follow up of 14 months, 39 patients had a recurrence, 22 (57%) of whom underwent reoperation. Ninety-four (45%) patients had granulomas present in the surgical specimen. Patients with granulomas were younger (P<0.001), had a lower preoperative body mass index (P=0.037), were more likely to be female (P=0.017) and were more likely to have extra-intestinal manifestations (P=0.026) or perianal disease (P=0.012). Sites of disease and procedures performed were similar in both groups. Disease recurrence and reoperative rates were similar in both groups, as were length of stay and morbidity rates. The average number of granulomas present in each sampled pathology slide was 7.2, and there was no correlation between number of granulomas and disease severity. No link was found between the depth of involvement of the granulomas and fistulizing or stricturing disease.

CONCLUSION

Granulomas were associated with increased extra-intestinal manifestations and perianal disease, a lower body mass index and younger or female patients. There was no correlation between the presence of granulomas and disease progression or recurrence rates during the short follow-up period of this study.

New insights into gastrointestinal and hepatic granulomatous disorders

Numerous diseases that involve the gastrointestinal tract reveal the presence of granulomas on histological analysis. Granulomatous diseases can be either primary or secondary to environmental factors. Granulomas are dynamic structures composed of organized collections of activated macrophages, including epithelioid and multinucleated giant cells, surrounded by lymphocytes. The formation of granulomas is usually in response to antigenic stimulation and is orchestrated through cytokines, immune cells and host genetics. In this Review, the pathogenesis and etiologies of granulomas of the gastrointestinal tract and liver are discussed, as are the available diagnostic tools to help differentiate their various underlying etiologies. In addition, the role of granulomas in harboring latent tuberculosis is reviewed. The effects of tumor necrosis factor antagonists and interferon-α on the development of granulomas are also discussed.

Pediatric modification of the Montreal classification for inflammatory bowel disease: the Paris classification

BACKGROUND

Crohn's disease and ulcerative colitis are complex disorders with some shared and many unique predisposing genes. Accurate phenotype classification is essential in determining the utility of genotype-phenotype correlation. The Montreal Classification of IBD has several weaknesses with respect to classification of children. The dynamic features of pediatric disease phenotype (change in disease location and behavior over time, growth failure) are not sufficiently captured by the current Montreal Classification.

METHODS

Focusing on facilitating research in pediatric inflammatory bowel disease (IBD), and creating uniform standards for defining IBD phenotypes, an international group of pediatric IBD experts met in Paris, France to develop evidence-based consensus recommendations for a pediatric modification of the Montreal criteria.

RESULTS

Important modifications developed include classifying age at diagnosis as A1a (0 to <10 years), A1b (10 to <17 years), A2 (17 to 40 years), and A3 (>40 years), distinguishing disease above the distal ileum as L4a (proximal to ligament of Treitz) and L4b (ligament of Treitz to above distal ileum), allowing both stenosing and penetrating disease to be classified in the same patient (B2B3), denoting the presence of growth failure in the patient at any time as G(1) versus G(0) (never growth failure), adding E4 to denote extent of ulcerative colitis that is proximal to the hepatic flexure, and denoting ever severe ulcerative colitis during disease course by S1.

CONCLUSIONS

These modifications are termed the Paris Classification. By adhering to the Montreal framework, we have not jeopardized or altered the ability to use this classification for adult onset disease or by adult gastroenterologists.

Lysozyme expression in microscopic colitis

AIMS

To audit the cellular expression of the innate antibacterial enzyme lysozyme in colonic biopsies from a cohort of patients having microscopic colitis (MC-collagenous colitis (CC) or lymphocytic colitis (LC)). Results were compared with those recorded in patients with inflammatory bowel disease (IBD) of the colon (ulcerative colitis (UC) or Crohn's colitis).

METHODS

Fifty-five consecutive cases having biopsies from the left colon were investigated: 27 MC (14 CC and 13 LC) and 28 IBD (14 UC and 14 Crohn's colitis). Sections were stained with antilysozyme antibody. Twelve cases (3 CC, 3 LC, 3 UC and 3 Crohn's colitis) were challenged with the macrophage marker CD68 (clone PG-M1).

RESULTS

In MC, marked lysozyme expression in the colonic crypts was recorded in CC (p<0.05). The number of cases with metaplastic Paneth cells was higher in CC than in LC (p<0.05). In IBD, only active Crohn's colitis displayed marked lysozyme expression in the colonic crypts. Marked lysozyme immune-reactivity in subepithelial lamina propria mucosa (lpm) macrophages was found in LC (LC vs CC p<0.05).

CONCLUSIONS

The increased production of the antibacterial enzyme lysozyme in CC and LC supports a bacterial aetiology for these two diseases. Lysozyme upregulation in different cell types (epithelial vs macrophages) supports the notion that CC and LC might be two different maladies.