Eosinophilic Gastrointestinal Disorders

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.

Pharmacologic Management of Non-Eosinophilic Esophagitis Eosinophilic Gastrointestinal Diseases

Data for pharmacologic treatments for non-eosinophilic esophagitis (EoE) eosinophilic gastrointestinal diseases (EGIDs) are limited. Nevertheless, because of the increasing understanding of EGID pathogenesis, a number of medications are used to treat EGIDs, though all are currently off-label. Initial therapy generally starts with corticosteroids, and "topical" delivery is preferred over systemic due to long-term side effects. A number of other small molecules could potentially be used, ranging from allergy medications to immunosuppressants. Biologics are also being used and investigated for EGIDs and represent promising targeted therapies. Multiple therapeutic targets have also been identified, many of which overlap with EoE targets.

Role of Mast Cells in Eosinophilic Gastrointestinal Diseases

Mast cells play a central role in the pathogenesis of eosinophilic gastrointestinal disorders (EGIDs), including eosinophilic esophagitis. Their interactions with immune and structural cells, involvement in tissue remodeling, and contribution to symptoms make them attractive targets for therapeutic intervention. More is being discovered regarding the intricate interplay of mast cells and eosinophils. Recent studies demonstrating that depletion of eosinophils is insufficient to improve symptoms of EGIDs have raised the question of whether other cells may play a role in symptomatology and pathogenesis of EGIDs.

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.

Autism in patients with eosinophilic gastrointestinal disease: A systematic review with meta-analysis

PURPOSE

Neurodevelopmental disorders, such as autism spectrum disorder (ASD), have been increasingly associated with eosinophilic gastrointestinal disorders (EGID). However, the relationship between these diseases remains unclear. We performed a systematic review with meta-analysis to address this issue.

METHODS

The search was performed according to the PRISMA guidelines using descriptors for ASD and EGIDs from the MEDLINE, Embase, PsycInfo, LILACS, and Web of Science databases. Observational studies with the prevalence of ASD in any EGID were included. The study protocol was registered on the PROSPERO platform under the number CRD42023455177.

RESULTS

The total dataset comprised 766,082 participants. The result of the single-arm meta-analysis showed an overall prevalence of ASD in the population with EGID of 21.59% (95% CI: 10.73-38.67). There was an association between EGID and ASD (OR: 3.44; 95% CI: 1.25-2.21), also significant when restricted only to EoE (OR: 3.70; 95% CI: 2.71-5.70).

DISCUSSION

Recent studies have implicated the influence of an inadequate epithelial barrier integrity in the pathogenesis of several diseases. The role of this mechanism can be extended to situations beyond allergic reactions, including other conditions with underlying immunological mechanisms. Several diseases are potentially related to the systemic effect of bacterial translocation in tissues with defective epithelial barriers.

CONCLUSION

Our meta-analysis provides evidence that supports the consideration of EGID in patients with ASD and ASD in patients with EGID. Despite its limitations, the results should also be validated by future studies, preferably using multicenter prospective designs in populations with low referral bias.

Common and disparate clinical presentations and mechanisms in different eosinophilic gastrointestinal diseases

Eosinophilic gastrointestinal diseases (EGIDs) are a group of diseases characterized by selective eosinophil infiltration of the gastrointestinal (GI) tract in the absence of other causes of eosinophilia. These diseases are generally driven by type 2 inflammation, often in response to food allergen exposure. Among all EGIDs, the clinical presentation often includes a history of atopic disease with a variety of GI symptoms. EGIDs are traditionally separated into eosinophilic esophagitis (EoE) and non-EoE EGIDs. EoE is relatively better understood and now associated with clinical guidelines and 2 US Food and Drug Administration-approved treatments, whereas non-EoE EGIDs are rarer and less well-understood diseases without US Food and Drug Administration-approved treatments. Non-EoE EGIDs are further subclassified by the area of the GI tract that is involved; they comprise eosinophilic gastritis, eosinophilic enteritis (including eosinophilic duodenitis), and eosinophilic colitis. As with other GI disorders, the disease presentations and mechanisms differ depending on the involved segment of the GI tract; however, the differences between EoE and non-EoE EGIDs extend beyond which GI tract segment is involved. The aim of this article is to summarize the commonalities and differences between the clinical presentations and disease mechanisms for EoE and non-EoE EGIDs.

Beyond Confirmed Mast Cell Activation Syndrome: Approaching Patients With Dysautonomia and Related Conditions

Allergist-immunologists face significant challenges as experts in an ever-evolving field of neuroimmunology. Among these challenges is the increasingly frequent need to counsel patients with suspected mast cell activation disorders about perceived comorbidities, which may include hypermobile Ehlers-Danlos syndrome, amplified pain syndrome, fibromyalgia, burning sensation syndromes, migraines, irritable bowel syndrome, and postural orthostatic tachycardia syndrome. Patients may experience comorbid anxiety, panic disorder, and depression associated with disturbed sleep, fatigue, and cognitive impairment that often worsen when their physical symptoms increase in severity. These conditions may mimic mast cell activation disorders and are emotionally taxing for patients and clinicians because they are often accompanied by vague diagnostic courses, perceived unmanageability, social stigma, and significant impairment in quality of life. Combined with relatively poorly researched therapies, it is no surprise that clinicians may feel overwhelmed or find it difficult to provide consistently compassionate care for this population. In this article, we review available therapies for these conditions, which run the gamut from physical therapy to antidepressants to multimodal pain control. We highlight the benefit of multidisciplinary care within the primary care home, which includes an important role by the allergist-immunologist. By outlining simple approaches to initial treatment, we hope to empower clinicians with the tools needed to curb emotional burnout and embrace this patient population with compassion.

