Primary Colonic Eosinophilia and Eosinophilic Colitis in Adults

Redefining Histological Cell Counts Using a Standardized Method: The Leuven Intestinal Counting Protocol

INTRODUCTION

The diagnosis of eosinophilic gastrointestinal diseases is largely based on mucosal eosinophil counts, but thresholds and normal ranges beyond the esophagus are debated, calling for much-needed methodological standardization. We aimed to develop a standardized workflow for duodenal cell quantification and estimate duodenal eosinophil and mast cell numbers in healthy controls.

METHODS

Software-based histological cell quantification using free-sized or fixed-sized regions was developed and applied to digitized hematoxylin and eosin (H&E)-stained slides from 58 individuals (healthy controls [HCs] and patients with functional dyspepsia). Intraclass correlation coefficients (ICCs) compared inter-rater reliability between software-based and microscopic quantification. Reproducibility of the software-based method was validated in an independent cohort of 37 control and functional dyspepsia subjects. Eosinophil identification on H&E staining was compared to immunohistochemistry (IHC). Normal eosinophil (H&E) and mast cell (cKit) ranges were determined in 70 adult HCs.

RESULTS

Eosinophil quantification on digitized slides demonstrated excellent (ICC = 0.909) and significantly improved reproducibility over microscopic evaluation (ICC = 0.796, P = 0.0014), validated in an independent cohort (ICC = 0.910). Duodenal eosinophils were more abundant around crypts than in villi ( P < 0.0001), while counts were similar on matched H&E- and IHC-stained slides ( P = 0.55). Mean ± SD (95th percentile) duodenal eosinophils and mast cells in HC were 228.8/mm 2 ± 94.7 (402.8/mm 2 ) and 419.5/mm 2 ± 132.2 (707.6/mm 2 ), respectively.

DISCUSSION

We developed and validated a standardized approach to duodenal histological cell quantification, generalizable to various mucosal cell types. Implementation of software-based quantification identified 400 eosinophils/mm 2 and 700 mast cells/mm 2 as thresholds for abnormal duodenal infiltration.

Eosinophilic gastroenteritis in an elderly men associated with antibiotic use post maxillofacial space infection: a case report

A 79-year-old man underwent operative drainage and 2-week cephalosporin treatment due to a maxillofacial space infection (bilateral submaxillaris, submentum, and left face). However, he experienced anorexia, nausea, vomiting, and emaciation in the following 2 months. It was initially considered that a malignancy might be present, thus a series of examinations were performed. Laboratory investigations showed increases in inflammatory markers and a significant eosinophilia, which seemed to be a hematological system disease. Combined with the gastrointestinal endoscopes and histology examination, the patient was diagnosed with eosinophilic gastroenteritis (EGE). After cessation of antibiotic treatment and administration of corticosteroid, our patient experienced a rapid progress in his clinical condition. Despite the low incidence, EGE should be considered in patients with unknown cause of gastrointestinal disorder, elevated eosinophilia, and so on.

The Natural History of Eosinophilic Gastrointestinal Diseases Is Influenced by Age of Onset and Location of Involvement

INTRODUCTION

It is unknown whether concomitant esophageal involvement or anatomic location of eosinophilic infiltration affects the natural history of eosinophilic gastrointestinal disease (EGID).

METHODS

A retrospective cohort study was performed using the University of North Carolina EGID Clinicopathologic Database. Patients were adults and children with a prior EGID diagnosis based on clinicopathologic features. Demographics, clinical characteristics, treatment information, and procedural data were extracted from medical records. Clinical course and flare history were characterized.

RESULTS

Among 97 patients, 43% had EGID + esophageal involvement and 57% had EGID only. Patients with esophageal involvement had a longer diagnostic delay preceding diagnosis (36.6 vs 11.6 months, P = 0.001), more dysphagia (50% vs 18%; P = 0.001), required more chronic therapy (77% vs 52%, P = 0.016), and exhibited more progressive disease (25% vs 6%, P = 0.027). A continuous disease course was most common in eosinophilic gastritis (78%) while patients with eosinophilic gastritis + eosinophilic enteritis (29%) and eosinophilic enteritis + eosinophilic colitis (50%) had the highest proportion of progressive and relapsing disease, respectively ( P = 0.045). A continuous disease course occurred more frequently in children (71%, P = 0.03) and those with single organ involvement (65%), whereas adults had more relapsing (39%) or progressive disease (18%).

DISCUSSION

EGIDs with and without esophageal involvement display many similarities, although patients with esophageal involvement more frequently had dysphagia, had progressive disease courses, and required more chronic therapy. Location of involvement and age of onset affected the natural history with higher proportions of relapsing or progressive disease seen in adults and patients with small bowel or multiorgan involvement while a continuous disease course was more common in children and patients with gastric-only involvement.

Histopathology of Eosinophilic Gastrointestinal Diseases Beyond Eosinophilic Esophagitis

Eosinophilic gastrointestinal diseases (EGID), such as eosinophilic gastritis (EoG), eosinophilic enteritis, and eosinophilic colitis (EoC), are chronic inflammatory conditions characterized by persistent gastrointestinal symptoms and elevated levels of activated eosinophils in the gastrointestinal tract. EoG and eosinophilic duodenitis (EoD) are strongly associated with food allergen triggers and TH2 inflammation, whereas EoC shows minimal transcriptomic overlap with other EGIDs. The level of expression of certain genes associated with TH2 immune response is associated with certain histopathologic findings of EoG, EoD, and EoC. Current immune therapy for EoG depletes tissue eosinophilia with persistence of other histopathologic features of disease.

Clinical Presentation of Patients with Eosinophilic Gastrointestinal Diseases beyond Eosinophilic Esophagitis

The clinical presentation of eosinophilic gastrointestinal diseases beyond eosinophilic esophagitis (non-EoE EGIDs) varies depending on the gastrointestinal segments affected by the eosinophilic inflammation, the extent of eosinophilic inflammation within the gastrointestinal tract and its depth through the bowel wall. Non-EoE EGIDs with mucosal involvement tend to present with diarrhea, malabsorption, and sometimes bleeding, those with muscular involvement may present with symptoms of obstruction or pseudo-obstruction, intussusception, and even perforation, whereas those with serosal involvement may present with eosinophilic ascites. Here we describe the differences in symptoms experienced by children with non-EoE EGIDs with varying degrees of eosinophilic inflammation through the bowel wall.

The Dual Lens of Endoscopy and Histology in the Diagnosis and Management of Eosinophilic Gastrointestinal Disorders-A Comprehensive Review

Eosinophilic Gastrointestinal Disorders (EGIDs) are a group of conditions characterized by abnormal eosinophil accumulation in the gastrointestinal tract. Among these EGIDs, Eosinophilic Esophagitis (EoE) is the most well documented, while less is known about Eosinophilic Gastritis (EoG), Eosinophilic Enteritis (EoN), and Eosinophilic Colitis (EoC). The role of endoscopy in EGIDs is pivotal, with applications in diagnosis, disease monitoring, and therapeutic intervention. In EoE, the endoscopic reference score (EREFS) has been shown to be accurate in raising diagnostic suspicion and effective in monitoring therapeutic responses. Additionally, endoscopic dilation is the first-line treatment for esophageal strictures. For EoG and EoN, while the literature is more limited, common endoscopic findings include erythema, nodules, and ulcerations. Histology remains the gold standard for diagnosing EGIDs, as it quantifies eosinophilic infiltration. In recent years, there have been significant advancements in the histological understanding of EoE, leading to the development of diagnostic scores and the identification of specific microscopic features associated with the disease. However, for EoG, EoN, and EoC, precise eosinophil count thresholds for diagnosis have not yet been established. This review aims to elucidate the role of endoscopy and histology in the diagnosis and management of the three main EGIDs and to analyze their strengths and limitations, their interconnection, and future research directions.

