Primary eosinophilic esophagitis

Possible Noninvasive Biomarker of Eosinophilic Esophagitis: Clinical and Experimental Evidence

Eosinophilic esophagitis (EoE) diagnosis and follow-up response to therapy is based on repeated endoscopies and histological examination for eosinophils/HPF. The procedure is invasive and risky in particular for the pediatric population. Presently, there is no highly sensitive and specific noninvasive blood test available to monitor the disease pathogenesis. Reports indicate the expression of PDL1 (CD274) on the eosinophils in allergic patients. Herein, we report that CD274-expressing and -nonexpressing eosinophils were detected in both examined pediatric and adult EoE patients. We show that CD274 expression on blood eosinophils and blood mRNA expression levels increase in the blood of EoE patients and decrease following treatment. These observations are consistent with the esophageal eosinophilia of before and after treatment in both examined patients. These two clinical and experimental analysis reports provide the possibility that the CD274 mRNA and CD274-expressing esinophil levels may be novel possible noninvasive biomarkers for EoE.

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.

Pathogenesis of allergen-induced eosinophilic esophagitis is independent of interleukin (IL)-13

Several studies have shown that IL-13 is induced in the esophageal biopsies of EoE patients and promotes esophageal eosinophilia in mice following an IL-13 challenge. However, the role of IL-13 has not been clearly investigated in allergen-induced EoE. Accordingly, we tested the hypothesis that IL-13 is required in allergen-induced EoE. Mice deficient in IL-13, STAT (signal transducer and activator of transcription)6 and both IL-4/IL-13 genes with their respective controls were challenged with aspergillus extract and IL-5 gene-deficient with their control were challenged with recombinant IL-13, intranasally The lung and esophageal eosinophils, mast cells and collagen accumulation were examined. Herein, we report that intranasal delivery of IL-13 promotes IL-5 dependent esophageal eosinophilia. However, allergen-induced EoE is not impaired in the IL-13 gene-deficient mice. In addition, wild type and IL-13 gene-deficient mice demonstrated a comparable level of mast cells and collagen accumulation in the esophagus following allergen-induced experimental EoE. Similarly, we found that esophageal eosinophilia in IL-4/IL-13 double gene-deficient and STAT6 gene-deficient mice were also not reduced following allergen-induced experimental EoE. In contrast, lung eosinophilia was significantly reduced in mice deficient in IL-13, both IL-4/IL-13 and STAT6 genes following allergen challenge. In conclusion, our data establish that allergen-induced EoE pathogenesis is independent of IL-13; whereas, IL-13 is required for allergen-induced lung eosinophilia.

The small-caliber esophagus: radiographic sign of idiopathic eosinophilic esophagitis

PURPOSE

To evaluate a small-caliber esophagus at barium esophagography with idiopathic eosinophilic esophagitis (IEE) and determine if there is a useful threshold diameter for suggesting this diagnosis.

MATERIALS AND METHODS

The institutional review board approved this retrospective study and waived informed consent. This study was HIPAA compliant. A search of the radiology database (by using the search term small-caliber esophagus) revealed 10 patients with a small-caliber esophagus at barium esophagography who had IEE (defined as more than 20 eosinophils per high-power field in endoscopic biopsy specimens). Images were reviewed to characterize findings and determine the length of narrowing. Luminal diameters were measured at three levels for nine patients and nine control subjects, and mean diameter, range, and standard deviation were determined at each level. An analysis of variance test was performed to determine whether the difference between the range of mean thoracic esophageal diameters in patients with IEE versus that in control subjects was significant.

RESULTS

All 10 patients had long-segment but variable-length narrowing of the thoracic esophagus (mean length, 15.4 cm) with tapered margins. The mean diameter at the aortic arch, carina, and one vertebral body above the gastroesophageal junction was 13.9, 14.3, and 15.1 mm, respectively, for patients with small-caliber esophagus versus 20.2, 30.3, and 28.7 mm for control subjects. The mean overall diameter was 14.7 mm for patients with small-caliber esophagus versus 26.3 mm for control subjects. In the nine patients in whom the luminal diameter was measured, the mean thoracic esophageal diameter was 20 mm or less; all nine control subjects had a mean thoracic esophageal diameter greater than 20 mm. The difference in the range of mean thoracic esophageal diameters between these two groups was highly significant (P < .0001), so 20 mm was a useful threshold diameter for suggesting this diagnosis.