Clinical and atopic features of patients with primary eosinophilic colitis: an Italian multicentre study

Eosinophilic colitis (EC) is the rarest among primary eosinophilic gastrointestinal disorders (EGID). EC is underdiagnosed due to its blurred and proteiform clinical manifestations. To explore the clinical and atopic characteristic of EC adult patients, the diagnostic delay, and relapse-associated factors, by comparison with patients with eosinophilic esophagitis (EoE) and irritable bowel syndrome (IBS). EC patients followed-up at four clinics were included, and clinical, histopathological, and laboratory data were retrieved. As control groups, age-matched patients with EoE and IBS were recruited. Allergy tests included skin prick test and serum specific IgE. Diagnostic delay was assessed. Overall, data from 73 patients were retrieved, including 40 with EC (median age 39 years IQR 22.5-59, F:M 2.1:1), 12 with EoE (F:M ratio: 1:5), and 21 with IBS (F:M ratio: 1:0.9). The most common features in EC patients were female sex (67.5%), atopy (77.5%), abdominal pain/distention (70%), diarrhoea (77.5%), and faecal calprotectin elevation (22.5%). Blood eosinophils were elevated in EoE, but not in EC (p < 0.001), while ECP did not differ across the three groups (p = 0.4). The frequency of allergen sensitization reached 25% of patients. Several frequent pan-allergens for this region were present. The overall diagnostic delay was 10 months (IQR 4-15). Factors contributing to a greater diagnostic delay were atopy, weight loss, and a previous misdiagnosis. EC is mostly a diagnosis of exclusion, burdened by a substantial diagnostic delay. In female patients the presence of allergen sensitization, abdominal symptoms and faecal calprotectin elevation should raise the suspicion of EC.

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.

Eosinophilic Enteritis Causing Recurrent Small Bowel Obstruction: A Case Report

Eosinophilic enteritis is an inflammatory condition characterized by eosinophilic infiltration of the gastrointestinal tract. This case report highlights a unique presentation of eosinophilic enteritis as a cause of recurrent small bowel obstruction. The diagnosis was elusive despite extensive abdominal imaging. A histopathologic examination of a full-thickness bowel segment showing extensive eosinophilic infiltration in the muscularis propria was vital in establishing the diagnosis. This report underscores the diagnostic complexities associated with eosinophilic enteritis and the need to consider this condition as a potential cause of recurrent abdominal pain and small bowel obstruction.

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.

Dupilumab Can Induce Remission of Eosinophilic Gastritis and Duodenitis: A Retrospective Case Series

INTRODUCTION

Noneosinophilic esophagitis eosinophilic gastrointestinal disorders (non-EoE-EGIDs) have limited treatment options to induce histologic and clinical remission. Dupilumab is a human monoclonal antibody against the interleukin-4 receptor ɑ subunit, which has been reported to induce improvement in pediatric patients with non-EoE-EGIDs.

METHODS

We conducted a retrospective chart review to identify if patients with eosinophilic gastritis (EoG) and/or eosinophilic duodenitis (EoD) experience clinical and histologic remission with dupilumab.

RESULTS

Twelve patients were included (2 patients with EoG and EoD, 3 patients with EoG only, and 7 patients with EoD only). All patients experienced improvement of at least 1 symptom on dupilumab, 3 patients (25%) had no change in severity of 1 or more of their symptoms, and no patients had worsening symptoms. On dupilumab, 2 patients with EoG (40%) and 3 patients with EoD (33.3%) were completely asymptomatic. Histologic changes were investigated in a subanalysis including 8 patients (2 patients with EoG and EoD, 2 patients with EoG only, and 4 patients with EoD only). Median peak gastric eosinophil counts in patients with EoG reduced from 80.5 eos/hpf (min-max 32-150, Q1-Q3 45.5-111) to 7.5 eos/hpf (min-max 0-28, Q1-Q3 1.5-16.8). Median peak duodenal eosinophil counts in patients with EoD reduced from 39 eos/hpf (min-max 30-50, Q1-Q3 37.3-46.3) to 16.5 eos/hpf (min-max 0-50, Q1-Q3 8-38.5). All 4 patients (100%) with EoG and 4 patients (66.6%) with EoD had histologic remission on dupilumab.

DISCUSSION

In this retrospective case series, we showed preliminary evidence that dupilumab may be effective in inducing histologic and symptomatic remission in patients with non-EoE-EGIDs.

A Case of Refractory Eosinophilic Gastrointestinal Disease Successfully Treated With Dupilumab

Eosinophilic infiltration of the gastrointestinal (GI) tract beyond the esophagus is a rare condition in adults with limited data on treatment. Current treatments with steroids and diet modifications have shown benefit, but when these treatments fall short, there is little research-driven guidance for further recommendations. We present a case of eosinophilic GI disease with extensive involvement of the GI tract successfully treated with dupilumab after failure of traditional treatment occurred.

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.

The impact of COVID-19 on Japanese patients with eosinophilic gastrointestinal disorders during the vaccination era

Background

Eosinophilic gastrointestinal disorders (EGIDs) are chronic allergic diseases categorized as eosinophilic esophagitis (EoE) and non-EoE EGIDs. Few studies regarding the association between EGIDs and coronavirus disease 2019 (COVID-19) have been reported. Although most Japanese individuals received the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine, the incidence of COVID-19 remained high in 2022. This study examines the incidence of COVID-19 in patients with EGIDs during the vaccination era.

Methods

Patients with EGIDs who visited our department between October and December 2022 were enrolled in the study. The incidence and severity of COVID-19 prior to October 1, 2022 were determined. Patients who reported having COVID-19 also reported their hospitalization history, intensive care unit admissions, and EGID flares. The number of SARS-CoV-2 vaccinations received and treatment for EGIDs were obtained from the patients' medical records.

