Histologic eosinophilic gastritis is a systemic disorder associated with blood and extragastric eosinophilia, TH2 immunity, and a unique gastric transcriptome

BACKGROUND

The definition of eosinophilic gastritis (EG) is currently limited to histologic EG based on the tissue eosinophil count.

OBJECTIVE

We aimed to provide additional fundamental information about the molecular, histopathologic, and clinical characteristics of EG.

METHODS

Genome-wide transcript profiles and histologic features of gastric biopsy specimens, as well as blood eosinophil counts, were analyzed in patients with EG and control subjects (n = 15 each).

RESULTS

The peak gastric antrum eosinophil count was 283 ± 164 eosinophils/×400 high-power field in patients with EG and 11 ± 9 eosinophils/×400 high-power field in control subjects (P = 6.1 × 10(-7)). Patients with EG (87%) had coexisting eosinophilic inflammation in multiple gastrointestinal segments; the esophagus represented the most common secondary site. Increased peripheral blood eosinophil counts (patients with EG: 1.09 ± 0.88 × 10(3)/μL vs control subjects: 0.09 ± 0.08 10(3)/μL, P = .0027) positively correlated with peak gastric eosinophil counts (Pearson r(2) = .8102, P < .0001). MIB-1(+) (proliferating), CD117(+) (mast cells), and FOXP3(+) (regulatory T cells, activated T cells, or both) cell counts were increased in patients with EG. Transcript profiling revealed changes in 8% of the genome in gastric tissue from patients with EG. Only 7% of this EG transcriptome overlapped with the eosinophilic esophagitis transcriptome. Significantly increased IL4, IL5, IL13, IL17, CCL26, and mast cell-specific transcripts and decreased IL33 transcripts were observed.

CONCLUSION

EG is a systemic disorder involving profound blood and gastrointestinal tract eosinophilia, TH2 immunity, and a conserved gastric transcriptome markedly distinct from the eosinophilic esophagitis transcriptome. The data herein define germane cellular and molecular pathways of EG and provide a basis for improving diagnosis and treatment.

Genome-wide association analysis of eosinophilic esophagitis provides insight into the tissue specificity of this allergic disease

Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder associated with allergic hypersensitivity to food. We interrogated >1.5 million genetic variants in EoE cases of European ancestry and subsequently in a multi-site cohort with local and out-of-study control subjects. In addition to replicating association of the 5q22 locus (meta-analysis P=1.9×10(-16)), we identified an association at 2p23 spanning CAPN14 (P=2.5×10(-10)). CAPN14 was specifically expressed in the esophagus, was dynamically upregulated as a function of disease activity and genetic haplotype and after exposure of epithelial cells to interleukin (IL)-13, and was located in an epigenetic hotspot modified by IL-13. Genes neighboring the top 208 EoE-associated sequence variants were enriched for esophageal expression, and multiple loci for allergic sensitization were associated with EoE susceptibility (4.8×10(-2) Collapse

Key Words Collapse

MESH Headings

• Adolescent
• Adult
• Calpain/genetics
• Child
• Child, Preschool
• Eosinophilic Esophagitis/genetics
• Epithelial Cells/metabolism
• Esophagus/metabolism
• Female
• Genetic Predisposition to Disease
• Genetic Variation
• Genome-Wide Association Study/methods
• Genotype
• Haplotypes
• Humans
• Interleukin-13/genetics
• Male
• Meta-Analysis as Topic
• Middle Aged
• Models, Genetic
• Organ Specificity/genetics
• Up-Regulation
• Young Adult

