Substantial Variability in Biopsy Practice Patterns Among Gastroenterologists for Suspected Eosinophilic Gastrointestinal Disorders

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.

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.

Non-esophageal eosinophilic gastrointestinal diseases: a narrative review

Eosinophilic gastrointestinal disorders are a group of rare diseases characterized by the infiltration of eosinophils in the gastrointestinal wall in a greater amount than in homeostatic conditions. 'Non-esophageal eosinophilic gastrointestinal disorders' is the umbrella term for all eosinophilic gastrointestinal disorders outside of the well known eosinophilic esophagitis. This includes eosinophilic gastritis, eosinophilic enteritis and eosinophilic colitis. The clinical presentation is atypical and not very different for the three disorders. The depth of infiltration has a bigger influence on the presenting symptoms than the disease location. Although the frequency of diagnosis and research in this subject is increasing over time, non-esophageal eosinophilic disorders are rare and high quality evidence is limited to date. In this narrative review, we provide an overview of the latest insights in the pathophysiology, diagnostic approach and available treatment options. Transcriptome studies have found the pathogenesis to be T helper type 2 driven. Various laboratory findings can be used to trigger raised suspicion and investigation with endoscopy. As the endoscopic appearance of the mucosa is normal in most cases, multiple biopsies in each segment are needed to quantify the amount of eosinophils in the tissue. Eosinophilic cut-offs for diagnosis are a controversial topic and a consensus is still lacking. A recently developed tissue based diagnostic platform which measures differentially expressed genes might be available in the future to classify patients with intermediate eosinophilic tissue levels under the cut-off. For the treatment, corticosteroids are still the cornerstone of treatment but promising research suggests a role of biologicals, such as Lirentelimab (anti-siglec 8) in particular.

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.

Low Prevalence of Extraesophageal Gastrointestinal Pathology in Patients with Eosinophilic Esophagitis

BACKGROUND

Limited data are available to support current guidelines recommendations on obtaining gastric and duodenal biopsies of patients with clinical and histologic manifestations consistent with eosinophilic esophagitis (EoE) to rule out eosinophilic gastritis (EG) or duodenitis (EoD). Our study examined the prevalence of concomitant extraesophageal, gastrointestinal pathology to better characterize the diagnostic yield of additional biopsies.

METHODS

This was a single-center, retrospective study which utilized ICD 9 codes (530.13) and search queries of pathology reports ("Eosinophilic esophagitis," "EoE") to identify EoE patients. Patient endoscopy reports, pathology reports, and office notes were manually reviewed to characterize cases.

RESULTS

The electronic health record search yielded 1,688 EoE adults. In those who had extra-esophageal biopsies obtained, EG was identified in 34 (3.4%), H. pylori in 45 (4.6%), EoD in 27 (3.3%), and histology consistent with celiac disease in 20 (2.5%). Endoscopic abnormalities were found in the stomach of 92% of patients with EoE and EG and in the duodenum of 50% of patients with EoE and EoD. Symptoms of dyspepsia and/or abdominal pain occurred in a significantly greater proportion of patients with extraesophageal disease (64% vs. 19% in EoE group, p < 0.001). Overall, extraesophageal pathology would have been missed in 1.4% of patients lacking either symptoms or endoscopic signs suggestive of extraesophageal disease.

CONCLUSIONS

The yield of gastric and duodenal biopsies in adults with EoE is low, with 6.5% of patients demonstrating histologic features of celiac disease, Helicobacter pylori, EG, and/or EoD. Biopsies of extraesophageal, gastrointestinal sites in patients with suspected or previously diagnosed EoE should consider symptom and endoscopy manifestations as well as the potential impact of histopathologic findings on clinical management.

Accurate and timely diagnosis of Eosinophilic Esophagitis improves over time in Europe. An analysis of the EoE CONNECT Registry

Background

Poor adherence to clinical practice guidelines for eosinophilic esophagitis (EoE) has been described and the diagnostic delay of the disease continues to be unacceptable in many settings.

Objective

To analyze the impact of improved knowledge provided by the successive international clinical practice guidelines on reducing diagnostic delay and improving the diagnostic process for European patients with EoE.

Methods

Cross‐sectional analysis of the EoE CONNECT registry based on clinical practice. Time periods defined by the publication dates of four major sets of guidelines over 10 years were considered. Patients were grouped per time period according to date of symptom onset.