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.

Eosinophilic enterocolitis: a case report

BACKGROUND

Eosinophilic enterocolitis is a rare disorder characterized by abnormal eosinophilic infiltration of the small intestine and the colon.

CASE PRESENTATION

We report a case of a 29-year-old White man, who presented with an acute bowel obstruction. He had a history of a 2 months non-bloody diarrhea. An abdominal computed tomography (CT) and a MR enterography showed a multifocal extensive ileitis. White blood cell and eosinophilic polynuclei count was elevated (700/mm3). Ileo-colonoscopy showed normal ileum and segmental petechial colitis. Pathology showed a high eosinophilic infiltration in the colon. The patient was treated with steroids, with a clinical, biological and radiological recovery.

CONCLUSION

Eosinophilic enterocolitis should be kept in mind as a rare differential diagnosis in patients presenting with small bowel obstruction.

Eosinophilic Gastroenteritis: Still a Diagnostic Challenge

Introduction

Eosinophilic gastroenteritis (EoG) is a rare condition with a yet poorly understood pathophysiology.

Case Presentation

We report on a case of a 36-year-old woman with a history of atopy presenting with nausea, abdominal discomfort, weight loss, and ascites. Laboratorial analysis revealed peripheral eosinophilia and a slight elevation of inflammatory markers. The patient pursued medical assistance several times with a delay in the diagnosis. The pathway to the diagnosis of EoG with serosal infiltration and further management is presented.

Discussion

Despite being diagnosed by exclusion, it is important to suspect EoG with subserosa involvement in patients presenting with the uncommon association of peripheral eosinophilia and ascites, particularly if there is a history of atopy.

Current and Novel Therapies for Eosinophilic Gastrointestinal Diseases

Eosinophilic gastrointestinal diseases (EGIDs) are an emerging group of pathological entities characterized by an eosinophil-predominant infiltration of different tracts of the gut in the absence of secondary causes of eosinophilia. According to the specific tract of the gut involved, EGIDs can be classified into eosinophilic esophagitis (EoE), eosinophilic gastritis (EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC). The epidemiology of EGIDs is evolving rapidly. EoE, once considered a rare disease, now has an incidence and prevalence of 7.7 new cases per 100,000 inhabitants per years and 34.4 cases per 100,000 inhabitants per year, respectively. Fewer data are available regarding non-EoE EGIDs, whose prevalence are estimated to range between 2.1 and 17.6 in 100,000 individuals, depending on age, sex, and ethnicity. Diagnosis requires the presence of suggestive symptoms, endoscopic biopsies showing abnormal values of eosinophils infiltrating the gut, and exclusion of secondary causes of eosinophilia. EoE typically presents with dysphagia and episodes of food bolus impactions, while EoG, EoN, and EoC may all present with abdominal pain and diarrhea, with or without other non-specific symptoms. In addition, although different EGIDs are currently classified as different entities, there may be overlap between different diseases in the same patient. Despite EGIDs being relatively novel pathological entities, the research on possible treatments is rapidly growing. In this regard, several randomized controlled trials are currently ongoing to investigate novel molecules, including ad-hoc steroid formulations, immunosuppressants, and mostly monoclonal antibodies that target the specific molecular mediators of EGIDs. This narrative review provides an up-to-date overview of available and investigational drugs for different EGIDs.

A Clinicopathologic Continuum of Eosinophilic Gastrointestinal Diseases in an Adult With Tuberculosis and Latent Hepatitis B Virus Infection

Eosinophilic gastroenteritis (EGE) is considered distinct from eosinophilic colitis (EC). A 59-year-old man presented with a colonic tumor, who had resolution of pain and diarrhea after surgery, then 7 months later developed proton-pump inhibitor-responsive dysphagia with esophagitis, and 9 months later presented again with pain and diarrhea where EGE with concurrent eosinophilic esophagitis was diagnosed. Review of the resected tumor specimen identified EC with an adenoma. Workup revealed tuberculosis and latent hepatitis B virus requiring treatment before commencing immunosuppressive therapy plus a 6-food elimination diet that led to complete resolution within 3 weeks. EC may precede EGE and eosinophilic esophagitis.

Increased mucosal eosinophils in colonic diverticulosis and diverticular disease

AIMS

Eosinophils contribute to tissue homeostasis, damage, and repair. The mucosa of colonic diverticula has not been evaluated for eosinophils by quantitative histology. We aimed to investigate whether mucosal eosinophils and other immune cells are increased in colonic diverticula.

METHODS

Hematoxylin and eosin stained sections from colonic surgical resections (n = 82) containing diverticula were examined. Eosinophils, neutrophils, and lymphocytes, in five high power fields in the lamina propria were counted at the base, neck, and ostia of the diverticulum and counts compared to non-diverticula mucosa. The cohort was further subgrouped by elective and emergency surgical indications.

RESULTS

Following an initial review of 10 surgical resections from patients with diverticulosis, a total of 82 patients with colonic resections containing diverticula from the descending colon were evaluated (median age 71.5, 42 M/40F). Eosinophil counts for the entire cohort were increased in the base and neck (median 99 and 42, both P = <0.001) compared with the control location (median 16). Eosinophil counts remained significantly increased in the diverticula base (both P = <0.001) and neck (P = 0.01 and <0.001, respectively) in both elective and emergency cases. Lymphocytes were also significantly increased at the diverticula base compared to controls in both elective and emergency subgroups.

CONCLUSION

Eosinophils are significantly and most strikingly increased within the diverticulum in resected colonic diverticula. While these observations are novel, the role of eosinophil and chronic inflammation is as yet unclear in the pathophysiology of colonic diverticulosis and diverticular disease.

A Marked Eosinophilic Infiltration in Mucosa Could Be a Better Predictive Factor for Intractable Non-Esophageal Eosinophilic Gastrointestinal Disorders

INTRODUCTION

Non-esophageal eosinophilic gastrointestinal disorders (non-EoE EGIDs) are rare, but their prevalence has recently increased. Although it has been reported that one-half of patients with non-EoE EGIDs have intractable clinical courses, their clinical features are not fully understood.

METHODS

This is a multicenter retrospective study in which 10 institutions in Japan participated. Clinical databases from January 1998 to December 2020 were reviewed to identify patients with non-EoE EGIDs. A total of 44 patients were identified; they were divided into two groups based on their clinical course: an intractable group and a non-intractable group. The clinical features were compared between the two groups by a logistic regression analysis. Remarkable eosinophilic infiltration (REI) was defined histologically when the maximal counts of mucosal eosinophils reached a threshold level in the respective area of biopsy.

RESULTS

Prevalence of drug allergy and eosinophil counts more than 500/μL (EOS), vomiting symptoms, abnormalities of the stomach, duodenum, and jejunum on computed tomography (upper gastrointestinal abnormality on computed tomography [UACT]), and REI were significantly different between the two groups. Among the factors that were potentially associated with an intractable clinical course, logistic regression revealed that REI, EOS, and UACT were significant factors. Based on an analysis of the area under the receiver operator characteristic curve, a combination of REI and EOS had the lowest Akaike's information criterion, indicating the best model to predict an intractable clinical course.