Results

Of 111 patients with EGIDs (65 with EoE and 46 with non-EoE EGIDs) included in this study, 31 (28%) patients reported having COVID-19, including 14 (22%) with EoE and 17 (37%) with non-EoE EGIDs. Fifty-nine (84%) patients received two or more vaccinations, and 11 (16%) patients received no vaccinations. COVID-19 was mild in all but one patient who had moderate symptoms. COVID-19 was not associated with EGID flares. EGID treatments and an unvaccinated status were not associated with an increased risk of COVID-19.

Conclusion

COVID-19 was mild in patients with EGIDs and not associated with EGIDs flares during the vaccination era. There was a relatively high incidence of COVID-19 among patients with non-EoE EGIDs.

Distinct CRTH2+CD161+ (peTh2) memory CD4+ T-cell cytokine profiles in food allergy and eosinophilic gastrointestinal disorders

INTRODUCTION

Although IgE-mediated food allergy (FA) and eosinophilic gastrointestinal disorders (EGID) are clinically distinct and treated differently, pathogenic effector Th2 (peTh2) cells are implicated in the pathogenesis of both FA and EGID. The aim of this study was to better characterize peTh2 cells in the context of FA and EGID and the overlap between these two conditions.

METHODS

Peripheral blood peTh2 cells (CD3+CD4+CD27-CD49d+CRTH2+CD161+) were profiled by intracellular cytokine flow cytometry in the following patient cohorts: patients with FA alone (n = 8), FA and food-triggered EGID (EGID+FA+FT, n = 7), food-triggered EGID alone (EGID+FT, n = 7), EGID without FA or specific food triggers (ONLY_EGID, n = 9), and healthy volunteers (HV, n = 7). Overnight peripheral blood mononuclear cell (PBMC) culture supernatants were assessed for cytokine production by multiplex analysis.

RESULTS

CRTH2+CD161+ (peTh2) memory CD4+ T cells were significantly increased in both patients with FA and those with ALL_EGID (inclusive of EGID+FA+FT, EGID+FT and ONLY_EGID) when compared to HV. However, ALL_EGID patients, particularly those with EGID+FA+FT, had significantly elevated IL-5+IL-13+ peTh2 cells, whereas FA patients had significantly elevated IFN-γ or IL-17A-expressing peTh2 cells. This finding was supported by increased spontaneous IL-5 and IL-13 production in overnight cultures of PBMC from EGID+FA+FT patients compared to spontaneous IL-10 and IFN-γ production by PBMC from FA patients. FA patients had increased IL-9, IL-10, IL-17A, and IFN-γ production in overnight cultures of stimulated PBMC.

CONCLUSIONS

EGID and IgE-mediated FA share a common cell subtype defined by specific surface markers and termed CRTH2+CD161+ (peTh2) memory CD4+ T cells. However, the cytokine profiles of these CRTH2+CD161+ (peTh2) memory CD4+ T cells are markedly different between the two disorders.

Eosinophilic Enteritis Flare-Up Mimicking Acute Gastroenteritis: A Rare Case

Eosinophilic enteritis is a rare subset of eosinophilic gastrointestinal disorders. It typically presents with chronic symptoms of abdominal pain, nausea, vomiting, diarrhea, and ascites. However, the clinical presentation can vary due to acute flare-ups. Here, we present a case of eosinophilic enteritis in a young female patient with intractable vomiting and diarrhea, mimicking acute gastroenteritis in the absence of other gastrointestinal symptoms. This case illustrates the challenge of diagnosing acute and diverse presentations of eosinophilic enteritis. It also highlights the importance of promptly treating and confirming the diagnosis through urgent tissue histopathology in adolescents with unexplained vomiting and diarrhea.

Eosinophilic gastrointestinal diseases with esophageal involvement: Analysis of 212 patients

BACKGROUND

Primary eosinophilic gastrointestinal diseases (EGID) are chronic inflammatory disorders of the gastrointestinal tract with unknown etiology. Features, utility, and evolution are still unknown in screening for EGID in adult patients with eosinophilic esophagitis (EoE).

OBJECTIVES

To evaluate the prevalence, characteristics, comorbidities, and evolution of EGID in adults diagnosed with EoE and investigate differences between both groups.

METHODS

Prospective unicenter observational and analytical study. Gastric and duodenal biopsies were obtained during upper baseline endoscopy in all consecutive EoE adult patients evaluated. A colonoscopy with colon biopsies was performed upon persistent diarrhea and normal duodenal biopsies.

RESULTS

212 EoE patients were included. Nine patients (4.3%) also showed significant eosinophilic infiltration in at least one organ within the digestive tract. The most common site affected was the small bowel (78%). Gastrointestinal symptoms (43% vs. 100%, p<0.002) and, more specifically, either abdominal pain or diarrhea (17% vs. 78%, p<0.001), some food sensitizations, and digestive comorbidities (p<0.05) were significantly more common in patients with EGID. Gastrointestinal symptoms were present in 94/212 (44%) patients, of whom 9 (10%) had EGID. Considering only abdominal pain or diarrhea, 20% suffered from it.

CONCLUSIONS

EGID rarely coexist with EoE, even when gastrointestinal symptoms are present. These findings advise against routine gastric, duodenal, or colon biopsies in adult EoE patients with gastrointestinal symptoms. Most of the characteristics of EoE do not change due to having EGID except gastrointestinal symptoms, digestive comorbidities, and sensitizations to some foods. The evolution was generally favorable despite intermittent adherence to treatment, especially maintenance.

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.

Local type 2 immunity in eosinophilic gastritis

BACKGROUND

Eosinophilic gastritis (EoG) associates with type 2 immunity. However, the type 2 cytokine cellular source, gastric T-cell composition, and gastric T-cell relationship (or relationships) with disease pathology remain understudied.

OBJECTIVE

We defined gastric T-cell populations and their association with histologic and endoscopic EoG pathology.