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Grants

• U01 AI066560 NIAID NIH HHS
• UL1 TR000039 NCATS NIH HHS
• U01 HG006828-S1 NHGRI NIH HHS
• T32 AI060515 NIAID NIH HHS
• P30 DK078392 NIDDK NIH HHS
• UL1 TR-000067 NCATS NIH HHS
• T32 HL7752-19 NHLBI NIH HHS
• T32 HL007752 NHLBI NIH HHS
• UL1 TR-000039 NCATS NIH HHS
• P01 AI083194 NIAID NIH HHS
• UL1 TR-000083 NCATS NIH HHS
• UL1 TR-000424 NCATS NIH HHS
• U01 HG006828-S2 NHGRI NIH HHS
• T32 GM063483 NIGMS NIH HHS
• U01 HG006828 NHGRI NIH HHS
• U19 AI066738 NIAID NIH HHS
• R37 AI024717 NIAID NIH HHS
• UL1 TR000424 NCATS NIH HHS
• UL1 TR000067 NCATS NIH HHS
• UL1 TR001425 NCATS NIH HHS
• I01 BX001834 BLRD VA
• UL1 TR000083 NCATS NIH HHS
• UL1 TR001082 NCATS NIH HHS
• UL1 RR029887 NCRR NIH HHS
• P01 AR049084 NIAMS NIH HHS
• P30 AR047363 NIAMS NIH HHS
• K23 AI099083 NIAID NIH HHS

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Efficacy, dose reduction, and resistance to high-dose fluticasone in patients with eosinophilic esophagitis

BACKGROUND & AIMS

We evaluated the efficacy and safety of high-dose swallowed fluticasone propionate (FP) and dose reduction in patients with eosinophilic esophagitis (EoE) and analyzed esophageal transcriptomes to identify mechanisms.

METHODS

We conducted a randomized, multisite, double-blind, placebo-controlled trial of daily 1760 mcg FP in participants age 3-30 years with active EoE. Twenty-eight participants received FP, and 14 participants received placebo. After 3 months, participants given FP who were in complete remission (CR) received 880 mcg FP daily, and participants in the FP or placebo groups who were not in CR continued or started, respectively, 1760 mcg FP daily for 3 additional months. The primary end point was histologic evidence for CR. Secondary end points were partial remission (PR), symptoms, compliance, esophageal gene expression, esophageal eosinophil count, and the relationship between clinical features and FP responsiveness.

RESULTS

After 3 months, 65% of subjects given FP and no subjects given placebo were in CR (P = .0001); 12% of those given FP and 8% of those given placebo were in PR. In the FP group, 73% of subjects remained in CR, and 20% were in PR after the daily dose was reduced by 50%. Extending FP therapy in FP-resistant participants did not induce remission. FP decreased heartburn severity (P = .041). Compliance, age, sex, atopic status, or anthropomorphic features were not associated with response to FP. Gene expression patterns in esophageal tissues of FP responders were similar to those of patients without EoE; there was evidence for heterogeneous steroid signaling in subjects who did not respond to FP and preliminary evidence for transcripts predictive of FP responsiveness.

CONCLUSIONS

Daily administration of a high dose of FP induces histologic remission in 65%-77% of patients with EoE after 3 months. A 50% dose reduction remained effective in 73%-93% of patients who initially responded to FP. Nonresponders had evidence of steroid resistance; histologic and molecular markers may predict resistance. Clinicaltrials.gov number: NCT00426283.

Increased prevalence of eosinophilic gastrointestinal disorders in pediatric PTEN hamartoma tumor syndromes

OBJECTIVES

The PTEN hamartoma tumor syndromes (PHTSs) are a collection of disorders caused by germline mutations of the tumor suppressor gene PTEN. Eosinophilic gastrointestinal disorders (EGIDs) are rare diseases characterized by food-induced, eosinophil-dominant inflammation in various segments of the gastrointestinal tract. On the basis of our clinical observations of several patients with EGID-PHTS, we investigated whether there is an association between these 2 disorders.

METHODS

The Cincinnati Children's Hospital Medical Center (CCHMC) Informatics for Integrating Biology and the Bedside (i2b2) warehouse was queried for the years 2007 to 2012 using International Classification of Diseases-9 codes for PTEN-related diseases; the results were cross-referenced with participants enrolled in the Cincinnati Center for Eosinophilic Disorder's EGID database to identify patients with both disorders. In an effort to replicate our findings, the Cleveland Clinic Genomic Medicine Institute PTEN database was queried for cases between 2005 and 2012. Inclusion criteria were age ≤ 18 years, history of PHTS, and an esophagogastroduodenoscopy (EGD) and/or colonoscopy with at least 1 histologic EGID diagnosis confirmed by a CCHMC pathologist. The Pearson χ(2) test was used to determine the odds of EGID enrichment in PHTS.

