Mirna Chehade

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 < P < 5.1 × 10−11). We propose a model to explain the tissue-specific nature of EoE that involves the interplay of allergic sensitization with an EoE-specific, IL-13–inducible esophageal response involving CAPN14.

Allergic eosinophilic gastroenteritis with protein-losing enteropathy: intestinal pathology, clinical course, and long-term follow-up.

Objectives: A subset of patients with allergic eosinophilic gastroenteritis (AEG) has anemia and hypoalbuminemia caused by protein-losing enteropathy (PLE). Our goals were to describe the response to therapy and the long-term outcome of patients in this subgroup and to evaluate their gastric and intestinal biopsies for distinguishing features that might explain their protein and blood loss. Methods: Patients with AEG + PLE were identified retrospectively and compared with controls and with patients with AEG only. Immunohistochemical staining for tryptase, a mast cell mediator, was performed on gastric and duodenal tissues. Eosinophils identified by hematoxylin/eosin stain and mast cells identified as tryptase-positive cells were counted in one high-power field area with maximal cell infiltration. Results: Although all patients had excellent response to therapy with amino acid-based formula and tolerated gradual introduction of some foods with time, food-responsive disease persisted in all patients over 2.5 to 5.5 years of follow-up. Routine histological evaluation did not show any features differentiating AEG + PLE from AEG. When eosinophils and mast cells were counted in intestinal biopsies, however, significantly more mast cells were found in biopsies of the AEG + PLE group despite comparable numbers of eosinophils. In contrast, in gastric biopsies, eosinophils were more prominent in AEG + PLE, but mast cell numbers were similar in all groups. Conclusions: Patients with AEG + PLE responded well to therapy with amino acid-based formula. Food hypersensitivities did not completely resolve over up to 5.5 years. Intestinal mast cells were significantly increased in maximally infiltrated areas of the intestine, possibly causing increased intestinal permeability and protein loss. JPGN 42:516-521, 2006.

Development and Validation of a Symptom-Based Activity Index for Adults With Eosinophilic Esophagitis

BACKGROUND & AIMS Standardized instruments are needed to assess the activity of eosinophilic esophagitis (EoE) and to provide end points for clinical trials and observational studies. We aimed to develop and validate a patient-reported outcome (PRO) instrument and score, based on items that could account for variations in patient assessments of disease severity. We also evaluated relationships between patient assessment of disease severity and EoE-associated endoscopic, histologic, and laboratory findings. METHODS We collected information from 186 patients with EoE in Switzerland and the United States (69.4% male; median age, 43 y) via surveys (n = 135), focus groups (n = 27), and semistructured interviews (n = 24). Items were generated for the instruments to assess biologic activity based on physician input. Linear regression was used to quantify the extent to which variations in patient-reported disease characteristics could account for variations in patient assessment of EoE severity. The PRO instrument was used prospectively in 153 adult patients with EoE (72.5% male; median age, 38 y), and validated in an independent group of 120 patients with EoE (60.8% male; median age, 40.5 y). RESULTS Seven PRO factors that are used to assess characteristics of dysphagia, behavioral adaptations to living with dysphagia, and pain while swallowing accounted for 67% of the variation in patient assessment of disease severity. Based on statistical consideration and patient input, a 7-day recall period was selected. Highly active EoE, based on endoscopic and histologic findings, was associated with an increase in patient-assessed disease severity. In the validation study, the mean difference between patient assessment of EoE severity (range, 0-10) and PRO score (range, 0-8.52) was 0.15. CONCLUSIONS We developed and validated an EoE scoring system based on 7 PRO items that assess symptoms over a 7-day recall period. Clinicaltrials.gov number: NCT00939263.