METHODS

Gastric biopsy samples (n = 6 EoG, n = 7 control) were subjected to histologic, endoscopic, and flow cytometry analyses. In a complementary cohort (n = 83 EoG), IL4, IL5, and IL13 mRNA levels were correlated with EoG pathologic parameters.

RESULTS

Gastric biopsy samples contained CD3+ T cells that were mainly CD8+; the CD8/CD4 ratio was comparable in EoG and control biopsy samples (5.7 ± 3.0 and 4.3 ± 0.6, respectively; P = .28). Gastric regulatory T (CD3+CD4+FOXP3+) and TH2 (CD3+CD4+GATA3+) cell levels were increased in EoG versus controls (2-fold, P < .05 and 10-fold, P < .001, respectively) and correlated with gastric eosinophil levels (r = 0.63, P < .05 and r = 0.85, P < .001, respectively), endoscopic pathology (r = 0.56, P < .01; r = 0.84, P < .001, respectively), and histopathology (r = 0.72, P < .01; r = 0.82, P < .01, respectively). Cytokine-positive, most notably IL-4+, TH2 cell levels strongly correlated with histologic and endoscopic scores (r = 0.82, P < .0001 and r = 0.78, P < .0001, respectively). In an independent EoG cohort (n = 83), bulk gastric IL4, IL5, and IL13 mRNA levels correlated with histologic score (r = 0.22, P < .005; r = 0.54, P < .0001; and r = 0.36, P < .0001, respectively) and endoscopic score (r = 0.27, P < .001; r = 0.40, P < .0001; and r = 0.35, P < .0001, respectively).

CONCLUSIONS

EoG is a TH2 cell-associated disease featuring increased gastric type 2 cytokine-producing CD3+CD4+GATA3+TH2 cells that strongly correlate with disease pathologies.

Eosinophilic gastroenteritis: Pathogenesis, diagnosis, and treatment

ABSTRACT

Eosinophilic gastroenteritis (EGE) is a gastrointestinal disorder of unclear etiology that is characterized by eosinophilic infiltration of the stomach and small intestine, and consists of mucosal, muscular, and serosal subtypes. Eosinophilic infiltration of the gastrointestinal tract is a fundamental histopathological characteristic of EGE and is driven by several T-helper type 2 (Th2)-dependent cytokines and induced by food allergy. Due to the lack of a diagnostic gold standard, EGE has a high rate of delayed diagnosis or misdiagnosis. However, several new diagnostic strategies have been developed, such as novel genetic biomarkers and imaging tests. Although dietary therapy and corticosteroids remain the common choices for EGE treatment, recent decades have seen the emergence of novel treatment alternatives, such as biologics that target particular molecules involved in the pathogenic process. Preliminary investigations and clinical trials have demonstrated the efficacy of biologics and provided additional insights for the era of refractory or corticosteroid-dependent EGE biologics.

The efficacy of dupilumab in induction and maintenance of remission in an adult patient with steroid-dependent eosinophilic enteritis (EoN)

Eosinophilic enteritis (EoN) is associated with an eosinophilic infiltrate confined to the small intestine, but treatment options other than diet and corticosteroid therapy are scarce. There is only one report of the use of dupilumab for eosinophilic gastrointestinal disease, involving three pediatric patients. We report a case of successful induction of remission with dupilumab in a 53 year-old female patient with steroid-dependent EoN. The patient presented to the emergency room with uncontrollable abdominal pain and CT revealed a thickened ileal wall and small amount of ascites. Despite no abnormalities on endoscopy, histological examination revealed numerous eosinophilic infiltrates (> 100/HPF) and degranulation in the ileal lamina propria, diagnosing the patient with EoN. The patient achieved clinical remission with prednisolone, but EoN relapsed during tapering. Long-term steroid therapy was inappropriate due to mandibular osteomyelitis and osteoporosis, and she was switched to 9 mg budesonide, an intestine-soluble topical steroid without effect. Dupilumab administration resulted in resolution of abdominal pain, and remission was maintained after discontinuation of budesonide. Histological remission was confirmed 2 months after dupilumab administration. This is the first report of remission induced and maintained with dupilumab in an adult patient with EoN.

Plant-Based Milk Alternatives in Child Nutrition

Plant-based milk alternatives can be distinguished in two main categories, differing in production processes and regulation: plant-based formulas and plant-based drinks. They are now a widely accepted class of products on the international market. The various plant-based milk alternatives differ in nutritional characteristics due to their origin and manufacturing; more importantly, whereas formulas from plant and cow origin can be used interchangeably, plant-based drinks are nutritionally different from cow's milk and can be consumed by children subsequently to the use of formula. Several scientific organizations have expressed differing opinions on the use of these products in the diets of children. In the face of unanimous conclusions regarding the use of these products during the first year of life, in subsequent ages there were conflicting opinions regarding the timing, quantities, and type of product to be used. From the viewpoint of the child's overall diet and health, it could be suggested that these foods be considered not as simple substitutes for cow's milk, but as part of a varied diet, within individual advice of use. We suggest accepting the presence of these products in a baby's diet (omnivores included), planning their use correctly in the context of a balanced diet, according to the specific product and the needs of the individual.

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.

Current Practice in Pediatric Cow's Milk Protein Allergy-Immunological Features and Beyond

Cow's milk protein allergy is one of the most common pediatric food allergies. It poses a significant socioeconomic burden in industrialized countries and has a profound effect on the quality of life of affected individuals and their families. Diverse immunologic pathways can lead to the clinical symptoms of cow's milk protein allergy; some of the pathomechanisms are known in detail, but others need further elucidation. A comprehensive understanding of the development of food allergies and the features of oral tolerance could have the potential to unlock more precise diagnostic tools and novel therapeutic approaches for patients with cow's milk protein allergy.

