Steady-state estradiol triggers a unique innate immune response to allergen resulting in increased airway resistance.

RATIONALE: Asthma is a chronic airway condition that occurs more often in women than men during reproductive years. Population studies have collectively shown that long-term use of oral contraceptives decreased the onset of asthma in women of reproductive age. In the current study, we hypothesized that steady-state levels of estrogen would reduce airway inflammation and airway hyperresponsiveness to methacholine challenge. METHODS: Ovariectomized BALB/c mice (Ovx) were implanted with subcutaneous hormone pellets (estrogen, OVX-E2) that deliver consistent levels of estrogen [68 ± 2 pg/mL], or placebo pellets (OVX-Placebo), followed by ovalbumin sensitization and challenge. In conjunction with methacholine challenge, immune phenotyping was performed to correlate inflammatory proteins and immune populations with better or worse pulmonary outcomes measured by invasive pulmonary mechanics techniques. RESULTS: Histologic analysis showed an increase in total cell infiltration and mucus staining around the airways leading to an increased inflammatory score in ovarectomized (OVX) animals with steady-state estrogen pellets (OVX-E2-OVA) as compared to other groups including female-sham operated (F-INTACT-OVA) and OVX implanted with a placebo pellet (OVX-Pl-OVA). Airway resistance (Rrs) and lung elastance (Ers) were increased in OVX-E2-OVA in comparison to F-INTACT-OVA following aerosolized intratracheal methacholine challenges. Immune phenotyping revealed that steady-state estrogen reduced CD3+ T cells, CD19+ B cells, ILC2 and eosinophils in the BAL across all experiments. While these commonly described allergic cells were reduced in the BAL, or airways, we found no changes in neutrophils, CD3+ T cells or CD19+ B cells in the remaining lung tissue. Similarly, inflammatory cytokines (IL-5 and IL-13) were also decreased in OVX-E2-OVA-treated animals in comparison to Female-INTACT-OVA mice in the BAL, but in the lung tissue IL-5, IL-13 and IL-33 were comparable in OVX-E2-OVA and F-INTACT OVA mice. ILC2 were sorted from the lungs and stimulated with exogenous IL-33. These ILC2 had reduced cytokine and chemokine expression when they were isolated from OVX-E2-OVA animals, indicating that steady-state estrogen suppresses IL-33-mediated activation of ILC2. CONCLUSIONS: Therapeutically targeting estrogen receptors may have a limiting effect on eosinophils, ILC2 and potentially other immune populations that may improve asthma symptoms in those females that experience perimenstrual worsening of asthma, with the caveat, that long-term use of estrogens or hormone receptor modulators may be detrimental to the lung microenvironment over time.

Esophageal Eosinophilia Is Common Among Relatives of Eosinophilic Esophagitis Patients.

BACKGROUND & AIMS: Familial clustering of eosinophilic esophagitis (EoE) has been described, and we report on the biopsy-assessed prevalence of esophageal eosinophilia (EE) in first-degree family members. The aim was to determine the prevalence of EE in first-degree adult relatives (FDRs) of EoE patients. METHODS: Index EoE patients diagnosed by EE (>15 eosinophils per high-power field) and proton pump inhibitor nonresponsiveness were identified and family trees were constructed. Adult FDRs were invited to undergo upper endoscopy with esophageal biopsies and to complete reflux, dysphagia, and allergy/atopy questionnaires. Questionnaire information was gathered only for those who responded as per institutional review board purview. Records from other children and adult FDRs with prior EoE diagnoses also were obtained when permission was obtained. Simple and multivariable logistic regression models were used to evaluate the unadjusted and odds ratios of EoE for demographic and clinical variables. RESULTS: A total of 239 FDRs from 37 index EoE patients were identified. Seventy-one of 239 adult (age, >18 y) FDRs completed endoscopy and questionnaires and 18 of 71 FDRs had EE. An additional 17 FDRs were confirmed to have EE after external medical record retrieval, resulting in a total of 35 of 239 (14.6%) FDRs with EE. Significantly more male FDRs had EE compared with female FDRs (P = .027). Proton pump inhibitors, dysphagia, gastroesophageal reflux disease, asthma, and reflux symptoms predicted EE in FDRs. FDRs who had EE reported hay fever, allergic eye symptoms, and food allergy more frequently than those without EE (P = .03, P = .001, and P = .02, respectively). Specifically, younger age, higher serum eosinophils, being male, and having food allergies all were associated with higher odds of EoE (P = .0211, P = .0031, P = .0362, and P = .0089, respectively). CONCLUSIONS: The prevalence of esophageal eosinophilia is extremely high and male-predominant in first-degree relatives of EoE patients. Symptoms of hay fever, allergic eye symptoms, and food allergy were predictors of EE in FDRs. Dysphagia did not predict esophageal eosinophilia. Family members of EoE patients are at risk for EE, particularly those who have atopic symptoms.

