An update on the immunopathogenesis of eosinophilic esophagitis

The clinical significance of allergen-specific IgG4 in allergic diseases

IgG4 is a subclass of IgG antibody with a unique molecular feature of (Fragment antigen- binding) Fab-arm exchange, allowing bispecific antigen binding in a mono-valent manner. With low binding affinity to C1q and Fcγreceptors, IgG4 is incapable of forming immune complexes and activating the complement pathway, exhibiting a non-inflammatory feature. IgG4 is produced similarly to IgE and is considered a modified reaction to IgE class-switching response under certain conditions. It could also counteract IgE-activated inflammation. However, the clinical significance of IgG4 in allergic diseases is complex and controversial. Three viewpoints have been suggested to describe the role of IgG4. IgG4 can act as a tolerance-inducer to play a protective role under repeated and rapid incremental dosing of allergen exposure in allergen immunotherapy (AIT), supported by allergies in cat raisers and venom desensitization in beekeepers. Another viewpoint accepted by mainstream specialists and guidelines of Food Allergy and Management in different countries points out that food-specific IgG4 is a bystander in food allergy and should not be used as a diagnostic tool in clinical work. However, eosinophilic esophagitis (EoE) investigation revealed a direct clinical relevance between physiopathology and serum IgG4 in cow milk and wheat. These factors indicate that allergen-specific IgG4 plays a multifaceted role in allergic diseases that is protective or pathogenic depending on different allergens or exposure conditions.

Eosinophilic Esophagitis and Microbiota: State of the Art

Eosinophilic esophagitis (EoE) is a chronic, food-triggered, immune-mediated disease of the oesophagus, clinically characterized by symptoms referred to oesophagal dysfunction, and histologically defined by an eosinophil productive inflammation of the oesophagal mucosa, among other cell types. The involvement of an adaptive Th2-type response to food antigens in EoE was known since 2000; several cytokines and chemokines promote food-specific responses, during which local production of IgE, but also IgG4 derived from plasma cells in lamina propria of oesophagal mucosa might play an important role. Evidence pointing towards a possible role for the innate immunity in EoE has arisen recently. Together, this evidence gives rise to a potential role that the innate immune system in general, and also the microbial pattern recognition receptors (PRRs) might play in EoE pathogenesis. Among PRRs, Toll-like receptors (TLRs) are type-I transmembrane receptors expressed both on epithelial and lamina propria cells with the capacity to distinguish between pathogen and commensal microbes. As TLRs in the different intestinal epithelia represent the primary mechanism of epithelial recognition of bacteria, this evidence underlines that oesophagal TLR-dependent signaling pathways in EoE support the potential implication of microbiota and the innate immune system in the pathogenesis of this disease. The oesophagal mucosa hosts a resident microbiota, although in a smaller population as compared with other districts of the gastrointestinal tract. Few studies have focused on the composition of the microbiota of the normal oesophagus alone. Still, additional information has come from studies investigating the oesophagal microbiota in disease and including healthy patients as controls. Our review aims to describe all the evidence on the oesophagal and intestinal microbiota in patients with EoE to identify the specific features of dysbiosis in this condition.

Esophageal perforation in eosinophilic esophagitis: A systematic review on clinical presentation, management and outcomes

There is evidence of an increased fragility in the inflamed esophagus of patients with eosinophilic esophagitis (EoE). We performed a systematic review on presentation, management and outcomes of and surgical interventions for esophageal perforation in these patients, by searching in the MEDLINE, Embase and Scopus databases. Of the 599 references identified, 41 full-papers and 9 abstract met the inclusion criteria. Overall, 76 esophageal perforation episodes in 70 individual patients aged between 9 and 65 years were reported. 51 patients had not been diagnosed with EoE at the time of perforation; 14 patients had an untreated disease and the remaining were non responsive to therapy. Acute or progressive pain after long-lasting dysphagia and food impaction was the most common symptom leading to diagnosis in 42 patients who presented with Boerhaave syndrome. Pushing impacted food into the stomach led to perforation in 5 cases. Eight episodes appeared after dilation. CT scans demonstrated perforation in 82.4% of patients. Conservative management (including esophageal stenting) was used in 67.1% patients. The 25 remaining patients underwent surgery. Recovery was uneventful in the vast majority of patients. No death was reported. Active inflammation due to undiagnosed or untreated EoE was present in most cases of esophageal perforation. Conservative treatment of perforation should always be considered in EoE.

Pathophysiology of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus associated with an atopic predisposition which appears to be increasing in prevalence over the last few decades. Symptoms stem from fibrosis, swelling, and smooth muscle dysfunction. In the past two decades, the etiology of EoE has been and is continuing to be revealed. This review provides an overview of the effects of genetics, environment, and immune function including discussions that touch on microbiome, the role of diet, food allergy, and aeroallergy. The review further concentrates on the pathophysiology of the disease with particular focus on the important concepts of the molecular etiology of EoE including barrier dysfunction and allergic hypersensitivity.

