Eosinophilic esophagitis: an emerging clinicopathologic entity

Epithelial-mesenchymal transition, regulated by β-catenin and Twist, leads to esophageal wall remodeling in pediatric eosinophilic esophagitis

Eosinophilic Esophagitis (EoE) is an antigen-triggered inflammatory condition of the esophageal lining characterized by eosinophilic infiltration. EoE is associated with significant remodeling, and although this remodeling is reversed by current treatment regimens, symptoms of EoE and associated remodeling reappear upon cessation of therapies. We hypothesized that structural remodeling of cell-cell adhesion is a key factor in the pathogenesis of EoE and that epithelial to mesenchymal transition (EMT) was a viable molecular process to lead to this remodeling. Endoscopically obtained biopsy samples from 18 EoE and 18 control pediatric patients were evaluated by transmission electron microscopy to measure intercellular spaces (IS) between cells. Biopsy samples from all groups were analyzed for cellular levels of cell-cell adhesion proteins: E-cadherin, zonula occludens associated protein-1 (ZO-1), and N-cadherin. We also analyzed for cellular levels and localization two of transcription factors, Twist1 and β-catenin, that are associated with promoting EMT. The IS was significantly increased in the EoE group compared to the control. We observed a significant decrease in E-cadherin and ZO-1 levels and a concomitant increase in N-cadherin levels in EoE samples compared to control. Further, while there was no significant change in cellular levels of β-catenin, we observed an altered localization of the protein from the cell membrane in control tissue to a nuclear/perinuclear localization in EoE. We observed higher levels of the transcription factor Twist1 in the EoE group compared to normal which was localized mainly at the nucleus. Our results suggest that the integrity of normally sealed esophageal epithelia is compromised in the EoE patients compared to control subjects, and this is due to alterations in the expression of cell adhesion molecules at the esophageal epithelium. Our data also suggest that EMT, potentially regulated by transcription factors β-catenin and Twist1, may be responsible for the molecular alteration which leads to the remodeling of esophageal epithelia in EoE.

How to select patients for antireflux surgery? The ICARUS guidelines (international consensus regarding preoperative examinations and clinical characteristics assessment to select adult patients for antireflux surgery)

OBJECTIVE

Antireflux surgery can be proposed in patients with GORD, especially when proton pump inhibitor (PPI) use leads to incomplete symptom improvement. However, to date, international consensus guidelines on the clinical criteria and additional technical examinations used in patient selection for antireflux surgery are lacking. We aimed at generating key recommendations in the selection of patients for antireflux surgery.

DESIGN

We included 35 international experts (gastroenterologists, surgeons and physiologists) in a Delphi process and developed 37 statements that were revised by the Consensus Group, to start the Delphi process. Three voting rounds followed where each statement was presented with the evidence summary. The panel indicated the degree of agreement for the statement. When 80% of the Consensus Group agreed (A+/A) with a statement, this was defined as consensus. All votes were mutually anonymous.

RESULTS

Patients with heartburn with a satisfactory response to PPIs, patients with a hiatal hernia (HH), patients with oesophagitis Los Angeles (LA) grade B or higher and patients with Barrett's oesophagus are good candidates for antireflux surgery. An endoscopy prior to antireflux surgery is mandatory and a barium swallow should be performed in patients with suspicion of a HH or short oesophagus. Oesophageal manometry is mandatory to rule out major motility disorders. Finally, oesophageal pH (±impedance) monitoring of PPI is mandatory to select patients for antireflux surgery, if endoscopy is negative for unequivocal reflux oesophagitis.

CONCLUSION

With the ICARUS guidelines, we generated key recommendations for selection of patients for antireflux surgery.

Airway Manifestations of Pediatric Eosinophilic Esophagitis: A Clinical and Histopathologic Report of an Emerging Association

Objectives:

Pediatric eosinophilic esophagitis (EE) typically presents with dysphagia, vomiting, dyspepsia, or food impaction. The purpose of this study was to highlight the emerging association of pediatric EE and airway disease. An additional goal of this study was to describe the unique histopathologic findings found in EE and specifically explore the potential role of the cytotoxic protein called eosinophil major basic protein (MBP) in the pathophysiology of the disease.