Development of a core outcome set for therapeutic studies in eosinophilic esophagitis (COREOS).

BACKGROUND: End points used to determine treatment efficacy in eosinophilic esophagitis (EoE) have evolved over time. With multiple novel therapies in development for EoE, harmonization of outcomes measures will facilitate evidence synthesis and appraisal when comparing different treatments. OBJECTIVE: We sought to develop a core outcome set (COS) for controlled and observational studies of pharmacologic and diet interventions in adult and pediatric patients with EoE. METHODS: Candidate outcomes were generated from systematic literature reviews and patient engagement interviews and surveys. Consensus was established using an iterative Delphi process, with items voted on using a 9-point Likert scale and with feedback from other participants to allow score refinement. Consensus meetings were held to ratify the outcome domains of importance and the core outcome measures. Stakeholders were recruited internationally and included adult and pediatric gastroenterologists, allergists, dieticians, pathologists, psychologists, researchers, and methodologists. RESULTS: The COS consists of 4 outcome domains for controlled and observational studies: histopathology, endoscopy, patient-reported symptoms, and EoE-specific quality of life. A total of 69 stakeholders (response rate 95.8%) prioritized 42 outcomes in a 2-round Delphi process, and the final ratification meeting generated consensus on 33 outcome measures. These included measurement of the peak eosinophil count, Eosinophilic Esophagitis Histology Scoring System, Eosinophilic Esophagitis Endoscopic Reference Score, and patient-reported measures of dysphagia and quality of life. CONCLUSIONS: This interdisciplinary collaboration involving global stakeholders has produced a COS that can be applied to adult and pediatric studies of pharmacologic and diet therapies for EoE and will facilitate meaningful treatment comparisons and improve the quality of data synthesis.

Primary Esophageal Angiosarcoma.

Primary esophageal angiosarcoma is an extremely rare cancer. Thus, evidence-based guidance on diagnosis and treatment is lacking. The current workup and management is extrapolated from other esophageal and angiosarcoma pathology. We describe a case report that depicts unique diagnostic and therapeutic challenges.

Pulmonary Eosinophilic Granulomatosis with Polyangiitis Has IgG4 Plasma Cells and Immunoregulatory Features.

The immunologic mechanisms promoting eosinophilic granulomatosis with polyangiitis (EGPA) are unclear. To characterize the mechanisms underlying pulmonary EGPA, we examined and compared EGPA paraffin-embedded lung biopsies with normal lung biopsies, using immunostaining, RNA sequencing, and RT-PCR. The results revealed novel type 2 as well as immuneregulatory features. These features included basophils and increased mast cell contents; increased immunostaining for tumor necrosis factor ligand superfamily member 14; sparse mast cell degranulation; numerous forkhead box protein P3 (FoxP3)+ regulatory T cells and IgG4 plasma cells; and abundant arachidonate 15-lipoxygenase and 25-hydroxyvitamin D-1 α hydroxylase, mitochondrial. Significantly decreased 15-hydroxyprostaglandin dehydrogenase [NAD(+)], which degrades eicosanoids, was observed in EGPA samples. In addition, there was significantly increased mRNA for chemokine (C-C motif) ligands 18 and 13 and major collagen genes, IgG4-rich immune complexes coating alveolar macrophages, and increased immunostaining for phosphorylated mothers against decapentaplegic homolog 2/SMAD2, suggesting transforming growth factor-ß activation. These findings suggest a novel self-promoting mechanism of activation of alveolar macrophages by arachidonate 15-lipoxygenase-derived eicosanoids to express chemokines that recruit a combined type 2/immunoregulatory immune response, which produces these eicosanoids. These results suggest that the pulmonary EGPA immune response resembles the immune response to a tissue-invasive parasite infection.

Oral Administration of 99mTechnetium-Labeled Heparin in Eosinophilic Esophagitis.