CONCLUSIONS

REI may predict an intractable course in patients with non-EoE EGIDs. In addition, the combination of REI and EOS was a better predictor than REI alone.

Number and distribution of eosinophils and lymphocytes in the Japanese pediatric gastrointestinal tract: in search of a definition for "abnormally increased eosinophils"

BACKGROUND

Primary eosinophilic gastrointestinal disorders (EGIDs) constitute chronic allergic inflammation. The number of eosinophils is one of the diagnostic criteria; more than 20 eosinophils per high-power field (HPF) in the gastrointestinal (GI) tract are considered abnormal in Japan. However, the quantity of eosinophils considered normal varies according to anatomical location and geographical region; such values have not been reported in Japanese pediatric patients, nor have the numbers of lymphocytes in the normal pediatric stomach. To establish a reference for defining diagnostic criteria for EGIDs, we evaluated the number of eosinophils in the normal Japanese pediatric GI tract.

METHODS

We examined 131 biopsy cases without significant clinical history, endoscopic abnormality, or histological abnormality. Immunohistochemical analysis of CD3 and CD20 was performed.

RESULTS

The mean eosinophil density was highest in the cecum (49.5 ± 22.4 per HPF). Counts of more than 20 eosinophils per HPF were observed in the duodenum [bulb (20.0 ± 9.6) and second portion (30.0 ± 15.8)], terminal ileum (38.3 ± 22.7), cecum (49.5 ± 22.4), ascending colon (42.3 ± 25.3), transverse colon (29.4 ± 17.0), and descending colon (32.2 ± 17.9). Counts of fewer than 10 eosinophils per HPF were observed in the stomach and rectum; a count of fewer than one eosinophil per HPF was observed in the esophagus. More than 100 CD3-positive T cells per HPF were observed in the stomach.

CONCLUSIONS

The mean numbers of eosinophils in the bowel were greater than 20 per HPF. For Japanese pediatrics, the current threshold eosinophil count should be revised.

Management of Adult Patients with Gastrointestinal Symptoms from Food Hypersensitivity-Narrative Review

The incidence of food hypersensitivity has increased dramatically over the years not only among children but also in adults. Adult patients are usually less suspected of food hypersensitivity symptoms since food allergies are more typical for small children, with a tendency to outgrow the condition. The aim of this article is to increase awareness of hypersensitivity to food symptoms and their diagnosis and treatment possibilities among gastroenterologists and other health care professionals dealing with this type of patient. Symptoms of many gastrointestinal disorders, especially functional, may be driven by different types of mechanisms, and food intolerance or allergy should be considered as a potential cause. This article presents the current understanding of the epidemiology, diagnosis and treatment of immune- and non-immune-mediated food-induced diseases. Diagnosis of food hypersensitivity is based mainly on medical history, different types of sensitivity tests, e.g., hydrogen breath test, specific IgE (sIgE) serum concentration, tissue eosinophil count, skin tests and oral food challenges considered as a "gold standard" for food allergy. Elimination diet and pharmacologic treatment for allergy symptoms are first-line therapies. Eosinophilic gastrointestinal diseases are often caused by non-IgE-mediated food allergies, require endoscopic biopsy samples to confirm diagnosis and proper elimination diet often combined with steroids or proton pump inhibitor agents for treatment. Mast cell activation syndrome (MCAS) derives from pathologic reaction of mast cells with increased tryptase serum level as a marker. Symptoms may occur in the digestive, respiratory, skin, neurologic and cardiovascular system. Treatment is based on histamine type 1, type 2 (H1, H2) receptor antagonists and other mast cell stabilizing agents. Carbohydrate intolerances are the most common type of food hypersensitivity in adult patients, and an elimination diet is effective for reducing symptoms. Food additives hypersensitivity remains difficult to diagnose, but use of a diet low in chemical substances alleviates symptoms and helps to diagnose the triggering factors.

The Clinical Significance of Eosinophils in Ulcerative Colitis: A Systematic Review

BACKGROUND AND AIMS

Ulcerative colitis [UC] is characterised by an unpredictable disease course and variable response to therapy. Recent studies suggest a role for eosinophils in both pathogenesis and predicting treatment response. The goal of this study was to determine the association between eosinophils and clinical outcomes in UC.

METHODS

A systematic review of the literature from database inception to May 2021 was performed to identify all studies evaluating the relationship between eosinophils and/or eosinophil-derived proteins [EDPs] and clinical outcomes, such as disease activity, clinical relapse, severity of disease, and response to treatment.

RESULTS

A total of 55 studies were identified. Of these, 34 studies evaluated the relationship between eosinophils in colonic tissue and outcomes and 15 in blood. Eighteen studies assessed the relationship between EDPs and outcomes. In 25 of 34 studies, a positive correlation between eosinophils and/or EDPs and disease activity was reported, three studies found a negative correlation, and nine studies found no correlation. Positive correlations between eosinophils and clinical relapse were shown in four of nine studies, and with disease outcome severity in five of seven studies. Four of 15 studies showed that subjects with higher eosinophil levels had a poor response to treatment.

CONCLUSIONS

These findings suggest that higher eosinophil levels may be associated with increased disease activity and poorer clinical outcomes and response to therapy. Future studies are needed to determine whether a distinct eosinophil-rich UC phenotype exists and whether eosinophil-targeted therapy can alter the disease course.

ECCO Position on Harmonisation of Crohn's Disease Mucosal Histopathology

In inflammatory bowel disease [IBD], mucosal healing is a major therapeutic target and a reliable predictor of clinical course. However, endoscopic mucosal healing is not synonymous with histological healing, and the additional benefits of including histological remission as a target are unclear. In Crohn´s disease [CD], there are few studies highlighting the value of histological remission as a therapeutic target. Histological activity can persist in CD patients who are in endoscopic remission, and the absence of histological activity may be associated with lower relapse rates. Therefore, standardisation of procedures to evaluate CD histological activity is desirable. Topics that would benefit from standardisation and harmonisation include biopsy procedures, biopsy processing techniques, the content of histological scores, and the definitions of histological remission, histological response, and histological activity. In line with these needs, the European Crohn's and Colitis Organisation [ECCO] assembled a consensus group with the objective of developing position statements on CD histology based on published evidence and expert consensus. There was agreement that definitions of histological remission should include absence of erosion, ulceration, and mucosal neutrophils; that the absence of neutrophilic inflammation is an appropriate histological target in CD; that CD histological scores, such as the Global Histological Disease Activity Score, lack formal validation; and that histological scoring systems for ulcerative colitis, including the Geboes Score, Robarts Histopathology Index, and Nancy Histological Index, can be used for scoring intestinal biopsies in CD patients.

Non-oesophageal eosinophilic gastrointestinal diseases are undersuspected clinically and underdiagnosed pathologically

BACKGROUND

Non-oesophageal gastrointestinal eosinophilic diseases (EGID) are considered rare. However, low disease awareness among clinicians and pathologists may contribute to underdiagnosis.

AIMS

To determine how frequently requests to evaluate for EGID accompany gastrointestinal biopsies and in what proportion of suspected cases pathologists address these requests, either confirming or refuting the clinical suspicion.

METHODS

All cases in which biopsy requisitions included an explicit suspicion of EGID were extracted from a large clinicopathologic database and manually reviewed for accuracy. The diagnoses for these cases were then analysed to determine whether clinical suspicions were confirmed, refuted or ignored.