Toll-like receptors-mediated pathways activate inflammatory responses in the esophageal mucosa of adult eosinophilic esophagitis

Objectives

Esophageal microbiota and regulation of adaptive immunity are increasingly being investigated in eosinophilic esophagitis (EoE). Toll-like receptors (TLRs) play a central role in the initiation and maintenance of innate immune activity. Our objective was to characterize the esophageal and duodenal innate immune response in EoE and its modulation by dietary therapy.

Methods

Esophageal and duodenal biopsy samples were collected from 10 adults with untreated EoE, before and after effective treatment with a six-food elimination diet (SFED), and 10 controls with normal esophagus. In all cases, bacterial load (by mRNA expression of 16S), TLRs, mucins, transcription factors, interleukins, components of the NKG2D system, and innate immunity effectors were assessed by qPCR. Protein expression of TLRs were also determined by immunofluorescence.

Results

Bacterial load and TLR1, TLR2, TLR4, and TLR9 were overexpressed on biopsies with active EoE compared with controls. Muc1 and Muc5B genes were downregulated while Muc4 was overexpressed. Upregulation of MyD88 and NFκB was found together with IL-1β, IL-6, IL-8, and IL-10 mediators and PER-1, iNOS, and GRZA effectors. NG-K2D components (KLRK1, IL-15, MICB) were also upregulated. In all cases, changes in active EoE were normalized following SFED and mucosal healing. Duodenal samples also showed increased expressions of TLR-1, TLR-2, and TLR-4, but not 16S or any other mediators nor effectors of inflammation.

Conclusions

Esophageal TLR-dependent signaling pathways in EoE support the potential implication of microbiota and the innate immune system in the pathogenesis of this disease.

Dietary treatment modulates mast cell phenotype, density, and activity in adult eosinophilic oesophagitis

BACKGROUND

Mast cells (MCs) are abundant in the inflammatory infiltrate in eosinophilic oesophagitis (EoE), but decrease with disease remission. However, their phenotype, role in the pathophysiology of the disease, and modulation after effective dietary therapy are still unclear.

OBJECTIVE

To define the phenotype of oesophageal MCs, their modulation through dietary therapy, and their association with clinical manifestations of EoE.

METHODS

Oesophageal mucosal samples from 10 adult patients with EoE obtained before and after effective six-food elimination diet (SFED) therapy, as well as from 10 control subjects were analysed. Eosinophil and MC density were quantified. Gene expression of chemoattractants for eosinophils (CCL11, CCL24, and CCL26), MCs (SCF), and their receptors (CCR3 and SCFR, respectively) were assessed by means of qPCR. Gene and protein expression of specific MC proteases (CPA3, CMA, and TPSB2) were evaluated with qPCR and immunofluorescence. Clinical manifestations and atopic background were recorded.

RESULTS

MC density was significantly increased in EoE compared with controls, decreasing after dietary treatment (18.6 to 1.44 cells/hpf, respectively; P < 0.001). The MCTC subtype predominated in the oesophageal mucosa (90%) in both patients with EoE and controls. Gene expression of MC-related proteases, eotaxins, and SCF were up-regulated in patients with EoE, but significantly decreased after therapy, regardless of atopic background. Epithelial peaks of MCs and eosinophils were significantly associated (ρ = 0.80) in EoE and correlated with the symptom score (ρ = 0.78). Gene expression of MC proteases and eotaxins also correlated with the symptom score (P < 0.05).

CONCLUSIONS AND CLINICAL RELEVANCE

MC and its proteases seem to play a relevant role in the pathophysiology and symptoms of EoE, which can be reversed after effective dietary treatment.

Mechanisms of Disease of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a recently recognized inflammatory disease of the esophagus with clinical symptoms derived from esophageal dysfunction. The etiology of EoE is now being elucidated, and food hypersensitivity is emerging as the central cornerstone of disease pathogenesis. Herein, we present a thorough picture of the current clinical, pathologic, and molecular understanding of the disease with a focus on disease mechanisms.

