Determination of Biopsy Yield That Optimally Detects Eosinophilic Gastritis and/or Duodenitis in a Randomized Trial of Lirentelimab

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.

Host-related low-prevalence gastritides: Epidemiological and clinical characterization

INTRODUCTION

A recent consensus meeting (RE.GA.IN) addressed "host-related, low-prevalence gastritis": eosinophilic (EoG), lymphocytic (Hp-pos_LyG and Hp-neg_LyG), collagenous (CollG), and granulomatous gastritis (GrG). Our study evaluates their clinico-epidemiological characteristics.

MATERIALS AND METHODS

We extracted all patients with a diagnosis of EoG, LyG, CollG, and GrG from a clinicopathological database and compared their demographics, clinical and endoscopic characteristics, associated conditions, and clinical awareness to those of all other subjects in the database (controls).

RESULTS

There were 1,781,005 unique patients (median age 57 years; 55.7 % female). Hispanics were overrepresented amongst those with Hp-pos_LyG. Subjects with GrG had a high prevalence of erosions and ulcers. Clinical awareness of these conditions was dismal (<1:10,000 patients). Some clinical manifestations were more common in patients with certain gastritides (e.g., vomiting and diarrhea in CollG; anemia in LyG), but none were sufficiently distinctive to suggest a clinical diagnosis. EoG was associated with EoE; LyG had a strong association with celiac disease; CollG with microscopic colitis; and GrG with Crohn disease.

CONCLUSIONS

The diagnosis of these gastritides (between <1: in 1,000 and 1 in 5000 subjects) rests on histopathology. They remain poorly characterized and clinically neglected. Yet, their associations may herald other conditions: eosinophilic gastrointestinal diseases (EGID), celiac, and Crohn disease. Patients might benefit from increased detection and characterization.

Endoscopic Features of Eosinophilic Gastrointestinal Diseases

Endoscopic evaluation with biopsies is a mainstay of the diagnosis of eosinophilic esophagitis (EoE) and non-EoE eosinophilic gastrointestinal diseases (EGIDs). Increasing knowledge has resulted in the development of 2 standardized scoring systems: the Endoscopic REFerence Score (EREFS) for EoE and the EG-REFS for eosinophilic gastritis, although the latter has not been validated. In EGIDs, diagnosis and follow-up focus on eosinophil infiltration in biopsies. In this article, we will discuss the most commonly used endoscopic scores in EoE and non-EoE EGIDs, their validity for the diagnosis and follow-up of disease activity, as well as endoscopic interventions and areas of uncertainty.

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.

A case of non-esophageal eosinophilic gastrointestinal disease diagnosed by mucosal incision-assisted biopsy

A 46-year-old woman presented at our hospital with anorexia, vomiting, and diarrhea. Blood tests indicated markedly increased eosinophil counts, and esophagogastroduodenoscopy revealed slight erythema in the gastric body. Computed tomography showed edematous thickening of the stomach and small intestinal walls and peritonitis. Thus, eosinophilic gastrointestinal disease was suspected. Endoscopic biopsies from the esophagus, stomach, and duodenum were collected, but no significant increases in eosinophil counts were observed. Little ascites effusion was detected and puncture cytology was difficult to perform. Thus, a sample of the muscularis propria layer was obtained by mucosal incision-assisted biopsy. Histopathological examination of the biopsy revealed significant eosinophilic infiltration within the muscularis propria layer of the stomach, confirming the diagnosis of non-eosinophilic esophagitis eosinophilic gastrointestinal disease. The patient was treated with a leukotriene receptor antagonist and prednisolone, and her clinical symptoms and gastrointestinal wall thickening rapidly improved. The Japanese diagnostic guideline for non-eosinophilic esophagitis eosinophilic gastrointestinal disease requires endoscopic biopsy or eosinophilic infiltration of ascites fluid. When diagnosis is difficult using conventional methods, as in this case, mucosal incision-assisted biopsy is useful as a next step.