RESULTS

Eosinophilic oesophagitis (EoE) was suspected in 12.8% of 903,516 patients with biopsies and confirmed in 14.9% of them. A suspicion of eosinophilic gastritis accompanied <0.001% of 1,438,206 gastric biopsy sets and was confirmed in 11.5% of them; eosinophilic duodenitis was suspected in 0.02% of ~675,519 patients with duodenal biopsies and confirmed in 8.0% of these; eosinophilic colitis was mentioned in <0.001% of 2,504,485 patients with colonic biopsies and confirmed in 0.1% of them. Less than 3% of endoscopists mentioned non-oesophageal EGID in the requisition, while most expressed a clinical suspicion of Barrett oesophagus, Helicobacter pylori gastritis, celiac disease and microscopic colitis (in 21.2%, 49.2%, 1% and 6.4% of the cases, respectively).

CONCLUSIONS

Gastroenterologists and pathologists commonly address and diagnose EoE. In contrast, both clinical suspicion and diagnosis of non-oesophageal EGID are extremely rare. Increased clinical awareness might result in a better understanding of the epidemiology and improved diagnosis of these still elusive conditions.

Evaluating Eosinophilic Colitis as a Unique Disease Using Colonic Molecular Profiles: A Multi-Site Study

BACKGROUND & AIMS

Colonic eosinophilia, an enigmatic finding often referred to as eosinophilic colitis (EoC), is a poorly understood condition. Whether EoC is a distinct disease or a colonic manifestation of eosinophilic gastrointestinal diseases (EGIDs) or inflammatory bowel disease (IBD) is undetermined.

METHODS

Subjects with EoC (n = 27) and controls (normal [NL, n = 20], Crohn's disease [CD, n = 14]) were enrolled across sites associated with the Consortium of Eosinophilic Gastrointestinal Disease Researchers. EoC was diagnosed as colonic eosinophilia (ascending ≥100, descending ≥85, sigmoid ≥65 eosinophils/high-power field) with related symptoms. Colon biopsies were subjected to RNA sequencing. Associations between gene expression and histologic features were analyzed with Spearman correlation; operational pathways and cellular constituents were computationally derived.

RESULTS

We identified 987 differentially expressed genes (EoC transcriptome) between EoC and NL (>1.5-fold change, P < .05). Colonic eosinophil count correlated with 31% of EoC transcriptome, most notably with CCL11 and CLC (r = 0.78 and 0.77, P < .0001). Among EoC and other EGIDs, there was minimal transcriptomic overlap and minimal evidence of a strong allergic type 2 immune response in EoC compared with other EGIDs. Decreased cell cycle and increased apoptosis in EoC compared with NL were identified by functional enrichment analysis and immunostaining using Ki-67 and cleaved caspase-3. Pericryptal circumferential eosinophil collars were associated with the EoC transcriptome (P < .001). EoC transcriptome-based scores were reversible with disease remission and differentiated EoC from IBD, even after controlling for colonic eosinophil levels (P < .0001).

CONCLUSIONS

We established EoC transcriptomic profiles, identified mechanistic pathways, and integrated findings with parallel IBD and EGID data. These findings establish EoC as a distinct disease compared with other EGIDs and IBD, thereby providing a basis for improving diagnosis and treatment.

Quantification of Mucosal Eosinophils for the Histopathologic Diagnosis of Eosinophilic Gastritis and Duodenitis: A Primer for Practicing Pathologists

Eosinophilic gastrointestinal diseases, specifically eosinophilic gastritis and duodenitis, are chronic inflammatory conditions characterized by persistent gastrointestinal (GI) symptoms and elevated levels of activated eosinophils in the GI tract. Both clinical and endoscopic findings are nonspecific, no clinical or histopathologic diagnostic guidelines are published, and disease awareness is low, both among clinicians and amongst pathologists, who tend to overlook mild or moderate increases in the density of eosinophils in GI biopsy specimens. Yet, evaluating and, at times, counting eosinophils in GI biopsies may have important clinical implications: the numbers of tissue eosinophils correlate with clinical manifestations, can be used as determinants of effective management, and are used to assess the effects of treatment. A most persuasive argument for providing a count rather than a value judgment is that patients read reports, understand numbers, and use them to help to understand the course of their disease. The objective of this primer is to provide pathologists with the tools to incorporate a quantitative assessment of eosinophilia in the diagnosis of gastric and duodenal biopsy specimens and to develop a systematic approach to their evaluation, counting, and reporting. To achieve this aim, we present our general approach to the biopsy (where to count), followed by details on the characteristics of a countable eosinophil (what to count), and provide with a set of suggestions on the counting methods (how to count). We conclude with suggestions on how to report GI tissue eosinophilia in a manner that alerts clinicians and prompts pertinent management steps.

Utilizing Deep Learning to Analyze Whole Slide Images of Colonic Biopsies for Associations Between Eosinophil Density and Clinicopathologic Features in Active Ulcerative Colitis

BACKGROUND

Eosinophils have been implicated in the pathogenesis of ulcerative colitis and have been associated with disease course and therapeutic response. However, associations between eosinophil density, histologic activity, and clinical features have not been rigorously studied.

METHODS

A deep learning algorithm was trained to identify eosinophils in colonic biopsies and validated against pathologists' interpretations. The algorithm was applied to sigmoid colon biopsies from a cross-sectional cohort of 88 ulcerative colitis patients with histologically active disease as measured by the Geboes score and Robarts histopathology index (RHI). Associations between eosinophil density, histologic activity, and clinical features were determined.

RESULTS

The eosinophil deep learning algorithm demonstrated almost perfect agreement with manual eosinophil counts determined by 4 pathologists (interclass correlation coefficients: 0.805-0.917). Eosinophil density varied widely across patients (median 113.5 cells per mm2, interquartile range 108.9). There was no association between eosinophil density and RHI (P = 0.5). Significant differences in eosinophil density were seen between patients with Montreal E3 vs E2 disease (146.2 cells per mm2 vs 88.2 cells per mm2, P = 0.005). Patients on corticosteroids had significantly lower eosinophil density (62.9 cells per mm2 vs 124.1 cells per mm2, P = 0.006). No association between eosinophil density and biologic use was observed (P = 0.5).

CONCLUSIONS

We developed a deep learning algorithm to quantify eosinophils in colonic biopsies. Eosinophil density did not correlate with histologic activity but did correlate with disease extent and corticosteroid use. Future studies applying this algorithm in larger cohorts with longitudinal follow-up are needed to further elucidate the role of eosinophils in ulcerative colitis.

Impressions and aspirations from the FDA GREAT VI Workshop on Eosinophilic Gastrointestinal Disorders Beyond Eosinophilic Esophagitis and Perspectives for Progress in the Field

The US Food and Drug Administration hosted a workshop on July 21, 2021, to discuss the disease characteristics, natural history, and end points to assess treatment benefit in patients with eosinophilic gastrointestinal disorders (EGIDs) beyond eosinophilic esophagitis (EoE). Notably, EGIDs beyond EoE, such as eosinophilic gastritis, eosinophilic enteritis, and eosinophilic colitis, herein referred to as non-EoE EGIDs, are understudied relative to EoE. This workshop provided a forum for open discussion among stakeholders-medical professionals (including their societies and research groups), Food and Drug Administration representatives, an industry representative, and a patient representative-to facilitate drug development. Experts in many disciplines related to EGIDs, including allergy, immunology, epidemiology, gastroenterology, and pathology, and both adult and pediatric clinicians contributed. Herein, we discuss some of the insights of the material presented at the meeting and present perspectives on moving the field forward toward drug approval.