"Imaging Findings of Eosinophilic Gastrointestinal Diseases in Adults"

Eosinophilic gastrointestinal (GI) disorders are a group of conditions marked by pathologic eosinophilic infiltration of one or multiple locations in the GI tract. Conditions include eosinophilic esophagitis, eosinophilic gastritis, eosinophilic enteritis, and eosinophilic colitis. The site and depth of eosinophilic infiltration of the GI tract usually determines clinical presentation. These conditions should be considered in the differential diagnosis for several GI symptoms, such as food impaction or dysphagia. Histopathology is the gold standard for diagnosis of eosinophilic disorders. Nevertheless, findings from endoscopy, barium studies, computed tomography or magnetic resonance imaging, can aid in the diagnosis, by allowing for earlier diagnosis as well as proper management. Eosinophilic gastrointestinal disorders are typically managed with corticosteroids or dietary elimination. A high index of suspicion is required for diagnosis as it can often be challenging.

Refractory Malignant Eosinophilic Colitis Leading to Ischemic Colitis

Eosinophilic colitis (EC) is the most uncommon disease within the spectrum of eosinophilic gastrointestinal disorders. Currently, there are no well-established diagnostic criteria and no approved Food and Drug Administration therapies. We discuss a case of a 30-year-old man with refractory malignant EC leading to ischemic colitis. The patient was tried on multiple therapies, including a combination therapy of benralizumab and vedolizumab, which were unsuccessful. Unfortunately, the patient ultimately required a total proctocolectomy. More studies need to be performed to treat patients with severe refractory cases of EC.

High proportion of inflammatory CD62Llow eosinophils in blood and nasal polyps of severe asthma patients

BACKGROUND

In mice models, eosinophils have been divided into different subpopulations with distinct phenotypes and functions, based on CD62L and CD101 patterns of membrane expression. Limited data are available in humans.

OBJECTIVE

To investigate eosinophils subpopulations in peripheral blood (PB) and nasal polyp tissue (NP) from severe eosinophilic asthma (SEA) patients plus concomitant chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

We recruited 23 SEA patients (14 with CRSwNP); as controls, we enrolled 15 non-severe asthma patients, 15 allergic rhinitis patients without asthma and 15 healthy donors. Eosinophils were isolated from PB and NP and analysed by FACS. Eotaxin-3 and eotaxin-1 mRNA expression in NP tissue was also evaluated.

RESULTS

A significantly higher percentage of circulating CD62L^low cells was observed in SEA, as compared with controls, expressing higher levels of CCR3, CD69 and lower levels of CD125 (IL-5R), CRTH2, CD86 and CD28 in comparison with CD62L^bright cells. In NP, eosinophils showed a high proportion of CD62L^low phenotype, significantly greater than that observed in PB. Surface expression of IL-3R, IL-5R, CD69 and CD86 was significantly higher in CD62L^low eosinophils from NP than in those from blood. Moreover, eotaxin-3 mRNA expression positively correlated with the percentage of CD62L^low cells in NP.

CONCLUSION

Two different eosinophil subphenotypes can be identified in blood and NP of SEA patients, with a preferential accumulation of CD62L^low inflammatory cells in NP.

"Tickle me pink": update in eosinophilic gastrointestinal disorders

PURPOSE OF REVIEW

Eosinophilic gastrointestinal diseases (EGIDs) outside of the esophagus have been previously enigmatic and rare diagnoses. Fortunately, increasing research over the past few decades has led to an improved understanding of disease pathophysiology and epidemiology. This has been foundational for developing accurate nomenclature, diagnostic criteria, and therapeutics.

RECENT FINDINGS

This article will review recent updates in nonesophageal EGIDs. Accurate disease classification and nomenclature developed from international consensus are now available, as well as data challenging the notion that abnormal endoscopic findings are rare in this population. Studies on natural history, outcomes, and impact on patient quality of life are reviewed. Lastly, retrospective studies and clinical trials on EGID therapies are summarized.

SUMMARY

With a standardized nomenclature system for EGIDs now established, formal diagnostic guidelines and criteria for nonesophageal EGIDs are in active development. While management remains challenging compared with eosinophilic esophagitis, research and development of effective, steroid-sparing therapies (primarily through biologics and dietary therapy) remain underway. In eosinophilic colitis, the rarest EGID, research remains focused on illuminating pathophysiology. Ongoing research will continue to improve understanding of natural history, outcomes, and therapeutic options for these diseases.

Endoscopic Diagnosis of Eosinophilic Esophagitis: Basics and Recent Advances

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated inflammatory disease, characterized by esophageal dysfunction and intense eosinophil infiltration localized in the esophagus. In recent decades, EoE has become a growing concern as a major cause of dysphagia and food impaction in adolescents and adults. EoE is a clinicopathological disease for which the histological demonstration of esophageal eosinophilia is essential for diagnosis. Therefore, the recognition of the characteristic endoscopic features with subsequent biopsy are critical for early definitive diagnosis and treatment, in order to prevent complications. Accumulating reports have revealed that EoE has several non-specific characteristic endoscopic findings, such as rings, furrows, white exudates, stricture/narrowing, edema, and crepe-paper esophagus. These findings were recently unified under the EoE endoscopic reference score (EREFS), which has been widely used as an objective, standard measurement for endoscopic EoE assessment. However, the diagnostic consistency of those findings among endoscopists is still inadequate, leading to underdiagnosis or misdiagnosis. Some endoscopic findings suggestive of EoE, such as multiple polypoid lesions, caterpillar sign, ankylosaurus back sign, and tug sign/pull sign, will aid the diagnosis. In addition, image-enhanced endoscopy represented by narrow band imaging, endocytoscopy, and artificial intelligence are expected to render endoscopic diagnosis more efficient and less invasive. This review focuses on suggestions for endoscopic assessment and biopsy, including recent advances in optical technology which may improve the diagnosis of EoE.