RESULTS

Of the 1,058,260 CCHMC distinct patients identified by the i2b2 search, 53 had clinical diagnoses suggestive of PHTS. Thirteen of the 53 had PTEN mutations, with 8 of 13 (62%) having had an EGD and/or colonoscopy. Five of the 8 had confirmed EGID. At the Cleveland Clinic, 3 of 75 patients (3/4 who had EGD and/or colonoscopy) with PHTS had confirmed EGID. CCHMC i2b2 query data showed a substantial enrichment of EGIDs in PHTSs (odds ratio  272; confidence interval 89-831, P < 0.0001). An EGID prevalence estimate from the i2b2 query supported a marked enrichment of EGIDs in PHTSs in the Cleveland Clinic database (P < 0.0001). Among the 8 subjects with EGIDs and PHTSs, the age at EGID and PHTS diagnosis was 7.6 ± 3.2 and 7.9 ± 5.8 years, respectively. Patients with EGID-PHTS had excess eosinophils in biopsies of the esophagus (75%), stomach (38%), and colon (13%), with a notable presence of eosinophil-rich gastrointestinal polyposis (88%).

CONCLUSIONS

EGID is a previously unrecognized comorbid disease in pediatric patients with PHTS. These data suggest a potential role of PTEN in contributing to EGID susceptibility.

Desmoglein-1 regulates esophageal epithelial barrier function and immune responses in eosinophilic esophagitis

The desmosomal cadherin desmoglein-1 (DSG1) is an essential intercellular adhesion molecule that is altered in various human cutaneous disorders; however, its regulation and function in allergic disease remains unexplored. Herein, we demonstrate a specific reduction in DSG1 in esophageal biopsies from patients with eosinophilic esophagitis (EoE), an emerging allergic disorder characterized by chronic inflammation within the esophageal mucosa. Further, we show that DSG1 gene silencing weakens esophageal epithelial integrity, and induces cell separation and impaired barrier function (IBF) despite high levels of desmoglein-3. Moreover, DSG1 deficiency induces transcriptional changes that partially overlap with the transcriptome of inflamed esophageal mucosa; notably, periostin (POSTN), a multipotent pro-inflammatory extracellular matrix molecule, is the top induced overlapping gene. We further demonstrate that IBF is a pathological feature in EoE, which can be partially induced through the downregulation of DSG1 by interleukin-13 (IL-13). Taken together, these data identify a functional role for DSG1 and its dysregulation by IL-13 in the pathophysiology of EoE and suggest that the loss of DSG1 may potentiate allergic inflammation through the induction of pro-inflammatory mediators such as POSTN.

Molecular diagnosis of eosinophilic esophagitis by gene expression profiling

BACKGROUND & AIMS

Gene expression profiling provides an opportunity for definitive diagnosis but has not yet been well applied to inflammatory diseases. Here we describe an approach for diagnosis of an emerging form of esophagitis, eosinophilic esophagitis (EoE), which is currently diagnosed by histology and clinical symptoms.

METHODS

We developed an EoE diagnostic panel (EDP) comprising a 96-gene quantitative polymerase chain reaction array and an associated dual-algorithm that uses cluster analysis and dimensionality reduction using a cohort of randomly selected esophageal biopsy samples from pediatric patients with EoE (n = 15) or without EoE (non-EoE controls, n = 14) and subsequently vetted the EDP using a separate cohort of 194 pediatric and adult patient samples derived from both fresh or formalin-fixed, paraffin-embedded tissue: active EoE (n = 91), control (non-EoE and EoE remission, n = 57), histologically ambiguous (n = 34), and reflux (n = 12) samples.