Review article: Emerging insights into the epidemiology, pathophysiology, diagnostic and therapeutic aspects of eosinophilic oesophagitis and other eosinophilic gastrointestinal diseases

BACKGROUND

Eosinophilic gastrointestinal diseases (EGIDs) are chronic, immune-mediated disorders characterised clinically by gastrointestinal symptoms and histologically by a pathologic increase in eosinophil-predominant inflammation in the gastrointestinal tract, in the absence of secondary causes of eosinophilia.

AIMS

To highlight emerging insights and research efforts into the epidemiology, pathophysiology, diagnostic and therapeutic aspects of eosinophilic oesophagitis (EoE) and non-EoE EGIDs, and discuss key remaining knowledge gaps.

METHODS

We selected and reviewed original research, retrospective studies, case series, randomised controlled trials, and meta-analyses.

RESULTS

Standardised nomenclature classifies EGIDs as EoE, eosinophilic gastritis (EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC). Incidence and prevalence of EoE are rising, emphasising the need to better understand how environmental risk factors and genetic features interact. Advances in understanding EoE pathophysiology have led to clinical trials of targeted therapy and the approval (in the United States) of dupilumab for EoE. Several therapies that are under investigation hope to satisfy both histologic and clinical targets. For non-EoE EGIDs, efforts are focused on better defining clinical and histopathologic disease determinants and natural history, as well as establishing new therapies.

CONCLUSIONS

Unmet needs for research are dramatically different for EoE and non-EoE EGIDs. In EoE, non-invasive diagnostic tests, clinicopathologic models that determine the risk of disease progression and therapeutic failure, and novel biologic therapies are emerging. In contrast, in non-EoE EGIDs, epidemiologic trends, diagnostic histopathologic thresholds, and natural history models are still developing for these more rare disorders.

Quantification of Mucosal Mast Cells in the Gastrointestinal Tract: A Primer for Practicing Pathologists

CONTEXT.—

Mast cells are essential components of the immune system and play crucial pathogenetic roles in several digestive diseases, including mastocytic enterocolitis and eosinophilic gastrointestinal disorders. Pathologists have rarely been asked to evaluate the distribution and density of mast cells in gastrointestinal (GI) biopsy specimens. However, such requests are becoming more common because of an increasing awareness of the role of mast cells in functional GI disease and in both esophageal and nonesophageal eosinophilic gastrointestinal disorders.

OBJECTIVE.—

To provide pathologists with tools to incorporate the assessment of mast cells in the evaluation of esophageal, gastric, and intestinal specimens by developing a systematic approach to their evaluation, counting, and reporting.

DESIGN.—

This study consisted of a review of the literature followed by multiple consensus sessions to decide where to count mast cells and what a countable mast cell is.

RESULTS.—

We reviewed 135 papers addressing the content of mast cells in the digestive tract, selected 21 that detailed how cells were counted (microscope lens, area of high-power fields, locations evaluated, type of cells considered as countable), and summarized their data in a table. Then, drawing from both the acceptable literature and our own extensive experience, we reached a tentative consensus on: (1) the normal numbers in the different segments of the GI tract; (2) the morphology of countable mast cells; and (3) the locations and strategies for counting them.

CONCLUSIONS.—

The result is a set of suggestions for reporting mast cell counts, their distribution, and their location in a way clinicians can understand and use for management decisions.

Joint ESPGHAN/NASPGHAN Guidelines on Childhood Eosinophilic Gastrointestinal Disorders Beyond Eosinophilic Esophagitis

INTRODUCTION

Eosinophilic gastrointestinal disorders beyond eosinophilic esophagitis (non-EoE EGIDs) are rare chronic inflammatory disorders of the gastrointestinal (GI) tract. Diagnosis is based on clinical symptoms and histologic findings of eosinophilic inflammation after exclusion of a secondary cause or systemic disease. Currently, no guidelines exist for the evaluation of non-EoE EGIDs. Therefore, the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) formed a task force group to provide consensus guidelines for childhood non-EoE EGIDs.