CONCLUSION

The small-caliber esophagus of IEE is characterized at barium esophagography by long-segment but variable-length narrowing of the thoracic esophagus, with a mean length of 15.4 cm, a diameter of 20 mm or less, smooth contours, and tapered margins.

Indoor insect allergens are potent inducers of experimental eosinophilic esophagitis in mice

EE is an emerging disease reported in children and adults of urbanized countries, where indoor insect allergens are major health risk factors. Review of our hospital patient database uncovered that a number of EE patients have hypersensitivity to indoor cat, dog, cockroach, and dust mite allergens. We tested the hypothesis whether inhaled indoor insect allergens are effective inducers of experimental EE. We delivered cat, dog, cockroach, and dust mite allergen extracts intranasally to wild-type and eotaxin-1/2-, CCR3-, and IL-5-deficient mice. Interestingly, wild-type mice exposed to cockroach or dust mite allergens develop a significant increase in the levels of esophageal eosinophils and mast cells compared with saline-challenged mice. The eosinophil numbers in the esophagus of cockroach- and dust mite-exposed mice were 18.3+/-6.8/mm2 and 33.4+/-11.1/mm2 compared with 2.3+/-1.8/mm2 and 2.1+/-1.2/mm2 in saline-challenged mice. Additionally, we observed an additive effect of these two allergens in inducing esophageal eosinophilia and mastocytosis. Histopathological analysis detected intraepithelial esophageal eosinophilia in mice exposed to both allergens. Furthermore, mice exposed to cockroach and/or dust mite had increased levels of total IgE and antigen-specific IgG1 in the blood and increased esophageal expression of eosinophil-active cytokines (IL-13) and chemokines (eotaxin-1). Notably, mice deficient in eotaxin-1/2, CCR3, and IL-5 showed ablated esophageal eosinophilia following cockroach or dust mite allergen exposure. These data indicate that indoor insect allergens are potent inducers of IL-5 and eotaxin-mediated esophageal eosinophilia. These experimental studies are in accordance with clinical data but may have some limitations inherent to animal models of human disease.

Mechanism of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a newly recognized disease and is an emerging entity throughout developing and developed countries, including the United States. Therefore, understanding the causes, natural history, diagnosis, and management is important for future therapeutic interventions. The pathogenesis of EoE is still not clear, but a growing body of evidence has established that this condition represents a T-cell-mediated immune response involving several proinflammatory mediators and chemoattractants known to regulate eosinophilic accumulation in the esophagus, such as IL-4, IL-5, IL-3 and eotaxin-1, -2, and -3. Determining the mechanism or mechanisms through which human esophageal-derived factors ultimately induce the functional abnormalities observed, and to which antigens patients who have EoE are sensitized that lead to the manifestation of symptoms, is of significant interest.

Biology and treatment of eosinophilic esophagitis

Eosinophilic esophagitis is a recently recognized but expanding disorder characterized by antigen-driven eosinophil accumulation in the esophagus. Symptoms frequently mimic those of gastroesophageal reflux disease, but the diseases are distinct in their histopathology, gene expression signature, response to therapy, hereditary risk, and association with allergies. The pathogenesis of eosinophilic esophagitis involves environmental and genetic factors, particularly food antigens and expression level of the eosinophil chemoattractant eotaxin-3, respectively. Analyses of gene expression signatures and animal models have indicated the importance of adaptive T-cell immunity that involves interleukin-5 and interleukin-13-induced esophageal epithelial cell responses. Symptoms, dysregulation of esophageal gene expression, and pathology are largely reversible following reduced exposure to specific food antigens as well as anti-inflammatory therapy, but chronic treatment is necessary to prevent relapse. Therefore, eosinophilic esophagitis is a disease with unique features that include chronic esophagitis, atopy, immune sensitization to oral antigens, reversibility, and familial association.

Patient and caregiver perspective on pediatric eosinophilic esophagitis and newly developed symptom questionnaires*

OBJECTIVE

Eosinophilic esophagitis (EE), a rare chronic inflammatory condition of the esophagus, is predominantly observed in children and is primarily manifested with feeding difficulties. To our knowledge, no self- or caregiver-reported questionnaires are available to assess pediatric EE symptoms and their impact as reported directly by children or their parents/caregivers. The objectives of this study were to characterize the symptoms and impact of EE among children as reported by patients and parents/caregivers and to assess the content validity of two newly developed pediatric eosinophilic esophagitis symptom questionnaires, one parent/caregiver-reported questionnaire for ages 2-7 years and one child-reported questionnaire for ages 8-17 years. The questionnaires were developed based on a review of the literature and clinical expert consultation.

