Allergic eosinophilic esophagitis: a primer for pathologists

Prevalence of Eosinophilic Esophagitis in Adult Patients with Upper Gastrointestinal Symptoms in a Locality in Upper Egypt

BACKGROUND/AIMS

Eosinophilic esophagitis (EoE) is gaining importance in the diagnosis of upper gastrointestinal (UGI) symptoms. Diagnosis is based on the clinical presentation of esophageal dysfunction and pathological findings in the absence of other causes of tissue eosinophilia. Our study was designed to evaluate EoE prevalence in patients with UGI symptoms in our locality (El-Minia, Egypt).

METHODS

This single-center, cross-sectional study recruited all patients with UGI symptoms who agreed for endoscopic evaluation. Esophageal biopsy samples were obtained and histological evaluation for the presence of eosinophils was performed for every patient. EoE was defined when at least 15 eosinophils were present in a single high-power field, in the absence of other causes of esophageal eosinophilia.

RESULTS

Between 2013 and 2015, 218 of 476 adult patients with UGI symptoms underwent upper endoscopy after giving consent. Among the 218 patients, only 4 (1.87%) had the diagnosis of EoE based on the presence of eosinophils in esophageal biopsies and exclusion of other causes of esophageal eosinophilia. Three patients with EoE presented mainly with dysphagia (75%) and/or other UGI symptoms, such as heartburn.

CONCLUSIONS

We observed a low prevalence of EoE in our locality. The diagnosis of EoE should be considered in patients with dysphagia and/or heartburn.

Diagnostic approaches and treatment of eosinophilic esophagitis. A review article

Eosinophilic Esophagitis (EoE) is a condition that involves eosinophilic influx into the esophageal epithelium. It affects both children and adults; Adults present with dysphagia whereas children with vague abdominal complaints. The clinical symptoms as well as pathologic features of EoE and gastro esophageal reflux disease (GERD) are similar. Since eosinophilia in the esophagus is a non-specific finding, the clinical presentation in conjunction with endoscopic findings and pathology, is crucial in determining a differential diagnosis. Infections such as parasites, allergic phenomenon, Crohn's disease, malignancies, medication, and chemotherapy are all associated with eosinophilia.

A primary endoscopic difference to note between EoE and GERD is that EoE often involves long segments of the esophagus, could be patchy or focal and frequently involves the proximal esophagus. GERD, however, typically involves the distal much more frequently than the proximal esophagus. Because of the similarity between them, GERD should be excluded by using high dose proton pump inhibitor (PPI) treatment or through evidence of a normal pH by esophageal testing, prior to treatment with an elimination diet or steroids. Until further research establishes different diagnostic tests and criteria, clinical and pathological response to therapy is considered to be the absolute confirmation of this diagnosis. The following is a more detailed discussion of this entity.

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EoE is an eosinophilic influx into the esophagus epithelium.

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It is an allergic reaction of esophagus to food particles and allergens.

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Adults present with dysphagia and reflux-like symptoms whereas children with vague abdominal complaints.

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Clinical presentation, endoscopic findings and pathology determine the definitive diagnosis.

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Treatment starts with an elimination diet and followed by orally swallowed inhaled steroids.

Distinguishing GERD from eosinophilic oesophagitis: concepts and controversies

Over the past three decades, the detection of oesophageal mucosal eosinophils has transitioned from a biomarker of GERD to a diagnostic criterion for eosinophilic oesophagitis (EoE). In GERD, oesophageal eosinophils are considered part of the chronic inflammatory response to acid reflux, whereas the marked eosinophilia in EoE is viewed as a central feature of the immune response to ingested food and/or environmental antigen stimulation. Descriptions of a considerable subset of patients with symptomatic, endoscopic and histological findings of EoE that resolve with PPI therapy has led to confusion and controversy regarding the distinction of EoE from GERD. Study findings indicate that PPI-responsive oesophageal eosinophilia (PPI-REE) more closely resembles EoE than GERD, both from a clinical and immunological aspect. Although responsiveness to PPI therapy should not be utilized to exclude EoE, PPI therapy is effective at reducing oesophageal eosinophilia in ∼40% of patients, and PPI therapy is both a safe and practical initial step in the management of patients with oesophageal eosinophilia. Ongoing studies elucidating the mechanism behind PPI-REE will improve our understanding and management of EoE. In this Review, the mechanisms and evidence that underlie the controversy in the distinction between GERD and EoE are evaluated.

