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.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Two cases of eosinophilic gastrointestinal disorder due to newly appearing food allergies after cord blood transplantation

Eosinophilic gastrointestinal disorders (EGIDs) are infrequent complications after allogeneic hematopoietic cell transplantation (allo-HCT). Furthermore, it is well-known that allergic diseases are transferable after allo-HCT from allergic donors to non-allergic recipients. However, the type of graft-versus host disease (GVHD) prophylaxis that leads to allergic disease transfer is unclear. Furthermore, no study has reported a case of acquired food allergy resulting in EGID that was detected based on the clinical course and the detection of antigen-specific immunoglobulin E after allo-HCT. We encountered two patients with acute leukemia accompanied by eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE) due to newly appearing food allergy after cord blood transplantation (CBT) with T-cell non-depletion GVHD prophylaxis. Despite having no history of allergic disease, the patients experienced allergic symptoms due to dairy products (Case 1) and eggs (Case 2) after CBT. They subsequently experienced severe nausea, heartburn, and anorexia (Case 1) and diarrhea (Case 2). Cases 1 and 2 were diagnosed with EoE and EGE, respectively, based on endoscopic and histological examinations. Dietary treatment without steroids improved the symptoms in both cases. These cases highlight that the unexpected transfer of food allergy after CBT can lead to EGIDs, especially in patients receiving T-cell non-depletion GVHD prophylaxis.

Recent topics on gastrointestinal allergic disorders

Gastrointestinal (GI) allergies are broadly associated with food allergies and divided into groups based on the degree of allergen-specific immunoglobulin E (IgE) involvement: IgE-mediated, non-IgE-mediated, and mixed. Non-IgE-mediated GI food allergies are mostly observed in neonates and infants and include food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), and food protein-induced enteropathy (FPE). In addition to the classical phenotype, unique phenotypes such as vomiting and bloody stool, suspected sepsis, and overlapping eosinophilic GI disorders (EGIDs) have increased in Japan over the past two decades. Some of these cases were defined as having chronic FPIES. More recently, cases of hen's-egg FPIES in Japan have increased dramatically since 2018, albeit for unknown reasons. Typical mixed-type food allergies are EGIDs, characterized by aberrant eosinophil infiltration in the GI tract leading to GI symptoms. EGIDs are broadly classified into eosinophilic esophagitis (EoE) and non-EoE EGIDs that involve the GI tract with the exception of the esophagus. Of the EGIDs, EoE is the best known, as the number of cases has increased dramatically in Western countries, whereas pediatric EoE remains rare in Asia and non-EoE EGIDs may be more prevalent in Japan. A recent Japanese national survey showed that pediatric non-EoE EGIDs were persistent and severe compared to those in adults, possibly requiring further effective therapeutic options. Among the EGIDs, FPIAP is pathologically diagnosed as an infantile form of eosinophilic colitis. In addition, recent FPIES and FPE cases also involved eosinophilic inflammation. Recent cases of GI allergies may be associated with type 2 inflammation. A better understanding of the interactions between GI allergies and type 2 inflammation may clarify the pathogenesis of the recent increase in GI allergies.

Eosinophilic enteritis accompanied by cytomegalovirus disease: a case report

Background

Eosinophilic enteritis is a chronic inflammatory disorder of the intestinal tract that is characterized by eosinophil infiltration. Cytomegalovirus (CMV), a common virus, has a broad infectivity range. CMV is retained in the host body after infection. Impairment of host immune defences may reactivate the latent CMV, leading to symptoms of overt disease.