Clinical features of eosinophilic esophagitis: differences between Asian and Western populations

The prevalence and incidence of eosinophilic esophagitis (EoE) have been rapidly increasing in Western countries. It is thought to be more common among Caucasians than other racial or ethnic groups, but epidemiological studies have not been fully evaluated in Asian populations, and its clinical manifestation is rarely documented. In this review, recent reports regarding EoE in Asian countries have been collected, and differences in the clinical features, including symptoms and endoscopic findings, between Asian and Western populations have been evaluated. In Asia, EoE is still much less prevalent than in Western countries. Baseline values for average age, male/female ratio, and personal history of allergic disease were comparable to those in Western populations. Predominant symptoms were dysphagia, and food impaction was extremely rare among Asian patients. Although the frequency of abnormal endoscopic findings varies among studies, over 90% of patients with EoE have shown abnormal findings such as linear furrow, which is the most common findings, in recent prospective studies in Asia. There are few reports regarding the treatment of EoE and no prospective studies evaluating drugs or elimination diet in patient with EoE have been reported in Asia. Overall, EoE had similar clinical characteristics in Asian populations. Because the incidence of EoE could increase in the future with the increase in allergic disorders in Asian countries, large-scale, nationwide prospective studies should be performed to more fully understand the epidemiology and pathophysiology of EoE in Asian populations.

Eosinophilic esophagitis: an autoimmune esophageal disorder

Eosinophilic esophagitis (EoE) represents a chronic, immune/antigen-mediated esophageal inflammatory disease associated with esophageal dysfunction resulting from severe inflammation. The incidence and prevalence of EoE have been increasing in the past decade; however, the reason for this increase is unclear. There is a chronic inflammatory infiltrate that is present in EoE which promotes inflammation, symptoms, and dysfunction. In addition to eosinophils, interleukin (IL)-5 expressing T cells, B cells, eotaxin-3, IL-13, and IgE-bearing mast cells are present in EoE and are thought to contribute to the disease process. Eosinophils are pro-inflammatory and modulate multiple aspects of the immune response. Eosinophils produce a wide range of inflammatory cytokines, chemokines, granulocyte-monocyte colony-stimulating factors, and tumor necrosis factors. Once activated, eosinophils release granule components, which are toxic to a variety of tissues. Transforming growth factor β1 is a pro-fibrotic molecule produced by epithelial and inflammatory cells, is overexpressed in EoE, and plays a role in esophageal remodeling. Fibrous remodeling in EoE could be associated with symptoms of dysphagia and may explain and predict future esophageal strictures and dysmotility. EoE is a complex disease involving multiple activation pathways, a large number of cells, and various inflammatory molecules. It, along with other atopic disease, is becoming increasingly prevalent and has an important genetic load and may represent as an immunological tolerance disorder of the GI tract.

Cellular and molecular immunological mechanisms in eosinophilic esophagitis: an updated overview of their clinical implications

Eosinophilic esophagitis (EoE) is a pathophysiologically complex disorder driven by distinct, multiple mechanisms involving a large number of cells, molecules, and genes. Associated with food allergy from its initial descriptions, a key role for the Th2-type cytokines IL-5 and IL-13 in recruiting and activating eosinophils has been described. Epithelial cells have been recognized as major effectors in initiating EoE, both through their recruitment of iNKT cells towards the esophageal epithelium, which constitutes a major cytokine source, and through the release of eotaxin-3 and other chemoattractants. Epithelial and mesenchymal-released TSLP is a key regulator for which a connecting role between the adaptive and innate mucosal-associated immune response has been suggested. Finally, activated eosinophil- and mast cell-derived TGF β1 secretion is crucial in EoE-associated tissue remodeling.

Efficacy of dietary interventions for inducing histologic remission in patients with eosinophilic esophagitis: a systematic review and meta-analysis

BACKGROUND & AIMS

Various dietary interventions have been used to treat patients with eosinophilic esophagitis (EoE), yielding varied results. This systematic review assesses the efficacy of different dietary therapies in inducing disease remission.

METHODS

We performed a systematic search of the MEDLINE, EMBASE, and SCOPUS databases for studies investigating the efficacy of dietary interventions (reducing infiltration by immune cells <15 eosinophils/high-power field in esophageal biopsies) for pediatric and adult patients with EoE. Summary estimates, including 95% confidence intervals (CI), were calculated for exclusive feeding with amino acid-based elemental formulas, allergy test result-directed food elimination diets, and 6-food elimination diets (SFED). A fixed- or random-effects model was used depending on heterogeneity (I(2)); publication bias risks were assessed by means of funnel plot analysis.

RESULTS

The search yielded 581 references; of these, 33 were included in the quantitative summary. We analyzed data on a total of 1317 patients with EoE (1128 children and 189 adults) who received different dietary treatments. Elemental diets were effective for 90.8% of cases (95% CI, 84.7%-95.5%; I(2) = 52.3%), SFED for 72.1% (95% CI, 65.8%-78.1%; I(2) = 0), and allergy test result-directed food elimination for 45.5% of cases (95% CI, 35.4%-55.7%; I(2) = 75.1%). Additional strategies (elimination of cow's milk, gluten-free diets, and 4-food elimination diet) were also evaluated. Adults vs children had no significant differences in remission after dietary interventions (67.2% vs 63.3%).