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.

The Role of the Gut Microbiome in Cow's Milk Allergy: A Clinical Approach

Cow's milk allergy (CMA) is the most prevalent food allergy (FA) in infancy and early childhood and can be present with various clinical phenotypes. The significant increase in FA rates recorded in recent decades has been associated with environmental and lifestyle changes that limit microbial exposure in early life and induce changes in gut microbiome composition. Gut microbiome is a diverse community of microbes that colonize the gastrointestinal tract (GIT) and perform beneficial functions for the host. This complex ecosystem interacts with the immune system and has a pivotal role in the development of oral tolerance to food antigens. Emerging evidence indicates that alterations of the gut microbiome (dysbiosis) in early life cause immune dysregulation and render the host susceptible to immune-mediated diseases later in life. Therefore, the colonization of the gut by "healthy" microbes that occurs in the first years of life determines the lifelong health of the host. Here, we present current data on the possible role of the gut microbiome in the development of CMA. Furthermore, we discuss how gut microbiome modification might be a potential strategy for CMA prevention and treatment.

Current and emerging biologic therapies targeting eosinophilic disorders

Eosinophilic disorders include a wide array of conditions in which eosinophils play a primary pathophysiologic role. While historically treated with corticosteroids and immunosuppressants, knowledge of eosinophil biology has led to the development of several biologics targeting eosinophils. In this review, we discuss the current US Food and Drug Administration (FDA) approved eosinophil-specific biologics targeting IL-5 (mepolizumab and reslizumab) and IL-5R (benralizumab) along with biologics under investigation targeting siglec-8 (lirentelimab). We discuss efficacy and safety data from trials of these medications in conditions including eosinophilic asthma, hypereosinophilic syndrome (HES), eosinophilic granulomatosis with polyangiitis (EGPA), chronic rhinosinusitis with nasal polyposis (CRSwNP), eosinophilic esophagitis (EoE), and eosinophilic gastrointestinal disease (EGID). Additionally, we discuss case reports utilizing these medications in conditions including drug reaction with eosinophilia and systemic symptoms (DRESS), allergic bronchopulmonary aspergillosis (ABPA), and eosinophilic pneumonia, among others. While eosinophilic targeting biologic therapy has been successful in eosinophilic asthma, HES, EGPA, and CRSwNP leading to FDA approval for these conditions, trials treating EoE and EGID have been disappointing to date. Given the increasing number of trials utilizing these biologics, it will be imperative for the allergist-immunologist to stay up to date on the latest treatment options to provide the most optimal care for eosinophilic disorders.

The Economic Burden of Eosinophilic Gastritis and Eosinophilic Enteritis in the United States

Introduction

Eosinophilic gastritis and eosinophilic enteritis (EoG/EoN) are associated with a substantial clinical burden. However, limited information is available regarding the economic burden of EoG/EoN. This study was conducted to compare healthcare resource use (HRU) and costs among patients with EoG/EoN versus without EoG/EoN in the USA.

Methods

Administrative claims data from the IBM MarketScan^® Commercial Claims and Encounters (CCAE) and Medicare Supplemental and Coordination of Benefits Databases (2009–2019) was used to identify two cohorts of patients. Patients without EoG/EoN were matched 3:1 to patients with EoG/EoN on sex, year of birth, and healthcare plan type. Study measures included demographic characteristics, select comorbidities, all-cause HRU, and costs. Comparisons were made over a 1-year period following EoG/EoN diagnosis for patients with EoG/EoN and an eligible date for patients without EoG/EoN.

Results

A total of 2219 patients with EoG/EoN and 6657 patients without EoG/EoN were analyzed. Significantly higher proportions of patients with EoG/EoN versus without EoG/EoN had comorbid conditions. Rates of all-cause HRU were significantly higher among patients with EoG/EoN versus patients without EoG/EoN (adjusted rate ratio [95% confidence interval]: inpatient visits, 6.26 [5.26, 7.46]; outpatient visits, 1.17 [1.16, 1.19]; emergency department visits, 2.11 [1.98, 2.25]; all p < 0.001). Patients with EoG/EoN incurred significantly higher costs versus patients without EoG/EoN (adjusted mean cost difference $31,180; p < 0.001). Cost differences were largely due to outpatient (adjusted mean cost difference $14,018; p < 0.001) and inpatient (adjusted mean cost difference $11,224; p < 0.001) costs.

Conclusion

The economic burden associated with EoG/EoN is substantial, with patients with EoG/EoN having a higher rate of HRU and incurring $31,180 more than patients without EoG/EoN on average. Most of the cost difference was attributable to outpatient and inpatient costs. Cost-saving strategies to lower the burden of illness in this patient population are needed.

Follow-Up of a Rare Case of Eosinophilic Gastroenteritis Associated with Persistent Blood Eosinophilia and Multiple Food Allergies

Eosinophilic gastroenteritis (EGE) is a subgroup of the eosinophilic gastro-intestinal disorders (EGIDs), characterized by eosinophilic infiltration and chronic inflammation of the gastrointestinal tract. These are rare diseases with still incompletely elucidated causes and mechanisms, with frequently delayed diagnosis and variable outcome. Despite increased interest in eosinophilic diseases in recent years, fewer data have been published on EGE and no standardized diagnostic and therapeutic approach exists. This paper reports the case of a young male patient diagnosed with EGE in 2017 based on clinical and histopathological criteria and constantly monitored during five years. Besides gastrointestinal eosinophilic infiltration, biopsies also revealed eosinophilic infiltration of the oesophagus, despite no declared characteristic oesophageal symptoms. We found increased specific IgE to multiple foods and progressive blood hypereosinophilia which preceded EGE diagnosis by three years. The EGE management included selective dietary restrictions and pharmacologic therapy based on daily budesonide non-enteric coated tablets, proton pumps inhibitors, antihistamines, cromoglycate, correction of iron, calcium and vitamin D deficiencies. The clinical outcome was good, while blood eosinophilia and endoscopic appearance remained almost unchanged. After one year the patient complained of respiratory symptoms suggesting asthma, needing continuous combined inhaled therapy. The reported case is illustrative for complex presentation, diagnosis and outcome of a rare case of mucosal chronic EGE associated with oesophageal involvement, peripheral eosinophilia, multiple food allergies and asthma.