Symptoms Have Modest Accuracy in Detecting Endoscopic and Histologic Remission in Adults With Eosinophilic Esophagitis

BACKGROUND & AIMS It is not clear whether symptoms alone can be used to estimate the biologic activity of eosinophilic esophagitis (EoE). We aimed to evaluate whether symptoms can be used to identify patients with endoscopic and histologic features of remission. METHODS Between April 2011 and June 2014, we performed a prospective, observational study and recruited 269 consecutive adults with EoE (67% male; median age, 39 years old) in Switzerland and the United States. Patients first completed the validated symptom-based EoE activity index patient-reported outcome instrument and then underwent esophagogastroduodenoscopy with esophageal biopsy collection. Endoscopic and histologic findings were evaluated with a validated grading system and standardized instrument, respectively. Clinical remission was defined as symptom score <20 (range, 0-100); histologic remission was defined as a peak count of <20 eosinophils/mm(2) in a high-power field (corresponds to approximately <5 eosinophils/median high-power field); and endoscopic remission as absence of white exudates, moderate or severe rings, strictures, or combination of furrows and edema. We used receiver operating characteristic analysis to determine the best symptom score cutoff values for detection of remission. RESULTS Of the study subjects, 111 were in clinical remission (41.3%), 79 were in endoscopic remission (29.7%), and 75 were in histologic remission (27.9%). When the symptom score was used as a continuous variable, patients in endoscopic, histologic, and combined (endoscopic and histologic remission) remission were detected with area under the curve values of 0.67, 0.60, and 0.67, respectively. A symptom score of 20 identified patients in endoscopic remission with 65.1% accuracy and histologic remission with 62.1% accuracy; a symptom score of 15 identified patients with both types of remission with 67.7% accuracy. CONCLUSIONS In patients with EoE, endoscopic or histologic remission can be identified with only modest accuracy based on symptoms alone. At any given time, physicians cannot rely on lack of symptoms to make assumptions about lack of biologic disease activity in adults with EoE. ClinicalTrials.gov, Number: NCT00939263.

Dietary therapy can reverse esophageal subepithelial fibrosis in patients with eosinophilic esophagitis: a historical cohort

Fibrosis of the esophageal lamina propria is a known complication of eosinophilic esophagitis (EoE). To date, therapy with topical corticosteroids has been shown to reverse esophageal fibrosis in some patients; however, there is little evidence to suggest that dietary therapy can also reverse it. Our aim was to examine whether dietary therapy alone can reverse esophageal fibrosis in children with EoE.

Food allergy and eosinophilic esophagitis.

Purpose of reviewEosinophilic esophagitis (EoE) is a chronic allergic disease of the esophagus. A mix of immediate, IgE-mediated and delayed, non-IgE-mediated immunological reactions to foods is thought to play a role in EoE. Our purpose is to review available clinical and research evidence for this link between food allergy and EoE. Recent findingsVarious food elimination trials resulted in various rates of disease remission. Exclusive amino acid formula-based dietary trials resulted in more than 90% remission in children with EoE. Empiric elimination diets consisting of avoidance of foods commonly known to cause hypersensitivity reactions resulted in 50–74% disease remission. When diets were tailored based on results from skin prick and atopy patch tests, remission rates were comparable. Translational research studies performed on esophageal tissues and peripheral blood of patients with EoE demonstrated an allergic T-helper type 2 phenotype, though mechanisms linking the disease to food allergens are not fully addressed. SummaryFoods appear to be important allergic triggers in EoE. Identification of these triggers, however, remains a challenge. Research is needed to elucidate at which point in the pathogenesis of EoE foods become important so that their role can be better understood, and develop better tests to identify these foods.

International consensus guidelines for the diagnosis and management of food protein-induced enterocolitis syndrome: Executive summary-Workgroup Report of the Adverse Reactions to Foods Committee, American Academy of Allergy, Asthma & Immunology.

&NA; Food protein–induced enterocolitis (FPIES) is a non‐IgE cell‐ mediated food allergy that can be severe and lead to shock. Despite the potential seriousness of reactions, awareness of FPIES is low; high‐quality studies providing insight into the pathophysiology, diagnosis, and management are lacking; and clinical outcomes are poorly established. This consensus document is the result of work done by an international workgroup convened through the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology and the International FPIES Association advocacy group. These are the first international evidence‐based guidelines to improve the diagnosis and management of patients with FPIES. Research on prevalence, pathophysiology, diagnostic markers, and future treatments is necessary to improve the care of patients with FPIES. These guidelines will be updated periodically as more evidence becomes available.