Correlation of ALOX15 expression with eosinophilic or reflux esophagitis in a cohort of pediatric patients with esophageal eosinophilia

The differential diagnosis between eosinophilic esophagitis (EoE) and gastroesophageal reflux disease (GERD) is often challenging. We recently showed that the ALOX15 protein is expressed in 95% of esophageal biopsies from patients with a definitive diagnosis of EoE. Here we correlated ALOX15 expression with the clinical classification of EoE or GERD in a cohort of consecutive pediatric patients (n = 62) with at least 1 esophageal biopsy containing at least 15 eosinophils per high-power field (eos/HPF). The patients were categorized into the following groups: (1) at least 15 eos/HPF in the distal esophagus only (n = 24), (2) at least 15 eos/HPF in the proximal esophagus only (n = 5), and (3) at least 15 eos/HPF in the distal and proximal biopsies (n = 33). Control groups included patients with GERD with biopsies containing 6 to 15 eos/HPF (n = 9), patients with GERD with 5 eos/HPF or less (n = 15), patients with candida esophagitis (n = 15), and patients with normal biopsies (n = 15). ALOX15 was positive in 90.5% of patients with EoE (13/16 in group 1, 4/4 in group 2, 31/33 in group 3) versus 44% of patients with GERD (4/8 in group 1, 0/1 in group 2, and 0/0 in group 3), 2 of 9 (22%) of patients with 6 to 15 eos/HPF, and was negative in all patients with GERD with biopsies containing 5 eos/HPF or less, all patients with candida esophagitis, and all normal controls. In conclusion, ALOX15 is a sensitive marker of EoE; however, subpopulations of patients with GERD with >5 eos/HPF also express ALOX15. Positive ALOX15 expression is more prevalent in EoE than in GERD and may prove to be a useful diagnostic marker in patients with discrepant biopsy findings between the proximal and distal esophagus.

Prevalence of eosinophilic esophagitis in patients with refractory gastroesophageal reflux disease symptoms: A prospective study

BACKGROUND

Eosinophilic esophagitis (EoE) is not routinely considered in the differential diagnosis of refractory gastroesophageal reflux disease (GERD).

AIMS

To prospectively evaluate the prevalence of EoE and describe the clinical features and predictors of EoE in patients with refractory symptoms of GERD.

METHODS

Esophageal biopsies were obtained in patients with symptoms of GERD refractory to 8 weeks of conventional antisecretory therapy. Diagnosis of EoE was defined as at least 20 eosinophils × high power field and clinical unresponsiveness to proton pump inhibitors. Clinical and manometric features were compared. Independent risk factors predicting EoE were identified.

RESULTS

Six out of 150 included patients (4%) met the diagnostic criteria for EoE. Patients with EoE were significantly younger, had significantly more dysphagia, atopy, ineffective esophageal peristalsis, esophageal rings and esophageal strictures than patients without EoE. Independent predictors of EoE were: age under 45 years (OR 4.8, 95% CI 2.4-8.6), dysphagia (OR 12.2, 95% CI 4.3-19.4), and atopy (OR 3.4, 95% CI 1.5-7.4).

CONCLUSIONS

EoE is an uncommon condition (4%) in patients with refractory symptoms of GERD. Age under 45 years, atopy or dysphagia may warrant suspicion of EoE in this subset of patients.

Do eosinophil numbers differentiate eosinophilic esophagitis from gastroesophageal reflux disease?

CONTEXT

Although the healthy esophageal mucosa contains no eosinophils, eosinophilic infiltration is observed in 2 major clinicopathologic settings: gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EE). The prevalence of EE is increasing in many countries, and this increase seems only partly to be due to a better awareness of the pathology, following the relatively recent description of EE. Gastroesophageal reflux disease and EE represent 2 entities that do not respond to the same treatment modalities and, thus, need to be distinguished. However, diagnostic criteria of EE have been defined arbitrarily, and the more recent articles tend to prove that the overlap with GERD is probably greater than initially believed, leading the authors to advise strict exclusion of GERD before considering the diagnosis of EE.