Methods:

A retrospective review of 3 children with EE and airway symptoms included symptom presentation, aerodigestive tract endoscopic findings, ambulatory 24-hour dual pH-metry, allergy tests, treatment modalities, and treatment response. Esophageal tissue obtained from biopsies of each patient was evaluated by hematoxylin and eosin to determine the number of eosinophils per high-power field, by immunofluorescent anti-MBP staining to determine the presence of MBP, and by standard light and transmission electron microscopy to evaluate eosinophil migration patterns.

Results:

All patients had airway inflammation that included nonspecific laryngeal edema and grade I or II subglottic stenosis. Allergy testing was positive in the 2 patients who were tested. All patients had symptoms refractory to standard reflux therapy. Ambulatory pH-metry findings were normal in 2 patients and abnormal in 1 patient despite maximum treatment. Two patients had visual abnormalities seen during esophageal examination. The number of eosinophils ranged from 20 to 45 per high-power field. Intracellular and extracellular MBP deposition was found in all esophageal biopsy specimens. All patients were treated with swallowed fluticasone, and 2 had symptom relapses that required repeat treatment.

Conclusions:

The spectrum of pediatric EE can include upper airway disease. Intracellular and extracellular MBP deposition is present in EE, which potentially releases cytotoxic mediators that explain the esophageal and airway clinical symptoms seen in those with the disease. Eosinophilic esophagitis should be considered in patients with a history of atopic diseases and unexplained upper airway findings refractory to reflux treatment. Treatment with swallowed fluticasone is successful; however, relapses are common and require repeat treatment and close follow-up.

Clinical Characteristics of Eosinophilic Esophagitis in Children

Objectives:

The role of eosinophilic esophagitis (EE) in aerodigestive tract disorders in children is underestimated and overlooked, primarily because of a lack of understanding of this disorder by otolaryngologists. We sought to better characterize the clinical presentation of EE in order to increase awareness among otolaryngologists.

Methods:

We retrospectively reviewed 71 children with biopsy-proven EE to determine the most common symptoms and laboratory findings that should increase the clinical suspicion of EE.

Results:

Dysphagia, food impaction, and emesis were the most common symptoms in children with EE. Asthma was the most common airway diagnosis. Rhinosinusitis was the most common otolaryngological diagnosis. Food allergy was present in 60% of the children tested. Eighty-three percent of the children with elevated immunoglobulin E levels had thick linear streaking or patchy white exudate of the esophagus seen on esophagoscopy. Other major medical comorbidities existed in more than half of the children with EE, of which psychiatric disorders and other disorders of the aerodigestive tract were the most common.

Conclusions:

Eosinophilic esophagitis may contribute to treatment failure in patients with common and complicated aerodigestive tract disorders. To encourage clinicians to avoid overlooking the diagnosis, we present an evaluative algorithm to increase the suspicion of this entity.

Angiogenic remodeling in pediatric EoE is associated with increased levels of VEGF-A, angiogenin, IL-8, and activation of the TNF-α-NFκB pathway

OBJECTIVES

Eosinophilic esophagitis (EoE) is a clinicopathologic diagnosis characterized by inflammation and infiltration of eosinophils at the esophageal mucosa. The underlying etiology of EoE remains elusive. Inflammatory diseases, such as asthma, are associated with structural remodeling of the airways, which includes angiogenesis. The aims of this study were to determine the angiogenic profile of esophageal mucosa in children presenting with EoE and to evaluate the putative mechanism(s) underlying the early inflammatory angiogenic response observed in EoE.

METHODS

Endoscopically obtained biopsy samples from 18 EoE and 18 control pediatric patients were analyzed for angiogenic markers (CD31, von Willebrand factor, vascular cell adhesion molecule-1) and tissue levels of angiogenic factors (vascular endothelial growth factor [VEGF]-A, VEGF-R2, angiogenin and interleukin [IL]-8). Expression levels of angiogenic factors and markers in EoE and control samples were characterized by immunofluorescence analysis and quantitative reverse transcriptase-polymerase chain reaction. Vascular density of biopsy samples was evaluated by immunofluorescence analysis.