RESULTS

The EDP identified adult and pediatric patients with EoE with approximately 96% sensitivity and approximately 98% specificity, and distinguished patients with EoE in remission from controls, as well as identified patients exposed to swallowed glucorticoids. The EDP could be used with formalin-fixed, paraffin-embedded tissue RNA and distinguished patients with EoE from those with reflux esophagitis, identified by pH-impedance testing. Preliminary evidence showed that the EDP could identify patients likely to have disease relapse after treatment.

CONCLUSIONS

We developed a molecular diagnostic test (referred to as the EDP) that identifies patients with esophagitis in a fast, objective, and mechanistic manner, offering an opportunity to improve diagnosis and treatment, and a platform approach for other inflammatory diseases.

PedsQL eosinophilic esophagitis module: feasibility, reliability, and validity

OBJECTIVE

Eosinophilic esophagitis (EoE) is a chronic esophageal inflammatory condition with a paucity of information on health-related quality of life (HRQOL). The objective of the study was to report on the measurement properties of the PedsQL EoE Module.

METHODS

The PedsQL EoE Module was completed in a multisite study by 196 pediatric patients with EoE and 262 parents of patients with EoE.

RESULTS

The PedsQL EoE Module scales evidenced excellent feasibility (0.6%-3.1% missing), excellent group comparison reliability across total scale scores (patient α 0.93; parent proxy α 0.94), good reliability for the 7 individual scales (patient α 0.75-0.87; parent proxy α 0.81-0.92), excellent test-retest reliability (patient intraclass correlation coefficient 0.88; parent intraclass correlation coefficient 0.82), demonstrated no floor effects and low ceiling effects, and demonstrated a high percentage of scaling success for most scales. Intercorrelations with the PedsQL Generic Core Scales were in the medium (0.30) to large (0.50) range. PedsQL EoE Module scores were worse among patients with active histologic disease (≥ 5 eos/hpf) compared with those in remission (patient self-report: 63.3 vs 69.9 [P < 0.05]; parent proxy report: 65.1 vs 72.3 [P < 0.01]), and those treated with dietary restrictions compared with those with no restrictions (patient self-report: 61.6 vs 74.3 [P < 0.01]; parent proxy report: 65.5 vs 74.7 [P < 0.01]).

CONCLUSIONS

The results demonstrate excellent measurement properties of the PedsQL EoE Module. Patients with active histologic disease and those treated with dietary restrictions demonstrated worse PedsQL scores. The PedsQL EoE Module may be used in the evaluation of pediatric EoE disease-specific HRQOL in clinical research and practice.

Development of the Pediatric Quality of Life Inventory™ Eosinophilic Esophagitis module items: qualitative methods

BACKGROUND

Currently there is no disease-specific outcome measure to assess the health-related quality of life (HRQOL) of pediatric patients with Eosinophilic Esophagitis (EoE). Therefore, the objective of this qualitative study was to further develop and finalize the items and support the content validity for the new Pediatric Quality of Life Inventory™ (PedsQL™) Eosinophilic Esophagitis Module.

METHODS

Multiphase qualitative methodology was utilized in the development of the PedsQL™ EoE Module conceptual model. Focus interview transcripts of pediatric patients with EoE and their parents and expert review were previously used to develop the initial items and domains for the PedsQL™ EoE Module. In the current investigation, utilizing the respondent debriefing methodology, cognitive interviewing was conducted individually with pediatric patients with EoE and their parents on each newly developed item.

RESULTS

Information from a total of 86 participants was obtained in combination from the previous investigation and the current study. From the previous 42 focus interviews, items were developed around the domain themes of symptoms, difficulties with eating food, treatment adherence, worry about symptoms and illness, feelings of being different than family and peers, and problems discussing EoE with others. In the current study's cognitive interviewing phase, a separate cohort of 44 participants systematically reviewed and provided feedback on each item. Items were added, modified or deleted based on this feedback. Items were finalized after this feedback from patients and parents.

CONCLUSIONS

Using well-established qualitative methods, the content validity of the new PedsQL™ Eosinophilic Esophagitis Module items was supported in the current investigation. In the next iterative instrument development phase, the PedsQL™ Eosinophilic Esophagitis Module is now undergoing multisite national field testing.

Quality of life in paediatric eosinophilic oesophagitis: what is important to patients?