OBJECTIVES

To provide pathologists with the currently proposed histologic criteria of GERD and EE, to stress the need to combine these criteria with clinical data and endoscopic findings, and to outline the remaining controversies.

DATA SOURCES

This review is based on selected articles identified by a PubMed (US National Library of Medicine, Bethesda, Maryland) search of the literature in English for GERD and EE, a recent review by the American Gastroenterological Association (Bethesda), the Proceedings of the First International Gastrointestinal Eosinophil Research Symposium, and the authors' experience.

CONCLUSION

Proper identification of the etiology of eosinophilic infiltration of the esophagus allows accurate medical or surgical treatment and follow-up. Eosinophilic esophagitis and GERD diagnoses require integration of the histologic findings with the clinical and endoscopic data.

[Eosinophilic esophagitis in 29 pediatric patients]

BACKGROUND

Eosinophilic esophagitis is a recently described entity with esophageal symptoms like gastroesophageal reflux disease and significant esophageal eosinophilic infiltration.

AIM

To present our clinical series of 29 children with eosinophilic esophagitis, describing the clinical and diagnostic features, treatment and outcome.

METHODS

We describe 29 patients (22 boys), 1-18 years-old, with 20 eosinophils per high-power field in esophageal biopsy specimens and absence of eosinophilic inflammation in the stomach and duodenum. Evaluation of the clinical, endoscopic and histologic findings, treatment and outcome was undertaken.

RESULTS

The most common presenting symptoms included vomiting in 15 patients (52%) and abdominal pain in 11 patients (38%). Children under the age of 4 years presented with feeding disorder and failure to thrive. Patients between 5 and 8 years of age presented commonly with abdominal pain or symptoms that may be associated with reflux (heartburn and/or vomiting). Patients over the age of 8 presented most often with abdominal pain, dysphagia and occasional food impaction. Endoscopic features included vertical furrowing in 14 patients (48%), whitish papules in 12 (41%), corrugated rings in 2 patients (7%) and esophageal erosions in 3 patients (10%). In seven patients endoscopy was normal (24%). Treatment included swallowed fluticasone propionate in 19 patients and restriction diet in 7 patients. Patients who returned for follow-up had either improvement or remission of symptoms. After treatment, endoscopic biopsies were repeated in 11 patients, and a significant decrease in esophageal eosinophil counts was observed.

CONCLUSIONS

The diagnosis of eosinophilic esophagitis must be considered when symptoms of reflux do not respond to conventional treatment. Upper gastrointestinal endoscopy must be complemented by a detailed analysis of histologic findings and eosinophil counts.

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.

Pathology of eosinophilic esophagitis: what the clinician needs to know

Eosinophilic esophagitis (EOE) is a clinical pathologic syndrome characterized by influx of numerous eosinophils into the esophageal epithelium. It is important for clinicians to be aware of the spectrum, as well as the characteristic location and distribution, of morphologic changes in EOE to maximize the diagnostic yield in mucosal biopsy specimens. The major pathologic features of EOE include eosinophilic microabscesses, surface layering of eosinophils often associated with surface sloughing of necrotic squamous cells, and peak eosinophil counts usually greater than 15 per high power field (hpf) within the squamous epithelium. Minor features, which are frequent but less specific, include marked basal cell hyperplasia, lengthening of lamina propria papillae, intercellular edema, and lamina propria fibrosis with chronic inflammation. The number, distribution, and location of intraepithelial eosinophils in EOE vary greatly between previously published studies. Thus, utilization of a diagnostic cutoff point for intraepithelial eosinophils in EOE, particularly in the absence of other major features of EOE, is currently considered unwise. In fact, some patients may show combined features of both gastroesophageal reflux disease (GERD) and EOE, which complicates the histologic analysis of these patients. In contrast to GERD, EOE typically involves longer lengths of the esophagus, affects the proximal equally, or even more, than the distal esophagus, and the pathologic findings are often patchy in distribution. As a result, it is highly recommended that clinicians obtain biopsies from patients suspected of have EOE only after treatment with high-dose proton pump inhibitor therapy, and that biopsies be obtained from both the proximal and distal esophagus in both normal and abnormal appearing areas.