RESULTS

Samples from patients with EoE exhibited higher levels of von Willebrand factor, CD31, and vascular cell adhesion molecule-1, which is suggestive of neovascularization and an activated endothelium. Moreover, EoE biopsies showed greater levels of the angiogenesis promoters VEGFA, angiogenin, and IL-8. Interestingly, there were greater cellular levels of tumor necrosis factor-α in EoE samples compared with controls. Furthermore, there were higher nuclear levels of p50 and p65 subunits of NFκB and lower cellular levels of the inhibitor of NFκB, IκB-α, in EoE samples compared with controls.

CONCLUSIONS

We demonstrate increased angiogenesis in the esophageal mucosa of pediatric patients with EoE. The data also provided evidence that the angiogenic factors VEGF-A, angiogenin, and IL-8 were prominently involved in promoting angiogenic remodeling.

Eosinophilic esophagitis in children needing emergency endoscopy for foreign body and food bolus impaction

OBJECTIVE

The objective of this study was to examine the prevalence of eosinophilic esophagitis (EoE) in children presenting with esophageal foreign body (FB)/food bolus impaction.

METHODS

A retrospective chart review for all children who underwent endoscopic esophageal FB extraction at the Stollery Children's Hospital between January 2005 and December 2008 was performed. The prevalence of EoE and characteristics of children who had EoE were documented.

RESULTS

A total of 140 children (mean age, 4.98 [SD, 4] years; range, 0.3-16.9 years; 81 boys) had esophageal FB/food impaction and needed endoscopic removal over the study period. Eleven children (mean age, 9.38 [SD, 5.35] years; range, 1.9-16.2 years; 8 boys) were diagnosed with EoE (8%). Seven (39%) of 18 children with food impaction were diagnosed with EoE. Four (3%) of 122 children with esophageal foreign bodies other than food had EoE.

CONCLUSIONS

Considerable number of children with esophageal FB/food bolus impaction may have EoE. Routine sampling of esophageal mucosa at different levels during esophageal FB extraction may be considered. Well-designed prospective studies with multiple-level esophageal biopsies taken from all children with FB/food impaction are needed to confirm our results.

A decade of hospital discharges related to eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a recently characterized chronic, allergic, gastrointestinal disorder. Using the Pediatric Health Information System, we report trends in diagnostic codes related to EoE in inpatients from 1999 through 2010. Esophagitis not elsewhere classifiable, EoE, and dysphagia have increased over time. Similar to other allergic disorders, EoE appears to be increasing across the United States.

Comparison of histological parameters for the diagnosis of eosinophilic oesophagitis versus gastro-oesophageal reflux disease on oesophageal biopsy material

AIMS

Eosinophil infiltration of the oesophageal epithelium is the cardinal pathomorphological finding in eosinophilic oesophagitis (EO), but gastro-oesophageal reflux disease (GORD) is also associated with increased eosinophils. The aim was to compare histological parameters for the diagnosis of EO versus GORD on routinely taken biopsy specimens.

METHODS AND RESULTS

One hundred and five routine biopsy specimens with EO (n = 62), GORD (n = 24) and probable EO (n = 19) from 74 patients (52 men, 22 women; mean age 43.7 years) were analysed for numbers of eosinophils, mast cells, degranulation and qualitative changes of oesophageal epithelium using immunohistochemistry with monoclonal antibodies against eosinophil peroxidase and eosinophil major basic protein and mast cell tryptase. Eosinophil infiltration was significantly higher in EO than in GORD both on haematoxylin and eosin staining (54.8 versus 9.1; P < 0.05) and immunohistochemistry (77.5 versus 24.7; P < 0.05). Eosinophil degranulation was significantly more intense in EO than in GORD (1.16 versus 0.41; P < 0.05). Furthermore, eosinophilia-codependent secondary qualitative changes of squamous epithelium in EO were generally more extensive than those in GORD.

