Frequency and significance of granulomas in a cohort of incident cases of Crohn's disease

A Combination of Pathological Features Identifies Crohn's Disease in Surgical Bowel Resection Specimens

BACKGROUND

Diagnosis of Crohn's disease is challenging. This study aims to compare the histological features of Crohn's disease and non-Crohn's disease (other intestinal inflammatory diseases) in surgical specimens to identify a set of histologic features distinguishing Crohn's disease from non-Crohn's disease.

METHODS

Patients with Crohn's disease (N = 171) and patients with non-Crohn's disease (N = 215) diagnosed between 2010 and 2015 who had surgical bowel resection were identified. The frequency of histological features in surgical resection specimens was compared between these two groups.

RESULTS

Univariate analysis revealed that transmural inflammation, subserosal lymphoid aggregates, fissures or sinus-like structures, granulomas or granuloma-like nodules, abnormalities of the enteric nervous system, and mucosa structure alterations (muscularis mucosa thickening or mucosal atrophy with pseudopyloric gland metaplasia) were more frequent in Crohn's disease than non-Crohn's disease cases (p < 0.001 for all). Some of the above histologic features were further grouped as chronic inflammatory change which includes granulomas or granuloma-like nodules, lymphoid aggregates in the muscularis propria or subserosa, fissures or sinus-like structures, and architectural abnormality which is defined as the presence of abnormal enteric nervous system and/or mucosa structural alterations (muscularis mucosa thickening or mucosal atrophy with pseudopyloric gland metaplasia). A combination of transmural inflammation, chronic inflammatory change, and architectural abnormality had a sensitivity of 92.4% and a specificity of 97.7% for Crohn's disease.

CONCLUSIONS

In surgical bowel resection specimens, a combination of transmural inflammation, chronic inflammatory change, and architectural abnormality help diagnose Crohn's disease.

Mucosal Architectural Change is an Important Feature in Distinguishing Crohn's Disease From Others in Terminal Ileum Ulcer Biopsy

BACKGROUND

Besides Crohn's disease (CD), there are a variety of other causes that can also lead to ulcerations in the terminal ileum. The purpose of this study was to identify useful diagnostic features for CD when evaluating terminal ileum biopsies in patients with endoscopic finding of ulcers.

METHODS

Five hundred and seventy-one patients with endoscopic finding of ulcers were included in this retrospective study. Five main histological features were analysed, which were crypt irregularity, mucosal thickening, villous stromal widening (including villous atrophy), granulomas, and pseudopyloric gland metaplasia. Clinical and pathological features were determined by uni- and multivariable logistic regression. Then another independent cohort of 99 patients was established for verifying this nomogram.

RESULTS

The crypt irregularity, mucosal thickening, and villous stromal widening were combined to be considered as one new variable named mucosal architectural change which was an independent variable in diagnosing CD. We found that mucosal architectural change, age <40 years, the presence of granulomas, and the presence of pseudopyloric gland metaplasia were independent factors for the pathological diagnosis of CD. Then nomogram was developed, with receiver operating characteristic (ROC) curve (area under the ROC curve [AUC] = 0.927) in training sets, and ROC curve (AUC = 0.913) in validation sets.

CONCLUSIONS

We found mucosal architectural change is very helpful in distinguishing CD from non-CD patients. In the context of small biopsy which may lack full scope of changes, the model developed by combining these key features is valuable in predicting a diagnosis of CD, especially in younger patients (age <40 years).

Single cell RNA-sequencing profiling to improve the translation between human IBD and in vivo models

Inflammatory bowel disease (IBD) is an umbrella term for two conditions (Crohn's Disease and Ulcerative Colitis) that is characterized by chronic inflammation of the gastrointestinal tract. The use of pre-clinical animal models has been invaluable for the understanding of potential disease mechanisms. However, despite promising results of numerous therapeutics in mouse colitis models, many of these therapies did not show clinical benefits in patients with IBD. Single cell RNA-sequencing (scRNA-seq) has recently revolutionized our understanding of complex interactions between the immune system, stromal cells, and epithelial cells by mapping novel cell subpopulations and their remodeling during disease. This technology has not been widely applied to pre-clinical models of IBD. ScRNA-seq profiling of murine models may provide an opportunity to increase the translatability into the clinic, and to choose the most appropriate model to test hypotheses and novel therapeutics. In this review, we have summarized some of the key findings at the single cell transcriptomic level in IBD, how specific signatures have been functionally validated in vivo, and highlighted the similarities and differences between scRNA-seq findings in human IBD and experimental mouse models. In each section of this review, we highlight the importance of utilizing this technology to find the most suitable or translational models of IBD based on the cellular therapeutic target.

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.