RESEARCH DESIGN AND METHODS

This cross-sectional study involving one-on-one interviews with patients and caregivers was conducted at an American Partnership for Eosinophilic Disorders conference. Parents of patients aged 2-7 years (n = 12) and patients aged 8-17 years (n = 16) were first asked about symptoms and their impact on everyday life, using open-ended questions. Participants then completed the appropriate symptom questionnaire and were asked to provide feedback on the relevance, comprehensiveness, and clarity of each item and other questionnaire issues (time to complete, length, format, etc.). All reported symptoms were enumerated, and the feedback on the symptom questionnaires was analyzed qualitatively.

RESULTS

The majority of study participants were white (82%) and male (86%). The most frequently reported symptoms of 2-7-year olds were vomiting (92%), "reflux" (50%), dysphagia (25%), abdominal pain (25%), and trouble sleeping (25%). The 8-17-year group reported abdominal pain (56%), vomiting (31%), throat pain (25%), diarrhea (25%), and food getting stuck (25%). Symptoms and treatment were reported to have a major impact on daily life, particularly on school, after-school activities and social events, feeling frustrated regarding symptoms and treatment, and feeling "different". Overall, participants thought that the questionnaires were clear, relevant, and appropriate for symptom assessment.

LIMITATION

This study was based on a small and convenient sample of participants attending an EE conference and hence may not be representative of the general EE patient population.

CONCLUSIONS

EE is associated with a range of symptoms that vary in terms of the type, frequency and severity across and within patients. The results provide adequate support for the content validity of the self- and caregiver-reported versions of the symptom-specific questionnaires. Minor modifications were made based on the feedback obtained. A psychometric evaluation of the revised questionnaires is needed next to assess the construct validity, reliability, and responsiveness of the measures.

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.

Gastrointestinal eosinophilia

Gastrointestinal eosinophilia, a broad term for abnormal eosinophil accumulation in the gastrointestinal tract, involves many different disease identities. These diseases include primary eosinophil associated gastrointestinal diseases, gastrointestinal eosinophilia in hypereosinophilic syndrome, and all gastrointestinal eosinophilic states associated with known causes. Each of these diseases has its unique features but there is no absolute boundary between them. All three groups of gastrointestinal eosinophila are described in this article, although the focus is on primary gastrointestinal eosinophilia.

Potential of blood eosinophils, eosinophil-derived neurotoxin, and eotaxin-3 as biomarkers of eosinophilic esophagitis

BACKGROUND & AIMS

Eosinophilic esophagitis (EE) is an increasingly recognized disorder characterized by eosinophilic inflammation of the esophageal mucosa, and typically requires serial invasive endoscopic biopsy examinations to document the characteristic histologic features of the disorder. The aim of this study was to identify noninvasive biomarkers that correlated with disease activity and response to treatment as measured by esophageal eosinophilia.

METHODS

A prospective, cross-sectional analysis was performed on 47 pediatric patients undergoing endoscopic evaluation of possible EE. Blood samples were collected for measurement of peripheral blood absolute eosinophil count (AEC) and levels of eosinophil-derived neurotoxin (EDN), eotaxin-1, -2, and -3, and interleukin-5. Stool samples were collected for measurement of EDN. Biomarker levels were correlated with esophageal eosinophil density, and differences in biomarker levels based on disease activity and treatment were determined.

RESULTS

AEC, plasma EDN levels, and eotaxin-3 levels significantly correlated with esophageal eosinophil density (AEC: r = 0.56, P < .0001; EDN: r = 0.54, P < .0001; eotaxin-3: r = 0.32, P = .04), and were increased in patients with active EE vs controls (AEC: 440 vs 140 eosinophils/muL, P < .05; EDN: 50.3 vs 31.1 ng/mL, P = .01; eotaxin-3: 37.7 vs 11.5 pg/mL, P = .01). Cut-off values were established to maximize the sensitivity, specificity, and predictive values of these biomarkers alone and in combination. Eotaxin-1, eotaxin-2, interleukin-5, and fecal EDN levels did not correlate with esophageal eosinophil density, and were not increased in active EE vs controls or those with inactive EE.