CONCLUSIONS

Histological differential diagnosis of EO and GORD should be based on eosinophil counts, secondary morphological changes of eosinophils and oesophageal squamous epithelium, especially in cases suspicious of EO.

IL-13 involvement in eosinophilic esophagitis: transcriptome analysis and reversibility with glucocorticoids

BACKGROUND

Eosinophilic esophagitis (EE) is an emerging worldwide disease that mimics gastroesophageal reflux disease. Early studies have established that esophageal eosinophilia occurs in association with T(H)2 allergic responses, and we recently identified an EE-specific esophageal transcriptome that included eotaxin-3.

OBJECTIVE

We sought to determine the mechanism by which this T(H)2 response leads to EE.

METHODS

Real-time PCR and microarray analysis were performed on RNA extracted from esophageal biopsy specimens and primary esophageal epithelial cell cultures stimulated with IL-13 (0-100 ng/mL). Transient transfections in esophageal cell lines were performed with plasmids containing the luciferase gene driven by eotaxin-3 promoter fragments and modified forms of signal transducer and activator of transcription 6.

RESULTS

The IL-13 mRNA level was markedly increased (16-fold) in esophageal biopsy specimens from patients with EE compared with those from healthy individuals. Furthermore, IL-13 treatment of primary esophageal epithelial cells was sufficient to induce a global-expression transcript profile that remarkably overlapped with the EE-specific esophageal transcriptome. In addition, esophageal epithelial cells markedly produce eotaxin-3 after IL-13 stimulation through a transcriptional mechanism dependent on signal transducer and activator of transcription 6. Lastly, increased IL-13 mRNA levels and the EE transcriptome were largely reversible with glucocorticoid treatment in vivo.

CONCLUSIONS

Taken together, we propose that the pathogenesis of EE is mediated by an IL-13-stimulated keratinocyte-derived transcriptome that is largely reversible with corticosteroid treatment. Furthermore, we identify an in vivo IL-13-induced transcriptome that has potential utility for target assessment after anti-IL-13 therapeutics.

CLINICAL IMPLICATIONS

IL-13-induced pathways and genes are fundamental processes in the cause and manifestations of EE; as such, therapeutic agents that interfere with IL-13 might be particularly useful for disease treatment.

Eosinophilic esophagitis: association with allergic disorders

Atopy has been linked to eosinophilic gastrointestinal disorders because of the role eosinophils play in atopic disorders. It has also been found that these disorders coexist. The goal of this article is to take a step back, and considering only eosinophilic esophagitis, attempt to determine from the available body of clinical and research literature: (1) Is the coexistence of these disorders attributable to a preconceived bias? If so, what is the source of the bias and how can it be removed? (2) Is there a cause and effect relationship? If so, can this relationship be harnessed for diagnostic and therapeutic modalities?

Variability in diagnostic criteria for eosinophilic esophagitis: a systematic review

BACKGROUND

Eosinophilic esophagitis (EoE) is an emerging clinicopathologic entity defined by abnormal esophageal eosinophilic infiltration. Our understanding of this disease is hampered by the lack of a uniform diagnostic standard. The aim of this systematic review was to determine the range of diagnostic strategies and histologic criteria in the EoE literature.

METHODS

The MEDLINE-indexed literature from 1950 through December 31, 2006 was independently searched by two investigators. To identify additional relevant studies, bibliographies were hand searched, as were the published proceedings of the 2000-2006 American College of Gastroenterology and American Gastroenterological Association national meetings. Data were extracted from all human EoE case reports, case series, cross-sectional and cohort studies, and clinical trials.

RESULTS

Of 318 publications initially identified, 116 original articles, 39 abstracts, and 69 reviews were included. We found 10 different histologic definitions of EoE, ranging from 5 to 30 eosinophils per high-powered field (hpf), though 41 (35%) of the original articles did not state their diagnostic criteria. In the 13 original articles (11%) reporting an hpf area, the eosinophil density per mm(2) varied 23-fold. There was also variation in esophageal biopsy protocols, but specific protocols were reported in just 45 (39%) original articles.