METHODS

The working group was composed of pediatric gastroenterologists, adult gastroenterologists, allergists/immunologists, and pathologists. An extensive electronic literature search of the MEDLINE, EMBASE, and Cochrane databases was conducted up to February 2022. General methodology was used in the formulation of recommendations according to the Appraisal of Guidelines for Research and Evaluation (AGREE) II and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to meet current standards of evidence assessment.

RESULTS

The guidelines provide information on the current concept of non-EoE EGIDs, disease pathogenesis, epidemiology, clinical manifestations, diagnostic and disease surveillance procedures, and current treatment options. Thirty-four statements based on available evidence and 41 recommendations based on expert opinion and best clinical practices were developed.

CONCLUSION

Non-EoE EGIDs literature is limited in scope and depth, making clear recommendations difficult. These consensus-based clinical practice guidelines are intended to assist clinicians caring for children affected by non-EoE EGIDs and to facilitate high-quality randomized controlled trials of various treatment modalities using standardized, uniform disease definitions.

Determination of Optimal Eosinophil Thresholds for Diagnosis of Eosinophilic Gastritis and Duodenitis: A Pooled Analysis of 4 Prospective Studies

INTRODUCTION

Consensus is lacking regarding the number of eosinophils (eos) required for the diagnosis of eosinophilic gastritis (EoG) and eosinophilic duodenitis (EoD). In addition, thresholds that require multiple high-power fields (HPFs) may not be practical for clinical use, resulting in delayed or missed diagnoses. This pooled analysis of 4 prospective studies assessed thresholds for multiple and single HPFs used to diagnose EoG and EoD.

METHODS

Studies included the phase 2 ENIGMA1, the phase 3 ENIGMA2, an EoG/EoD prevalence study and a healthy volunteer study. Eos were quantified in the epithelium and lamina propria for controls and symptomatic participants. Symptomatic participants were further divided by histologic diagnosis of EoG/EoD. Peak eos counts were assessed, and the area under the receiver operating characteristic curve was analyzed to identify eos cutoffs for detection of EoG/EoD using the Youden index and sensitivity and specificity equality approaches.

RESULTS

Based on the highest specificity analysis in 740 patients, the optimal eos threshold was determined to be 20 eos/HPF in 5 gastric HPFs for EoG (71% sensitivity and 94% specificity) and 33 eos/HPF in 3 duodenal HPFs for EoD (49% sensitivity and 100% specificity). For single-field analysis, the optimal eos thresholds were 33 eos/HPF (EoG) and 37 eos/HPF (EoD), both corresponding to 93% sensitivity and 93% specificity.

DISCUSSION

Highly specific single gastric and duodenal HPF thresholds may have more clinical applicability than thresholds requiring multiple HPFs and could better facilitate development of practical histopathologic guidelines to aid pathologists and clinicians in the detection and diagnosis of EoG and/or EoD.

Breakthroughs in understanding and treating eosinophilic gastrointestinal diseases presented at the CEGIR/TIGERs Symposium at the 2022 American Academy of Allergy, Asthma & Immunology Meeting

The Consortium of Eosinophilic Gastrointestinal Diseases and The International Gastrointestinal Eosinophil Researchers organized a day-long symposium at the 2022 Annual Meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured a review of recent discoveries in the basic biology and pathogenesis of eosinophilic gastrointestinal diseases (EGIDs) in addition to advances in our understanding of the clinical features of EGIDs. Diagnostic and management approaches were reviewed and debated, and clinical trials of emerging therapies were highlighted. Herein, we briefly summarize the breakthrough discoveries in EGIDs.

Irritable Bowel Syndrome-Like Symptoms in Quiescent Inflammatory Bowel Disease: A Practical Approach to Diagnosis and Treatment of Organic Causes

BACKGROUND

Despite achieving remission in inflammatory bowel disease (IBD), persistent gastrointestinal symptoms are common in quiescent IBD. While irritable bowel syndrome (IBS) is commonly diagnosed in IBD, IBS-like symptoms of recurrent abdominal pain and altered bowel habits can also be attributed to a wide range of overlapping gastrointestinal (GI) etiologies and systemic disorders with GI manifestations that often do not respond to conventional IBS therapies. Delay in diagnosis of these conditions can lead to ongoing patient suffering, reduced quality of life, repetition of invasive testing, increased healthcare utilization, and potentially unnecessary empirical escalation of IBD-related treatments.