CONCLUSIONS

Dietary interventions are effective in producing histologic remission in patients with EoE. Elemental diets and SFEDs were the most effective, achieving <15 eosinophils/high-power field in 90.8% and 72.1% of patients, respectively.

Treatment of adult eosinophilic esophagitis with diet

BACKGROUND/AIMS

A growing body of research indicates that dietary therapy is an effective treatment option for children with eosinophilic esophagitis (EoE). Its ability to achieve sustained symptomatic and histological responses is comparable to that of topical steroids, but avoids their use and side effects. Recent studies also support dietary therapy as a preferred treatment option for adult patients.

METHODS

A comprehensive literature review was carried out to assess the efficacy of the most commonly used dietary interventions in inducing and maintaining disease remission in adult EoE patients as compared with results from pediatric studies.

RESULTS

The only available study assessing exclusive feeding with an elemental diet carried out in adults demonstrated a 94% disease remission rate, comparable to the high efficacy reported in pediatric studies. The major drawbacks of this therapy are poor adherence and a rapid disease recurrence after resumption of a normal diet. Although there is limited data on skin allergy testing-directed food elimination in adult patients, the highest efficacy rates observed do not exceed 26% histological remission. Prospective studies on empirical six-food elimination diets in adults provided efficacy rates comparable to those reported in children, achieving disease remission in approximately 75% of patients. However, specific food triggers can only be identified after documented recurrence of eosinophilic inflammation as determined with repeated endoscopic biopsies. Prolonged avoidance of the offending food(s) produces sustained remission of adult EoE.

CONCLUSIONS

Diet is a feasible therapeutic option for adult EoE patients, providing them with the same effective drug-free alternative as in pediatric patients.

Dietary therapies for eosinophilic esophagitis

Eosinophilic esophagitis (EoE) represents a prevalent chronic esophageal disorder. Since the condition was first described, its pathophysiology has been known to have an immune-allergic origin, but the high response rate to dietary therapies based on feeding patients exclusively with amino acid-based elemental formulas (with complete elimination of table foods) has clearly established EoE as a particular form of food allergy. Nevertheless, the management of EoE in clinical practice remains widely heterogeneous, with topical steroids being a therapeutic mainstay. However, a growing body of evidence points to dietary therapy as an effective treatment option for both children and adults with EoE, as this approach is capable of achieving a sustained symptomatic and histological response without resorting to drugs. This article reviews the available data on the major types of dietary therapy for EoE, including elemental formula diets, skin allergy testing-directed elimination diets and empirical elimination diets based on common food allergens.

Limited role of allergy testing in patients with eosinophilic gastrointestinal disorders

BACKGROUND AND AIM

Allergies have been implicated in the pathogenesis of eosinophilic gastrointestinal disorders, although it remains unknown what type of allergen is closely associated with their development. The aim of this study is to investigate the possible involvement of food and/or aeroallergen factors in eosinophilic gastrointestinal disorders.

METHODS

Eighteen patients with eosinophilic esophagitis (EoE), 23 with eosinophilic gastroenteritis (EGE), and 28 healthy volunteers were enrolled. The levels of total serum immunoglobulin E (IgE) and 33 different allergen-specific IgE antibodies, including those for six foods used in a standard EoE elimination diet, were determined in each subject. Serum antigen-specific IgE levels were measured using a chemiluminescence enzyme immunoassay with a multiple antigen simultaneous test 33 (MAST33). The expression patterns of specific antigens were compared among the groups.

RESULTS

The mean level of total IgE antibodies was significantly higher in patients with EGE (553.6 ± 115.3 IU/mL) than the healthy volunteers (230.6 ± 87.1 IU/mL). Two thirds of all subjects had sensitivity to at least one inhaled antigen. In positive cases, allergies against multiple antigens were more frequently seen in the EoE and EGE patients. Japanese cedar and dust mite aeroallergens were more prevalent than food antigens.

CONCLUSIONS

Consistent with higher levels of serum total IgE antibodies, patients with EoE and EGE were frequently sensitized to several different allergens. Reactions to aeroallergens were more prevalent in these groups, although no particular antigen causing EoE and/or EGE was detected by measuring serum antigen-specific IgE antibodies.

Tolerance of a cow's milk-based hydrolyzed formula in patients with eosinophilic esophagitis triggered by milk

BACKGROUND

Cow's milk protein, a major food trigger for EoE in both children and adults, should be continuously avoided once identified as such. This study evaluates tolerance of a cow's milk-based extensively hydrolyzed formula (eHF) with regard to disease remission maintenance in adult patients with milk-triggered EoE.