CONCLUSIONS

Significant variability in diagnostic criteria for eosinophilic esophagitis exists, and in a large proportion of studies, criteria are not reported. Because of this lack of a common disease definition, conclusions drawn from the cumulative EoE literature should be viewed with caution. A consensus research-quality standard for diagnosis of eosinophilic esophagitis is needed.

Allergy and intestinal dysmotility--evidence of genuine causal linkage?

PURPOSE OF REVIEW

The relationship between allergy and motility has been controversial. There is, however, accumulating evidence demonstrating that mucosal allergic responses may disrupt gut motility, and may also potentially alter nociceptive pathways to cause visceral hyperalgesia.

RECENT FINDINGS

Experimental studies implicate T helper 2 cells and the cytokines interleukin-4 and -13 in antigen-induced dysmotility, and interleukin-5 in the pathogenesis of mucosal eosinophilia. Both mast cells and eosinophils play obligatory roles in different forms of experimental antigen-induced dysmotility. Overall clinical findings appear to implicate eosinophil infiltration in proximal and distal dysmotility syndromes (oesophageal, gastric and colorectal), and induced mast cell degranulation in mid-gut dysmotility. There is also evidence that mucosal allergic responses may induce long-term changes in visceral perception, including alteration of limbic response, leading to sustained abnormality in visceral sensation.

SUMMARY

Clinical evidence implicating mucosal allergic responses in dysmotility has been extended to include disorders considered previously entirely functional, such as in some cases of irritable bowel syndrome. Only a proportion of cases are, however, caused by food allergy and a future challenge is to differentiate patients with similar symptoms, but induced by different mechanisms.

Clinical manifestations of food allergy: the old and the new

Food allergies are increasing in incidence, and the variety of triggering antigens is widening. There is also an increased recognition of the breadth of immunologically mediated responses to dietary antigens; the area of non-IgE-mediated food allergy is belatedly acquiring scientific respectability, aided by improved clinical recognition and basic scientific studies. The role of mucosal mast cells and eosinophils in intestinal allergic responses is now better recognized, and conditions such as eosinophilic oesophagitis are more prevalent than previously thought. However, the diagnostic difficulties of non-IgE-mediated allergies remain challenging.

Eosinophilic esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis (EE) is an isolated, eosinophilic inflammation of the esophagus. In the past, the symptoms of EE were often confused for gastroesophageal reflux (GER). Thus, many physicians unsuccessfully treated patients with EE with medications used for GER. Because the incidence of EE is rising and EE is easily diagnosed by endoscopy with biopsy, it is important for physicians to not only accurately identify patients with EE but also understand the treatment options available.

RECENT FINDINGS

While patients with acid reflux may have a few eosinophils, patients with EE have high levels of eosinophils in their esophagus as part of an allergic response to food antigens. The inflammation may cause abdominal pain, nausea, or vomiting. If EE persists for years, it may cause a narrowing of the esophagus that leads to dysphagia. In young children, many of the symptoms of EE mimic those of gastroesophageal reflux. Medications used to treat reflux are not effective against EE. Over the past few years, many new reports and retrospective studies have been written on the subject of EE. The focus of these papers concentrated on the etiology and treatment of EE.

SUMMARY

The diagnosis of EE requires a biopsy of the esophagus. Typical allergy tests are not effective for diagnosis of EE because the allergic reaction involved in EE is non-IgE mediated. The most commonly involved foods include milk, eggs, nuts, beef, wheat, fish, shellfish, corn, and soy; however, almost all foods have been implicated. Because allergy tests are often unable to determine the causative foods, complete elimination of all foods is often required. In these cases, patients must be placed on a strict elemental formula for 1 to 3 months to heal the esophagus. Repeat endoscopy with biopsy is often necessary. Several medications have been used including corticosteroids, cromolyn sodium, and leukotriene inhibitors. This review discusses the past year's literature, concentrating on the etiology, diagnosis, and treatment of EE in both children and adults.