AIMS

This review provides a practical approach for the evaluation and diagnosis of IBS mimickers in IBD. We summarize the definition, pathophysiology, diagnosis and treatment of the potential etiologies causing unexplained GI symptoms.

CONCLUSION

Overlapping conditions can co-exist with IBD and explain IBS-like symptoms. The diagnostic work-up in this population should be individualized and tailored to the predominant symptom pattern, associated clinical signs and symptoms and predisposing conditions that can be obtained from a detailed history and physical examination.

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.

Do General Pathologists Assess Gastric and Duodenal Eosinophilia?

CONTEXT.—

Eosinophilic diseases of the gastrointestinal tract (EGIDs), eosinophilic gastritis (EoG), and eosinophilic duodenitis (EoD) are rarely suspected clinically and infrequently detected by pathologists.

OBJECTIVE.—

To determine whether histories of allergic or eosinophilic disorders and requests to rule out EoG and EoD affect pathologists' awareness of eosinophils in gastrointestinal biopsies.

DESIGN.—

Thirty-one community-based pathologists were given 16 sets of biopsies from gastric and duodenal mucosa with elevated eosinophils, Helicobacter pylori gastritis, atrophic gastritis, normal stomach and duodenum, lymphocytosis, and celiac disease. Participants were assigned to 3 groups: group A did not receive histories of allergic or eosinophilic conditions; group B received similar histories plus a clue of possible allergic or eosinophilic conditions; and group C received the same histories as B and was asked to rule out EoG/EoD. A list of gastric and duodenal diagnoses and a space for comments were provided. Results were analyzed descriptively.

RESULTS.—

Pathologists correctly diagnosed most noneosinophilic gastrointestinal disorders, indicating competence in gastrointestinal pathology. With respect to EoG and EoD, pathologists in group C performed significantly better that those in groups A and B. The combined odds ratio with 95% CI was 12.34 (2.87-53.04), P < .001, for A versus C and 4.02 (1.60-10.09), P < .02, for B versus C.

CONCLUSIONS.—

Most pathologists neither reported gastric/duodenal eosinophilia nor diagnosed EoG/EoD, even when provided histories of eosinophilic disorders. Requests to rule out EoG/EoD resulted in only 4 of 11 participants evaluating and counting eosinophils in some cases. Simple evidence-based histopathologic criteria are needed before pathologists can be expected to consider and diagnose EGIDs.

Early life exposures as risk factors for non-esophageal eosinophilic gastrointestinal diseases

OBJECTIVES

Early life exposures increase risk of eosinophilic esophagitis (EoE), but it is unknown whether they contribute to increased risk for non-EoE eosinophilic gastrointestinal diseases (EGIDs). We aimed to assess the association between prenatal, antenatal, and early life factors and non-EoE EGIDs.

METHODS

We conducted a case-control study based in EGID Partners, an online patient-centered research network. Adults (≥18 years) with non-EoE EGIDs, caregivers of children <18 years of age with an EGID, and non-EGID adult controls were eligible. Subjects completed our Early Life Exposure Questionnaire, detailing maternal and early childhood exposures. We assessed for associations between non-EoE EGIDs and early life exposures, focusing on exposures previously evaluated in association with EoE.

RESULTS

We analyzed 61 non-EoE EGID cases and 20 controls. Of the EGID cases, 14 had eosinophilic gastritis, 19 had eosinophilic enteritis, 6 had eosinophilic colitis, and 22 had multiple areas affected; additionally, 30 had esophageal involvement. Relative to controls, EGID cases were more likely to have had antenatal/perinatal pregnancy-related complications (43% vs 13%; p = 0.02), NICU admission (20% vs 0%; p = 0.03), and antibiotics in infancy (43% vs 10%; p = 0.01). With adjustment for age at diagnosis, we observed increased odds of an EGID for pregnancy complications (aOR 3.83; 95% CI: 0.99-14.9) and antibiotic use in infancy (aOR 7.65; 95% CI: 1.28-45.7).