Exome Sequencing Implicates DGKZ , ESRRA , and GXYLT1 for Modulating Granuloma Formation in Crohn Disease

Non-caseating granulomas may indicate a more aggressive phenotype of Crohn disease (CD). Genetic associations of granulomatous CD (GCD) may help elucidate disease pathogenesis. Whole-exome sequencing was performed on peripheral blood-derived DNA from 17 pediatric patients with GCD and 19 with non-GCD (NGCD), and from an independent validation cohort of 44 GCD and 19 NGCD cases. PLINK (a tool set for whole-genome association and population-based linkage analyses) analysis was used to identify single nucleotide polymorphisms (SNPs) differentiating between groups, and subgroup allele frequencies were also compared to a public genomic database (gnomAD). The Combined Annotation Dependent Depletion scoring tool was used to predict deleteriousness of SNPs. Human leukocyte antigen (HLA) haplotype findings were compared to a control group (n = 8496). PLINK-based analysis between GCD and NGCD groups did not find consistently significant hits. gnomAD control comparisons, however, showed consistent subgroup associations with DGKZ , ESRRA , and GXYLT1 , genes that have been implicated in mammalian granulomatous inflammation. Our findings may guide future research and precision medicine.

PF-431396 hydrate inhibition of kinase phosphorylation during adherent-invasive Escherichia coli infection inhibits intra-macrophage replication and inflammatory cytokine release

Adherent-invasive Escherichia coli (AIEC) have been implicated in the aetiology of Crohn's disease (CD). They are characterized by an ability to adhere to and invade intestinal epithelial cells, and to replicate intracellularly in macrophages resulting in inflammation. Proline-rich tyrosine kinase 2 (PYK2) has previously been identified as a risk locus for inflammatory bowel disease and a regulator of intestinal inflammation. It is overexpressed in patients with colorectal cancer, a major long-term complication of CD. Here we show that Pyk2 levels are significantly increased during AIEC infection of murine macrophages while the inhibitor PF-431396 hydrate, which blocks Pyk2 activation, significantly decreased intramacrophage AIEC numbers. Imaging flow cytometry indicated that Pyk2 inhibition blocked intramacrophage replication of AIEC with no change in the overall number of infected cells, but a significant reduction in bacterial burden per cell. This reduction in intracellular bacteria resulted in a 20-fold decrease in tumour necrosis factor α secretion by cells post-AIEC infection. These data demonstrate a key role for Pyk2 in modulating AIEC intracellular replication and associated inflammation and may provide a new avenue for future therapeutic intervention in CD.

Macrophages in intestinal homeostasis and inflammatory bowel disease

Macrophages are essential for the maintenance of intestinal homeostasis, yet appear to be drivers of inflammation in the context of inflammatory bowel disease (IBD). How these peacekeepers become powerful aggressors in IBD is still unclear, but technological advances have revolutionized our understanding of many facets of their biology. In this Review, we discuss the progress made in understanding the heterogeneity of intestinal macrophages, the functions they perform in gut health and how the environment and origin can control the differentiation and longevity of these cells. We describe how these processes might change in the context of chronic inflammation and how aberrant macrophage behaviour contributes to IBD pathology, and discuss how therapeutic approaches might target dysregulated macrophages to dampen inflammation and promote mucosal healing. Finally, we set out key areas in the field of intestinal macrophage biology for which further investigation is warranted.

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.

Escherichia coli bacteria associated with Crohn's disease persist within phagolysosomes

Crohn's disease (CD) is characterized by an imbalance of intestinal microbiota and a colonization of subepithelial tissues by pathogen and pathobiont bacteria. Adherent invasive Escherichia coli (AIEC) strains recovered from CD lesions survive and multiply within macrophages. Persistence is one of the mechanisms deployed by AIEC to tolerate macrophages' attack. The challenging intracellular environment induces a heterogeneity in AIEC LF82 phenotype, including the presence of nongrowing bacteria. This could provide a reservoir for antibiotic-tolerant bacteria responsible for relapsing infections. In this article, we review the conditions leading to AIEC persistence, the relevance of this state for bacterial survival and disease's etiology, and its implication for therapeutic strategies.

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.

Composite outcomes in observational studies of Crohn's disease: a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aims to assess composite and aggregate outcomes of observational studies in Crohn's disease and to evaluate whether the number and type of variables included affect the frequency of the outcome.

METHODS

MEDLINE [via PubMed], Scopus and Web of Science were searched to identify observational studies that enrolled patients with Crohn's disease and evaluated a composite or aggregate outcome. The proportion of patients achieving the outcome was determined and a random-effects meta-analysis was performed to evaluate how the frequency of each outcome varies according to the reporting of predefined variables.

RESULTS

From 10,257 identified records, 46 were included in the qualitative analysis and 38 in the meta-analysis. The frequency for composite and aggregate outcomes was 0.445 [95% confidence interval (CI): 0.389-0.501] and 0.140 (95% CI: 0.000-0.211), respectively. When comparing composite outcomes by number of included variables, the frequency was 0.271 (95% CI: 0.000-0.405) and 0.698 (95% CI: 0.651-0.746), for one and six variables, respectively. The frequency of the composite outcome varied according to the identity of the variables being reported. Specific pairs of predefined variables had a significant effect in the frequency of composite outcomes.

CONCLUSION

Composite outcomes with increasing number of predefined variables show an increase in frequency. Outcomes including variables such as 'Surgery' and 'Steroids' had higher frequencies when compared with the ones that did not include these variables. These results show that the frequency of composite outcomes is dependent on the number and type of variables being reported.

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.

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.

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.