OBJECTIVE: To determine if heparin labeled with 99mTechnetium (99mTc) could be an imaging probe to detect eosinophil-related inflammation in eosinophilic esophagitis and to determine the biodistribution and radiation dosimetry of 99mTc-heparin oral administration using image-based dosimetry models with esophageal modeling. METHODS: Freshly prepared 99mTc-heparin was administered orally to 5 research subjects. Radioactivity was measured by whole-body scintigraphy and single-photon emission computed tomography during the 24 hours postadministration. Following imaging, endoscopic examination was performed. The biodistribution of esophageal radioactivity was compared with endoscopic findings, eosinophil counts in biopsy tissues, and immunostaining for eosinophil granule major basic protein-1 (eMBP1). These studies were conducted from July 1, 2013, until April 22, 2017. RESULTS: Oral administration of 99mTc-heparin was well tolerated in all 5 subjects. The entire esophagus could be visualized dynamically during oral administration. Bound esophageal radioactivity marked areas of inflammation as judged by endoscopy scores, by eosinophils per high power field and by localization of eMBP1 using immunostaining. Ninety percent of the radioactivity did not bind to the esophagus and passed through the gastrointestinal tract. CONCLUSION: The biodistribution of ingested 99mTc-heparin is almost exclusively localized to the gastrointestinal tract. Radiation exposure was highest in the lower gastrointestinal tract and was comparable with other orally administered diagnostic radiopharmaceuticals. The use of swallowed 99mTc-heparin may aid in assessing eosinophil-related inflammation in the esophagus.

Epithelial Inclusions in Gallbladder Specimens Mimic Parasite Infection: Histologic and Molecular Examination of Reported Cystoisospora belli Infection in Gallbladders of Immunocompetent Patients.

Recent publications have described epithelial cytoplasmic vacuoles and inclusions incidentally noted within gallbladder epithelium and concluded that they represent coccidian parasite infection, in particular, Cystoisospora belli. We identified 8 gallbladder specimens from our institution in the past 3 years in which this diagnosis was suggested or in which similar epithelial alterations were prominent. Molecular analysis was performed on the 8 gallbladder specimens and on 3 positive control specimens: small bowel biopsies from acquired immunodeficiency syndrome patients with diarrhea. Polymerase chain reaction using primers designed to amplify an internal transcribed spacer (ITS2) in the C. belli ribosomal gene cluster was performed on the DNA samples. All 8 gallbladder specimens were negative for amplification, while a product consistent with C. belli was amplified from all 3 positive controls. Histologically, the gallbladder cytoplasmic inclusions stained diffusely positive for Grocott-Gomori's methenamine silver and Periodic acid-Schiff with diastase. In contrast, sections from a positive control small bowel biopsy demonstrated organisms that were negative for Grocott-Gomori's methenamine silver and showed a distinct capsular and punctate internal staining on Periodic acid-Schiff with diastase in various parasite forms. Together, the lack of molecular evidence of C. belli and the distinct morphologic and special staining patterns in these gallbladders compared with positive control small bowel suggest that these epithelial changes do not represent true C. belli infection. Our results suggest that gallbladders of immunocompetent patients may occasionally show epithelial changes that can morphologically mimic C. belli infection. Pathologists should be aware of this histologic variant to minimize unnecessary treatment, testing, and patient anxiety.

Eosinophilic Esophagitis: Pathophysiology and Definition.

Eosinophilic esophagitis is an adaptive immune response to patient-specific antigens, mostly foods. Eosinophilic esophagitis is not solely IgE-mediated and is likely characterized by Th2 lymphocytes with an impaired esophageal barrier function. The key cytokines and chemokines are thymic stromal lymphopoeitin, interleukin-13, CCL26/eotaxin-3, and transforming growth factor-ß, all involved in eosinophil recruitment and remodeling. Chronic food dysphagia and food impactions, the feared late complications, are related in part to dense subepithelial fibrosis, likely induced by interleukin-13 and transforming growth factor-ß.

Measurement of Inflammation in Eosinophilic Esophagitis Using an Eosinophil Peroxidase Assay.