Results

Data from 1,132 patients was analyzed and median (IQR) diagnostic delay in the whole series was 2.1 (0.7‐6.2) years. This gradually decreased over time with subsequent release of new guidelines (p < 0.001), from 12.7 years up to 2007 to 0.7 years after 2017. The proportion of patients with stricturing of mixed phenotypes at the point of EoE diagnosis also decreased over time (41.3% vs. 16%; p < 0.001), as did EREFS scores. The fibrotic sub‐score decreased from a median (IQR) of 2 (1‐2) to 0 (0‐1) when patients whose symptoms started up to 2007 and after 2017 were compared (p < 0.001). In parallel, symptoms measured with the Dysphagia Symptoms Score reduced significantly when patients with symptoms starting before 2007 and after 2012 were compared. A reduction in the number of endoscopies patients underwent before the one that achieved an EoE diagnosis, and the use of allergy testing as part of the diagnostic workout of EoE, also reduced significantly over time (p = 0.010 and p < 0.001, respectively).

Conclusion

The diagnostic work‐up of EoE patients improved substantially over time at the European sites contributing to EoE CONNECT, with a dramatic reduction in diagnostic delay.

Mast Cell and Eosinophil Counts in Gastric and Duodenal Biopsy Specimens From Patients With and Without Eosinophilic Gastroenteritis

BACKGROUND & AIMS

Mast cells are believed to contribute to the development of eosinophilic gastrointestinal disorders (EGIDs). We quantified mast cells and eosinophils in biopsy specimens from patients with EGIDs and without known esophageal or gastrointestinal disease to investigate associations between these cell types and EGID and its features.

METHODS

We conducted a retrospective study of patients with EGID (n = 52) and of children and adults who underwent upper endoscopy and were found to have no evidence of gastrointestinal or systemic conditions (n = 123). We re-reviewed archived gastric and duodenal biopsy specimens to quantify mast cells (by tryptase immunohistochemistry) and eosinophils. We calculated the specificity of cell count thresholds for identification of patients with EGIDs and evaluated the correlation between mast cell and eosinophil counts and clinical and endoscopic features.

RESULTS

In the gastric biopsy specimens from patients without esophageal or gastrointestinal diseases, the mean mast cell count was 18.1 ± 7.2 cells per high-power field (hpf), and the peak mast cell count was 21.9 ± 8.2 cells/hpf. In the duodenal biopsy specimens from patients without esophageal or gastrointestinal diseases, the mean mast cell count was 23.6 ± 8.1 cells/hpf and the peak mast cell count was 28.1 ± 9.3 cells/hpf. The mean and peak eosinophil counts in gastric biopsy specimens from patients without disease were 3.8 ± 3.6 eosinophils/hpf and 5.8 ± 5.0 eosinophils/hpf; the mean and peak eosinophil counts in duodenal biopsy specimens were 14.6 ± 8.9 eosinophils/hpf and 19.5 ± 11.0 eosinophils/hpf. A mean count of 20 eosinophils/hpf in gastric biopsy specimens or 30 eosinophils/hpf in duodenal biopsy specimens identified patients with EGIDs with high specificity. Gastric and duodenal biopsy specimens from patients with EGIDs had significant increases in mean mast cell counts compared with biopsy specimens from patients without EGIDs. There was a correlation between mean mast cell and eosinophil counts in duodenal biopsy specimens (R = 0.47; P = .01). The mean mast cell and eosinophil counts did not correlate with symptoms or endoscopic features of EGIDs.

CONCLUSIONS

We identified thresholds for each cell type that identified patients with EGIDs with 100% specificity. The increased numbers of mast cells and eosinophils in gastric and duodenal tissues from patients with EGIDs supports the concept that these cell types are involved in pathogenesis. However, cell counts are not associated with symptoms or endoscopic features of EGIDs.

Peripheral eosinophilia and hypoalbuminemia are associated with a higher biopsy diagnostic yield for eosinophilic gastroenteritis

BACKGROUND

Gastric and duodenal mucosa may appear normal in eosinophilic gastroenteritis (EGE). Adult gastroenterologists typically biopsy only in the setting of mucosal abnormalities or symptoms, while pediatric providers biopsy all patients. The biopsy yield of EGE has not been adequately evaluated.

AIMS

To evaluate the biopsy yield of EGE in a pediatric cohort and assess predictors of increased biopsy yield.