Pathologist's approach to paediatric and neonatal eosinophilic gastrointestinal disorders

Children are not simply miniature adults. The evaluation of their gastrointestinal disorders is therefore different from that in full-grown adults and requires a particular clinical/pathologic approach.

Different studies have tried to assess the normal eosinophil distribution in the gastrointestinal tract in adults while very few studies have investigated the paediatric population, consequently complicating the pathologist’s ability in identifying an abnormal number of eosinophils in this setting of patients.

When evaluating gastrointestinal tract biopsies with eosinophilia, eosinophilic count must be considered along with other histological features like eosinophil distribution in the gastrointestinal wall, their degranulation, cryptitis and crypt abscesses, other accompanying inflammatory cells, apoptotic bodies, foreign material or microorganisms; these findings, although rarely specific, may be a useful aid for diagnosis.

Reports should not include a diagnosis of primary eosinophilic gastrointestinal disorders (EoGID) if clinical data and test results do not rule out other forms of gastrointestinal eosinophilia. A more descriptive definition like “with eosinophilic pattern” should be favoured over a specific diagnosis of “eosinophilic disorder” in order to avoid potential confusion between different entities.

Prevalence of primary eosinophilic colitis in patients with chronic diarrhea and diarrhea-predominant irritable bowel syndrome

INTRODUCTION

Primary eosinophilic colitis (PEC) is an inflammatory disease caused by the infiltration of eosinophils into the mucosa of the colon, determined after having ruled out other possible causes. It is characterized by abdominal pain and diarrhea and its prevalence is unknown.

AIMS

To know the prevalence of PEC in patients with chronic diarrhea and in those with clinical criteria for diarrhea-predominant irritable bowel syndrome (IBS-D).

PATIENTS AND METHODS

All patients with chronic noninflammatory diarrhea that were consecutively seen over a decade were studied through colonoscopy, with systematic biopsy. Patients with a known or decompensated organic disease, alarm features, abnormal minimal laboratory test results, and factors associated with eosinophilia were excluded. Patients with the clinical criteria for IBS-D (Rome III) were selected from the general group. Eosinophilic colitis was defined as the presence of > 35 eosinophils/100 epithelial cells per field in any of the segments.

RESULTS

From the 683 patients seen, a total of 545 patients (361 women) were included in the study. Twenty-two cases of PEC were detected, resulting in a prevalence of 4.0%. A total of 343 patients had IBS-D criteria (223 women), with 16 cases of PEC detected, for a prevalence of 4.7%. Colonoscopy was normal, or almost normal, in all the PEC cases detected.

CONCLUSIONS

The prevalence of PEC was 4.0% in the patients with chronic diarrhea and 4.7% in the patients with IBS-D. Peripheral eosinophilia appeared to be the main distinctive clinical characteristic, but systematic biopsy was essential for making the diagnosis.

Eosinophilic Colitis that Presented with Subepithelial Tumor-like Lesions

Eosinophilic colitis is a rare disease that is characterized by eosinophilic infiltration in the colon wall in symptomatic patients. Thus far, the epidemiology and pathophysiology of eosinophilic colitis have not been well defined, but the hypersensitivity response is likely to play a role in its pathogenesis. The clinical presentation of eosinophilic colitis is usually nonspecific and depends on the layer of the intestinal wall affected by the eosinophilic infiltrate. Eosinophilic colitis is diagnosed generally by exclusion, i.e., after all other causes of eosinophilic infiltration have been excluded. Although there is no consensus over its diagnostic criteria, the laboratory results and radiology and endoscopy findings can provide important diagnostic evidence. This paper reports a case of eosinophilic colitis presenting as subepithelial tumor-like lesions in a 41-year-old man with the chief complaints of abdominal pain and loose stools. The patient had no diseases and no food or drug allergies in his medical history. In general, the endoscopic findings of eosinophilic colitis can vary from a normal mucosa to frank ulcerations. In this case, however, endoscopy revealed subepithelial tumor-like lesions. The colon biopsy showed eosinophilic infiltration in the lamina propria. The patient was treated with steroids, and his symptoms regressed with no signs of relapse.

Colonic mucosal eosinophilia in children without inflammatory bowel disease

Children undergoing colonoscopy and mucosal biopsies may show increased colonic mucosal eosinophils, which may or may not be associated with inflammatory bowel disease. There is not much clinical data on American children who have isolated increased colonic mucosal eosinophils. We sought to study the clinical correlates of children without inflammatory bowel disease who show increased mucosal eosinophils to understand their clinical presentation, etiological associations, and outcome. A retrospective analysis of children seen at a tertiary-level Children's hospital was performed by reviewing their medical charts and extracting pertinent data. There were 110 children in the study who had increased colonic mucosal eosinophils. Most children presented with abdominal pain, but several of them also had constipation, blood in stools, and diarrhea. Food allergies, irritable bowel syndrome, asthma, and lactase deficiency were the top four conditions present in these patients. Pathology of the colonic distribution revealed involvement of more than two colonic regions in 86% of the subjects, and only two subjects showing epithelial or crypt involvement by eosinophils. All subjects had a good outcome. Children with colonic mucosal eosinophilia (CME) who do not have an inflammatory bowel disease most frequently present with abdominal pain and primarily an increase of lamina propria eosinophils in two or more colonic regions. Based on the etiological associations we noted in the study, a work-up of children with CME may encompass detailed history for functional gastrointestinal disorders and lactose intolerance, testing for food and environmental allergies, stool examination for parasites, and peripheral blood counts. Almost all children had resolution of symptoms in the studied period suggesting that CME in children has a good clinical outcome.

Prevalence of primary eosinophilic colitis in patients with chronic diarrhea and diarrhea-predominant irritable bowel syndrome

INTRODUCTION

Primary eosinophilic colitis (PEC) is an inflammatory disease caused by the infiltration of eosinophils into the mucosa of the colon, determined after having ruled out other possible causes. It is characterized by abdominal pain and diarrhea and its prevalence is unknown.

AIMS

To know the prevalence of PEC in patients with chronic diarrhea and in those with clinical criteria for diarrhea-predominant irritable bowel syndrome (IBS-D).

PATIENTS AND METHODS

All patients with chronic noninflammatory diarrhea that were consecutively seen over a decade were studied through colonoscopy, with systematic biopsy. Patients with a known or decompensated organic disease, alarm features, abnormal minimal laboratory test results, and factors associated with eosinophilia were excluded. Patients with the clinical criteria for IBS-D (Rome III) were selected from the general group. Eosinophilic colitis was defined as the presence of>35eosinophils/100 epithelial cells per field in any of the segments.

RESULTS

From the 683 patients seen, a total of 545 patients (361 women) were included in the study. Twenty-two cases of PEC were detected, resulting in a prevalence of 4.0%. A total of 343 patients had IBS-D criteria (223 women), with 16 cases of PEC detected, for a prevalence of 4.7%. Colonoscopy was normal, or almost normal, in all the PEC cases detected.

CONCLUSIONS

The prevalence of PEC was 4.0% in the patients with chronic diarrhea and 4.7% in the patients with IBS-D. Peripheral eosinophilia appeared to be the main distinctive clinical characteristic, but systematic biopsy was essential for making the diagnosis.

Primary Eosinophilic Gastrointestinal Diseases Beyond Eosinophilic Esophagitis in Children

OBJECTIVES

There are many unknowns about primary eosinophilic gastrointestinal disease (EGID) in childhood. The aim of this study is to provide data about the frequency, management, control level, and prognosis of well documented primary EGID in childhood.