BACKGROUND AND AIMS

Current research outcomes in paediatric eosinophilic oesophagitis (EoE) are directed towards histological improvement with no attention to health-related quality of life (HRQOL). The primary objective of this study was to identify key patient-reported and parent proxy outcome elements of EoE disease-specific HRQOL.

METHODS

The research team comprised clinical allergists and gastroenterologists with expertise in paediatric EoE as well as two PhD psychologists with extensive experience in qualitative research. Focused interview techniques were adapted from the Pediatric Quality of Life Inventory 4.0™ methodology and the consolidated criteria for reporting qualitative research. A semi-structured interview guide of open-ended questions was developed, and extensive review of audio-taped transcripts was performed.

RESULTS

A total of 42 focus interviews were conducted. Child self-reports were obtained for patients in the 5-7, 8-12 and 13-18 years of age groups, and parent proxy reports were obtained in the 2-4, 5-7, 8-12 and 13-18 years of age groups. We discovered that patients and parents often had different concerns, illustrating unique aspects of EoE-specific HRQOL that were not captured in generic HRQOL instruments. Specific themes that emerged from these interviews included, but are not limited to: feelings of being different than family and peers, diet and medication adherence, difficulties with eating food and worry about symptoms and illness.

CONCLUSION

Paediatric EoE patient and parent proxy interviews revealed many EoE-specific aspects of HRQOL that are not captured in generic HRQOL instruments. Outcome measures that reflect patient- and parent proxy-reported HRQOL are a critical need in paediatric EoE.

Comparative dietary therapy effectiveness in remission of pediatric eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis is a chronic, immune-mediated inflammatory disorder that responds to dietary therapy; however, data evaluating the effectiveness of dietary therapeutic strategies are limited.

OBJECTIVE

This study compared the effectiveness of 3 frequently prescribed dietary therapies (elemental, 6-food elimination, and skin prick and atopy patch-directed elimination diets) and assessed the remission predictability of skin tests and their utility in directing dietary planning.

METHODS

A retrospective cohort of proton-pump inhibitor-unresponsive, non-glucocorticoid-treated patients with eosinophilic esophagitis who had 2 consecutive endoscopic biopsy specimens associated with dietary intervention was identified. Biopsy histology and remissions (<15 eosinophils/high-power field) after dietary therapy and food reintroductions were evaluated.

RESULTS

Ninety-eight of 513 patients met the eligibility criteria. Of these 98 patients, 50% (n= 49), 27% (n= 26), and 23% (n= 23) received elemental, 6-food elimination, and directed diets, respectively. Remission occurred in 96%, 81%, and 65% of patients on elemental, 6-food elimination, and directed diets, respectively. The odds of postdiet remission versus nonremission were 5.6-fold higher (P= .05) on elemental versus 6-food elimination diets and 12.5-fold higher (P= .003) on elemental versus directed diets and were not significantly different (P= .22) on 6-food elimination versus directed diets. After 116 single-food reintroductions, the negative predictive value of skin testing for remission was 40% to 67% (milk, 40%; egg, 56%; soy, 64%; and wheat, 67%).

CONCLUSION

All 3 dietary therapies are effective; however, an elemental diet is superior at inducing histologic remission compared with 6-food elimination and skin test-directed diets. Notably, an empiric 6-food elimination diet is as effective as a skin test-directed diet. The negative predictive values of foods most commonly reintroduced in single-food challenges are not sufficient to support the development of dietary advancement plans solely based on skin test results.

Development of a validated patient-reported symptom metric for pediatric eosinophilic esophagitis: qualitative methods

Background

Previous attempts to measure symptoms in pediatric Eosinophilic Esophagitis (EoE) have not fully included patients and parents in the item development process. We sought to identify and validate key patient self-reported and parent proxy-reported outcomes (PROs) specific to EoE.

Methods

We developed methodology for focus and cognitive interviews based on the Food and Drug Administration (FDA) guidelines for PROs, the validated generic PedsQL™ guidelines, and the consolidated criteria for reporting qualitative research (COREQ). Both child (ages 8-12 and 13-18) and parent-proxy (ages 2-4, 5-7, 8-12, and 13-18) interviews were conducted.