METHODS

We identified patients age 0-18 who underwent upper endoscopy. We recorded endoscopic findings, pathology, demographics, and clinical and laboratory characteristics. We identified EGE cases (>20 eosinophils per high-power field on stomach and/or duodenum biopsy). We compared characteristics between EGE and non-EGE cases, calculated biopsy diagnostic yield, and performed multivariate analysis for predictors of increased biopsy yield.

RESULTS

In 509 patients (55.6% female, mean age 10.3 years, 69.7% white, 58.7% atopic), biopsy diagnostic yield for EGE was 1.2% (6/509) among all subjects, 7.7% (3/39) for those with peripheral eosinophilia (≥500 eos/uL), 9.1% (3/33) for those with hypoalbuminemia (<3.5 g/dL), and 25.0% (3/12) for those with peripheral eosinophilia and hypoalbuminemia. The odds of EGE were 27.8 (95% CI 3.3-231.8) times greater among those with peripheral eosinophilia. The mean total biopsy surface area and number of fragments was similar between patients with and without EGE. The area under the ROC curve for blood eosinophil counts and albumin level for predicting EGE was 0.926.

CONCLUSIONS

The biopsy diagnostic yield for EGE is low but increases with peripheral eosinophilia and hypoalbuminemia. Patients with these features should have biopsies obtained, regardless of endoscopic appearance.

Association Between Endoscopic and Histologic Findings in a Multicenter Retrospective Cohort of Patients with Non-esophageal Eosinophilic Gastrointestinal Disorders

BACKGROUND

Little is known about the endoscopic and histologic findings of non-esophageal eosinophilic gastrointestinal diseases (EGID).

AIM

To characterize the presenting endoscopic and histologic findings in patients with eosinophilic gastritis (EG), eosinophilic gastroenteritis (EGE), and eosinophilic colitis (EC) at diagnosis and 6 months after initiating the treatment.

METHODS

We conducted a retrospective cohort study at 6 US centers associated with the Consortium of Eosinophilic Gastrointestinal Researchers. Data abstracted included demographics, endoscopic findings, tissue eosinophil counts, and associated histologic findings at diagnosis and, when available, after initial treatment.

RESULTS

Of 373 subjects (317 children and 56 adults), 142 had EG, 123 EGE, and 108 EC. Normal endoscopic appearance was the most common finding across all EGIDs (62% of subjects). Baseline tissue eosinophil counts were quantified in 105 (74%) EG, 36 (29%) EGE, and 80 (74%) EC subjects. The mean peak gastric eosinophil count across all sites was 87 eos/hpf for EG and 78 eos/hpf for EGE. The mean peak colonic eosinophil count for EC subjects was 76 eos/hpf (range 10-500). Of the 29% of subjects with post-treatment follow-up, most had an improvement in clinical, endoscopic, and histologic findings regardless of treatment utilized. Reductions in tissue eosinophilia correlated with improvements in clinical symptoms as well as endoscopic and histologic findings.

CONCLUSIONS

In this large cohort, normal appearance was the most common endoscopic finding, emphasizing the importance of biopsy, regardless of endoscopic appearance. Decreased tissue eosinophilia was associated with improvement in symptoms, endoscopic, and histologic findings, showing that disease activity is reversible.

Increasing Rates of Diagnosis, Substantial Co-Occurrence, and Variable Treatment Patterns of Eosinophilic Gastritis, Gastroenteritis, and Colitis Based on 10-Year Data Across a Multicenter Consortium

OBJECTIVES

The literature related to eosinophilic gastritis (EG), gastroenteritis (EGE), and colitis (EC) is limited. We aimed to characterize rates of diagnosis, clinical features, and initial treatments for patients with EG, EGE, and EC.

METHODS

In this retrospective study, data were collected from 6 centers in the Consortium of Eosinophilic Gastrointestinal Researchers from 2005 to 2016. We analyzed demographics, time trends in diagnosis, medical history, presenting symptoms, disease overlap, and initial treatment patterns/responses.

RESULTS

Of 373 subjects (317 children and 56 adults), 38% had EG, 33% EGE, and 29% EC. Rates of diagnosis of all diseases increased over time. There was no male predominance, and the majority of subjects had atopy. Presenting symptoms were similar between diseases with nausea/vomiting and abdominal pain, the most common. One hundred fifty-four subjects (41%) had eosinophilic inflammation outside of their primary disease location with the esophagus the second most common gastrointestinal (GI) segment involved. Multisite inflammation was more common in children than in adults (68% vs 37%; P < 0.001). Initial treatment patterns varied highly between centers. One hundred-nine subjects (29%) had follow-up within 6 months, and the majority had clinical, endoscopic, and histologic improvements.