Case presentation

A Japanese female in her 70 s was admitted to a hospital due to diarrhoea and then transferred to our hospital. Laboratory data showed hypoalbuminemia. Computed tomography (CT) revealed oedema of the small intestine. Lower gastrointestinal endoscopy revealed oedema of the submucosa, without any remarkable changes in the mucosa of the terminal ileum. Histological examination of the terminal ileum revealed infiltration of > 20 eosinophils per high-power field (HPF). These findings aided in diagnosing eosinophilic enteritis. We administered methylprednisolone (500 mg/day) for three days, followed by tapering prednisolone. However, the patient’s general condition and hypoalbuminemia failed to improve. Immunoglobulin (Ig) G- CMV and IgM-CMV tests were positive. CMV antigenemia was extremely high. Therefore, we administered ganciclovir intravenously, which improved the patient’s condition. Furthermore, azathioprine was administered to taper and discontinue prednisolone without relapse of eosinophilic enteritis. This treatment helped stabilize the patient’s condition for approximately four years.

Conclusion

We present a case of eosinophilic enteritis accompanied by CMV disease during prednisolone treatment. The patient’s condition improved after administration of ganciclovir. Azathioprine aided in discontinuing prednisolone and stabilizing the patient’s condition for approximately four years.

Nutritional status in eosinophilic gastrointestinal disorders: A pediatric case-control study

Eosinophilic gastrointestinal disorders (EGIDs) represent an emerging group of heterogeneous diseases associated with failure to thrive, weight loss, protein-losing enteropathy, and malnutrition. To date, no studies have assessed the nutritional status, vitamin D, and other vitamin levels in patients with non-esophageal EGIDs. We aim to evaluate the nutritional profile of a cohort of children and adolescents with EGIDs. We performed a case-control study, enrolling a total of 98 patients, 38 (39%) patients with EoE, 22 (22%) patients with non-esophageal EGIDs, and 38 (39%) patients with non-allergic controls. Children with EGIDs had both mean ferritin and mean hemoglobin levels, together with other values such as folates and vitamin B12, within normal range and therefore did not have anemia. Albumin and prealbumin levels were within normal limits. Patients with EGIDs have mean vitamin D values slightly higher than non-allergic controls. Although this study is retrospective and referred to only one pediatric center, we found that Italian children and adolescents with EGIDs are neither malnourished nor deficient in vitamin D compared with controls.

Clinical Characteristics and Treatment Outcomes of Patients with Eosinophilic Esophagitis and Eosinophilic Gastroenteritis

BACKGROUND

Eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), part of the spectrum of eosinophilic gastrointestinal disorders (EGID), share pathogenic similarities. We examined differences regarding clinical characteristics and treatment outcomes between EoE and EGE cases.

METHODS

Two-hundred fifteen EGID patients, including 181 with EoE and 34 with EGE, diagnosed at Shimane University Hospital between February 2011 and March 2019 were enrolled. Information regarding clinical parameters and treatment outcomes was reviewed.

RESULTS

EoE showed significant male predominance (82.3%) as compared with EGE (50.0%) (p < 0.001). Furthermore, patients with EoE were significantly older and had a higher body mass index (24.8 ± 4.0 vs. 22.2 ± 4.3, p < 0.05). Over 90% of the EoE patients were initially given proton pump inhibitor (PPI) treatment, of whom 73.2% showed clinical and histological remission. Vonoprazan, a more potent acid inhibitor than PPI, was effective in two-thirds of the nonresponsive EoE patients initially treated with a PPI. In contrast, oral glucocorticoid administration was mainly given to patients with EGE (58.8%). Of 13 EGE patients treated with a food-elimination diet, responsible foods were successfully identified in 9, with 7 controlled in a state of remission without glucocorticoid therapy.

CONCLUSIONS

We found different clinical characteristics and treatment strategies in the present EoE and EGE cases. Most of the EoE patients responded to and were maintained by acid suppressive therapy, using PPI or vonoprazan. For EGE patients, glucocorticoid administration was mainly used though food-elimination diet therapy also showed beneficial effects.