OBJECTIVES: We describe a simple, quick method to measure an eosinophil granule protein, eosinophil peroxidase (EPO), as a marker of eosinophil activity, in eosinophilic esophagitis (EoE). METHODS: Esophageal mucosal brushings initially were collected from 36 patients with active EoE (n=13), resolved EoE (n=13), and controls (n=10) before endoscopic biopsy collection; the brushes were frozen at -80 ºC until assayed. EPO on the brush was measured in a colorimetric assay visually and by spectrophotometric absorbance measurements (at 492 nm), and was compared with peak eosinophil counts in esophageal biopsy specimens. The assay was calibrated with known EPO concentrations; as EPO increased in the assay, the color changed from light yellow to dark brown. RESULTS: Mucosal brush specimens from active EoE yielded orange to dark brown colors with absorbance measurements > 1.1 U; in contrast, control and resolved EoE brush specimens yielded a light to dark yellow color with absorbance measurements < 1.1. We then corroborated the results at the bedside (real time) in 16 additional patients. EPO on the brush was measured directly in < 1 h in the assay visually and by absorbance at 492 nm. Absorbance units strongly correlated with peak eosinophil counts both with the frozen brush (rs=0.79, P<0.0001) and with the bedside (rs=0.86, P<0.00017) approaches. CONCLUSIONS: The results support the use of this rapid method to detect and monitor EoE disease activity. Moreover, because eosinophils infiltrate and degranulate in the esophagus in EoE in a patchy manner, this method may be more accurate than current practice by testing for an eosinophil constituent from both intact and degranulated cells, and by sampling large portions of the esophageal lumen rather than small biopsy specimens that may not be representative of eosinophil involvement.

Biomarkers of the involvement of mast cells, basophils and eosinophils in asthma and allergic diseases.

Biomarkers of disease activity have come into wide use in the study of mechanisms of human disease and in clinical medicine to both diagnose and predict disease course; as well as to monitor response to therapeutic intervention. Here we review biomarkers of the involvement of mast cells, basophils, and eosinophils in human allergic inflammation. Included are surface markers of cell activation as well as specific products of these inflammatory cells that implicate specific cell types in the inflammatory process and are of possible value in clinical research as well as within decisions made in the practice of allergy-immunology.

Association of rituximab with graphene oxide confers direct cytotoxicity for CD20-positive lymphoma cells.

Non-Hodgkin lymphoma (NHL) is one of the most common hematologic malignancies among adults for which the chimeric monoclonal anti-CD20 antibody (Ab) rituximab (RTX) is used as first-line therapy. As RTX itself is not directly cytotoxic but relies on host immune effector mechanisms or chemotherapeutic agents to attack target cells, its therapeutic capacity may become limited when host effector mechanisms are compromised. Currently, refractory disease and relapse with NHL are still common, highlighting the need for novel anti-CD20 antibody strategies with superior therapeutic efficacy over current protocols. We hypothesized that making RTX directly cytotoxic might improve the therapeutic efficacy. Graphene oxide (GO) has recently emerged as a highly attractive nanomaterial for biomedical applications; and several studies have reported cytotoxic effect of GO on benign and malignant cells in vitro. Herein, we report that RTX can be stably associated with GO, and that GO-associated RTX (RTX/GO) demonstrates remarkably high avidity for CD20. Binding of GO-associated RTX to CD20-positive lymphoma cells induces CD20 capping and target cell death through an actin dependent mechanism. In vivo, GO-associated RTX, but not free RTX, quickly eliminates high-grade lymphomas in the absence of host effector mechanisms in a xenograft lymphoma mouse model. Our findings represent the first demonstration of using GO-associated antibody as effective cytotoxic therapy for human B cell malignancies in the absence of chemotherapy, and these findings could have important clinical implications.

Benign melanocytic lymph node deposits in the setting of giant congenital melanocytic nevi: the large congenital nodal nevus.

BACKGROUND: Benign melanocytic rests are a frequent finding in superficial lymph nodes removed during sentinel lymph node biopsies for melanoma. Whereas the histopathology of these deposits is well understood, very little is known regarding melanocytic lymph node deposits in the setting of giant congenital melanocytic nevi. METHODS: We analyzed lymph nodes removed from the drainage basin of giant congenital melanocytic nevi in three patients who had developed melanoma within their giant congenital nevi. RESULTS: Two of three patients showed widespread, capsular and parenchymal melanocytic deposits in multiple nodes (9 of 11 nodes in one patient and 6 of 8 in the other). Melanocytes were small, non-mitotically active and resembled those in the associated giant congenital melanocytic nevus. Melanocytes were arranged singly and in small nests ∼0.05 mm in diameter, with some larger sheets up to 1 mm. Nodal melanocytes stained for Melan A and S100 on immunohistochemical evaluation, but showed negative or minimal HMB-45 reactivity. CONCLUSIONS: Evaluation of lymph nodes in the setting of giant congenital melanocytic nevi is complicated by the presence of often numerous, parenchymal melanocytic nevic deposits. Bland cytology and minimal or absent HMB-45 staining may be helpful in differentiating these nodal melanocytic nevi from metastatic melanoma. We term this phenomena large congenital nodal nevus.