High diagnostic yield of gastrointestinal endoscopy in children with intestinal failure

PURPOSE

Children with intestinal failure (IF) often have gastrointestinal (GI) symptoms, including bleeding, increased stool output, and feeding intolerance. The use of endoscopic assessment of these symptoms has not been previously reported. This report evaluates the diagnostic yield of GI endoscopy in the setting of IF.

METHODS

After institutional review board approval, we reviewed the medical records (including endoscopy, pathology and microbiology data) of patients with IF who underwent GI endoscopies between September 1999 and March 2007.

RESULTS

Twenty-seven patients underwent 61 GI endoscopies: 34 esophagogastroduodenoscopies, 17 colonoscopies, 7 flexible sigmoidoscopies, and 3 ileoscopies. Indications for endoscopy, which were not mutually exclusive, included chronic diarrhea (39%, n = 24), GI bleeding (36%, n = 22), suspected bacterial overgrowth (36%, n = 22), and suspected peptic disease (15%, n = 9). Based on gross endoscopic appearance, histopathology, or microbiology, 43 (70%) procedures yielded abnormalities. These included infectious (20%, n = 12), anatomical (18%, n = 11), peptic (15%, n = 9), allergic (15%, n = 9), and other (2%, n = 1) findings. Eleven (73%) of 15 duodenal cultures grew a spectrum of 17 bacterial species. Overall, 24 (89%) of 27 patients had gross endoscopic, histopathologic, or microbiologic abnormalities.

CONCLUSIONS

In pediatric patients with IF, diagnostic upper and lower GI endoscopies yield high rates of abnormalities and can help guide clinical management.

Oesophagitis in children: reflux or allergy?

The prevalence of eosinophilic oesophagitis appears to be increasing in many countries, sometimes rapidly, although this may be partly due to increased disease recognition. Histological methods of assessment and diagnostic criteria vary considerably between major clinical centres. Oesophagitis with over 20 intraepithelial eosinophils per high power field is more likely to be due to allergy than gastro-oesophageal reflux induced acid-peptic mucosal injury. Typical eosinophilic oesophagitis shows involvement of the entire oesophagus, with basal cell proliferation occupying more than 50% of the thickness of the surface epithelium, and high numbers of intraepithelial eosinophils, sometimes concentrated on the surface or as contiguous clusters. Ulceration and prominent neutrophils are atypical and should suggest an alternative or co-existent disease. On endoscopy, the oesophagus may display the typical 'corrugated' mucosal appearance. Clinically, dysphagia or food impaction are the most characteristic symptoms. There is a strong association with other atopic diseases, especially asthma and eczema. To date no evidence has emerged of an increased malignancy risk. Patients with eosinophilic oesophagitis typically fail to respond to acid suppressive medications but respond well to either elemental/elimination diets or aerosolised swallowed corticosteroids. Long-term uncontrolled oesophageal eosinophilic inflammation may lead to progressive subepithelial fibrosis, potentially resulting in strictures or oesophageal narrowing.

Clinical and pathological features of eosinophilic oesophagitis: a review

Eosinophilic oesophagitis (EOE) is a newly described clinicopathological entity that is being diagnosed with increasing frequency both in children and in adults. It is presumed to be an atopic disease involving both immediate and delayed-type hypersensitivity to inhaled and ingested allergens. Because of the reflux-type symptomatology, it is commonly misdiagnosed and treated as severe gastro-oesophageal reflux disease (GORD) before an appropriate diagnosis is made. Pathologically, EOE is an inflammatory disorder with a predominantly eosinophilic infiltrate that is unresponsive to acid suppression therapy. The diagnosis of this disease requires histological confirmation with oesophageal biopsy specimens showing an intense eosinophilic infiltration. Although precise criteria or a specific cutoff point for the diagnosis of eosinophilic oesophagitis have not been established, many authors suggest that one high-power field with >20 eosinophils or multiple high-power fields with >15 eosinophils, together with clinical and endoscopic findings, should be sufficient for diagnosis. Recognition of EOE and differentiation from GORD are important, since allergen elimination or anti-inflammatory therapy appears to be more effective than acid suppression in these patients. This review focuses on clinicopathological features and diagnosis of EOE in adults and children.