Eosinophilic Gastritis/Gastroenteritis

PURPOSE OF REVIEW

Eosinophilic gastritis/gastroenteritis (EG/EGE) are rare eosinophilic infiltrative disorders in children and adults that fall under the umbrella term eosinophilic gastrointestinal disorders (EGIDs). EGIDs also include eosinophilic esophagitis (EoE) and eosinophilic colitis. In this article, we present the current literature regarding the clinical presentation, diagnostic criteria, and management of EG/EGE.

RECENT FINDINGS

The underlying complex pathophysiology remains unknown, yet hypersensitivity response is a central component. Unlike EoE, standardized diagnostic criteria are lacking but, promising research employing tissue-based and blood-based methods of diagnosis have been reported. Non-EoE EGIDs are more challenging to treat than EoE. More than a third of patients may achieve spontaneous remission. Still, most will require dietary elimination and/or pharmaceutical interventions, mainly corticosteroids, but also biologics (monoclonal antibodies against IL-4, IL-5, TNFα, integrin α4β7, and IgE), mast-cell stabilizers, leukotriene (LT)-receptor antagonists, and antihistamines. Promising research suggests the role of AK002, an anti-siglec antibody, in clinical and histological improvement. Given the rarity and underdiagnosis of EG/EGE, different natural progression compared to EoE, heterogeneous clinical manifestations, and probable normal endoscopic appearance, it is vital to maintain a high suspicion index in atopic patients, obtain at least 5-6 random biopsies from each site for gastro/duodenal eosinophilic infiltrate with the subsequent exclusion of inflammatory, allergic and infectious differential diagnoses to increase the yield of an accurate diagnosis. Corticosteroids remain the mainstay of treatment, often requiring long-term use. Steroid-sparing agents remain experimental. Goals of therapy move beyond clinical remission but lack evidence to support histological remission.

Comparison of Nonesophageal Eosinophilic Gastrointestinal Disorders with Eosinophilic Esophagitis: A Nationwide Survey

BACKGROUND

Eosinophilic esophagitis (EoE) has increased rapidly and has been well characterized. However, no nationwide survey has been conducted regarding non-esophageal eosinophilic gastrointestinal disorders (non-EoE EGIDs), and they remain poorly understood.

OBJECTIVE

To compare the clinical features and natural histories of non-EoE EGIDs and EoE by using the same questionnaire, for all ages.

METHODS

We conducted a nationwide hospital-based survey of patients who visited hospitals from January 2013 through December 2017. We randomly selected 10,000 hospitals that perform endoscopy. We analyzed the demographics, symptoms, gastrointestinal histology, treatments, and natural histories of EoE and non-EoE EGIDs.

RESULTS

A total of 2906 hospitals responded to the questionnaire. We identified 1542 patients and obtained detailed data for 786 patients, consisting of 39% EoE and 61% non-EoE EGIDs. The clinical characteristics were analyzed for patients who met the "definite" criteria that excluded comorbidities. Non-EoE EGIDs showed no gender difference, whereas EoE was male-predominant. Tissue eosinophilia was often seen in the small intestine (62%) and stomach (49%). The frequency of hypoproteinemia was high (27%) in childhood. Children also had more serious symptoms and complications than adults: restriction of daily life activity (P = .009), failure to grow/weight loss (P = .008), and surgery (P = .01). For both diseases, the most common natural history was the continuous type: 66% (95% confidence interval [CI]: 58-74) in EoE and 64% (95% CI: 55-72) in non-EoE EGIDs.

CONCLUSIONS

The percentage of persistent patients with non-EoE EGIDs was almost the same as those with EoE. Complications were more frequent in children than in adults.