Episodic, severe abdominal pain due to isolated jejunal Crohn's disease

Small bowel Crohn's disease can present with episodic, relapsing, and remitting symptoms and delays in the diagnosis are common. We present a case of a young woman with three years of intermittent abdominal pain and nausea with negative previous evaluations. On presentation, inflammatory markers were elevated, and repeat imaging showed jejunal inflammation, with histopathological examination showing non-caseating granulomas of the small bowel consistent with Crohn's disease. This case highlights the importance of gastroenterologist recognizing the alarm signs in a patient with unexplained symptoms and adds to the literature on the clinical presentation of a rare diagnosis of isolated jejunal Crohn's disease.

Associations between the Presence of Granulomata and Disease Phenotype and Outcomes in Children Diagnosed with Crohn’s Disease

Background: The finding of a mucosal granuloma on histological analysis of endoscopically obtained biopsies in children with Crohn’s disease has been suggested to provide prognostic information. The aim of this study was to retrospectively assess the rate of granuloma detection and the impact of this upon specific disease characteristics and outcomes in children diagnosed with Crohn’s disease. After identification of a group of children previously diagnosed with Crohn’s disease, chart reviews were undertaken to characterise the children as granuloma positive or negative. Disease characteristics at diagnosis (such as disease location and nutritional status) and following diagnosis (such as requirement for immunosuppressive medications and surgical intervention) were noted for each patient. Results: Ninety-four children from two distinct geographical areas were identified. Forty-nine (52.1%) of the children had mucosal granulomata. Children with colonic disease were likely to have granulomata detected (RR = 3.04; p < 0.001). Granulomata were associated with lower weight z-scores at diagnosis (p < 0.05), but not other disease features (e.g., perianal disease or extra-intestinal manifestations). The presence of a granuloma at diagnosis was also associated with increased rates of the subsequent requirement for an immunosuppressive medication (RR = 1.26; p = 0.002). The presence of granulomata on histological assessment of mucosal biopsies at diagnosis of children with Crohn’s disease appears to be associated with specific disease features and outcomes. These findings should be clarified prospectively in a larger cohort of children with Crohn’s disease.

Clinical significance of granulomas in Crohn's disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Epithelioid granuloma is one hallmark used to histologically diagnose Crohn's disease (CD). However, the clinical significance of granulomas in CD is unclear. Therefore, we performed a meta-analysis to compare the clinical features with CD according to the presence of granulomas.

METHODS

A literature search in PubMed, EMBASE, and Cochrane databases was performed on manuscripts published until October 2018. We included studies that met the following inclusion criteria: (i) patient: patients with CD; (ii) exposure: granulomas on the pathology; (iii) comparator: no granulomas; and (iv) outcomes: disease location, disease behavior, perianal disease, disease activity, use of biologics, and CD-associated hospitalization, surgery.

RESULTS

Nineteen studies met our inclusion criteria. Granulomas in CD patients were associated with a higher proportion of ileocolonic disease (odds ratio [OR]: 1.49, 95% confidence interval [CI]: 1.21-1.83), a higher proportion of upper gastrointestinal disease (OR: 2.25, 95% CI: 1.28-3.95), a higher proportion of penetrating behavior (OR: 1.48, 95% CI: 1.09-2.01), a higher prevalence of perianal disease (OR: 2.15, 95% CI: 1.48-3.11), and a higher severity index at presentation (standardized mean difference: 0.20, 95% CI: 0.09-0.32). In addition, the use of biologics was significantly higher in CD patients with granulomas compared with without granulomas (OR: 1.66, 95% CI: 1.07-2.59). The presence of granulomas was significantly associated with CD-associated hospitalization (OR: 3.88, 95% CI: 1.44-10.49), but not with CD-associated surgery.

CONCLUSIONS

Clinical features in CD patients were significantly different according to the presence of granulomas. It may indicate a more aggressive phenotype of CD.

Differentiation of Crohn's disease and ulcerative colitis using intestinal wall thickness of the colon: A Diagnostic accuracy study of endoscopic ultrasonography

Background: The differentiation between Ulcerative Colitis (UC) and Crohn's Disease (CD) is an important issue for choosing the appropriate treatment. Endoscopic Ultrasonography (EUS) has been used to distinguish different layers of the gastrointestinal wall. We performed this study to evaluate the accuracy of EUS in differentiating colonic UC from CD compared to standard tests (colonoscopy, pathology, imaging, and clinical presentation). Methods: This is a prospective, single-blinded diagnostic accuracy study, on 70 patients (30 UC, 30 CD, and 10 healthy controls). After obtaining informed consent, patients underwent a complete workup and were referred to an endosonographist who was blind to the diagnosis. The thickness of mucosa, submucosa and the total wall (TWT) of mid-sigmoid colon were measured by Pentax radial echoendoscope EPKI-7000 with Avius Hitachi ultrasound system (Japan). Statistical analyses were performed using the SPSS statistical software (v23). Statistical significance was considered if P-values were less than 0.05. Results: Our study revealed a sensitivity of 100% (90.7-100%) and specificity of 90.9% (70.8-98.8%) for EUS to differentiate UC and CD compared to standard diagnostic tests. Mean mucosal thickness in patients with UC was significantly greater than patients with CD, while, the mean sub-mucosal thickness was significantly greater in patients with CD (p<0.001). The sensitivity and specificity of mean mucosal thickness for differentiating UC from CD and controls were 92.3% and 88.6% with a cut-off point of 1.1 mm (p<0.001). Moreover, sensitivity and specificity of mean submucosal thickness for differentiating CD from UC and controls were 100% and 86.1% with a cut-off point of 1.08 mm (p<0.001). Conclusion: EUS can be used as an efficient modality with acceptable accuracy to differentiate Crohn's disease and Ulcerative Colitis and to determine disease activity.