Results

We conducted 75 interviews to construct the new instrument. Items were identified and developed from individual focus interviews, followed by cognitive interviews for face and content validation. Initial domains of symptom frequency and severity were developed, and open-ended questions were used to generate specific items during the focus interviews. Once developed, the instrument construct, instructions, timeframe, scoring, and specific items were systematically reviewed with a separate group of patients and their parents during the cognitive interviews.

Conclusions

To capture the full impact of pediatric EoE, both histologic findings and PROs need to be included as equally important outcome measures. We have developed the face and content validated Pediatric Eosinophilic Esophagitis Symptom Score (PEESS™ v2.0). The PEESS™ v2.0 metric is now undergoing multisite national field testing as the next iterative instrument development phase.

Mepolizumab in eosinophilic disorders

Mepolizumab (Bosatria(®), GlaxoSmithKline) is a biologic agent developed to treat asthma. It represents a humanized monoclonal antibody of IgG1 κ type, which targets human IL-5 and thus prevents its interaction with the α-chain of the IL-5 receptor. To date, it has not been approved for use in any eosinophil-related disorder; however, several studies have suggested some therapeutic benefit across a spectrum of eosinophil-related disorders. This article evaluates the currently available preclinical and clinical studies, and the impact of mepolizumab against a variety of eosinophilic disorders.

Eosinophilic esophagitis: rapidly advancing insights

Eosinophilic esophagitis (EoE) now represents a commonly recognized disorder among both pediatric and adult patients presenting to allergy and gastroenterology clinics throughout the world. The consequences of this localized and eosinophil-predominant inflammation of the esophagus can have an outsized and profound systemic and emotional impact for patients and their families. Unlike gastroesophageal reflux disease (GERD), whose symptoms closely overlap with those of EoE, EoE represents a primarily antigen-driven disorder whose symptoms and pathology are therapeutically mitigated with either long-term dietary control or chronic steroid therapies, rather than the acid-suppressive medications that are the mainstay of GERD treatment. Beyond the dissimilarities in their responses to treatment, these disorders are distinct in their gene expression profiles, heredity, genetic underpinning, and linkage with atopy. The antigen-driven nature of EoE has been reinforced by the remarkable impact of therapies utilizing elemental formulas to control the disease as well as a number of reports linking aeroallergens to seasonal worsening of disease.

Variants of thymic stromal lymphopoietin and its receptor associate with eosinophilic esophagitis

BACKGROUND

The genetic cause of eosinophilic esophagitis (EE) has been largely unexplored until a recent genome-wide association study identified a disease susceptibility locus on 5q22, a region that harbors the thymic stromal lymphopoietin (TSLP) gene. However, it is unclear whether the observed genetic associations with EE are disease-specific or confounded by the high rate of allergy in patients with EE. In addition, the genetic contributions of other allergy-associated genes to EE risk have not been explored.

OBJECTIVE

We aimed to delineate single nucleotide polymorphisms (SNPs) that associated with EE apart from allergy.

METHODS

We used a custom array containing 738 SNPs in 53 genes implicated in allergic responses, immune responses, or both to genotype 220 allergic or 246 nonallergic control subjects and a discovery cohort of 170 patients with EE. We replicated a statistically significant SNP association in an independent case-control cohort and examined the induction of the candidate gene in primary esophageal epithelial cells.

RESULTS

A single SNP residing in the TSLP gene reached Bonferroni linkage disequilibrium-adjusted significance but only when patients with EE were compared with allergic control subjects (rs10062929; P = 4.11 x 10(-5); odds ratio, 0.35). A nonsynonymous polymorphism in the thymic stromal lymphopoietin receptor (TSLPR) gene on Xp22.3 and Yp11.3 was significantly associated with disease only in male patients with EE. Primary esophageal epithelial cells expressed TSLP mRNA after Toll-like receptor 3 stimulation.

CONCLUSION

These data collectively identify TSLP as a candidate gene critically involved in EE susceptibility beyond its role in promoting T(H)2 responses.