Internalized Stigma in Patients with Eosinophilic Gastrointestinal Disorders

The aim of the current study is to evaluate internalized stigma in individuals diagnosed with an eosinophilic gastrointestinal disorder (EGID) and its impact on psychosocial and health-related outcomes. The final study sample consisted of 149 patients with a self-reported EGID diagnosis for at least 6 months. Participants completed measures evaluating internalized stigma, disease-specific quality of life, emotional distress (anxiety, depression) and answered questions regarding healthcare utilization. Overall, increased internalized stigma was associated with decreased disease-specific quality of life, and increased anxiety and depression. In addition, participants with greater overall internalized stigma felt that treatments were less effective, and the internalized stigma subscales of alienation and discrimination were associated with increased outpatient visits and endoscopies, respectively. Providers working with EGID patients should assess for signs of internalized stigma, such as social withdrawal and alienation. Psychogastroenterology services that deliver evidence-based psychological interventions may reduce some of the negative impacts of internalized stigma.

The Emerging Role of Eosinophils as Multifunctional Leukocytes in Health and Disease

Eosinophils are terminally differentiated cytotoxic effector cells that have a role in parasitic infections and allergy by releasing their granule-derived cytotoxic proteins. However, an increasing number of recent observations indicate that eosinophils are not only associated with the pathogenesis of a wide range of diseases, but also contribute to the maintenance of homeostatic responses in previously underappreciated diverse tissues, such as the gastrointestinal (GI) tract and adipose tissue. In this review, we describe biological characteristics of eosinophils, as their developmental properties, permissive proliferation and survival, degranulation activity, and migration properties enable them to distribute to both homeostatic and inflamed tissues. We describe pathologic aspects of eosinophils with a role in asthma and in various GI diseases, including eosinophilic GI disorders, inflammatory bowel disease, and radiation-induced enteropathy. Finally, we discuss the beneficial role of eosinophils, which contribute to the resolution of pathogenic conditions and to the modulation of homeostatic biologic responses.

Distribution of eosinophils in the gastrointestinal tract of children with no organic disease

Background

This study aimed to assess the eosinophil (eos) density of the mucosa of the gastrointestinal (GI) tract in children undergoing endoscopic procedures following an extensive workup, without diagnosis of an organic disease.

Methods

Biopsies from GI endoscopies performed at 3 major children’s hospitals (Athens, Madrid and Rome), between January 2012 and June 2018, were evaluated by a single pathologist in each center. Peak eos counts were expressed /high power field and /mm². Other histological abnormalities were also reported.

Results

A total of 111 children (median age 11 years; 48 boys) underwent upper endoscopy (333 biopsies), while 44 (median age 12; 25 boys) underwent ileocolonoscopy (262 biopsies). The median (interquartile range) eos/mm² were as follows: esophagus 0 (0-0); stomach 10.2 (3.3-15.3); duodenum 56.1 (26.1-86.7); ileum 61.2 (49.0-91.8); cecum 76.5 (40.9-99.7); ascending colon 73.9 (49.5-131.4); transverse colon 66.3 (40.8-91.5); descending colon 66.3 (30.6-81.6); sigmoid colon 39.2 (27.8-51.0); and rectum 25.5 (9.8-45.8). Geographical variations in GI tissue eos counts were found amongst the participating centers, but the causative factors need further evaluation. Functional GI disorders according to the Rome IV criteria were diagnosed in 73 children (37 boys, median age 13 years). No differences were found between children with or without functional GI disorder diagnosis, with regard to eos density in the GI tract.

Conclusion

The reported peak counts of GI tissue eos in children with no organic diseases provide normative values that may be useful in the evaluation of children with GI symptoms suggestive of eosinophilic GI disorders.

Single-Organ and Multisystem Hypereosinophilic Syndrome Patients with Gastrointestinal Manifestations Share Common Characteristics

BACKGROUND

Eosinophilic gastrointestinal diseases (EGIDs) are defined by marked eosinophilia in the gastrointestinal (GI) tract resulting in a wide variety of GI symptoms. When accompanied by blood hypereosinophilia (HE; absolute eosinophil count ≥1500/mm³), EGID can occur as an isolated GI disorder (hypereosinophilic syndrome [HES]/EGID overlap) or as part of a multisystem hypereosinophilic syndrome (Multisystem HES).