Use of omalizumab in the treatment of food allergy and anaphylaxis.

Omalizumab is a humanized monoclonal anti-IgE antibody that is currently FDA-approved for allergic asthma. Given its mechanism of action, recent reports have suggested its possible clinical use for food allergy and some forms of anaphylaxis. Omalizumab exerts its action by binding to circulating IgE, reducing IgE receptor expression, and decreasing mediator release from mast cells and basophils. Clinical trials using omalizumab in patients with food allergy resulted in achieving tolerance to higher amounts of the allergen in some patients. When used as an adjunct therapy during immunotherapy trials in patients with food allergy and anaphylaxis, omalizumab allowed more rapid and higher doses of immunotherapy to be given. Omalizumab has also been reported to be effective in a few patients with idiopathic anaphylaxis and mast cell disorders. Large multi-center trials are needed to confirm the above findings, and to identify subsets of patients that would benefit the most from omalizumab.

Eosinophilic Gastritis in Children: Clinicopathological Correlation, Disease Course, and Response to Therapy

OBJECTIVES:Eosinophilic gastritis (EG), defined by histological criteria as marked eosinophilia in the stomach, is rare, and large studies in children are lacking. We sought to describe the clinical, endoscopic, and histopathological features of EG, assess for any concurrent eosinophilia at other sites of the gastrointestinal (GI) tract, and evaluate response to dietary and pharmacological therapies.METHODS:Pathology files at our medical center were searched for histological eosinophilic gastritis (HEG) with ≥70 gastric eosinophils per high-power field in children from 2005 to 2011. Pathology slides were evaluated for concurrent eosinophilia in the esophagus, duodenum, and colon. Medical records were reviewed for demographic characteristics, symptoms, endoscopic findings, comorbidities, and response to therapy.RESULTS:Thirty children with severe gastric eosinophilia were identified, median age 7.5 years, 14 of whom had both eosinophilia limited to the stomach and clinical symptoms, fulfilling the clinicopathological definition of EG. Symptoms and endoscopic features were highly variable. History of atopy and food allergies was common. A total of 22% had protein-losing enteropathy (PLE). Gastric eosinophilia was limited to the fundus in two patients. Many patients had associated eosinophilic esophagitis (EoE, 43%) and 21% had eosinophilic enteritis. Response to dietary restriction therapy was high (82% clinical response and 78% histological response). Six out of sixteen patients had persistent EoE despite resolution of their gastric eosinophilia; two children with persistent HEG post therapy developed de novo concurrent EoE.CONCLUSIONS:HEG in children can be present in the antrum and/or fundus. Symptoms and endoscopic findings vary, highlighting the importance of biopsies for diagnosis. HEG is associated with PLE, and with eosinophilia elsewhere in the GI tract including the esophagus. The disease is highly responsive to dietary restriction therapies in children, implicating an allergic etiology. Associated EoE is more resistant to therapy.

IgE and non-IgE-mediated food allergy: treatment in 2007.

Purpose of review Our understanding of the mechanism of food allergy has substantially increased over the past decade. Food allergies can be classified into those that are IgE mediated and those that are non-IgE mediated. Recent findings Various advances have been made in treating IgE-mediated food allergies. A phase II clinical trial of a second anti-IgE antibody, omalizumab, was recently initiated in subjects with peanut allergy, but was stopped as a result of safety concerns after severe reactions occurred during initial oral challenges. Oral immunotherapy is showing promise in various studies on patients with IgE-mediated food allergies. Gastrointestinal food allergic disorders involving non-IgE-mediated food allergies have recently received attention, particularly eosinophilic esophagitis. Although amino acid-based formula therapy remains the most successful in controlling inflammation and symptoms in these disorders, other therapeutic options including various dietary elimination protocols and swallowed fluticasone are showing success. Anti-IL-5 therapy may prove to be a promising future therapeutic option for refractory patients. Summary Although there are no specific therapeutic recommendations for many IgE-mediated and non-IgE-mediated food allergic disorders besides allergen avoidance, various novel approaches are currently being investigated and may influence treatment approaches in the future.