METHODS

This study was conducted in children who underwent endoscopy and/or colonoscopy at a single center over 10-year period up to August 2018. Primary EGID was diagnosed after exclusion of secondary EGID and classified as eosinophilic gastritis (EG), eosinophilic enteritis (EE), eosinophilic gastroenteritis (EGE: eosinophilic gastritis with eosinophilic enteritis) and eosinophilic colitis (EC) according to histopathological evaluation. The pathological number of eosinophil counts were accepted as >30 hpf for gastric mucosa in 5 hpf area, ≥20/hpf for duodenal, jejunal, and ileal mucosa, >50/hpf for right colonic mucosa, >35/hpf for transverse colonic mucosa, and >25/hpf for left colonic mucosa. Presenting symptoms, signs, management, follow-up, disease control level, and remission were analyzed. Remission is defined if the patient is controlled with all clinical, endoscopic/colonoscopic, and histopathologic parameters without any treatments or diet for at least a year.

RESULTS

During the study period, 7457 biopsies were taken in 8262 endoscopy and/or colonoscopy procedures. Primary and secondary EGID frequencies were found 0.23% (n = 17 patients) and 0.1% (n =8 patients) per procedure with biopsy in children, respectively. Endoscopy/colonoscopy procedures were not able to performed in 9 patients because of short follow-up period (n = 6) or patients leaving follow-up (n = 3). Nine of the primary EGID patients had esophageal eosinophilia (EsE) at the time of diagnosis, 5 of them were previously managed as EoE. The median follow-up period of primary EGID patients excluding the ones without a control endoscopy/colonoscopy procedure was 3.35 years (min-max: 1.1-9.0 years). Proton pump inhibitors (PPI) were the most frequently used treatment alone or in combination with diet, systemic and/or topical corticosteroids. Disease control was evaluated in 8 of 17 patients and it was uncontrolled in 4, partially controlled in 1, and controlled in 3 patients. Remission was achieved in 2 patients.

CONCLUSIONS

The frequency of primary EGID beyond eosinophilic esophagitis (EoE) in children is low. It may be difficult to achieve control in children with primary EGID in the long-term follow-up.

ECCO Position Paper: Harmonization of the Approach to Ulcerative Colitis Histopathology

Currently, the main targets of drug therapy for ulcerative colitis [UC] are endoscopic and clinical remission. However, there is active discussion about the additional advantages of including histological remission as a target. Accumulating evidence indicates that microscopic activity persists in endoscopically quiescent UC, that histological changes may lag behind clinical remission after treatment, and that absence of histological activity predicts lower rates of relapse, hospitalization, surgery and subsequent neoplasia. Obtaining useful information from mucosal biopsies in this setting depends on accurate and consistent evaluation of histological features. However, there is no standardization of biopsy procedures, histological sample processing technique or histological scoring systems, and there is no agreement on the definitions of histological remission, response or activity. Accordingly, a consensus expert panel convened by the European Crohn's and Colitis Organisation [ECCO] reviewed the literature and agreed a number of position statements regarding harmonization of UC histopathology. The objective was to provide evidence-based guidance for the standardization and harmonization of procedures, definitions and scoring systems for histology in UC, and to reach expert consensus where possible. We propose the absence of intraepithelial neutrophils, erosion and ulceration as a minimum requirement for the definition of histological remission. For randomized control trials we recommend the use of the Robarts histopathology index [RHI] or the Nancy index [NI]. For observational studies or in clinical practice we recommend the use of the NI. To predict the risk of future neoplasia in UC, cumulative histological scores over time are more useful than single scores.

Eosinophilic colitis in adults

Eosinophilic colitis (EoC) is a pathological entity associated with abnormal infiltration of colonic mucosa by eosinophilic polynuclear cells (Eo). This is a relatively common pathology in infants and children under 2 years old, but is more rare and has been less studied in adults. EoC can be classified as primary or secondary. Primary EoC is, in the majority of cases, related to an allergic reaction, either IgE-mediated and capable of causing an anaphylactic-type food allergy, or not mediated by IgE and capable of giving rise to food enteropathy. The symptoms for adults with EoC are variable and non-specific, diarrhoea and abdominal pain being the most common signs. There is no histological consensus for the diagnosis of EoC. The presence of over 40 Eo per high-power field (×400) in at least two different colonic segments could be suggested as the criterion for the diagnosis. In adults with primary EoC, skin tests are of limited value and the response to a restrictive diet is less effective than in young children, given that IgE or non-IgE-mediated allergic reactions are rarely identified and EoC generally require medical treatment. There is no consensus on the treatment of EoC, but the potential efficacy of corticosteroids and budesonide has been demonstrated in the vast majority of cases studied.

Complete Resolution of Mucosal Neutrophils Associates With Improved Long-Term Clinical Outcomes of Patients With Ulcerative Colitis

BACKGROUND & AIMS

We investigated correlations between histologic features of the colonic mucosa in patients with ulcerative colitis (UC) and clinical outcomes during a 3-year follow-up period.

METHODS

We obtained baseline biopsies from all colorectal segments (n = 889) from 281 patients with UC enrolled in a prospective study at a single center from 2009 through 2013. Biopsies were assessed in a blinded manner using validated histologic scoring systems (the Geboes score, Nancy histopathologic index, and Robarts histopathologic index). Clinical, endoscopic, and histologic data were collected and tested for correlations with systemic corticosteroid use, hospitalization, and colectomy within 3 years of the index colonoscopy.

RESULTS

We found histologic evidence of UC activity (Geboes score ≥ 2B.1) in biopsies from 182 patients (65%) and endoscopic evidence of UC activity in 149 patients (53%) (substantial agreement, κ = 0.60). Histologic features of UC activity were associated with increased rates of systemic corticosteroid use, colectomy, and hospitalization in the entire cohort (P < .05 for all) and associated with increased rates of systemic corticosteroid use in an analysis limited to patients in endoscopic remission (P < .001). In patients in endoscopic remission, only histologic activity was independently associated with use of systemic corticosteroids (multivariate odds ratio, 6.34; 95% CI, 2.20-18.28; P = .001). Similar results were seen when the entire cohort was analyzed. Compared with patients without histologic evidence of UC activity, patients with only a small number of mucosal neutrophils still had higher rates of systemic corticosteroid use (P < .001).

CONCLUSIONS

Histologic evidence of UC activity, including small numbers of neutrophils in the colonic mucosa, is the only factor independently associated with use of systemic corticosteroids. Complete resolution of neutrophil-associated inflammation should be a target for treatment of UC.

Conversion from tacrolimus to sirolimus as a treatment modality in de novo allergies and immune-mediated disorders in pediatric liver transplant recipients

De novo PTAID may develop in pediatric solid organ transplant recipients, have a diverse spectrum, and are occasionally treatment resistant. Previous reports showed resolution of immune cytopenias in solid organ transplant recipients following replacement of the calcineurin inhibitor tacrolimus with the mTOR inhibitor sirolimus. Herein we describe a retrospective review (2000-2017) of subjects who developed PTAID in whom immunosuppression was changed to sirolimus. Eight recipients (6 males) of either liver (n = 7) or multivisceral transplant (n = 1) suffered from severe, treatment-resistant PTAID and were switched from tacrolimus to sirolimus. The median age at transplant was 1 year (range 0.5-2.4 years). Six (75%) recipients developed de novo allergy and 2 immune-mediated diseases. The median age at presentation of PTAID was 2.7 (1.4-9) years at a median of 1.3 (0.25-8) years after transplantation. The median time from PTAID presentation to conversion to sirolimus was 1.8 (0.45-10) years. Complete resolution of symptoms was seen in 4 (50%) patients after a median of 12 (range 4-24) months including 2 patients with immune-mediated disease, 1 eczema, and 1 with eosinophilic colitis. One patient with multiple food allergies had a partial response and 3 (38%) had no response. None of the 8 recipients developed sirolimus-attributed adverse events or acute rejection during a median follow-up of 5 (0.6-8) years after the conversion. Immunosuppression conversion from tacrolimus to sirolimus can be an effective therapy in patients suffering severe or treatment-resistant PTAID, suggesting a potential role for tacrolimus in the pathogenesis of PTAID.