METHODS

Seventeen adult patients in whom cow's milk was consecutively demonstrated to trigger EoE after an empiric six-food elimination diet-based study protocol and who subsequently maintained disease remission were prospectively recruited. They were given 400 ml of a cow's milk-based eHF daily for 8 weeks. Intraepithelial peak eosinophil and blood eosinophil counts, esophageal-related symptoms, serum total and specific IgE to major milk proteins, and eosinophil cationic protein were monitored before and after eHF intake.

RESULTS

Thirteen male and four female patients aged 17-56 completed the study protocol. 15 patients (88.24%) achieved and maintained EoE remission, while an infiltration of ≥15 eosinophils/hpf reappeared in the remaining two patients. No differences in age, gender, symptoms, and endoscopic appearance at baseline conditions or personal/family allergic background were observed between those patients who tolerated the eHF and those who did not. Symptom scores did not significantly change after eHF intake and were significantly lower than those documented at baseline conditions or after cow's milk challenge. No differences were documented in blood eosinophil counts or serum markers after eHF intake.

CONCLUSION

Most adult patients with EoE triggered by cow's milk tolerate a cow's milk-based eHF, thus providing them with a safe, economical alternative to cow's milk.

Pathogenic role of mast cells in experimental eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic allergic disease characterized by esophageal intraepithelial eosinophils, extracellular eosinophil granule deposition, induced mast cell accumulation, and epithelial cell hyperplasia. However, the processes involved in the development of a number of these characteristics are largely unknown. Herein, we tested the hypothesis whether induced mast cell accumulation in the esophagus has a role in promoting EoE pathogenesis. Accordingly, we induced experimental EoE in wild-type mice, mast cell-deficient WWv mice, and mast cell-reconstituted WWv mice. We report that esophageal mast cell numbers increase in parallel with eosinophils in a dose- and time-dependent manner following the induction of allergen-induced EoE. The induced mast cells are localized in the esophageal lamina propria and muscular mucosa but have no influence on promoting esophageal eosinophilia. The 5'-bromodeoxyuridine (BrdU) incorporation analysis indicated that mast cells have a significant role in muscle cell hyperplasia and hypertrophy. In addition, the wild-type and mast cell-reconstituted WWv mice showed a comparable number of BrdU⁺ cells in the esophageal muscular mucosa following allergen-induced EoE. In conclusion, we provide for the first time direct evidence that mast cell promotes muscle cell hyperplasia and hypertrophy and may have a significant role in promoting esophageal functional abnormalities in EoE.

Adult versus pediatric eosinophilic esophagitis: important differences and similarities for the clinician to understand

Eosinophilic esophagitis (EoE) is recognized as a common, allergy-associated cause of chronic esophageal symptoms affecting both children and adults. Research has begun to shed light on its epidemiology with consistent results from various geographical areas. Differences in clinical presentation, endoscopic aspects and response to treatment have all been reported for patients of different ages, and the question as to whether adult and pediatric EoE are manifestations of a single entity or in fact two distinct disorders has been posed. The most relevant differences between pediatric and adult EoE come from evolutionary changes in the consequences of the disease, including fibrous remodeling, and the ability to express symptoms. However, most studies support a common pathogenesis and similar histopathological features for adult and pediatric patients, being the same diagnostic criteria applied to them. This article comprehensively reviews the most recently published information and addresses important questions about the natural history of EoE.

Empiric 6-food elimination diet induced and maintained prolonged remission in patients with adult eosinophilic esophagitis: a prospective study on the food cause of the disease

BACKGROUND

Although empiric exclusion from the diet of the 6 food groups most likely to trigger allergies achieves eosinophilic esophagitis (EoE) remission in children, data on its prolonged efficacy and effects on adults are lacking.

OBJECTIVE

We sought to evaluate the efficacy of a 6-food elimination diet in inducing and maintaining prolonged remission in patients with adult EoE.

METHODS

Sixty-seven consecutive patients with adult EoE were prospectively recruited and treated exclusively with a diet avoiding cereals, milk, eggs, fish/seafood, legumes/peanuts, and soy for 6 weeks. Subsequent challenge was undertaken by sequentially reintroducing all excluded single foods, followed by endoscopy and biopsies, which were developed every 6 weeks in case of response (eosinophil peak count reduction to <15/high-power field [hpf]). A food was considered a trigger for EoE and removed from the diet if pathologic eosinophilic infiltration (≥15 eosinophils/hpf) reappeared. Food-specific serum IgE measurements and skin prick tests were performed before initiating the diet.

RESULTS

Forty-nine (73.1%) patients exhibited significantly reduced eosinophil peak counts (<15 eosinophils/hpf) before sequential single-food reintroduction. A single offending food antigen was identified in 35.71% of patients, 2 food triggers were identified in 30.95%, and 3 or more food triggers were identified in 33.3%. Cow's milk was the most common food antigen (61.9%), followed by wheat (28.6%), eggs (26.2%), and legumes (23.8%). Prior allergy tests showed no concordance with food-reintroduction challenge results. All patients who continued to avoid the offending foods maintained histopathologic and clinical EoE remission for up to 3 years.