White specks in the esophageal mucosa: An endoscopic manifestation of non-reflux eosinophilic esophagitis in children

BACKGROUND

White specks in the esophageal mucosa have been observed in children with eosinophilic esophagitis. The aim of this study was to determine the relationship between white specks in the esophageal mucosa and allergic (non-reflux) eosinophilic esophagitis.

METHODS

Endoscopic data, pH probe results, and histopathology reports for children with esophageal endoscopic abnormalities seen during a 17-month period were reviewed. Eosinophilic esophagitis was grouped according to the number of eosinophils per high power field (non-allergic, <15 eosinophils/high power field; allergic, > or =15 eosinophils/high power field).

RESULTS

Of 1041 endoscopies performed during the study period, 153 revealed evidence of eosinophilic esophagitis. Of these 153, 61 had fewer than 15 eosinophils/high power field and 92 had 15 or more eosinophils/high power field. At 31 of the 153 procedures, white specks were noted in the esophageal mucosa. The sensitivity of white specks in the esophageal mucosa for allergic eosinophilic esophagitis was only 30%, but the specificity was 95%. pH probe testing was performed in 21 patients with white specks and was normal in all.

CONCLUSIONS

This report describes a new endoscopic finding associated with allergic eosinophilic esophagitis in children. Eosinophilic esophagitis tends to be severe when white specks are present (> or =15 eosinophils/high power field) and is not associated with pathologic gastroesophageal reflux, as demonstrated by pH probe testing.

Clinical expressions of food allergy

BACKGROUND

The perception, by both the public and health professionals, of the clinical expressions of food allergy (FA) varies widely, from one extreme of nonexistence to another extreme of causing almost every ailment. Critical investigations in recent years led to a better clarification, as well as a reasonable classification, of FA manifestations.

OBJECTIVE

To provide a differential diagnosis of adverse reactions to foods and a classification of well proven FA manifestations.

DATA SOURCES

Reviews and original articles published in peer-reviewed journals, as well as classic textbooks on FA.

RESULTS

FA can affect several body systems. The gastro-intestinal tract is probably the most affected organ, but it does not always exhibit overt symptoms. Cutaneous manifestations are next in frequency, and in some studies are the most frequent perhaps because they are visible. Respiratory symptoms as sole manifestations of FA are less common, but have high frequency in children with atopic dermatitis. Systemic anaphylaxis has been responsible for sudden fatalities, although the exposure was often to minute quantities of the offending food. Other rare manifestations have been reported and are probably underdiagnosed.

CONCLUSIONS

FA is defined as the immunologically mediated adverse reactions to foods. It can be expressed in a wide array of clinical manifestations, ranging from simple gastro-intestinal, cutaneous, or respiratory symptoms to fatal anaphylaxis. Studies are needed to verify some rare or anecdotal manifestations that have been reported but are still considered controversial.

Treatment of Eosinophilic Esophagitis in Children

Eosinophilic esophagitis (EE) is an important esophageal disorder with distinct clinicopathologic features, and the condition is associated with a high prevalence of food allergies and atopy. In the past decade, we have improved our ability to recognize the phenotype of EE, but our ability to treat EE effectively remains limited despite several reports of successful treatment using elemental or elimination diets, and systemic and topical corticosteroids. The limitations for developing effective treatment regimens are due to some still unresolved and ambiguous aspects of the pathogenesis of EE. Neither the predisposing factors for developing EE in a subset of patients with atopy, nor the variable responsiveness to control measures for allergens are fully understood. There also remain questions about the precise role of gastroesophageal reflux, and the natural history of the disorder, contingent on which is the optimal treatment of EE. In devising treatment for a patient with EE, all attempts should be made to identify and control food and other allergies. In patients who have no diagnosed allergies or who are unresponsive to allergy treatment, topical steroids are a safe and effective treatment option. Systemic steroids should be reserved for those patients who are refractory to topical steroids. Beyond the initial phase of induction treatment, it is crucial to develop effective and safe maintenance treatment regimens based on ongoing allergen control and mast cell inhibitors. There are limited but encouraging data to support further exploration of the role of leukotriene and interleukin-5 inhibitors as safe, effective, and steroid-sparing treatment options.