Eosinophilic Colitis and Clostridioides difficile Sepsis With Rapid Remission After Antimicrobial Treatment; A Rare Coincidence and Its Pathogenic Implications

Eosinophilic colitis is a rare inflammatory disorder of the digestive tract with chronic evolution and unknown pathophysiological mechanisms. The article describes the case of a 64-year old woman with a history of asthma and hypereosinophilia, who presented to a surgical department for persistent abdominal pain in the past 4 months, weight loss and malabsorption. She was diagnosed with eosinophilic colitis based on the colonoscopic result indicating extensive eosinophilic infiltration of the colonic mucosa correlated with the laboratory data and abdominal CT scan results. Following the colonoscopy, the patient developed fever, hypotension and diarrhea and was transferred to an Infectious Diseases Department with a presumptive diagnosis of abdominal sepsis. Treatment with ertapenem was immediately started. Metronidazole was also added due to a PCR positive stool test for Clostridioides difficile toxins encoding-genes. The patient displayed a rapid remission of the fever and of the intestinal complaints following antibiotic therapy and was discharged after 14 days. During a 3 months follow-up, the patient remained asymptomatic with normal values of laboratory parameters except for a persistent hypereosinophilia. The case outlines two distinguishing features: a histopathologic diagnosis of eosinophilic colitis, a rare diagnosis of a patient with chronic abdominal pain and an unexpected and rapid remission of the eosinophilic colitis following the antibiotic treatment and the restoration of the intestinal eubiosis.

Eosinophilic pancreatitis versus pancreatitis associated with eosinophilic gastroenteritis - a systematic review regarding clinical features and diagnosis

BACKGROUND

Over the past years, eosinophil infiltration involving the gastrointestinal tract and pancreas leading to eosinophilic pancreatitis, eosinophilic gastroenteritis and hypereosinophilic syndrome has been reported in the literature. We aimed to analyze and compare the features involving patients with eosinophilic pancreatitis and pancreatitis associated with eosinophilic gastroenteritis and to determine if there is a connection between the two disorders or if they in fact meet the diagnostic criteria for hypereosinophilic syndrome.

MATERIAL AND METHODS

The following search was performed in March 2019 on PubMed (MEDLINE) database using the medical terms "pancreatitis", "eosinophilic pancreatitis", "eosinophilic gastroenteritis" and "hypereosinophilic syndrome".

RESULTS

The search revealed 119 publications from 1970 onwards. A total of 83 papers were excluded, and the remaining 36 publications, consisting in case reports and case series, were analyzed. From 45 patients, 20 subjects with eosinophilic gastroenteritis developed pancreatitis, 20/45 had eosinophilic pancreatitis, and 5/45 hypereosinophilic syndrome involving the pancreas. There was no significant difference regarding clinical, laboratory and imaging features between the three groups, despite the multiple theories that explain the association of pancreatic and gastrointestinal eosinophilic infiltration. Although there was a strong resemblance between the three groups, histological evidence of eosinophilic gastrointestinal infiltration guided the treatment towards a less invasive way, while subjects with eosinophilic pancreatitis underwent pancreatic surgery to exclude potentially malignant lesions.

CONCLUSION

Although there are various theories that explain pancreatitis development in patients with eosinophilic gastroenteritis, hypereosinophilia diagnostic work-up should be taken into account in all patients with high number of blood eosinophils, even in those with eosinophilic pancreatitis in order to establish the diagnosis using a minimally invasive approach and to apply an adequate treatment.

Outcomes of inflammatory bowel disease in patients with eosinophil-predominant colonic inflammation

Background

Inflammatory bowel disease (IBD) is characterised by acute intestinal mucosal inflammation with chronic inflammatory features. Various degrees of mucosal eosinophilia are present along with the typical acute (neutrophil-predominant) inflammation. The effect of intestinal eosinophils on IBD outcomes remains unclear.

Methods

This is a retrospective study. Archived intestinal mucosal biopsy specimens of treatment-naïve IBD patients were examined by two pathologists. The number of eosinophils per high-power field was counted, and the mucosal inflammation was classified according to the eosinophilic inflammatory patterns. Clinical outcomes during the follow-up period were recorded.

Results

142 treatment-naïve IBD patients were included. Mean age was 39 years. 83% of patients had ulcerative colitis, and median follow-up was 3 years. 41% of patients had disease flare(s) and 24% required hospitalisation. Eosinophil count was not associated with risk of disease flare or hospitalisation. Patients with neutrophil-predominant inflammation (>70% neutrophils) had greater risk of disease flare(s): 27(55%) versus 24(36%) and 7(28%) in patients with mixed and eosinophil-predominant inflammation, respectively (p=0.04). Overall, patients with neutrophil-predominant inflammation were more likely to have a disease flare; HR: 2.49, 95% CI (1.0 to 5.6). Hospitalisation rate was higher in patients with neutrophil-predominant inflammation: 17(35%) compared to 17(19%) in patients with eosinophil-rich inflammation (p=0.04). Kaplan-Meier analysis showed higher flare-free survival in patients with eosinophil-predominant inflammation compared to mixed and neutrophil-predominant inflammation.

Conclusion

IBD patients with eosinophil-predominant inflammation phenotype might have reduced risk of disease flares and hospitalisation. Larger prospective studies to assess IBD outcomes in this subpopulation are warranted.

Severe Colitis Caused by Hepatic Arterial Infusion Chemotherapy with Cisplatin for Hepatocellular Carcinoma

A 78-year-old man with chronic hepatitis C underwent hepatectomy for hepatocellular carcinoma (HCC) 11 years prior to presentation. He was diagnosed with multiple intrahepatic recurrences of HCC with portal vein invasion and received hepatic arterial infusion chemotherapy (HAIC) with cisplatin. He developed abdominal pain, diarrhea, and blood-stained stool following treatment. Computed tomography revealed significant bowel wall thickening throughout the colon. Colonoscopy revealed reddish edematous mucosa with a reduced vascular pattern without ischemic changes. Conservative treatment with total parenteral nutrition improved his condition and his imaging findings. This is the first report of severe colitis following HAIC with cisplatin.

