International Consensus Recommendations for Eosinophilic Gastrointestinal Disease Nomenclature

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.

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.

Eosinophilic enteritis requiring differentiation from chronic enteropathy associated with SLCO2A1 gene: A case report

BACKGROUND

Eosinophilic gastrointestinal disease (EGID) is a disorder characterized by infiltration of eosinophils causing mucosal damage and dysfunction of the gastrointestinal tract. The endoscopic findings of eosinophilic enteritis (EoN), an EGID variant, are nonspecific and occasionally difficult to diagnose. In contrast, chronic enteropathy associated with SLCO2A1 (CEAS) is a chronic persistent small intestinal disorder characterized by endoscopic findings such as multiple oblique and circular ulcers.

CASE SUMMARY

We report the case of a 10-year-old boy who had suffered abdominal pain and fatigue for the preceding 6 mo. He was referred to our institute for investigation of suspected gastrointestinal bleeding because of severe anemia with hypoproteinemia and positive fecal human hemoglobin. The upper and lower gastrointestinal endoscopic findings were normal; however, double-balloon small bowel endoscopy showed multiple oblique and circular ulcers with discrete margins and mild constriction of the intestinal lumen in the ileum. The findings were highly consistent with CEAS, but urine prostaglandin metabolites were within normal limits, and no previously reported mutations in the SLCO2A1 gene were identified. Histological evaluation demonstrated moderate to severe eosinophilic infiltration localized to the small intestine suggesting a diagnosis of EoN. Clinical remission was maintained with montelukast and a partial elemental diet, but emergent surgery for bowel obstruction due to small intestinal stenosis was performed two years after the initial treatment.

CONCLUSION

EoN should be considered in the differential diagnosis of CEAS-like small intestinal ulcerative lesions and normal urinary prostaglandin metabolite levels.

Clinical guidance for the use of dupilumab in eosinophilic esophagitis: A yardstick

The Joint Task Force for the American Academy of Allergy Asthma Immunology and American College of Allergy Asthma Immunology and the American Gastroenterology Association recently published guidelines for the management of eosinophilic esophagitis (EoE). Because the guideline was published, dupilumab became the first and only medication to gain regulatory approval for the treatment of EoE. This expert opinion document provides a framework for how the clinician can consider using dupilumab in the treatment strategy for patients with EoE.

Eosinophilic Gastrointestinal Diseases in Inborn Errors of Immunity

Inborn errors of immunity (IEI) are disorders mostly caused by mutations in genes involved in host defense and immune regulation. Different degrees of gastrointestinal (GI) involvement have been described in IEI, and for some IEI the GI manifestations represent the main and characteristic clinical feature. IEI also carry an increased risk for atopic manifestations. Eosinophilic gastrointestinal diseases (EGIDs) are emerging disorders characterized by a chronic/remittent and prevalent eosinophilic inflammation affecting the GI tract from the esophagus to the anus in the absence of secondary causes of intestinal eosinophilia. Data from the U.S. Immunodeficiency Network (USIDNET) reported that EGIDs are more commonly found in patients with IEI. Considering this element, it is reasonable to highlight the importance of an accurate differential diagnosis in patients with IEI associated with mucosal eosinophilia to avoid potential misdiagnosis. For this reason, we provide a potential algorithm to suspect an EGID in patients with IEI or an IEI in individuals with a diagnosis of primary EGID. The early diagnosis and detection of suspicious symptoms of both conditions are fundamental to prevent clinically relevant complications.

Dupilumab Leads to Clinical Improvements including the Acquisition of Tolerance to Causative Foods in Non-Eosinophilic Esophagitis Eosinophilic Gastrointestinal Disorders

A recent report showed that most pediatric cases of non-eosinophilic esophagitis (EoE) eosinophilic gastrointestinal disorders (EGIDs) (non-EoE EGIDs) are persistent and severe compared with those of EoE, thus requiring further effective therapeutic approaches. In this study, we present the first case based on a systematic search of non-EoE EGID for which tolerance to causative foods and histological and symptomatic improvements were achieved following dupilumab administration, after elimination diets and omalizumab and mepolizumab treatments. Driven by this case, we investigated the efficacies of biological treatments in non-EoE EGID cases based on the patient studied herein, and other patients identified in the conducted systematic review. Seven articles, including five different biologics, were reviewed. Both clinical efficacies and impact differences among the targeted molecules are demonstrated in this study. Our findings show that dupilumab may affect mechanisms that can suppress symptoms induced by offending foods that are different from those induced by other biologics as identified in the conducted systematic review. Additional studies are required to address the unmet needs of non-EoE EGID treatments.

"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.