Crohn’s disease of esophagus, stomach and duodenum

Crohn’s disease with involvement of the esophagus, stomach and duodenum has a prevalence of 0.5% to 4% in symptomatic adult patients, but some studies have shown that these results may be underestimated, since upper gastrointestinal endoscopy is not performed routinely in the initial evaluation of the disease in adult patients, as it is in the pediatric population. In general, involvement of the upper gastrointestinal tract in Crohn’s disease occurs concomitantly with involvement of the lower gastrointestinal tract. The diagnosis depends on clinical, endoscopic, histological and radiological evaluation. The presence of aphthoid ulcers, longitudinal ulcers, bamboo-joint-like appearance, stenoses and fistulas are endoscopic findings suggestive of the disease, and it is important to exclude the presence of Helicobacter pylori infection. The primary histological findings, which facilitate the diagnosis, are the presence of a chronic inflammatory process with a predominance of lymphoplasmacytic cells and active focal gastritis. The presence of epithelioid granuloma, although less frequent, is highly suggestive of the disease in the absence of chronic granulomatous disease. Treatment should include the use of proton pump inhibitors associated with corticosteroids, immunomodulators and biological therapy according to the severity of the disease.

Mesenteric Lymphatic Vessel Density Is Associated with Disease Behavior and Postoperative Recurrence in Crohn's Disease

PURPOSE

The aims of the present study were to examine the density of lymphatic vessels in the mesentery and to assess the predictive value of the mesenteric lymphatic vessel density for postoperative clinical recurrence.

METHODS

Ileocolonic resection specimens were obtained from 53 patients with Crohn's disease and 10 non-inflammatory bowel disease control subjects. Mesentery adipose tissues adjacent to the bowel wall were used for the histological quantification of lymphatic vessels using immunohistochemistry with the D2-40 antibody. The relationships between lymphatic vessel density and disease behavior, the presence of granulomas, the presence of creeping fat, and postoperative clinical recurrence were assessed.

RESULTS

Median lymphatic vessel density in the mesentery adjacent to inflamed or non-inflamed intestine was lower in control subjects than in Crohn's disease patients (2.13‰; interquartile range [IQR], 1.83-2.61; 8.34‰; IQR, 6.39-10.22; 4.43‰; IQR, 3.32-5.78; P ˂ 0.001). Increased mesenteric lymphatic vessel density was significantly associated with stricturing behavior, the presence of intestinal granulomas, the presence of creeping fat, and bowel thickness. Interestingly, patients with disease recurrence had an increased mesenteric lymphatic vessel density of the proximal mesenteric margin at the time of resection compared with those who did not have disease recurrence (6.23‰; IQR, 5.43-6.75 vs. 3.28‰; IQR, 2.93-4.29; P ˂ 0.001).

CONCLUSIONS

In addition to its correlation with disease behavior, bowel thickness, and the presence of intestinal granulomas and creeping fat, increased mesenteric lymphatic vessel density in the proximal margin is predictive of early clinical recurrence after surgery in patients with Crohn's disease.

Viewpoint: Toward the Genetic Architecture of Disease Severity in Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is characterized by uneven disease courses with various clinical outcomes. A few prognostic markers of disease severity may help stratify patients and identify those who will benefit the most from early aggressive treatment. The concept of disease severity remains too broad and vague, mainly because the definition must embrace several disease mechanisms, mainly inflammation and fibrosis, with various rates of disease progression. The magnitude of inflammation is an obvious key driver of disease severity in IBD that ultimately influence disease behavior. Advances in the genetics underlying disease severity are currently emerging, but attempts to overlap the genetics of disease susceptibility and severity have until now been unsatisfactory, suggesting that the genetic architecture of disease severity may be distinct from the genetics of disease susceptibility. In this review, we report on the current knowledge on disease severity and on the main research venues to decipher the genetic architecture of disease severity.

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.

Prognostic significance of granulomas in children with Crohn's disease

OBJECTIVES

Granulomas have long been considered the histological hallmark of Crohn's disease (CD). Currently, there is considerable dispute with regards to their prognostic implications. We aimed to determine the effect of granulomas on phenotypic features and disease's long-term outcomes in a large cohort of pediatric CD patients.

MATERIALS AND METHODS

Medical records of pediatric CD patients diagnosed at the Schneider Children's Medical Center were reviewed retrospectively. Patients were categorized into two groups based on the presence or absence of granulomas at diagnosis. Baseline characteristics included anthropometric, clinical, laboratory, radiological and endoscopic data. Outcome measures included flares, hospitalizations, biological therapy and surgery.