CONCLUSIONS

Early life factors, including pregnancy complications, NICU admission, and antibiotics in infancy, were associated with development of non-EoE EGIDs. The impact of early life exposures on non-EoE EGID pathogenic mechanisms should be investigated.

Review article: Functional dyspepsia-a gastric disorder, a duodenal disorder or a combination of both?

BACKGROUND

Functional dyspepsia (FD) is one of the most frequent conditions in gastroenterological outpatient health care. Most recent research in FD has shifted its focus to duodenal pathophysiological mechanisms, although current treatments still focus mainly the stomach.

AIM

The aim of the study was to provide a comprehensive overview of the pathophysiology of FD focusing on a paradigm shift from gastric towards duodenal mechanisms.

METHODS

We conducted a literature search in PubMed for studies describing mechanisms that could possibly cause FD.

RESULTS

The pathophysiology of FD remains incompletely understood. Recent studies show that duodenal factors such as acid, bile salt exposure and eosinophil and mast cell activation correlate with symptom pattern and burden and can be associated with gastric sensorimotor dysfunction. The evolving data identify the duodenum an interesting target for new therapeutic approaches. Furthermore, the current first-line treatment, that is proton pump inhibitors, reduces duodenal low-grade inflammation and FD symptoms.

CONCLUSION

Future research for the treatment of FD should focus on the inhibition of duodenal mast cell activation, eosinophilia and loss of mucosal integrity.

Molecular analysis of duodenal eosinophilia

BACKGROUND

Eosinophilic duodenitis (EoD), characterized by nonspecific gastrointestinal symptoms and increased numbers of duodenal eosinophils, may be in the eosinophilic gastrointestinal disease spectrum. However, diagnostic thresholds and pathogenic processes of duodenal tissue eosinophilia are inadequately characterized.

OBJECTIVE

We aimed to define an EoD transcriptome and pathologic pathways.

METHODS

RNA sequencing and histologic features of human duodenal biopsy samples were analyzed as a function of duodenal eosinophils levels. For analyses, we defined EoD as more than 52 peak eosinophils/hpf (n = 8), duodenal eosinophilia as 30 to 52 eosinophils/hpf (n = 11), and normal controls as fewer than 30 eosinophils/hpf (n = 8). Associations between gene expression and histologic features were analyzed with Spearman correlation.

RESULTS

We identified 382 differentially expressed genes (EoD transcriptome) between EoD and normal controls (>2-fold change [adjusted P < .05]). The EoD transcriptome distinguished EoD from controls (duodenal eosinophilia and normal controls). The duodenal eosinophil count was correlated with a distinct EoD transcriptome when 50 to 60 peak eosinophils/hpf were present. The EoD transcriptome was enriched in genes involved in IL-4/IL-13 signaling, mast cells, and myeloid progenitor cells. Among duodenal histologic features, lamina propria eosinophil sheets was the most associated with transcriptomic changes (r = 0.66; P < .01). EoD gene signatures were shared with eosinophilic esophagitis and eosinophilic gastritis but not with eosinophilic colitis or celiac disease.

CONCLUSION

We have identified an EoD transcriptomic signature that emerges at 50 to 60 peak eosinophils/hpf and established EoD as part of a spectrum of upper eosinophilic gastrointestinal disorder associated with type 2 immunity and distinct from eosinophilic colitis and celiac disease. These findings provide a basis for improving diagnosis and treatment.