Identification, epidemiology, and chronicity of pediatric esophageal eosinophilia, 1982-1999

BACKGROUND

Eosinophilic esophagitis (EE) is now a commonly encountered disorder that was rarely diagnosed a decade ago.

OBJECTIVE

We aimed to determine the epidemiologic and histologic features of retrospective pediatric esophageal eosinophilia before the first case of EE at our institution was recognized.

METHODS

Esophageal biopsy specimens obtained between 1982 and 1999 with reflux esophagitis were re-examined and reorganized into 2 groups based on peak esophageal eosinophil number (<15 eosinophils per high-powered field [hpf] and > or =15 eosinophils/hpf). The epidemiology and histology of the entire cohort and a population-based cohort were evaluated.

RESULTS

Eight hundred seven biopsy specimens from 666 patients were re-examined; 198 patients had 15 eosinophils/hpf or greater. Among a population-based cohort of patients with 15 eosinophils/hpf or greater, there was a modest increase in incidence (P < .001; incidence rate ratio, 1.18; 95% CI, 1.09-1.28). After correcting for a 40-fold increase in the number of endoscopies during this time period, the proportion of biopsy specimens with 15 eosinophils/hpf or greater did not change (0.08 in 1982 vs 0.08 in 1996 [peak]; P = .9; incidence rate ratio, 1.02; 95% CI, 0.73-1.44). Patients who had as few as 5 eosinophils/hpf were more likely to have persistent esophageal eosinophilia on repeat esophagogastroduodenoscopy, evidence of basal layer hyperplasia, and lamina propria fibrosis compared with patients with less than 5 eosinophils/hpf (P < .001).

CONCLUSIONS

Esophageal eosinophilia at levels consistent with EE was present among 30% of patients given diagnoses of reflux esophagitis, and the incidence of esophageal eosinophilia did not change over time. Patients with 5 eosinophils/hpf or greater had evidence of other histologic abnormalities and were likely to have persistent esophageal eosinophilia.

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.

Coordinate interaction between IL-13 and epithelial differentiation cluster genes in eosinophilic esophagitis

We have previously proposed that the pathogenesis of eosinophilic esophagitis (EE) is mediated by an IL-13-driven epithelial cell response associated with marked gene dysregulation including eotaxin-3 overproduction. In this study, we compared epithelial responses between healthy patients and those with EE, aiming to uncover molecular explanations for EE pathogenesis. Esophageal epithelial cells could be maintained for up to five passages, with 67% and 62% of cell lines reaching confluence in healthy controls and EE cases, respectively. Both sets of epithelial cells avidly responded to IL-13 at similar levels as assessed by eotaxin-3 production. Acidic pH increased cellular release of eotaxin-3 (4.6 +/- 1.98 ng/ml versus 12.46 +/- 2.90 ng/ml at pH 7.4 and 4, respectively; p < 0.05). Numerous epidermal differentiation complex (EDC) genes, such as filaggrin and SPRR3, were downregulated both in IL-13-stimulated esophageal epithelial cells and in EE biopsies specimens compared with healthy controls. Whereas the filaggrin loss of function mutation 2282del4 was overrepresented in EE compared with control individuals (6.1% versus 1.3% respectively; p = 0.0172), the decreased filaggrin expression was uniformly seen in all EE cases in vivo. Indeed, expression of the EDC genes filaggrin and involucrin was strongly decreased directly by IL-13. These results establish that the epithelial response in EE involves a cooperative interaction between IL-13 and expression of EDC genes.

Local B cells and IgE production in the oesophageal mucosa in eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis (EO) is an emerging yet increasingly prevalent disorder characterised by a dense and selective eosinophilic infiltration of the oesophageal wall. While EO is considered an atopic disease primarily triggered by food antigens, disparities between standard allergen testing and clinical responses to exclusion diets suggest the participation of distinct antigen-specific immunoglobulin E (IgE) in the pathophysiology of EO.

AIM

To find evidence for a local IgE response.