OBJECTIVE

To describe the GI disease of patients categorized as those with HES/EGID overlap versus those with Multisystem HES.

METHODS

Consecutively enrolled patients on a natural history protocol to study eosinophilia with biopsy-proven EGID involving the esophagus, stomach, small-bowel, and/or colon were evaluated for clinical, histopathologic, and endoscopic features by retrospective chart review.

RESULTS

Among the 56 patients with EGID and HE, 34 were categorized as HES/EGID overlap and 22 as Multisystem HES. Demographics, GI symptoms, and associated comorbidities were similar between the 2 groups. Multisegment GI eosinophilia was present in 20 of 30 (67%) patients who underwent tissue sampling of all 4 GI segments. Tissue eosinophilia in all 4 GI segments was found in 5 of 30 (17%) patients. Dietary therapy was more common in patients with HES/EGID overlap (65% vs 23%, P = .0028). Patients with Multisystem HES were more likely to receive glucocorticoids (100% vs 79%, P = .0349) and nonglucocorticoid systemic therapies (77% vs 38%, P = .0061). One-third (8 of 22) of patients with Multisystem HES presented with isolated GI symptoms before developing extraintestinal manifestations at a median of 1 year (range, 0.25-15 years).

CONCLUSION

There are striking clinical similarities between patients with Multisystem HES and those with HES/EGID overlap, despite differing treatment approaches. Moreover, Multisystem HES can present with isolated GI involvement. Larger prospective studies are needed to confirm these findings.

A rare case of diarrhea and ascites

BACKGROUND

Eosinophilic enterocolitis is a rare condition included in the spectrum of the eosinophilic gastrointestinal disorders. Diagnosis is based on clinical presentation combined with an increase infiltration of eosinophils in the gastrointestinal tract, in the absence of other secondary causes of eosinophilic infiltration.

CASE PRESENTATION

We report a case of a 22-year-old male with eosinophilic enterocolitis presenting with malabsorption syndrome (diarrhea, vomiting, weight loss), bowel wall thickening, and ascites. Secondary causes of intestinal eosinophilia were excluded, and diagnosis was established in a timely manner. Treatment plan included a 6-food elimination diet and corticosteroid therapy, with clinical remission after 2 weeks of therapy. The patient remains asymptomatic after 12 months of follow-up, with no relapse.

Current role of colonoscopy in infants and young children: a multicenter study

Background

To evaluate the role of colonoscopy in infants and young children and clarify the distribution of colonoscopy-requiring diseases in this age group.

Methods

Cohorts of colonoscopies performed at three children’s hospitals in Japan between April 2011 and March 2016 including infants and children younger than six years of age were retrospectively reviewed.

Results

In total, 453 colonoscopies were performed in 276 infants and young children. Of these 275 (60.8%) were for diagnostic purposes, 177 (39.2%) were performed as follow-up, and one case was performed for treatment. The median patient age at the time of diagnostic colonoscopy was 2.49 years, and there was a male-to-female ratio of 1.72:1. Abnormal macroscopic and/or histopathological findings were noted in 212 (77.1%) cases. Of these, definite diagnoses were established for the presence of eosinophilic gastrointestinal disorders (EGIDs), inflammatory bowel disease (IBD), and polyp/polyposis in 23, 18.5, and 14% of patients, respectively. Among 51 IBD cases, ulcerative colitis, Crohn’s disease, and IBD-unclassified were identified in 47.1, 33.3, and 7.8%, retrospectively via endoscopic examination. Of these, 11 (22%) were eventually diagnosed with monogenic diseases via genetic testing. Of those with rectal bleeding, EGIDs, polyps/polyposis, and IBD were found in 27, 19, and 18%, retrospectively. There were significantly more cases of EGIDs and fewer ones of IBD and polyps/polyposis in patients with rectal bleeding younger than two years of age. Furthermore, 68% of all follow-up colonoscopies were performed in children with IBD. There were no serious complications in our study cohort.