Biologic Therapies for Asthma and Allergic Disease: Past, Present, and Future

The discovery of the mechanism underlying allergic disease, mouse models of asthma, and bronchoscopy studies provided initial insights into the role of Th2-type cytokines, including interlukin (IL)-4, IL-5 and IL-13, which became the target of monoclonal antibody therapy. Omalizumab, Benralizumab, Mepolizumab, Reslizumab, and Tezepelumab have been approved. These biologicals have been shown to be good alternative therapies to corticosteroids, particularly in severe asthma management, where they can improve the quality of life of many patients. Given the success in asthma, these drugs have been used in other diseases with type 2 inflammation, including chronic rhinosinusitis with nasal polyps (CRSwNP), atopic dermatitis, and chronic urticaria. Like the Th2-type cytokines, chemokines have also been the target of novel monoclonal therapies. However, they have not proved successful to date. In this review, targeted therapy is addressed from its inception to future applications in allergic diseases.

Treatment Trends for Eosinophilic Esophagitis and the Other Eosinophilic Gastrointestinal Diseases: Systematic Review of Clinical Trials

BACKGROUND

Eosinophilic gastrointestinal diseases (EGIDs) are chronic inflammatory disorders of the gut, including eosinophilic esophagitis (EoE), gastritis (EoG), duodenitis (EoD), gastroenteritis (EoGE), and colitis (EoC). Available treatments may be ineffective in some patients, and several clinical trials are investigating alternative treatments.

AIM

We performed a systematic review of clinical trials to illustrate EGIDs treatment research trends.

METHODS

We searched clinicaltrials.gov to identify studies investigating EGIDs treatment. For each trial we analysed relevant data, including therapeutic intervention, method of administration, study outcomes, and temporal trends.

RESULTS

For EoE, 66 studies were eligible: 26 testing topical corticosteroids (39.4%), 17 (25.8%) monoclonal antibodies, eight (12.1%) dietary measures, five (7.6%) immunomodulators, one (1.5%) esophageal dilation, and nine (13.6%) other medical treatment strategies. With regard to EoG, EoD, and EoGE, 10 studies were testing monoclonal antibodies (71.5%), one immunomodulators (7.1%), one dietary measures (7.1%), and two other treatments (14.3%). There were no trials for EoC. Ongoing studies on corticosteroids are focused on novel delivery systems, including viscous suspensions, orally disintegrating tablets, or capsules. Increased research on monoclonal antibodies was seen from 2018, with interleukin (IL)-4 receptor-α, IL-5 receptor-α, IL-5, IL-13, IL-15, and Siglec-8 as the targets.

CONCLUSION

Clinical trials on EGIDs are predominantly investigating corticosteroids or monoclonal antibodies. EGIDs therapeutic landscape will be trasnformed imminently.

Biologics in eosinophilic gastrointestinal diseases

Eosinophilic gastrointestinal diseases are a constellation of conditions categorized by the location of eosinophilic infiltration in the gastrointestinal tract. Symptoms vary based on location of eosinophils and age of the patient. There are no approved medications at the current time with individuals using off-label steroids or dietary therapy. Translational research has identified potential pathways to target in the treatment of eosinophilic esophagitis (EoE), gastritis (EoG), and enteritis (EoN), including type 2 pathways, mast cells, and eosinophils. Preliminary studies found cendakimab (anti-interleukin [IL]-13) and dupilumab (anti-IL-4 receptor alpha) to have an effect on eosinophil count and symptoms with dupilumab recently approved. In addition, mepolizumab (anti-IL-5), reslizumab (anti-IL-5), and lirentelimab (anti-Siglec 8) were found to have reduction in eosinophils without reduction of symptoms. For EoG and EoN, both benralizumab (anti-IL-5 receptor) and lirentelimab were found to have histologic and symptom improvement. There are no agents studied for eosinophilic colitis. Results of ongoing phase 3 trials in EoE and EoG/EoN are also anticipated.