CONCLUSIONS

An empiric 6-food elimination diet effectively induced remission of active adult EoE, which was maintained for up to 3 years with individually tailored, limited exclusion diets.

Gluten-free diet does not appear to induce endoscopic remission of eosinophilic esophagitis in children with coexistent celiac disease

BACKGROUND

Celiac disease and eosinophilic esophagitis are usually considered to be separate gastrointestinal diseases; however, it appears that they may coexist more often than would be expected. It is unknown whether eosinophilic esophagitis in patients with celiac disease responds to a gluten-free diet.

OBJECTIVES

To examine the clinical, endoscopic and histological features of children with both conditions to evaluate whether eosinophilic esophagitis responds to a gluten-free diet.

METHODS

From January 1, 2009, to June 30, 2011, the medical records of children <18 years of age diagnosed with eosinophilic esophagitis and⁄or celiac disease were reviewed. Patients with clinical, endoscopic and histological diagnoses of both diseases were identified and included. These findings were analyzed, as were laboratory results, treatment and follow-up.

RESULTS

During the study period, there were 206 celiac disease patients, 86 eosinophilic esophagitis patients and nine (4.4% of total celiac) patients with both diagnoses. Gluten-free diet was the primary treatment for both conditions in seven of nine (78%) cases. In six of these seven (86%) patients, no endoscopic or histological improvement of eosinophilic esophagitis was observed, while in one patient, histological remission of esophageal eosinophilia occurred while on a gluten-free diet.

CONCLUSION

The prevalence of eosinophilic esophagitis in patients with celiac disease was 4.4%, confirming a higher than expected prevalence of eosinophilic esophagitis compared with the general population. In patients with celiac disease, a gluten-free diet did not appear to induce remission of coexistent endoscopic and histological features of eosinophilic esophagitis.

Biomechanics of esophageal function in eosinophilic esophagitis

Eosinophilic Esophagitis (EoE) is a chronic inflammatory disease of the esophagus triggered by an immune response that leads to symptoms of dysphagia, chest pain, and food impaction. EoE is a clinicopathologic syndrome that requires clinical symptoms and pathologic findings for a diagnosis. The inflammatory process and eosinophilic infiltration of the esophagus in EoE lead to fibrosis and structural changes within the esophagus that cause esophageal dysfunction. The biomechanics of the esophageal function in EoE have been explored using manometry, impedance planimetry, barium esophagograms, and endoscopic ultrasound. These studies have identified several biomechanical changes to the esophagus in EoE including pan-esophageal pressurization on manometry, changes in esophageal compliance with decreased distentisbility by impedance planimetry, decreased esophageal luminal diameter by esophagograms, and dysfunction in the esophageal longitudinal muscles by endoscopic ultrasound. Treatments for the disease involve dietary changes, immunosuppressive drugs, and dilation techniques. However, the data regarding the effect of these therapies on altering mechanical properties of the esophagus is limited. As the pathogenesis of esophageal dysfunction in EoE appears multifactorial, further study of the biomechanics of EoE is critical to better diagnose, monitor and treat the disease.

Eosinophilic gastroenteritis: an update

Eosinophilic gastroenteritis (EGE) is characterized by dense eosinophilic inflammation of one or several digestive tract sections. The symptoms include abdominal pain, weight loss, vomiting and diarrhea. Biopsy samples taken during endoscopic examination allows the diagnosis of the disease. An infiltration of >30 eosinophils per high-power field in at least five high-power fields, exhibiting signs of eosinophilic degranulation and extending to the muscularis mucosa or submucosa are all histological indications of EGE. EGE is traditionally classified into three forms depending on the depth of inflammation in the wall (mucosal, muscular or serosal). This, together with the digestive tract segments involved, determines the clinical presentation. The natural history of EGE includes three different evolutionary patterns, since patients may suffer a single outbreak, a recurrent course or even chronic disease. Corticosteroids are the most frequently used therapy for EGE; dietary treatments should be also considered. Surgery has been limited to solving obstruction and small bowel perforation.