Extracellular Eosinophil Granule Protein Deposition in Ringed Esophagus with Sparse Eosinophils.

BACKGROUND: Eosinophilic esophagitis (EoE) remains difficult to classify because of varying presentations. Not uncommonly, patients present with symptoms of esophageal dysfunction and have esophageal changes on endoscopy resembling EoE but without >15 eosinophils/HPF. Patients with low numbers of eosinophils in esophageal biopsy specimens may have esophageal changes and symptomatic disease brought about by eosinophil granule protein deposition without recognizable intact cells. AIM: To determine whether extracellular eosinophil granule protein deposition is present in the esophagi of patients with low eosinophil numbers who have clinical symptoms and characteristic endoscopic esophageal changes of EoE including ringed esophagus (RE). METHODS: Esophageal biopsy specimens were studied from eight EoE patients with >15 eosinophils per high power field (HPF) and nine patients with RE (<15 eosinophils/HPF). The specimens were analyzed for eosinophil granule proteins, major basic protein 1 (eMBP1) and eosinophil-derived neurotoxin (EDN), by indirect immunofluorescence. RESULTS: Both EoE and RE showed positive EDN and eMBP1 extracellular deposition; control esophagus showed minimal or none. Comparing EoE and RE, extracellular EDN and eMBP1 were similar except that EDN in EoE was greater in the distal esophagus. CONCLUSIONS: This study highlights the importance of assessing eosinophil granule protein deposition in esophageal disease with potential eosinophil involvement. Persistent/progressive esophageal changes may be brought about by eosinophil granule proteins despite low numbers of intact cells. The meaning of "resolution" in EoE may need to be redefined based on numbers of esophageal eosinophils, extracellular eosinophil granule protein deposition, and subsequent clinical course of patients.

Rapidly Fatal Internal Carotid Artery Mycotic Aneurysm Rupture in a Rheumatoid Patient Taking a TNF-α Inhibitor: Case Report and Literature Review.

OBJECT: Tumor necrosis factor (TNF)-α inhibitors are effective at treating certain inflammatory and autoimmune disorders. They are generally safe; potential adverse events include infections (bacterial, fungal, and viral), congestive heart failure exacerbations, and the potential for demyelinating diseases and possibly certain malignancies. We present the first documented case of fungal internal carotid artery (ICA) mycotic aneurysm in a patient being treated with a TNF-α inhibitor. We also review the literature on infections with TNF-α inhibition and the management of previously reported fungal ICA mycotic aneurysm cases. CASE DESCRIPTION: A 76-year-old woman with rheumatoid arthritis, treated with etanercept and methotrexate, presented with a 2-week history of left temporal headaches. She was treated empirically for giant cell arteritis (GCA) with oral prednisone, which provided no symptom relief. She was subsequently hospitalized for a superficial temporal artery biopsy, which was negative for GCA. She returned 2 weeks later after experiencing a left thromboembolic ischemic stroke. She had an acute neurologic decline, and a head computed tomography scan showed diffuse subarachnoid hemorrhage from a ruptured left fusiform paraclinoid ICA aneurysm. She was taken emergently for a craniotomy for clip-wrapping of the aneurysm, but intraoperative ultrasound revealed poor flow in the left anterior cerebral circulation and a complete infarct of the left-sided anterior circulation. The family withdrew care and the patient died. Postmortem analysis demonstrated fungi consistent with Aspergillus invading the necrotic left ICA. CONCLUSIONS: Although fungal mycotic aneurysms of the ICA are rare, their incidence may increase with the expanded use of immunosuppressive medications. Patients with rheumatoid arthritis who take potent immunosuppression regimens may be prime candidates for mycotic aneurysms because they often have two favoring conditions: atherosclerosis and immunosuppression. These ICA aneurysms carry a high mortality rate, so early diagnosis and aggressive therapy, potentially by endovascular trapping/vessel occlusion coupled with long-term antifungal therapy, is essential.