Assessment of Esophageal Motility in Patients With Eosinophilic Esophagitis: A Scoping Review

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated condition causing esophageal symptoms, particularly dysphagia. Despite the important progress in the treatment of EoE, a significant proportion of patients continue to report symptoms that negatively impact quality of life. Esophageal manometry is used to assess motility and function, but is not routinely used in EoE. We aimed to systematically review and describe current literature evaluating esophageal manometry in EoE. Forty-eight studies meeting the criteria were identified, describing 802 patients. Using standard water swallow protocols, the proportion of abnormalities detected was not dissimilar to other populations, apart from disorders of esophago-gastric outflow, which were found in 5%. Twelve studies described pretreatment and posttreatment manometry, with motility normalization after pharmacological therapy reported in 20%. Early, brief panesophageal pressurization was described in a number of studies and was more prevalent in the few studies utilizing additional provocation testing. Reports in the literature regarding temporal relationships between manometric findings and symptoms are variable. Esophageal manometry may be capable of detecting clinically relevant changes to esophageal function in EoE. Possible mechanisms are altered neuromuscular function because of secretory products of EoE and/or fibroinflammatory processes, manifesting as pressurization because of altered esophageal compliance. Some changes may be reversible with therapy. Drawing strong conclusions from the literature is difficult, with bias toward case reports and retrospective observation. Adaptations to assessment protocols to include provocation testing may provide more robust evaluation and detect clinically relevant, subtle changes in esophageal function, earlier within the patient pathway.

Small Bowel Endoscopic Features of Eosinophilic Gastroenteritis

Eosinophilic gastroenteritis (EoGE) is a rare digestive disorder characterized by eosinophilic infiltration of the stomach and intestines. In the diagnosis of EoE, it is extremely important to recognize distinctive endoscopic findings and accurately detect increased eosinophilia in gastrointestinal tissues. However, endoscopic findings of EoGE in the small intestine remain poorly understood. Therefore, we conducted a literature review of 16 eligible papers. Redness or erythema was the most common endoscopic finding in the small bowel, followed by villous atrophy, erosion, ulceration, and edema. In some cases, stenosis due to circumferential ulceration was observed, which led to retention of the capsule during small bowel capsule endoscopy. Although many aspects of small bowel endoscopic findings in EoGE remain elusive, the findings presented in this review are expected to contribute to the further development of EoGE practice.

Gastroenterology Practice Patterns Contribute to Missed Diagnoses of Eosinophilic Gastritis and Duodenitis

Background and Aims

Eosinophilic gastritis and eosinophilic duodenitis (EoG/EoD) are often misdiagnosed as functional gastrointestinal (GI) disorders. Consequently, patients with GI symptoms of EoG/EoD may not undergo the necessary steps for diagnosis. We studied gastroenterologists' evaluations of patients with chronic, unexplained, moderate-to-severe GI symptoms that were unresponsive to over-the-counter medications.

Methods

We performed a cross-sectional online survey of 202 board-certified gastroenterologists at office-based practices, community hospitals, or academic institutions. Respondents had been in active clinical practice for 3-35 years post-residency training, spent most of their time on direct patient care, managed ≥1 patient with irritable bowel syndrome and/or functional dyspepsia, and performed ≥1 endoscopy per month. Responses were analyzed to identify barriers to EoG/EoD diagnosis and management.

Results

Respondents managed a mean of 1880 patients per year; the most common diagnoses were functional dyspepsia (36%) and gastroesophageal reflux disease (19%). Mean proportions of patients who underwent upper endoscopy ranged from 42% to 84%. Biopsies were collected from >90% of patients with visible endoscopic mucosal abnormalities vs 42%-72% of patients with normal-appearing mucosae. Approximately 20% of respondents collected only 1-2 biopsies from each site of the GI tract. Only 30% routinely requested pathologists to count eosinophils, and nearly 40% had no histologic threshold for EoG/EoD diagnosis.

Conclusion

Gastroenterologists vary in their evaluation of patients with chronic, unexplained moderate-to-severe GI symptoms. Limited gastric and duodenal biopsy collection, particularly from normal-appearing mucosae, and failure to request tissue eosinophil counts might contribute to underdiagnosis of EoG/EoD. Availability and awareness of EoG/EoD diagnostic guidelines should improve detection in clinical practice.