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

Background and Aims

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

Methods

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

Results

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

Conclusion

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

Esophageal lichen planus: Current knowledge, challenges and future perspectives

Lichen planus (LP) is a frequent, chronic inflammatory disease involving the skin, mucous membranes and/or skin appendages. Esophageal involvement in lichen planus (ELP) is a clinically important albeit underdiagnosed inflammatory condition. This narrative review aims to give an overview of the current knowledge on ELP, its prevalence, pathogenesis, clinical manifestation, diagnostic criteria, and therapeutic options in order to provide support in clinical management. Studies on ELP were collected using PubMed/Medline. Relevant clinical and therapeutical characteristics from published patient cohorts including our own cohort were extracted and summarized. ELP mainly affects middle-aged women. The principal symptom is dysphagia. However, asymptomatic cases despite progressed macroscopic esophageal lesions may occur. The pathogenesis is unknown, however an immune-mediated mechanism is probable. Endoscopically, ELP is characterized by mucosal denudation and tearing, trachealization, and hyperkeratosis. Scarring esophageal stenosis may occur in chronic courses. Histologic findings include mucosal detachment, T-lymphocytic infiltrations, epithelial apoptosis (Civatte bodies), dyskeratosis, and hyperkeratosis. Direct immuno-fluorescence shows fibrinogen deposits along the basement membrane zone. To date, there is no established therapy. However, treatment with topical steroids induces symptomatic and histologic improvement in two thirds of ELP patients in general. More severe cases may require therapy with immunosuppressors. In symptomatic esophageal stenosis, endoscopic dilation may be necessary. ELP may be regarded as a precancerous condition as transition to squamous cell carcinoma has been documented in literature. ELP is an underdiagnosed yet clinically important differential diagnosis for patients with unclear dysphagia or esophagitis. Timely diagnosis and therapy might prevent potential sequelae such as esophageal stenosis or development of invasive squamous cell carcinoma. Further studies are needed to gain more knowledge about the pathogenesis and treatment options.

Tolerability and safety of a new elimination diet for pediatric eosinophilic gastritis and duodenitis

BACKGROUND

Non-esophageal eosinophilic gastrointestinal disorders (non-EoE EGIDs) are chronic inflammatory disorders with massive infiltration of eosinophils into the gastrointestinal tract. Food elimination diets are potentially effective treatments. But the existing dietary therapies have various weak points. We developed a new regimen to compensate for the shortcomings of the elemental diet and 6-food elimination diet. The new regimen consists of an amino-acid-based formula, potatoes, vegetables, fruits and restricted seasonings. We named it the "Rainbow Elimination Diet (ED)." The aims of this study were to evaluate the tolerability and safety of this diet.

METHODS

A retrospective medical record examination was conducted at the National Center for Child Health and Development covering the period from January 2010 through December 2018. The medical records of patients (age 2-17 y) with histologically diagnosed non-EoE EGIDs were reviewed. The tolerability, nutritional intake, symptoms, and blood test findings were evaluated.

RESULTS

Nineteen patients were offered several kinds of food-elimination diets. Seven patients (eosinophilic gastritis: 5; gastroenteritis: 1; duodenitis: 1) were treated with Rainbow ED. Six patients were compliant with this diet. The median duration of the diet induction phase was 15 days (range 14-30). All 5 patients who had had symptoms just before the induction phase became symptom-free. The body weight decreased in 5 patients (median -0.6 kg), probably because the serum protein increased, resulting in reduced edema. All 5 patients with hypoproteinemia had elevated serum albumin (median 2.9-3.5 g/dL). The ingested nutritional elements were calculated, and most of them were sufficient, except for fat and selenium.

CONCLUSIONS

The Rainbow ED was well-tolerated and safe for pediatric non-EoE EGIDs.

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

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

Psychological Stress Exacerbates Inflammation of the Ileum via the Corticotropin-Releasing Hormone-Mast Cell Axis in a Mouse Model of Eosinophilic Enteritis

The effects of psychological stress on eosinophilic gastrointestinal disorders have not been elucidated. This study investigated the effects of psychological stress in a mouse model of eosinophilic enteritis (EoN). BALB/c mice were treated with ovalbumin (OVA) to create an EoN model and subjected to either water avoidance stress (WAS) or sham stress (SS). Microscopic inflammation, eosinophil and mast cell counts, mRNA expression, and protein levels of type 2 helper T cell (Th2) cytokines in the ileum were compared between groups. We evaluated ex vivo intestinal permeability using an Ussing chamber. A corticotropin-releasing hormone type 1 receptor (CRH-R1) antagonist was administered before WAS, and its effects were analyzed. WAS significantly increased diarrhea occurrence and, eosinophil and mast cell counts, and decreased the villus/crypt ratio compared to those in the SS group. The mRNA expression of CRH, interleukin IL-4, IL-5, IL-13, eotaxin-1, and mast cell tryptase β2 significantly increased, and the protein levels of IL-5, IL-13, and OVA-specific immunoglobulin E (IgE) also significantly increased in the WAS group. Moreover, WAS significantly increased the intestinal permeability. The CRH-R1 antagonist significantly inhibited all changes induced by WAS. Psychological stress exacerbated ileal inflammation via the CRH-mast cell axis in an EoN mouse model.

A Case Series on the Use of Dupilumab for Treatment of Refractory Eosinophilic Gastrointestinal Disorders

The incidence and prevalence of eosinophilic esophagitis (EoE), eosinophilic gastritis (EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC) are increasing ( 1 ). These conditions will inevitably become more widely recognized and better understood. There is currently no Food and Drug Administration (FDA)-approved treatment for EoE, but there are standard-of-care treatments that are well established and widely used. In contrast, there is a paucity of data regarding standard-of-care treatment for non-EoE eosinophilic gastrointestinal disorders (EGID). We identified 3 patients that all achieved clinical and histopathologic remission on dupilumab, a monoclonal antibody that blocks the downstream signaling of interleukin (IL)-4 and IL-13. These patients had extra-esophageal forms of EGID with two patients failing to achieve remission on standard-of-care therapies and one patient experiencing significant side effects on swallowed budesonide therapy. The reduction in mucosal eosinophilia in several GI tract segments in these 3 patients highlights a new potential clinical indication for dupilumab in the treatment of pediatric EGID patients.

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.