RESULTS

Of 289 CD patients diagnosed between 2001 and 2015, 99 patients (34%) had granulomas. Median age of the entire cohort at diagnosis was 14.2 years (females, 42.6%), with a median follow-up of 8.5 years. Patients with granulomas had a significantly higher percentage (47.5% vs. 23.7%, p = .001) of upper gastrointestinal involvement and ileo-colonic disease (64.9% vs. 49.5%, p = .01). Extraintestinal manifestations were twice as common in patients without granulomas (16.3% vs. 8.1%, p = .05). Patients with granulomas were more likely to be hospitalized (HR =1.43, 95% CI: 1.0-2.0) and to receive biologic therapy (HR = 1.52, 95% CI: 1.1-2.11). Additionally, both of these disease outcomes occurred significantly earlier (p = .013 and p = .027, respectively). In contrast, patients with granulomas did not exhibit increased risk of flares or bowel resection.

CONCLUSION

Patients with granulomas exhibited a distinct phenotype at diagnosis and demonstrated a more severe disease course.

Perianal Pediatric Crohn Disease Is Associated With a Distinct Phenotype and Greater Inflammatory Burden

OBJECTIVES

Data on the outcomes of children with perianal Crohn disease (pCD) are limited, although its presence is often used for justifying early use of biologics. We aimed to assess whether pCD in children is associated with more severe outcomes as found in adults.

METHODS

Data were extracted from the ImageKids database, a prospective, multicenter, longitudinal cohort study. The study enrolled 246 children at disease onset or thereafter. All patients underwent comprehensive clinical, endoscopic, and radiologic evaluation at enrollment; 98 children had repeat evaluation at 18 months.

RESULTS

Of the 234 included patients (mean age 14.2 ± 2.4 years; 131 [56%] boys), 57 (24%) had perianal findings, whereas only 21 (9%) had fistulizing perianal disease. Children with pCD had reduced weight and height z scores compared with non-pCD patients (-0.9 vs -0.35, P = 0.03 and -0.68 vs -0.23, respectively; P = 0.04), higher weighted pediatric CD activity index (32 [interquartile range 16-50] vs 20 [8-37]; P = 0.004), lower serum albumin (3.6 ± 0.7 vs 4.5 ± 0.8, P = 0.016), and higher magnetic resonance enterography global inflammatory score (P = 0.04). Children with pCD had more rectal (57% vs 38%, P = 0.04), and jejunal involvement (31% vs 11% P = 0.003) and a higher prevalence of granulomas (64% vs 23%, P = 0.0001). Magnetic resonance enterography-based damage scores did not differ between groups. Patients with skin tags/fissures only, had similar clinical, endoscopic, and radiologic characteristics as patients with no perianal findings.

CONCLUSIONS

Pediatric patients with pCD with fistulizing disease have distinct phenotypic features and a predisposition to a greater inflammatory burden.

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.

Association of granulomas in mesenteric lymph nodes in Crohn's disease with younger age and transmural inflammation

BACKGROUND AND AIMS

Mesenteric lymph nodes were usually removed during bowel resection surgery for Crohn's disease (CD). Mesenteric lymph node (MLN) granuloma predicted postoperative disease recurrence in patients with CD after ileocolic resection (ICR). This study was aimed to identify factors associated with MLN granulomas in a cohort of CD patients who underwent ICR.

METHODS

The study group consisted of 18 patients with CD who underwent the index ICR between 2004 and 2012 and had MLN granulomas. The control group included 32 cases negative for MLN granulomas, which were randomly selected from the same period. Clinicodemographic and histological features were compared in these two groups.

RESULTS

The presence of MLN granuloma was associated with younger age, perianal disease, and ileocolic disease. Gender, body mass index, smoking status, disease duration, extraintestinal manifestation, length of bowel resected, total number of nodes examined, medical treatment, and indications for surgery were not significantly different between the groups. The presence of MLN granuloma was associated with mural granuloma, transmural inflammation, mural abscess, hypertrophy of the muscularis propria, fibrosis of the muscularis propria, and serosal fibrosis in the small bowel. The multivariable analysis confirms that MLN granuloma was associated with age and transmural inflammation.

CONCLUSIONS

In CD patients who underwent the index ICR, the presence of MLN granuloma was associated with younger age and transmural inflammation. Our current results suggest that the detection of MLN granulomas may be enhanced in patients at higher risk, that is, younger patients or those with transmural inflammation on imaging or histopathology.

NF-kappa B activation correlates with disease phenotype in Crohn's disease

Background/Aims

Unregulated activation of nuclear factor-κB (NF-κB) plays a critical role in the pathogenesis of Crohn’s disease. In this study, we investigated the clinical characteristics and disease outcome of Crohn’s disease patients with varying levels of the NF-κB activation.

Methods

Crohn’s disease patients who underwent surgical bowel resection were divided into two groups, based on the activation status of NF-κB. NF-κB activation was assessed by the immunoreactivity of nuclear NF-κB during immunohistochemical staining of bowel resection specimens. We compared the demographic, clinical and histologic characteristics between groups. Furthermore, the occurrence of reoperation, readmission, and medication change due to disease flare-up were investigated according to NF-κB activation status.