CONCLUSIONS

These data show that blood levels of AEC, EDN, and eotaxin-3 may have value as noninvasive biomarkers for monitoring EE.

Idiopathic eosinophilic esophagitis in adults: the ringed esophagus

PURPOSE

To retrospectively assess the findings of idiopathic eosinophilic esophagitis (IEE) at barium studies and determine the frequency of the ringed esophagus in patients with this condition.

MATERIALS AND METHODS

The institutional review board approved all aspects of this retrospective study and did not require informed consent from patients whose records were included in the study. The study was compliant with the Health Insurance Portability and Accountability Act. A review of the pathology and radiology databases at the authors' institution revealed 14 patients (11 men and three women; mean age, 41.3 years) with IEE (defined as more than 20 eosinophils per high-power field in biopsy specimens) who had undergone barium studies and endoscopy. The radiographs were reviewed for strictures, esophagitis, or other abnormalities. The endoscopic reports, clinical records, and laboratory data were also reviewed and compared with the radiographic findings.

RESULTS

Seven of the 14 patients (50%) had a history of allergies, and two of nine patients with complete blood cell counts (22%) had peripheral eosinophilia. Thirteen patients (93%) had dysphagia, six (43%) had food impactions, and six (43%) had reflux symptoms. Ten patients (71%) had a total of 11 strictures at barium studies (two in the upper part of the esophagus, two in the middle part, three in the distal part, one in the middle and distal parts, and three at the gastroesophageal junction). The strictures had a mean length of 5.1 cm. In seven patients (50%), the strictures contained multiple fixed ringlike indentations that produced a ringed esophagus. The ringlike indentations appeared as multiple, fixed, closely spaced, concentric rings traversing the stricture. Four patients (28%) had esophagitis. Of 13 patients who underwent recumbent imaging, 10 (77%) had hiatal hernias and nine (69%) had reflux. Eight of the 10 patients (80%) with strictures underwent endoscopic dilation procedures, which resulted in only temporary relief of dysphagia.

CONCLUSION

The findings suggest that most patients with IEE have esophageal strictures, often with distinctive ringlike indentations that produce a ringed esophagus.

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.

Eosinophilic esophagitis: asthma of the esophagus?

Eosinophilic esophagitis (EE) is rapidly emerging as a distinct disease entity in both pediatric and adult gastroenterology. The typical clinical presentation includes solid food dysphagia in young men who have an atopic predisposition. Food impaction necessitating endoscopic intervention is common. EE should be suspected, in particular, in patients with unexplained dysphagia or those with no response to antacid or anti-acid secretory therapy. Careful endoscopic and radiographic examinations reveal furrows, corrugations, rings, whitish plaques, fragile crêpe paper-like appearance, and a small-caliber esophagus. Mucosal erosion in the distal esophagus, characteristic to reflux esophagitis, is absent in EE. Marked eosinophil infiltration in the esophageal epithelia (>20 eosinophils per high-power field) is the diagnostic hallmark. Food antigens and aeroallergens may play a role in the pathogenesis of EE. The mechanisms may be dependent or independent of immunoglobulin E. Elimination diets, systemic and topical corticosteroids, leukotriene receptor antagonists, and, most recently, an anti-interleukin-5 monoclonal antibody have been used to treat EE. EE likely represents another example of eosinophil-associated inflammation of epithelia at the interface between external and internal milieu, similar to bronchial asthma and atopic dermatitis. This review summarizes recent progress in the diagnosis and management of EE and discusses future research directions.

A new case of eosinophilic esophagitis

Eosinophilic esophagitis (EE) is a rarely diagnosed condition involving eosinophilic infiltration of the esophageal mucosa The hallmark of this condition is intermittent and often painful dysphagia that may become constant as the disease progresses. It was initially included within the more general condition known as eosinophilic gastroenteritis but it is now considered an independent entity. Attwood et al. called attention to eosinophilic esophagitis as a distinct clinical condition in 1993. Although eosinophilic esophagitis was thought to occur primarily in children, a significant body of evidence suggests that it affects adults as well. We describe a clinical case of a young woman with a long-standing history of dysphagia affected of this rare entity.