Mimics of Crohn's Disease

Crohn's disease is a chronic inflammatory disease that can affect any portion of the gastrointestinal tract. Associated symptoms can vary based on the severity of disease, extent of involvement, presence of extraintestinal manifestations, and development of complications. Diagnosis is based on a constellation of findings. Many diseases can mimic Crohn's disease and lead to diagnostic conundrums. These include entities associated with the gastrointestinal luminal tract, vascular disease, autoimmune processes, various infections, malignancies and complications, drug- or treatment-induced conditions, and genetic diseases. Careful consideration of possible causes is necessary to establish the correct diagnosis.

Improving Care in Eosinophil-Associated Diseases: A Charter

Eosinophil-associated diseases (EADs) are a range of heterogeneous conditions in which eosinophils are believed to play a critical pathological role. EADs include common illnesses such as eosinophilic asthma and chronic rhinosinusitis and rare conditions such as hypereosinophilic syndromes (HES) and eosinophilic gastrointestinal disorders (EGIDs). EADs are associated with substantial burdens for the patient, including chronic, debilitating symptoms, increased financial burden, decreased health-related quality of life, and the need for repeated visits to multiple different healthcare professionals (HCPs), emergency departments, and/or hospitals. Poor EAD recognition by HCPs often contributes to delayed diagnoses, which further delays patient access to appropriate care and effective treatments, contributing to poor health outcomes. The objective of this charter is to outline key patient rights and expectations with respect to the management of their condition(s) and to set forth an ambitious action plan to improve health outcomes for patients with EADs: (1) people with EADs, their caretakers, HCPs, and the public must have greater awareness and education about EADs; (2) people with EADs must receive a timely, accurate diagnosis; (3) all people with EADs must have access to an appropriate multidisciplinary team, when necessary; and (4) people with EADs must have access to safe and effective treatment options without unnecessary regulatory delays. The principles described in this charter demonstrate the core elements of quality care that people with EADs must receive, and they represent clear steps by which to reduce patient and caregiver burden and improve patient outcomes. We urge HCPs, healthcare systems, and policymakers worldwide to swiftly adopt these principles to ensure patients with EADs have an accurate diagnosis in a timely manner and access to high-level care and treatment in an appropriate setting.

Primary eosinophilic gastrointestinal disorders and allergy: Clinical and therapeutic implications

Primary eosinophilic gastrointestinal disorders (EGID) are increasingly prevalent, immune‐mediated, chronic conditions which primarily affect pediatric and young adult patients, leading to substantial disease burden, and poor quality of life. EGID may either involve single portions of the gastrointestinal tract (i.e., esophagus, stomach, small bowel, and colon) or a combination. Their strong association with allergic disorders has been recently recognized, and although their shared pathophysiological basis remains partly elusive, this feature greatly impacts the diagnostic and treatment work‐up. We herein critically discuss the current knowledge on the association of EGID and allergic disorders, including atopic dermatitis, allergic rhinitis, allergic asthma, and food or drug allergy. In particular, we reviewed the literature focusing on their epidemiology, pathophysiological basis and mechanisms, and diagnostic strategies. Finally, we discuss the currently ongoing clinical trials targeting EGID and allergic diseases, including, among others the monoclonal antibodies dupilumab, mepolizumab, benralizumab, and lirentelimab.

Effects of Energy Drink Acute Assumption in Gastrointestinal Tract of Rats

Energy drinks (EDs) are non-alcoholic beverages containing high amounts of caffeine and other psychoactive substances. EDs also contain herbal extract whose concentration is usually unknown. EDs can have several adverse effects on different organs and systems, but their effects on the gastrointestinal (GI) tract have been poorly investigated. To determine the acute effects of EDs on the GI tract, we administered EDs, coffee, soda cola, or water to Sprague–Dawley rats (n = 7 per group, randomly assigned) for up to five days, and analyzed the histopathological changes in the GI tract. Data were compared among groups by Kruskal–Wallis or Mann–Whitney tests. We found that, while EDs did not cause any evident acute lesion to the GI tract, they triggered eosinophilic infiltration in the intestinal mucosa; treatment with caffeine alone at the same doses found in EDs leads to the same effects, suggesting that it is caffeine and not other substances present in the EDs that causes this infiltration. The interruption of caffeine administration leads to the complete resolution of eosinophilic infiltration. As no systemic changes in pro-inflammatory or immunomodulating molecules were observed, our data suggest that caffeine present in ED can cause a local, transient inflammatory status that recruits eosinophils.

Helicobacter pylori-negative Chronic Gastritis in Children: A Systematic Review

OBJECTIVES

To systematically review the current evidence on Helicobacter pylori-negative chronic gastritis including natural history, available therapies and outcomes.

METHODS

Articles providing data on the prevalence, treatment or outcomes of Helicobacter pylori-negative gastritis were identified through a systematic search in the MEDLINE and EMBASE databases. All original research articles from human studies until October 31, 2021, were included.