METHODS

Endoscopic biopsies of the distal oesophagus of atopic and non-atopic EO and control individuals (CTL) were processed for immunohistochemistry and immunofluorescence to assess the presence of B cells, mast cells, and IgE-bearing cells. Oesophageal RNA was analysed for the expression of genes involved in B cell activation, class switch recombination to IgE and IgE production, including germline transcripts (GLTs), activation-induced cytidine deaminase (AID), IgE heavy chain (Cepsilon) and mature IgE mRNA using polymerase chain reaction and microarray analysis.

RESULTS

Regardless of atopy, EO showed increased density of B cells (p<0.05) and of IgE-bounded mast cells compared to CTL. Both EO and CTL expressed muGLT, epsilonGLT, gamma4GLT, AID, Cepsilon and IgE mRNA. However, the frequency of expression of total GLTs (p = 0.002), epsilonGLT (p = 0.024), and Cepsilon (p = 0.0003) was significantly higher in EO than in CTL, independent of the atopic status.

CONCLUSION

These results support the heretofore unproven occurrence of both local immunoglobulin class switching to IgE and IgE production in the oesophageal mucosa of EO patients. Sensitisation and activation of mast cells involving local IgE may therefore critically contribute to disease pathogenesis.

Periostin facilitates eosinophil tissue infiltration in allergic lung and esophageal responses

Periostin is an extracellular matrix protein that has been primarily studied in the context of the heart, where it has been shown to promote cardiac repair and remodeling. In this study, we focused on the role of periostin in an allergic eosinophilic inflammatory disease (eosinophilic esophagitis (EE)) known to involve extensive tissue remodeling. Periostin was indeed markedly overexpressed (35-fold) in the esophagus of EE patients, particularly in the papillae, compared with control individuals. Periostin expression was downstream from transforming growth factor-beta and interleukin-13, as these cytokines were elevated in EE esophageal samples and markedly induced periostin production by primary esophageal fibroblasts (107- and 295-fold, respectively, at 10 ng ml(-1)). A functional role for periostin in eliciting esophageal eosinophilia was demonstrated, as periostin-null mice had a specific defect in allergen-induced eosinophil recruitment to the lungs and esophagus (66 and 72% decrease, respectively). Mechanistic analyses revealed that periostin increased (5.8-fold) eosinophil adhesion to fibronectin. As such, these findings extend the involvement of periostin to esophagitis and uncover a novel role for periostin in directly regulating leukocyte (eosinophil) accumulation in T helper type 2-associated mucosal inflammation in both mice and humans.

Clinical, pathologic, and molecular characterization of familial eosinophilic esophagitis compared with sporadic cases

BACKGROUND & AIMS

Eosinophilic esophagitis (EE) occurs in families.

METHODS

Record review confirmed patient kinship and provided clinical information. Slide review confirmed the diagnosis (threshold peak number > or = 24 eosinophils/high-power field).

RESULTS

Fifty-nine members (41 males, 18 females) of 26 families were 3 months to 47 years of age (mean age, 10.3 y) at diagnosis. The only recorded race was Caucasian. In 4 families a parent of an affected male had EE. The most common complaint at diagnosis was dysphagia (68% of patients). Endoscopy showed esophageal mucosal furrows (93% of patients) and exudates (44%). Fifty-one percent had asthma. Skin prick tests to food and aeroallergens were positive in 76% and 71%, respectively. Familial EE characteristics (clinical, endoscopic, pathologic, and global esophageal transcript expression profile analysis) were similar to sporadic EE, except among patients with mucosal furrows: familial patients had lower peak eosinophil counts in the distal esophagus (P = .03) compared with sporadic patients. The basic characteristics of EE (eg, eosinophil levels, rate of atopy) did not vary with patient age. By using genome-wide microarray analysis, no significant differences (P < .05, false-discovery rate) were observed between familial and sporadic EE. Among all patients, chest pain was more common in females (P = .02), and thickened mucosa was more common in males (P = .006).

CONCLUSIONS

These data support a familial pattern of inheritance of EE and a pathogenesis shared with sporadic EE. EE should be considered in symptomatic family members of patients who have EE.