CONCLUSIONS

In this cohort, EG, EGE, and EC were diagnosed more frequently over time, and inflammation of GI segments outside the primary disease site co-occurrence of atopy was common with a lack of male predominance. Symptoms were similar between diseases, and initial treatment strategies were highly variable. Future investigation should assess the cause of the increased prevalence of eosinophilic GI disorders and prospectively assess outcomes to establish treatment algorithms.

Practice Pattern Variation in Pediatric Eosinophilic Esophagitis in the Carolinas EoE Collaborative: A Research Model in Community and Academic Practices

OBJECTIVES

Differences in the initial management of pediatric eosinophilic esophagitis (EoE) by practice setting have not been well characterized. We aimed to characterize these differences for sites in the Carolinas EoE Collaborative (CEoEC), a multicenter network of academic and community practices.

METHODS

We performed a retrospective cohort study of pediatric EoE patients at five CEoEC sites: University of North Carolina (UNC) Hospital, Charlotte Asthma and Allergy Specialists, Greenville Health Systems, Wake Forest Baptist Medical Center, and the Medical University of South Carolina Hospital. Cases of EoE were defined by consensus guidelines. Data were extracted from electronic medical records. We tested for differences among sites and used a multinomial model (polytomous regression) to assess associations between treatment and site, adjusting on patient factors.

RESULTS

We identified 464 children with EoE across the CEoEC sites. The median age was highest at Wake Forest (11.4 years), the median eosinophil count was highest at UNC (69 eos/hpf), and UNC had the most male patients (82%). UNC used topical steroids for initial treatment in 86% of cases, compared with <1% in Greenville (P < 0.01). Greenville used dietary elimination more frequently than UNC (81% vs 2%, P < 0.01). Differences in treatment approach held after adjusting for potential baseline confounders. There was no significant association between patient factors and initial treatment approach.

CONCLUSIONS

Significant differences in EoE patient factors and treatment approaches were identified across CEoEC sites and were not explained by patient or practice factors. This suggests that institutional or provider preferences drive initial treatment approaches, and that more data are needed to drive best practice decisions.

Individuals affected by eosinophilic gastrointestinal disorders have complex unmet needs and frequently experience unique barriers to care

INTRODUCTION

Eosinophilic gastrointestinal disorders (EGIDs) are a rare but emerging healthcare problem. Patient advocacy groups (PAGs) have an important role in representing the EGID community, and serve as valuable research partners. By leveraging the partnership between medical researchers and PAGs, we examined the unmet needs and barriers to care perceived by individuals affected by EGIDs. Next, we examined if these varied between adult EGID patients and adult caregivers of children with EGID.

METHODS

Adult EGID patients and adult caregivers of children (<18 years) with EGIDs participated in this study. PAGs conducted focus groups comprised of individuals affected by EGIDs to identify domains and questions meaningful to the EGID community and this information was used to develop an online REDCap survey. The survey consisted of 58 questions across medical, healthcare, social, and emotional impact domains. It was distributed via the PAGs' web-based platforms. Demographic data, and responses to questions on a six-point Likert scale were collected and analyzed.

RESULTS

Of the 361 responses analyzed, 90 (25%) were from adult EGID patients and 271 (75%) were from adult caregivers. Of the applicable responses, in the medical domain only 19% of participants indicated that repeated endoscopies to monitor response to treatment was convenient. In the healthcare domain, 67% indicated that lack of insurance coverage for elemental formula was a barrier. In the social domain, only 5% of respondents reported adequate awareness of EGIDs in schools. In the emotional domain, 64% had experienced significant stress due to EGID related out-of-pocket costs. Multivariate logistic regression revealed that some of these responses varied between adult EGID patients and adult caregivers of children with EGID. The respondents indicated highest priority for improvement in the medical domain compared to other domains.

CONCLUSIONS

Individuals affected by EGIDs have a constellation of complex unmet needs and perceived barriers across medical, healthcare, social and emotional domains. Addressing unmet needs in the medical domain is relatively more important for the EGID community. Understanding unmet needs and barriers will likely help design improved patient-centered EGID care paradigms.