Eosinophilic Gastrointestinal Diseases in Children: A Practical Review

Primary eosinophilic gastrointestinal diseases (EGIDs) represent a heterogeneous group of disorders characterized by eosinophilic inflammation in the absence of known causes for eosinophilia, selectively affecting different segments of the gastrointestinal tract. While pediatric eosinophilic esophagitis (EoE) is a well-defined disease with established guidelines, Eosinophilic Gastritis (EoG), Eosinophilic Gastroenteritis (EoGE) and Eosinophilic Colitis (EoC) remain a clinical enigma with evidence based on limited anecdotal case reports. Large cross-sectional studies in the US defined a prevalence of EoG and EoGE ranging from 1,5 to 6,4/100.000 and from 2,7 to 8,3/100.000 subjects respectively, while the prevalence of EoC ranges from 1,7 to 3,5/100.000 subjects. Regarding the pathogenesis, it is hypothesized that EGIDs result from the interplay between genetic predisposition, intestinal dysbiosis and environmental triggers. Clinically, EGIDs might present with different and nonspecific gastrointestinal symptoms depending on the involved intestinal tract and the extension of eosinophilic inflammatory infiltrate. The diagnosis of EGIDs requires: 1. recurrent gastrointestinal symptoms, 2. increased eosinophils for high power field in biopsy specimens, 3. absence of secondary causes of gastrointestinal eosinophilia. No validated guidelines are available on the clinical management of patients with EGIDs. Evidence from case reports and small uncontrolled case series suggests the use of dietary and corticosteroids as the first-line treatments. Considering the clinical follow-up of EGIDs, three different patterns of disease course are identified: single flare, recurring course-disease and chronic course-disease. This review will focus on pediatric EGIDs distal to esophagus, including Eosinophilic Gastritis (EoG), Eosinophilic Gastroenteritis (EoGE) and Eosinophilic Colitis (EoC).

Eosinophilic esophagitis, gastroenteritis, and colitis in a patient with prior parasite exposure

Eosinophilic gastrointestinal disorders (EGID) comprise a spectrum of inflammatory diseases that can affect any segment of the gastrointestinal tract. The pathogenesis of these conditions is complex; differentiating between primary and secondary forms of these disorders can be clinically challenging. We report a case of primary EGID in a patient with remote parasite exposure, whose symptoms were initially attributed to irritable bowel syndrome. Endoscopy revealed the rare finding of EGID involving the entire gastrointestinal tract; symptoms improved with an elimination diet. This case raises the possibility of a link between prior parasite exposure and development of EGID, and underscores the necessity of exploring alternative diagnoses in patients with presumed IBS who present with severe symptoms.

Eosinophilic colitis: A clinical review

Eosinophilic colitis is a rare entity characterized by the presence of a high eosinophilic infiltrate into the colonic wall in symptomatic patients, more often presenting with abdominal pain or diarrhea. These characteristics distinguish eosinophilic colitis from primary colonic eosinophilia, in which patients are asymptomatic. Primary colonic eosinophilia does not need any therapy, while eosinophilic colitis requires a strict treatment, similar to that of the more codified chronic intestinal inflammatory diseases. To date the lack of codified guidelines regarding the diagnostic criteria and the eosinophil threshold values for each colonic segment are the main diagnostic challenge for eosinophilic colitis. In addition, eosinophilic colitis is a diagnosis of exclusion, once all other causes of colonic eosinophilia (food allergens, infections, drugs, etc.) have been excluded. Several treatment options are available for eosinophilic colitis, although the evidence for most of them is limited to case reports and small case series. We examine the epidemiology, etiology, pathophysiology, diagnostic criteria and therapeutic options of eosinophilic colitis reporting recent evidence from the current literature.

Eosinophilic Gastrointestinal Diseases in Childhood

Eosinophilic gastrointestinal diseases (EGIDs) comprise a group of chronic, inflammatory diseases of the gastrointestinal (GI) tract, that are characterized, clinically, by symptoms related to the dysfunction of the involved segment(s) of the GI tract, and histologically, by dense eosinophilic inflammation, in the absence of an identifiable secondary cause. The group of EGIDs comprises eosinophilic esophagitis (EoE), eosinophilic gastritis (EG), eosinophilic gastroenteritis (EGE), and eosinophilic colitis (EC). EoE is the most common and the best described EGID compared to EG, EGE, and EC. The clinical presentation of the EGIDs differs depending on the location and the extent of the eosinophilic infiltration in the GI tract, as well as its depth through the bowel wall. In the absence of biological markers, the diagnosis is based on the combination of clinical symptoms with the histological features of EGIDs, after the exclusion of secondary causes of eosinophilic inflammation of the GI tract. Treatment is individualized and includes elimination diets (mainly empiric or elemental) and/or drugs, according to the involved GI segment: proton pump inhibitors or local steroids in EoE; local or oral systemic steroids in EG/EGE limited to the duodenum; oral systemic steroids in EGE with lower small intestine and/or colon involvement. In patients with EoE, maintenance treatment with lower doses may be considered following histological remission with the means of drugs. In patients treated with elimination diets, disease food triggers identified during food reintroduction need to be further eliminated. Esophageal stenosis despite medical treatment requires endoscopic dilation, while the use of thiopurines or anti-TNF drugs may be considered in refractory or steroid-dependent EGID (other than EoE). The aim of this review is to provide the available evidence on each of the above disorders, to aid clinicians to interpret the clinical manifestations and the laboratory findings and choose the best available treatment option.

Eosinophil counts in colonic tissue eosinophilia: Investigating specificity and sensitivity of cutoff points and comparing two counting methods

BACKGROUND/AIMS

The aim of this study was to investigate the specificity and sensitivity of eosinophil cutoff points defining the colonic tissue eosinophilia (TE) and compare the yield of reporting the highest count versus the mean of five high-power fields (HPFs).

MATERIALS AND METHODS

One hundred and seventy-one cases of colonic TE, including 22 primary eosinophilic colitis (PEC) cases, were compared to one hundred and twenty-one normal controls in the University of Jordan. The highest eosinophil count (EC) and the mean of five HPFs were recorded. The receiver operating characteristic curve (ROC) analysis was used to find the cutoff point with the best sensitivity and specificity.

RESULTS

There was no significant advantage of counting five fields over counting the most densely populated HPF. Using 30 eosinophils per HPF achieved 80% sensitivity and 65% specificity. This point is close to the mean in normal controls plus one standard deviation (SD) (29 per HPF). However, there was overlap between normal counts and TE, using 30 as a cutoff point resulted in 35% false-positive rate. There was no reliable cutoff point to differentiate PEC from secondary TE.

CONCLUSION

We recommend reporting the highest EC in colonic biopsies and using 30 as a cutoff point, bearing in mind the overlap with normal and correlating with the clinical team to not treat asymptomatic patients. Clinicopathological correlation is essential to separate PEC from secondary TE.

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

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

Eosinophilic colitis and colonic eosinophilia

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Eosinophil Counts in Mucosal Biopsies of the Ileum and Colon: Interobserver Variance Affects Diagnostic Accuracy

Primary eosinophilic gastroenteritis and colitis (EGE) is a rare entity with unspecific clinical and endoscopic findings. Validated histopathologic criteria for confirming the diagnosis are lacking, because numeric values for normal or elevated concentrations of eosinophils in mucosal biopsies are varying between observers. To quantify this interobserver variance, we had the same set of 30 slides of eosinophilic-rich mucosal biopsies from the ileum and colon systematically reviewed by a panel of six independent pathologists, each with more than a ten-year experience in the field. Using a highly standardized biopsy and slide preparation protocol, we ruled out any influence by the preparation, the patient, the endoscopist, the endoscopes and calipers used, the sampling site, the fixation and staining method, and the microscopic field sizes. Still, all numeric results differed between pathologists up to a factor greater than 30. Calculated positive or negative diagnosis of EGE differed up to a factor greater than 8. A theoretical incidence for EGE calculated from these numbers differed by a factor greater than 1500. We conclude that eosinophil counts in mucosal biopsies from the lower gastrointestinal tract are subject to a very high interobserver variance. Until further research provides objective and validated methods for standardization, all epidemiologic numbers derived from histopathologic findings may have to be questioned. When diagnosing individual patients with EGE, overall morphologic picture together with clinical and endoscopic findings is more important than numeric eosinophil count.