Results

Among 83 Crohn’s disease patients, 47 (56%) showed high NF-κB activity and 36 (44%) showed low NF-κB activity. Patients with high NF-κB activity had higher frequency of ileocolonic involvement (P = 0.028) and lower frequency of perianal involvement (P = 0.042) relative to those with low NF-κB activity. Total histologic scores were significantly higher in patients with high NF-κB activity than those with low NF-κB activity (P = 0.044). There was no significant difference in the frequency of reoperation, readmission, and medication change in relation to NF-κB activation status.

Conclusions

Crohn’s disease patients with high NF-κB activation showed specific clinical manifestations of higher frequency of ileocolonic involvement and lower frequency of perianal involvement relative to those with low NF-κB activation. High NF-κB activity was associated with higher histologic scores. However, the NF-κB activity did not affect the outcome and disease course after surgery.

Crohn Disease: Epidemiology, Diagnosis, and Management

Crohn disease is a chronic idiopathic inflammatory bowel disease condition characterized by skip lesions and transmural inflammation that can affect the entire gastrointestinal tract from the mouth to the anus. For this review article, we performed a review of articles in PubMed through February 1, 2017, by using the following Medical Subject Heading terms: crohns disease, crohn's disease, crohn disease, inflammatory bowel disease, and inflammatory bowel diseases. Presenting symptoms are often variable and may include diarrhea, abdominal pain, weight loss, nausea, vomiting, and in certain cases fevers or chills. There are 3 main disease phenotypes: inflammatory, structuring, and penetrating. In addition to the underlying disease phenotype, up to a third of patients will develop perianal involvement of their disease. In addition, in some cases, extraintestinal manifestations may develop. The diagnosis is typically made with endoscopic and/or radiologic findings. Disease management is usually with pharmacologic therapy, which is determined on the basis of disease severity and underlying disease phenotype. Although the goal of management is to control the inflammation and induce a clinical remission with pharmacologic therapy, most patients will eventually require surgery for their disease. Unfortunately, surgery is not curative and patients still require ongoing therapy even after surgery for disease recurrence. Importantly, given the risks of complications from both Crohn disease and the medications used to treat the disease process, primary care physicians play an important role in optimizing the preventative care management to reduce the risk of complications.

Crohn's disease for the general physician: presentation and investigations

Crohn's disease presents to general physicians in a variety of ways. This article outlines the clinical features and initial investigation of suspected Crohn's disease. The accompanying article reviews treatment strategies.

Identification of the distinguishing features of Crohn's disease and ischemic colitis using computed tomographic enterography

Background and aims: The differential diagnosis between Crohn’s disease (CD) and ischemic colitis (ISC) is important as their clinical management is different. ISC can easily be misdiagnosed as CD, especially in elderly populations. The distinctive radiographic features of the two disease entities have not been investigated. The aim of this study is to assess the utility of computed tomographic enterography (CTE) in the differential diagnosis between CD and ISC.

Methods: Patients with confirmed CD and ISC were identified through an electronic medical record search of the Cleveland Clinic Foundation. Patients who had undergone CTE, with or without concurrent colonoscopy and histopathological specimens, were included in this study. CTE images were blindly re-reviewed by an expert gastrointestinal radiologist. The sensitivities, specificities, accuracies and positive and negative predictive values for each of the CTE findings in differentiating CD from ISC were estimated. Kappa coefficients (κ) were calculated to measure diagnosis agreement between CTE and the reference standard.

Results: A total of 34 eligible patients were included in this study with 17 having CD and 17 having ISC. In differentiating CD from ISC, the presence of mucosal hyperenhancement and absence of the “target sign” on CTE showed a sensitivity of 100% each for CD, while the two radiographic features yielded a low specificity of 35.3% and 76.5%, respectively. The presence of stricture had a lower sensitivity of 64.7% for the detection of CD but had a high specificity of 100%. In distinguishing CD from ISC, the accuracy of presence of mucosal hyperenhancement, stricture and absence of target sign were 67.7%, 82.4% and 88.2%, respectively. The combination of the presence of mucosal hyperenhancement and the absence of the target sign achieved an accuracy of 100% for distinguishing CD from ISC. There was a good correlation between CTE and the reference standard for distinguishing CD from ISC (κ = 0.882).

Conclusions: CTE appeared to be clinically useful in distinguishing CD from ISC.

Immunopathogenesis of granulomas in chronic autoinflammatory diseases

Granulomas are clusters of immune cells. These structures can be formed in reaction to infection and display signs of necrosis, such as in tuberculosis. Alternatively, in several immune disorders, such as sarcoidosis, Crohn's disease and common variable immunodeficiency, non-caseating granulomas are formed without an obvious infectious trigger. Despite advances in our understanding of the human immune system, the pathogenesis underlying these non-caseating granulomas in chronic inflammatory diseases is still poorly understood. Here, we review the current knowledge about the immunopathogenesis of granulomas, and we discuss how the involved immune cells can be targeted with novel therapeutics.