Practice Differences in the Diagnosis and Management of Eosinophilic Esophagitis Among Adult and Pediatric Gastroenterologists in Israel

OBJECTIVES

Eosinophilic esophagitis (EoE) guidelines call for similar practices in adults and children with EoE. We compared the diagnostic and management practices of gastroenterologists treating adult and pediatric patients suspected of having, or diagnosed with, EoE.

METHODS

A 19-question multiple-choice questionnaire was given to gastroenterologists treating either adults or children. Questions explored 4 areas of interest: physician demographics, diagnosis and tissue sampling practices, management, and the need for societal publications on EoE.

RESULTS

Completed questionnaires were returned by 85/180 adult and 30/40 pediatric gastroenterologists (PGs). Compared to PGs, adult gastroenterologists (AGs) took esophageal biopsies significantly less frequently in the following scenarios: endoscopy without esophageal symptoms or macroscopic endoscopic findings (10% vs 57%; P < 0.001), dysphagia without macroscopic findings (83% vs 100%; P = 0.019), and gastroesophageal reflux symptoms with distal esophageal erythema (44% vs 100%; P < 0.001). Significantly fewer AGs reported taking gastric and duodenal biopsies when EoE was suspected (29% vs 90%; P < 0.001). AGs more often followed patients clinically (30% vs 0%; P < 0.001) rather than endoscopically, and were far less inclined to implement elimination diets compared to PGs (23% vs 68%; P < 0.001).

CONCLUSIONS

Significant disparities exist between gastroenterologists treating adult and pediatric patients with EoE. These findings may impact rates of diagnosis, appropriate treatment, monitoring, long-term outcomes, and may affect negatively transition from pediatric to adult care.

Creating a multi-center rare disease consortium - the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR)

 Eosinophilic gastrointestinal disorders (EGIDs) affect various segments of the gastrointestinal tract. Since these disorders are rare, collaboration is essential to enroll subjects in clinical studies and study the broader population. The Rare Diseases Clinical Research Network (RDCRN), a program of the National Center for Advancing Translational Sciences (NCATS), funded the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR) in 2014 to advance the field of EGIDs. CEGIR facilitates collaboration among various centers, subspecialties, patients, professional organizations and patient-advocacy groups and includes 14 clinical sites. It has successfully initiated two large multi-center clinical studies looking to refine EGID diagnoses and management. Several pilot studies are underway that focus on various aspects of EGIDs including novel therapeutic interventions, diagnostic and monitoring methods, and the role of the microbiome in pathogenesis. CEGIR currently nurtures five physician-scholars through a career training development program and has published more than 40 manuscripts since its inception. This review focuses on CEGIR's operating model and progress and how it facilitates a framework for exchange of ideas and stimulates research and innovation. This consortium provides a model for progress on other potential clinical areas.

Gene Expression Patterns in Distinct Endoscopic Findings for Eosinophilic Gastritis in Children

BACKGROUND

Eosinophilic gastritis (EG) is clinicopathologically characterized by both marked gastric eosinophilia and clinical symptoms. The endoscopic findings in EG vary among patients, leading to clinical confusion. However, little is known about the relationship between precise endoscopic findings and the pathophysiological process responsible for EG.

OBJECTIVE

We aimed to elucidate whether the gross endoscopic findings of EG can be classified into distinct gene expression profiles.

METHODS

We enrolled pediatric patients who underwent gastrointestinal endoscopy for clinical symptoms suggestive of eosinophilic gastrointestinal disorder between 2011 and 2016. EG was diagnosed when gastric eosinophilia was greater than or equal to 30 eosinophils/hpf. The gene expression profiles of gastric biopsies were assessed using microarray technology.

RESULTS

Patients with EG and control subjects (n = 8, each) were examined. On the microarray, 1,999 genes were differentially expressed between EG and the controls (≥2-fold difference, adjusted P value < .05), including significant upregulation of eotaxin-3 (C-C chemokine ligand 26). The endoscopic findings of patients with EG fell roughly into 2 types, namely, ulcerative and nodular lesions. Despite identifying distinct patterns of gene expression, most differentially regulated genes overlapped between the 2 endoscopic finding types. Several gene ontology terms were enriched in the substantially overlapped genes, but not in each of the distinct genes.

CONCLUSIONS

Our results strongly indicate that ulcerative and nodular lesions are a single disease, EG, or a variation thereof, in spite of morphological differences. Our findings may contribute to a better understanding of the pathogenesis of EG, as well as to more accurate diagnosis of this disease.