Overlap of reflux and eosinophilic esophagitis in two patients requiring different therapies: A review of the literature

Eosinophilic esophagitis (EE) and gastroesophageal reflux disease (GERD) have overlapping clinical, manometric, endoscopic and histopathologic features. The diagnosis of EE is nowadays based upon the presence of 15 or more eosinophils per high power field (eo/HPF) in esophageal biopsies. We report the cases of two young males suffering from dysphagia and recurrent food impaction with reflux esophagitis and more than 20 eo/HPF in upper-mid esophagus biopsies, both of which became asymptomatic on proton pump inhibitor (PPI) therapy. The first patient also achieved a histologic response, while EE remained in the other patient after effective PPI treatment, as shown by 24-h esophageal pH monitoring. Topical steroid therapy combined with PPI led to complete remission in this latter patient. GERD and EE may be undistinguishable, even by histology, so diagnosis of EE should only be established after a careful correlation of clinical, endoscopic and pathologic data obtained under vigorous acid suppression. These diagnostic difficulties are maximal when both diseases overlap. Limited data are available about this topic, and the interaction between EE and GERD is a matter of debate. In this setting, upper-mid esophagus step biopsies and esophageal pH monitoring of patients on PPI therapy are pivotal to evaluate the role of each disease. A PPI trial is mandatory in patients with a histopathologic diagnosis of EE; in those unresponsive to PPI treatment, EE should be suggested. However, a clinical response to PPI may not rule out quiescent EE, as shown in this report.

High intraepithelial eosinophil counts in esophageal squamous epithelium are not specific for eosinophilic esophagitis in adults

OBJECTIVES

The histologic criterion of >20 eosinophils per high power field (hpf) is presently believed to establish the diagnosis of idiopathic eosinophilic esophagitis (IEE). This is based on data that the number of intraepithelial eosinophils in gastroesophageal reflux disease (GERD) is less than 20/hpf. This study tests this belief.

METHODS

Pathology records were searched for patients who had an eosinophil count >20/hpf in an esophageal biopsy. This patient population was biased toward adults with GERD who had routine multilevel biopsies of the esophagus. The clinical, radiological, and manometric data and biopsies were studied.

RESULTS

Forty patients out of a total of 3,648 reports examined had an eosinophil count >20/hpf in squamous epithelium of an esophageal biopsy. Analysis of these 40 cases indicated that 6 (15%) patients had IEE, 2 (5%) had coincident IEE and GERD, 28 (70%) had GERD, and 2 (5%) each had achalasia and diverticulum. There was no significant difference among these groups in terms of maximum eosinophil number, biopsy levels with >20 esoinophils/hpf, presence of eosinophilic microabscesses, involvement of surface layers by eosinophils, and severity of basal cell hyperplasia and dilated intercellular spaces.

CONCLUSION

All histologic features presently ascribed to IEE can occur in other esophageal diseases, notably GERD. As such, the finding of intraepithelial eosinophilia in any number is not specific for IEE. When a patient with GERD has an esophageal biopsy with an eosinophil count >20/hpf, it does not mean that the patient has IEE.

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.

Thoughts on the complex relationship between gastroesophageal reflux disease and eosinophilic esophagitis

Recent data suggest that the interaction between gastroesophageal reflux disease (GERD) and eosinophilic esophagitis can be complex, and that the notion of establishing a clear distinction between the two disorders may be too simplistic. There are at least four situations in which GERD might be associated with esophageal eosinophils: (a) GERD causes esophageal injury that results in a mild eosinophilic infiltration, (b) GERD and eosinophilic esophagitis coexist but are unrelated, (c) eosinophilic esophagitis contributes to or causes GERD, or (d) GERD contributes to or causes eosinophilic esophagitis. The high frequency of GERD described in adult patients with eosinophilic esophagitis suggests that there may be more than a chance association between the two disorders. This report discusses potential mechanisms for the complex interaction between GERD and eosinophilic esophagitis. We hope that this information will serve as a conceptual basis for future studies on the relationship between the two disorders. Whereas there are a number of plausible mechanisms whereby GERD might contribute to the accumulation of eosinophils in the esophageal epithelium, it seems prudent to recommend a clinical trial of proton pump inhibitor (PPI) therapy even when the diagnosis of eosinophilic esophagitis seems clear-cut. Furthermore, we suggest that a favorable response to PPI therapy does not preclude a diagnosis of eosinophilic esophagitis.