Gastroduodenal Involvement in Asymptomatic Crohn's Disease Patients in Two Areas of Emerging Disease: Asia and Eastern Europe

BACKGROUND

The incidence of Crohn's disease [CD] is increasing in Asia and Eastern Europe. Limited studies have reported on the frequency of upper gastrointestinal [GI] involvement in patients with CD in non-Western countries. This prospective study compared the rate of macroscopic and microscopic upper GI manifestations and Helicobacter pylori positivity in asymptomatic CD patients in Asia and Eastern Europe.

METHODS

Consecutive asymptomatic CD patients were prospectively recruited for upper GI endoscopy between 2013 and 2015 in Hong Kong and in Hungary. Endoscopy and biopsy findings were recorded and histology was performed to assess for H. pylori and microscopic signs characteristic for CD, using standardized diagnostic criteria.

RESULTS

One hundred and eighty CD patients [100 Hong Kong; 80 Hungary; 70.6% male; mean age, 38.5 years] and 189 controls [100 Hong Kong; 89 Hungary; 57.7% male; mean age 41 years] were included. Gastroduodenal involvement of CD was significantly higher in Hungary than in Hong Kong [16.5% vs 2.0%, p ≤ 0.001]. H. pylori positivity was significantly higher in Hungarian than Chinese CD patients [13.9% vs 4.0%, p ≤ 0.001]. Granulomas were detected in 1% in Hong Kong and 7.6% in Hungary [p ≤ 0.001]. Chinese CD subjects had a significantly lower H. pylori positivity compared with controls [6% vs. 15%; p ≤ 0.001].

CONCLUSIONS

Upper GI CD was significantly higher in Eastern Europe than in Asia. The detection of granuloma in Hungary was similar to the literature data, whereas focal gastritis was lower than expected in both cohorts.

Macrophages Versus Escherichia coli: A Decisive Fight in Crohn's Disease

The pathophysiology of Crohn's disease (CD), a chronic inflammatory bowel disease, remains imperfectly elucidated. Consequently, the therapeutic armamentarium remains limited and has not changed the natural history of CD hitherto. Accordingly, physicians need to identify new therapeutic targets to be able to alter the intestinal damage. The most recent hypothesis considered CD as resulting from an abnormal interaction between microbiota and host immune system influenced by genetics and environmental factors. Several experimental and genetic evidence point out intestinal macrophages in CD etiology. An increase of macrophages number and the presence of granulomas are especially observed in the intestinal mucosa of patients with CD. These macrophages could be defective and particularly in responses to infectious agents like CD-associated Escherichia coli. This review focuses on, what is currently known regarding the role of macrophages, macrophages/E. coli interaction, and the impact of CD therapies on macrophages in CD. We also speculate that macrophages modulation could lead to important translational implications in CD with the end goal of promoting gut health.

B-Cell Dysregulation in Crohn's Disease Is Partially Restored with Infliximab Therapy

BACKGROUND

B-cell depletion can improve a variety of chronic inflammatory diseases, but does not appear beneficial for patients with Crohn's disease.

OBJECTIVE

To elucidate the involvement of B cells in Crohn's disease, we here performed an 'in depth' analysis of intestinal and blood B-cells in this chronic inflammatory disease.

METHODS

Patients with Crohn's disease were recruited to study B-cell infiltrates in intestinal biopsies (n = 5), serum immunoglobulin levels and the phenotype and molecular characteristics of blood B-cell subsets (n = 21). The effects of infliximab treatment were studied in 9 patients.

RESULTS

Granulomatous tissue showed infiltrates of B lymphocytes rather than Ig-secreting plasma cells. Circulating transitional B cells and CD21low B cells were elevated. IgM memory B cells were reduced and natural effector cells showed decreased replication histories and somatic hypermutation (SHM) levels. In contrast, IgG and IgA memory B cells were normally present and their Ig gene transcripts carried increased SHM levels. The numbers of transitional and natural effector cells were normal in patients who responded clinically well to infliximab.

CONCLUSIONS

B cells in patients with Crohn's disease showed signs of chronic stimulation with localization to granulomatous tissue and increased molecular maturation of IgA and IgG. Therapy with TNFα-blockers restored the defect in IgM memory B-cell generation and normalized transitional B-cell levels, making these subsets candidate markers for treatment monitoring. Together, these results suggest a chronic, aberrant B-cell response in patients with Crohn's disease, which could be targeted with new therapeutics that specifically regulate B-cell function.

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.

Association of TNFSF15 polymorphisms in Korean children with Crohn's disease

BACKGROUND

Genome-wide association studies have identified tumor necrosis factor superfamily member 15 (TNFSF15) as a Crohn's disease (CD)-related gene. The aim of this study was to evaluate the association between five TNFSF15 polymorphisms and CD in Korean children and analyze their genotypes in relation to phenotype.

METHODS

Five single-nucleotide polymorphisms of TNFSF15 (rs3810936, rs6478108, rs6478109, rs7848647, rs7865494) were genotyped in 108 CD patients and in 599 healthy controls. Risk allele, genotype, and haplotype were analyzed in CD patients and controls, and genotype-phenotype relationships were studied.