Conclusion

We determined the role of colonoscopy in infants and young children. Diseases diagnosed using colonoscopy in this age group included IBD, EGIDs, and polyps/polyposis. The increasing trend of patients with IBD and EGIDs worldwide means that the role of colonoscopy in infants and younger children will be more important in the future.

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.

Pharmacological treatment of eosinophilic gastrointestinal disorders

INTRODUCTION

Eosinophilic gastrointestinal disorders (EGIDs) are increasingly prevalent chronic inflammatory diseases characterized by eosinophilic infiltration of the gastrointestinal (GI) tract, in the absence of other known causes of eosinophilia.

AREAS COVERED

Clinical management of EGIDs is challenging, as there are currently limited therapeutic options available. The most common EGID is eosinophilic esophagitis (EoE), and rarer forms are eosinophilic gastritis, eosinophilic gastroenteritis, and eosinophilic colitis. Clinical presentation depends on the affected GI site. Recently duodenal eosinophilia has been recognized to commonly be present in patients with functional dyspepsia. This review will provide an overview of the pathogenesis and therapeutic management of EGIDs, with particular focus on the pharmacological strategies for these conditions. Expert commentary: Despite the considerable progress made in understanding the pathogenesis of EGIDs, there is still an urgent need for the development of specific and effective therapeutic approaches. Therapeutic management protocols are required that are based on rigorous clinical investigation in large prospective controlled trials to better understand the risks, benefits and limitations of each therapy. More well-defined and consistent end-points are also required to assess treatment outcomes, as there has been variability between patient reported outcomes, clinical outcomes, and histological outcomes in the studies to date.

Biologic therapies targeting eosinophils: current status and future prospects

The recent explosion in the number of biologic therapies in clinical development for the treatment of eosinophilic disorders is unprecedented. As these agents become available for clinical use, the selection of the most appropriate agent for a given patient will become increasingly complicated. The aims of this review were 2-fold: (1) to present the lessons learned from clinical trials using the first generation of eosinophil-targeted biologics (anti-IL-5 antibodies) and (2) to discuss the advantages and potential limitations of currently available and novel targeted therapies to treat eosinophilic disorders.

Racial differences in eosinophilic gastrointestinal disorders among Caucasian and Asian

BACKGROUND

Although there is an increasing number of eosinophilic gastrointestinal disorders (EGID) cases including eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), being reported globally, no systematic reviews have been conducted to elucidate the racial differences in these disorders. We aimed to show the racial differences, especially among Caucasians and Asians, in the risk of EoE and EGE.

METHODS

We conducted a systematic review using PubMed in September 2012. All case reports and case series on EGID that involved human subjects and described race or ethnicity, as well as pathological findings, were included. For the comparison of reported cases between Caucasians and Asians, a chi-squared test was used.

RESULTS

Among the 687 studies found in PubMed, 121 studies fulfilled the eligibility criteria. In total, 2621 patients were reviewed. Among Caucasian EGID patients, 94% had EoE; while among Asian EGID patients, 72% had EGE (p < 0.001). Among EoE, Asians were significantly less likely to have dysphagia and heartburn, but more likely to have vomit and abdominal pain, compared to Caucasians (p < 0.001). Further, among EGE, Asians were significantly more likely to have eosinophil-infiltrated colon than Caucasians (OR: 3.22, 95% confidence interval [CI]: 1.60-7.04), but were less likely to have eosinophil-infiltrated stomach (OR: 0.29, 95% CI: 0.17-0.49).

CONCLUSIONS

We found that EoE occurs more frequently in Caucasian EGID patients than Asian EGID patients, while the reverse is true for EGE. Also, racial disparities in symptoms and eosinophil-infiltrated tissues were observed. Our findings suggest further genetic and environmental studies to elucidate the etiology of EGID.