Eosinophilic infiltration of the esophagus following endoscopic ablation of Barrett's neoplasia

To assess the incidence of esophageal intra-epithelial eosinophilic infiltration following endoscopic ablation of Barrett's esophagus (BE), a retrospective study of consecutive cases of endoscopic ablation of BE with dysplasia or cancer using radiofrequency ablation (RFA) and spray cryotherapy at two centers in the United States was performed. Post-ablation eosinophilia was defined as ≥ 5 eosinophils per high power field during post-treatment surveillance. Twenty of 122 patients (16%) undergoing ablation developed esophageal eosinophilia after ablation, including 8/77 (10%) treated with RFA and 12/44 (27%) treated with cryotherapy. No patient had clinical or endoscopic findings of or risk factors for eosinophilic esophagitis. Esophageal eosinophilia persisted in 30% over a median of 20.2 months. On multivariate analysis, post-ablation eosinophilia was independently associated with increasing BE segment length (adjusted odds ratio 1.46 for every 2-cm increase, 95% confidence interval 1.24-1.71) and cryotherapy as the ablation modality (adjusted odds ratio 5.23, 95% confidence interval 1.67-16.39). Esophageal eosinophilic infiltration after endoscopic ablation with RFA and cryotherapy is common and is associated with the BE segment length and treatment modality. The clinical significance of post-ablation eosinophilia is unclear.

Management of pediatric eosinophilic esophagitis: an update

Eosinophilic esophagitis is an important chronic esophageal disorder with gastroesophageal reflux disease (GERD)-like symptoms, prominent esophageal mucosal eosinophilia, strongly associated with allergic disorders and unresponsive to anti-GERD therapy. Treatment of eosinophilic esophagitis has been successful with the use of dietary restrictions and topical corticosteroids. A subset of patients benefits from concurrent anti-GERD therapy; those with demonstrable esophageal strictures report variable duration symptom relief after esophageal dilation. At the current time, anti-interleukin-5 monoclonal antibody agents are being investigated in multicenter trials, and it is hoped that future therapy may be targeted against mediators of esophageal remodeling and fibrosis in eosinophilic esophagitis.

Eosinophilic esophagitis for the otolaryngologist

Objectives. This paper focuses on current diagnostic and treatment options for Eosinophilic Esophagitis (EE). Study Design. literature review. Results. EE can be suspected on history and endoscopy although definitive diagnosis is strictly based on histopathology. It is a relatively new entity and is often misdiagnosed as gastroesophageal reflux (GERD). Eosinophilic infiltration of the esophageal mucosa is responsible for esophageal symptoms which can range from mild to debilitating dysphagia and food impaction, when untreated. In fact recurrent foreign body and food impaction can often be blamed for undiagnosed EE. There seems to be a strong familial component and association with allergy. The introduction of transnasal esophagoscopy in adult laryngology has enabled otolaryngologists to readily diagnose EE and promoted awareness of this often difficult to recognize entity. Conclusions. Despite higher awareness, the literature suggests that EE remains a commonly misdiagnosed condition especially in the otolaryngology community. Genetic studies are required to unfold the true familial and genetic component of this fascinating entity.

Montelukast was inefficient in maintaining steroid-induced remission in adult eosinophilic esophagitis

BACKGROUND AND AIMS

Leukotriene D4 is produced by and functions as a chemotactic factor for eosinophils. Eosinophilic esophagitis (EoE) is characterized by esophageal eosinophilic infiltration, determining structural changes and dismotility symptoms. Montelukast, a selective leukotriene D4 receptor antagonist, has gained increasing consideration as a therapeutic agent for EoE. However, limited available information has shown that montelukast is not effective in reducing eosinophilic infiltration. Our paper aims at evaluating whether montelukast could be consider as a steroid-sparing therapy by assessing its efficacy in maintaining both clinical and histopathological remission achieved after topical corticosteroids in adult EoE patients.

METHODS

Eleven consecutively diagnosed adult EoE patients were prospectively studied. Esophageal biopsies were obtained before and after a 6-month treatment with fluticasone propionate 400 μg/twice a day. Immediately after that, montelukast 10 mg/day was instituted. A new endoscopy was foreseen after a new 3-month period, or as soon as the patients presented esophageal symptoms. Symptoms were assessed by using a questionnaire before and after fluticasone propionate treatment and after montelukast therapy.

RESULTS

Eosinophils density into the esophageal epithelium and lamina propria was significantly reduced after a 6-month treatment with topical steroids (P = 0.003) and increased to levels similar to baseline level into the first 3 months after treatment with montelukast. Baseline symptom scores significantly decreased after treatment with topical steroids (P = 0.003) and increased again after montelukast therapy, but baseline levels improved.

CONCLUSIONS

Montelukast was not efficient in maintaining the histopathological or clinical response achieved by topical steroids in adult EoE patients.

Subepithelial collagen deposition, profibrogenic cytokine gene expression, and changes after prolonged fluticasone propionate treatment in adult eosinophilic esophagitis: a prospective study

BACKGROUND

Recent research shows that both pediatric and adult patients with eosinophilic esophagitis (EoE) experience esophageal remodeling marked by increased collagen deposition in which TGF-β plays an important role. However, limited data are available on the intensity and reversibility of fibrous remodeling in adults with EoE.