International Consensus Recommendations for Eosinophilic Gastrointestinal Disease Nomenclature

BACKGROUND & AIMS

Substantial heterogeneity in terminology used for eosinophilic gastrointestinal diseases (EGIDs), particularly the catchall term "eosinophilic gastroenteritis," limits clinical and research advances. We aimed to achieve an international consensus for standardized EGID nomenclature.

METHODS

This consensus process utilized Delphi methodology. An initial naming framework was proposed and refined in iterative fashion, then assessed in a first round of Delphi voting. Results were discussed in 2 consensus meetings, and the framework was updated and reassessed in a second Delphi vote, with a 70% threshold set for agreement.

RESULTS

Of 91 experts participating, 85 (93%) completed the first and 82 (90%) completed the second Delphi surveys. Consensus was reached on all but 2 statements. "EGID" was the preferred umbrella term for disorders of gastrointestinal (GI) tract eosinophilic inflammation in the absence of secondary causes (100% agreement). Involved GI tract segments will be named specifically and use an "Eo" abbreviation convention: eosinophilic gastritis (now abbreviated EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC). The term "eosinophilic gastroenteritis" is no longer preferred as the overall name (96% agreement). When >2 GI tract areas are involved, the name should reflect all of the involved areas.

CONCLUSIONS

This international process resulted in consensus for updated EGID nomenclature for both clinical and research use. EGID will be the umbrella term, rather than "eosinophilic gastroenteritis," and specific naming conventions by location of GI tract involvement are recommended. As more data are developed, this framework can be updated to reflect best practices and the underlying science.

Eosinophilic Gastrointestinal Diseases Beyond the Esophagus: An Evolving Field and Nomenclature

The eosinophilic gastrointestinal diseases (EGIDs) are a group of chronic, immune-mediated gastrointestinal (GI) diseases characterized by GI symptoms and pathologic eosinophilic infiltration of specific areas within the GI tract in the absence of secondary causes of eosinophilia. The non-eosinophilic esophagitis EGIDs remain understudied and likely underdiagnosed, owing in part to the lack of clarity in the terminology previously used to describe these diseases. The newly established EGID nomenclature framework includes a first-tier description of the specific location of GI tract involvement and a second-tier description with more granular characterizations of disease involvement. EGIDs can involve any segment or layer of the GI tract, so patients can present with a wide array of common, nonspecific GI symptoms. Diagnosing EGIDs requires endoscopic evaluation and biopsies showing increased eosinophilic tissue infiltration in the correct clinical context after ruling out other causes of eosinophilia. Although the pathogenesis is not yet fully understood, EGIDs are likely allergic conditions triggered by food antigen exposure. Most patients are currently treated with corticosteroids, but investigations of other pharmacologic and dietary therapies are ongoing. This article highlights the recently updated EGID nomenclature and summarizes the current understanding of the diagnosis, pathogenesis, and treatment of EGIDs.

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.

Eosinophilic Gastrointestinal Diseases Beyond Eosinophilic Esophagitis

The eosinophilic gastrointestinal diseases (EGIDs) are chronic, immune-mediated conditions characterized clinically by GI symptoms and histologically by pathologic infiltration of the GI tract by eosinophils. The most well-studied is eosinophilic esophagitis (EoE), but non-EoE EGIDs are becoming more frequently encountered. These have traditionally been classified by the predominant location inflammation, including eosinophilic gastritis (EoG; stomach only), eosinophilic enteritis (EoN; small bowel only), and eosinophilic colitis (EoC; colon only).(1 , 2 ) However, multiple locations can be involved (e.g. gastric and small bowel involvement), specific segments of the small bowel can be named (e.g. eosinophilic duodenitis; EoD), and efforts are underway to standardize this nomenclature. The non-EoE EGIDs are considered rare diseases, with studies of administrative databases estimating the prevalence to be approximately 3–8/100,000, or ~50,000 cases in the United States.(3 ) However, recent data suggest these conditions may be under diagnosed.(4 ) In this paper, I will review my approach to the diagnosis and management of the non-EoE EGIDs, highlighting a number of principles that can be applied in most settings.

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.