Eosinophilic esophagitis in adults is associated with IgG4 and not mediated by IgE.

BACKGROUND & AIMS: Eosinophilic esophagitis is usually triggered by foods, by unclear mechanisms. We evaluated the roles of IgE and IgG4 in the development of eosinophilic esophagitis. METHODS: We performed a prospective, randomized, double-blind, placebo-controlled trial of adults with eosinophilic esophagitis given an antibody against IgE (omalizumab, n = 16) or placebo (n = 14) every 2-4 weeks for 16 weeks, based on weight and serum level of IgE. Endoscopy was performed, esophageal biopsy specimens were collected, and symptoms were assessed at baseline and at 16 weeks. Maximum numbers of eosinophils/high-power field were determined. Homogenates of esophageal biopsy specimens from 11 subjects with eosinophilic esophagitis and 8 without (controls) were assessed for IgM, IgA, and IgG subclasses. In a retrospective analysis, we performed immunofluorescence analysis of IgG4 in fixed esophageal tissues from 2 patients with eosinophilic esophagitis who underwent esophagectomy and 47 consecutive autopsies (controls). We also performed immunofluorescence analysis of IgG4 in esophageal mucosal biopsy specimens from 24 subjects with eosinophilic esophagitis and 9 without (controls). Finally, sera were collected from 15 subjects with eosinophilic esophagitis and from 41 without (controls), and assayed for total and food-reactive IgG4. RESULTS: Omalizumab did not alter symptoms of eosinophilic esophagitis or eosinophil counts in biopsy samples compared with placebo. Homogenates of esophageal tissues from patients with eosinophilic esophagitis had a 45-fold increase in IgG4 compared with controls (P < 3 × 10(-5)), but no significant increases in other IgG subclasses, IgM, or IgA. Sparse stromal deposits resembling immune complexes were found in 2 of 5 eosinophilic esophagitis biopsy specimens based on ultrastructural analysis. Esophagectomy samples from 2 patients with eosinophilic esophagitis contained 180 and 300 IgG4 plasma cells/maximal high-power field, mainly in the deep lamina propria; these levels were greater than in tissues from controls. Fibrosis essentially was exclusive to the lamina propria. Granular extracellular IgG4 was detected in biopsy specimens from 21 of 24 patients with eosinophilic esophagitis, but in none of the specimens from 9 controls (P = 6 × 10(-6)). The total serum level of IgG4 increased only slightly in patients with eosinophilic esophagitis, compared with controls. Subjects with eosinophilic esophagitis had increased serum levels of IgG4 that reacted with milk, wheat, egg, and nuts-the 4 foods that most commonly trigger this condition (P ≤ 3 × 10(-4) for each food). CONCLUSIONS: In a prospective trial, omalizumab did not reduce symptoms of eosinophilic esophagitis or tissue eosinophil counts compared with placebo. This finding, along with observed granular deposits of IgG4, abundant IgG4-containing plasma cells, and serum levels of IgG4 reactive to specific foods, indicate that, in adults, eosinophilic esophagitis is IgG4-associated, and not an IgE-induced allergy. ClinicalTrials.gov number: NCT 00123630.

Elemental diet induces histologic response in adult eosinophilic esophagitis.

OBJECTIVES: Elemental diets have not been studied in adults with eosinophilic esophagitis (EoE). The goal of this trial was to assess the efficacy of an elemental diet in adults with EoE. METHODS: A total of 18 adults with EoE were given an elemental diet for 4 weeks, or just 2 weeks if their response was complete. Symptoms and histologic findings, based on biweekly biopsies, were monitored. Six subjects were rebiopsied 2-7 days after resuming a normal diet. RESULTS: After therapy, esophageal tissue eosinophil content decreased from 54 to 10 per maximal high power field (P=0.0006). There was complete or nearly complete response (≤10 eosinophils) in 72% of subjects. Mast cell content, parabasal layer thickness, and endoscopic furrows and exudates also significantly decreased. Of the 29 qualified subjects, 11 (38%) failed to adhere to the diet. Several subjects had significant weight loss. Symptoms and endoscopic fixed strictures did not improve. After the subjects resumed a normal diet, the eosinophil content increased substantially in 3-7 days. CONCLUSIONS: While symptoms did not improve and dietary compliance was problematic, there was substantial histologic improvement after 4 weeks on the elemental diet. EoE in adults is substantially triggered by foods.