RESULTS

A total of 54 studies were included consisted of eosinophilic gastritis (n = 9), autoimmune gastritis (n = 11), collagenous gastritis (n = 16), focally enhanced gastritis (n = 6), lymphocytic gastritis (n = 5) and other causes including idiopathic gastritis and chronic renal failure related (n = 7). Most of the included studies were either cross-sectional or longitudinal cohorts except for collagenous gastritis, which mainly included case reports and case series. The prevalence of paediatric eosinophilic gastritis ranges between 5 and 7/100,000 and patients have generally favourable outcome with 50% to 70% clinical and histological response to either corticosteroids or elimination diets. Autoimmune gastritis and collagenous gastritis are extremely rare entities, commonly present with refractory iron deficiency anaemia, while lymphocytic gastritis is relatively common (10%-45%) in children with coeliac disease. Data on treatments and outcomes of autoimmune, collagenous, and focally enhanced gastritis are lacking with limited data implying poor response to therapy in the former 2 diagnoses.

CONCLUSIONS

Helicobacter pylori-negative gastritis is uncommonly reported, mainly in small cohorts, mixed adult-paediatric cohorts or as sporadic case reports. As common symptoms are not specific, thus not always result in an endoscopic evaluation, the true prevalence of these distinct disorders may be underestimated, and thus under reported.

Controversies in Allergy: The Potential Role of Biologics as First-Line Therapy in Eosinophilic Disorders

With advances in understanding the role of eosinophils in disease pathogenesis, particularly in the airways, gastrointestinal tract, and skin, targeting eosinophils or the cytokines that lead to their production, activation, and survival has become an increasingly pursued therapeutic approach. Newly developed biologic agents target eosinophils directly, other cells interacting with or activating eosinophils, or cytokines in the type 2 inflammatory pathway with specific antibodies. Current treatment paradigms reserve therapy with biologics for patients refractory to or intolerant of corticosteroids or immunosuppressants. Given accumulating data for safety and efficacy of these biologics, however, there is the question of whether targeted treatments should be used earlier in the treatment algorithm. In this article, we discuss the pros and cons of using biologics as first-line therapy for eosinophilic diseases of the airways, gastrointestinal tract, and skin. We highlight emerging biologic agents and future directions for research, as well as a rationale for the early use of some biologics to prevent tissue damage, disease progression, and organ dysfunction in selected 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.

Transition of care of patients with eosinophilic gastrointestinal diseases: Challenges and opportunities

Eosinophilic gastrointestinal disorders (EGID) are a group of allergen-mediated conditions which are characterized by eosinophilic inflammation affecting one or more parts of the gastrointestinal tract. A disproportionately higher number of EGID patients are diagnosed in the pediatric age group. Given the chronic course of EGIDs and lack of curative therapies at this time, majority of the pediatric EGID patients may require continued care well into their adulthood. However, to date, scant data are available regarding the health care transition (HCT), the transition of care (TC), and the effectiveness of transfer of care EGID patients from pediatric-oriented to adult-oriented providers. Herein, we review the lessons learnt from transfer of care of children with other chronic gastrointestinal and allergic conditions, analyze the current knowledge, potential barriers, the role of various stakeholders in successful transfer of care of EGID patients, propose a conceptual framework for HCT and TC of EGID patients, and identify outcome measures to ensure the quality of progression of care.

Psychiatric Comorbidities Are Highly Prevalent in Nonesophageal Eosinophilic Gastrointestinal Diseases

BACKGROUND & AIMS

The prevalence of psychiatric comorbidity in nonesophageal eosinophilic gastrointestinal disorders (EGIDs) has not been studied. We aimed to ascertain the prevalence of psychiatric diagnoses and psychiatric medication use in children, adolescents, and adults with EGIDs and to assess whether psychiatric comorbidity affects clinical presentation.

METHODS

This was a retrospective cohort study of newly diagnosed patients with a nonesophageal EGID at the University of North Carolina from 2008 to 2020. Psychiatric diagnoses and medications were extracted from medical records. We compared the clinical and demographic features of EGID patients with and without psychiatric diagnoses.

RESULTS

Of 79 patients (mean 23.3 years of age, 53% male, 78% White) with a nonesophageal EGID diagnosis, 40 (51%) were diagnosed with a comorbid psychiatric disease. Anxiety (37%) and depression (28%) were most common. There were also 40 (51%) patients treated medically for a psychiatric diagnosis. Patients with a psychiatric diagnosis were more commonly ≥18 years of age at the time of EGID diagnosis (odds ratio [OR], 3.95, 95% confidence interval [CI], 1.20-13.02) and had endorsed symptoms of nausea (OR, 5.31; 95% CI, 1.33-21.22) and dysphagia (OR, 4.24; 95% CI, 1.18-15.26).

CONCLUSION

Psychiatric diagnoses were very common in nonesophageal EGID patients with approximately 7 in 10 adults and one-third of children diagnosed. Similar proportions were found for psychiatric medication use. We also found that psychiatric illness may influence age of clinical presentation and symptoms. Providers should assess for concomitant psychiatric comorbidities in EGID patients.

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.

Eosinophils and eosinophilic immune dysfunction in health and disease

The functions ascribed to eosinophils have classically been limited to host defence against certain parasitic infections and potentially deleterious effects in the setting of specific diseases that are associated with elevated eosinophil counts in blood and/or tissue. The ability to induce eosinophil depletion either experimentally in animal models or through targeted therapies in humans has extended our understanding of the roles played by eosinophils in health and homeostasis as well as in disease pathogenesis. When associated with human disease aetiology, the eosinophil takes on a pathogenic rather than a protective role. This maladaptive response, called "eosinophilic immune dysfunction" herein, appears central to exacerbation pathogenesis and disease control in severe asthma and may be involved in the aetiology of other eosinophil-related conditions ranging from organ-system-limited diseases such as phenotypic subsets of chronic obstructive pulmonary disease and chronic rhinosinusitis with nasal polyposis to more broadly systemic diseases such as eosinophilic granulomatosis with polyangiitis and hypereosinophilic syndrome. In this review, we describe the evidence supporting eosinophilic functions related to health and homeostasis and explore the contribution of eosinophilic immune dysfunction to human disease.