RESULTS

There were significant associations of rs3810936, rs6478108, rs6478109, rs7848647 with CD in Korean pediatric patients (P = 6.5×10(-8), P = 1.3×10(-8), P = 3.7×10(-8), P = 2.9×10(-8), respectively). The adjusted OR (aOR) for the homozygous risk allele genotype was significantly higher than that for the homozygous genotype for the opposite allele: rs3810936, aOR, 5.36 (95%CI: 2.61-10.98, P = 4.6×10(-6)); rs6478108, aOR, 6.62 (95%CI: 3.03-14.46, P = 2.2×10(-6)); rs6478109, aOR, 6.24 (95%CI: 2.85-13.66, P = 4.6×10(-6)); rs7848647, aOR, 6.32 (95%CI: 2.89-13.81, P = 3.8×10(-6)). The risk allele of rs3810936 was associated with later symptom onset, later diagnosis, and the presence of perianal lesion (P = 0.013, P = 0.016 and P = 0.029).

CONCLUSION

There was a significant association of TNFSF15 with pediatric CD in Korean patients.

Presence of Granulomas in Mesenteric Lymph Nodes Is Associated with Postoperative Recurrence in Crohn's Disease

BACKGROUND

The association between the presence of granulomas in the mesenteric lymph node (MLN) and postoperative recurrent Crohn's disease (CD) is unknown. Our aim was to assess the predictive value of the presence of granulomas in MLN as well as in bowel wall for postoperative recurrence of CD.

METHODS

Patients with CD who underwent the index ileocolonic resection between 2004 and 2012 were included. Surgical pathology reports were reviewed for the presence and location of granulomas. The status of MLN granulomas was confirmed by re-review of surgical pathology specimen from randomly sampled patients by an expert pathologist. Both univariable and multivariable analyses were performed to assess the risk factors associated with postoperative recurrent CD.

RESULTS

A total of 194 patients were included. Granulomas were detected in the MLN in 23 patients (11.9%), and in the intestinal wall in 57 (29.4%). On Kaplan-Meier curve, the presence of granulomas in MLN was found to be a risk factor for postoperative endoscopic recurrence (P = 0.015) as well as surgical recurrence (P = 0.035). In contrast, granulomas in the bowel wall, which was not found to be associated with neither endoscopic recurrence (P = 0.94) or surgical recurrence (P = 0.56). On Cox proportional hazards regression analysis, the presence of MLN granulomas was independently associated with an increased risk for both postoperative endoscopic recurrence (hazard ratio [HR] = 1.91; 95% confidence interval [CI], 1.06-3.45; P = 0.031) and surgical recurrence (HR = 3.43; 95% CI, 1.18-9.99; P = 0.023).

CONCLUSIONS

The presence of granulomas in MLN but not in intestine per se was found to be an independent risk factor for recurrence in CD patients undergoing ileocolonic resection.

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.

Histologic features predicting postoperative Crohn's disease recurrence

Recurrence of Crohn's disease (CD) after ileal or colonic resection is common. Many studies have tried to identify predictors of postoperative recurrence (POR) in CD. A wide range of histologic features have been identified, but for most of them, the literature provided conflicting data. In last years, several studies have suggested that histologic findings including inflammatory changes within the enteric nervous system of the resection margin may be associated with CD recurrence. Herein, after briefly summarizing pathophysiology of POR, we review all histological features that have been studied so far: granulomas, histologic appearance at the margin of resection, plexitis, lymphatic vessel density in proximal margin of resection, and morphological analysis of Paneth cells. Granulomas and chronic inflammation at the margin of resection do not seem to predict POR in CD. Active disease at the margin of resection, plexitis, lymphatic vessels density, morphological analysis of Paneth cells may predict POR. Most of these histological features await replication in independent studies. Available evidence indicates that histological findings may be taken into account when developing strategies aimed at preventing postoperative CD recurrence.

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.

Pediatric Crohn's disease from onset to adulthood: granulomas are associated with an early need for immunomodulation

OBJECTIVE

Childhood onset Crohn's disease (CD) is considered more aggressive than adult onset disease. Epithelioid cell granulomas in intestinal biopsies are one, non-obligate, criterion of CD. We investigated granulomas as markers of CD severity in children followed to adulthood.

MATERIAL AND METHODS

Forty-five individuals with childhood onset CD were studied from diagnosis until attainment of final height, with data on disease location, medical and surgical management and with detailed growth data analyses. A blinded review of diagnostic biopsies was also performed.

RESULTS

We found granulomas in 22/45 (49%) children at diagnosis, altogether in 28/45 (62%) patients during the disease course (median overall follow-up - 12.3 years, range 9.3-18). Granulomas were found in 9/11 (82%) with upper gastrointestinal involvement (cumulatively 17/20, 85%) (p = 0.017 and p = 0.006, respectively). The time from diagnosis to initiating immune modulating treatment (median 4.5 months, range 0-75) was shorter in the granuloma-positive group (16/22) compared to the granuloma-negative group (18/23) (median 33 months, range 2-105; p = 0.01). The median standard deviation score height at diagnosis and final adult height (both adjusted for target height) did not correlate to findings of granulomas.

CONCLUSIONS

Epithelioid cell granulomas were associated with a shorter time to initiating immune modulating drugs, as a possible sign of more severe disease, but growth was not affected.

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.