OBJECTIVE

We sought to analyze differences in collagen deposition in the lamina propria (LP) and profibrogenic cytokine gene expression along with other changes induced by prolonged treatment with fluticasone propionate in adults with EoE.

METHODS

Ten adults given consecutive diagnoses of EoE were studied prospectively. Deep esophageal biopsy specimens were obtained before and after 1 year of treatment with fluticasone propionate. Collagen deposition in the LP was assessed in tissue sections with the aid of the Masson trichrome technique. IL5, TGFB1, fibroblast growth factor 9 (FGF9), and CCL18 gene expression was quantified through real-time PCR. EoE results were compared among samples from 10 adult patients with gastroesophageal reflux disease and 10 control subjects with healthy esophagi.

RESULTS

Patients with EoE showed a significant increase in subepithelial collagen deposition; this correlated positively with eosinophil density in the LP and the patient's age. Prolonged steroid treatment induced a nonsignificant reduction in subepithelial fibrosis, which remained significantly higher than in control subjects. Profibrogenic cytokine gene expression also increased in patients with EoE, with IL5 (P < .001), FGF9 (P = .005), and CCL18 (P = .008) all significantly upregulated. After 1 year of treatment, a reduction was observed in gene expression; for CCL18 expression, this decrease was statistically significant (P < .001).

CONCLUSIONS

Esophageal remodeling is associated with upregulated gene expression of profibrogenic cytokines in adults with EoE. Prolonged treatment with fluticasone propionate leads to a nonsignificant reduction in subepithelial collagen deposition accompanied by downregulation of profibrogenic cytokine gene expression, with that of CCL18 being especially significant.

Adult patients with eosinophilic esophagitis do not show an increased frequency of the HLA-DQ2/DQ8 genotypes predisposing to celiac disease

BACKGROUND

Recent articles have described patients that share eosinophilic esophagitis (EoE) and celiac disease (CD) suggesting a true relationship between both diseases.

AIMS

The purpose of this study was to investigate whether HLA DQ2 and DQ8 predisposing to CD are increased in adult patients with EoE.

METHODS

HLA alleles conferring risk for CD was assessed in 75 adult EoE patients attended at two hospitals located in different Spanish regions over the past 2 years. We compared the frequencies to the registered data of 421 healthy kidney and bone marrow donors from our hospitals for the following alleles: (a) DR3-DQ2 haplotype; (b) the combination of DR3-DQ2 and DR4-DQ8; (c) DR4-DQ8 haplotype; (d) the simultaneous presence of the DR5-DQ7 and DR7-DQ2 haplotypes; and lastly (e) any combination of haplotypes not conferring risk for the development of CD.

RESULTS

The HLA DQ2 and DQ8 alleles were analyzed in 58 adult EoE patients from hospital #1 and in 20 patients from hospital #2, and they were compared to recorded HLA genotyping data from 298 and 123 healthy donors, respectively. No differences were found between the distribution of the HLA frequencies of the patients and controls at both hospitals and the data could be combined. EoE patients did not show increased frequencies of DQ2 and DQ8 alleles compared to controls.

CONCLUSIONS

Our work does not allow us to establish a common genetic basis for EoE and CD because an increased frequency of the HLA DQ2 and DQ8 alleles predisposing to CD was not observed in adult EoE patients compared to controls.

Eosinophilic Esophagitis: Current Aspects of a Recently Recognized Disease

Eosinophilic esophagitis (EoE) is a chronic clinicopathological entity characterized by large numbers of intraepithelial eosinophils infiltrating the esophageal mucosa. The inflammation leads to alterations in the caliber and the motility of the organ, which determines esophageal symptoms, especially dysphagia and frequent food impaction. Firstly described in 1978, EoE represents today an increasingly recognized disease, with cases coming from all developed countries and rising epidemiology. The origin of EoE has been related to allergy to food components or inhalants, and a number of studies support a Th2-type reaction in the origin of the disease. Thus, several treatment strategies based on controlling the exposition to triggering allergens or therapies using anti-allergic drugs have demonstrated efficacy in EoE. Since EoE frequently presents with esophageal stenosis, endoscopic dilation has been also used in treating these patients, but a high risk of complications has been documented. However, single treatment strategies have not been compared to a placebo group in most of studies, and we do not know the long-term consequences of eosinophilic inflammation, esophageal fibrous remodeling or its possible modifications using different therapies. Furthermore, we lack of a common accepted therapeutic end-point to assess the efficacy of the treatment: from mere resolution of symptoms to full control of esophageal inflammation. This article summarizes the current knowledge about the epidemiology, origin and pathogenesis of the disease, and discuses several practical questions, especially those related to how the affected patients should be treated.