Publications by authors named "Amanda Muir"

In homeostatic conditions, the basal progenitor cells of the esophagus differentiate into a stratified squamous epithelium. However, in the setting of acid exposure or inflammation, there is a marked failure of basal cell differentiation, leading to basal cell hyperplasia. We have previously shown that lysyl oxidase (LOX), a collagen crosslinking enzyme, is upregulated in the setting of allergic inflammation of the esophagus; however, its role beyond collagen crosslinking is unknown.

View Article and Find Full Text PDF
Article Synopsis
  • Eosinophilic esophagitis (EoE) is a chronic immune disease characterized by symptoms of esophageal dysfunction and an eosinophil-dominated infiltration in the esophagus.
  • The incidence of EoE is rising, requiring attention in various medical settings, leading to updated guidelines that focus on improved diagnosis and treatment strategies.
  • Recommended treatments include proton pump inhibitors, topical steroids, dietary elimination, and esophageal dilation, with an emphasis on monitoring patients for treatment response and managing both inflammatory and structural aspects of the disease.
View Article and Find Full Text PDF

Esophageal organoids from a variety of pathologies including cancer are grown in Advanced Dulbecco's Modified Eagle Medium-Nutrient Mixture F12 (hereafter ADF). However, the currently available ADF-based formulations are suboptimal for normal human esophageal organoids, limiting the ability to compare normal esophageal organoids with those representing a given disease state. We have utilized immortalized normal human esophageal epithelial cell (keratinocyte) lines EPC1 and EPC2 and endoscopic normal esophageal biopsies to generate three-dimensional (3D) organoids.

View Article and Find Full Text PDF

We present the first case of a dupilumab-induced hyperinflammatory state in the setting of underlying eosinophilic esophagitis characterized by multisystem granulomatous inflammation. Although clinical trial data and subsequent real-world experience support dupilumab as a highly effective therapy for eosinophilic esophagitis, close monitoring for development of adverse symptoms following initiation remains paramount.

View Article and Find Full Text PDF

Background: Esophageal organoids from a variety of pathologies including cancer are grown in Advanced Dulbecco's Modified Eagle Medium-Nutrient Mixture F12 (hereafter ADF). However, the currently available ADF-based formulations are suboptimal for normal human esophageal organoids, limiting the ability to compare normal esophageal organoids with those representing a given disease state.

Methods: We have utilized immortalized normal human esophageal epithelial cell (keratinocyte) lines EPC1 and EPC2 and endoscopic normal esophageal biopsies to generate three-dimensional (3D) organoids.

View Article and Find Full Text PDF

Background: The demographic characteristics of patients with eosinophilic gastrointestinal diseases (EGIDs) are poorly understood. Population-based assessments of EGID demographics may indicate health disparities in diagnosis.

Objectives: We aimed to characterize the demographic distribution of EGIDs and evaluate the potential for bias in reporting patient characteristics.

View Article and Find Full Text PDF

Patients with chronic diseases have increasingly turned to social media to discuss symptoms and share the challenges they face with disease management. The primary aim of this study is to use naturally occurring data from X (formerly known as Twitter) to identify barriers to care faced by individuals affected by eosinophilic esophagitis (EoE). For this qualitative study, the X application programming interface with academic research access was used to search for posts that referenced EoE between 1 January 2019 and 10 August 2022.

View Article and Find Full Text PDF

Introduction: There are limited longitudinal data on the impact of chronic therapy on the natural history of eosinophilic esophagitis (EoE), a chronic allergic disease of the esophagus. The purpose of this study was to evaluate if patients with well-controlled EoE were less likely to develop fibrostenotic complications.

Methods: Subjects were identified from a database of pediatric patients with EoE at the Children's Hospital of Philadelphia started in 2000.

View Article and Find Full Text PDF
Article Synopsis
  • The study evaluates the use and effectiveness of genetic testing in diagnosing infants with esophageal atresia (EA) and tracheoesophageal fistula (TEF) over a 12-year period to improve future care and management.
  • It involves a retrospective analysis of 212 infants, identifying different classifications (complex/syndromic, isolated/nonsyndromic) and noting varying success rates for different genetic tests performed.
  • The findings suggest that EA/TEF has a complex genetic landscape, highlighting the need for advanced testing methods like exome sequencing to better understand its causes and improve diagnosis.
View Article and Find Full Text PDF

Eosinophilic gastrointestinal diseases (EGIDs) including eosinophilic esophagitis (EoE) are rare diseases in which eosinophils abnormally infiltrate the gastrointestinal tract. Because these are rare diseases, there is limited information regarding race and ethnicity in EGIDs and even less is known about the impact of socioeconomic factors. There is some evidence that access to care in rural settings may be affecting epidemiologic understanding of EGIDs in the pediatric populations.

View Article and Find Full Text PDF

Eosinophilic esophagitis (EoE) is a chronic, progressive immune-mediated disease associated with antigen-driven type 2 inflammation and symptoms of esophageal dysfunction. Research over the last 2 decades has dramatically furthered our understanding of the complex interplay between genetics, environmental exposures, and cellular and molecular interactions involved in EoE. This review provides an overview of our current understanding of EoE pathogenesis.

View Article and Find Full Text PDF

Unsedated transnasal endoscopy (TNE) is an alternative method of examining the esophageal mucosa in pediatric patients with eosinophilic esophagitis (EoE), reducing cost, time, and risk associated with frequent surveillance esophagogastroduodenoscopies (EGD). Adequacy of transnasal esophageal biopsies for the evaluation of eosinophilic esophagitis histologic scoring system (EoEHSS) has not yet been evaluated. We compared procedure times, endoscopic findings, and EoEHSS scoring for EoE patients undergoing TNE versus standard EGD.

View Article and Find Full Text PDF

Background & Aims: Autophagy plays roles in esophageal pathologies both benign and malignant. Here, we aim to define the role of autophagy in esophageal epithelial homeostasis.

Methods: We generated tamoxifen-inducible, squamous epithelial-specific Atg7 (autophagy related 7) conditional knockout mice to evaluate effects on esophageal homeostasis and response to the carcinogen 4-nitroquinoline 1-oxide (4NQO) using histologic and biochemical analyses.

View Article and Find Full Text PDF

Objective: Eosinophilic esophagitis (EoE) is a chronic esophageal inflammatory disorder characterized by eosinophil-rich mucosal inflammation and tissue remodeling. Transcriptional profiling of esophageal biopsies has previously revealed upregulation of type I and II interferon (IFN) response genes. We aim to unravel interactions between immune and epithelial cells and examine functional significance in esophageal epithelial cells.

View Article and Find Full Text PDF

Background & Aims: Epithelial disruption in eosinophilic esophagitis (EoE) encompasses both impaired differentiation and diminished barrier integrity. We have shown that lysyl oxidase (LOX), a collagen cross-linking enzyme, is up-regulated in the esophageal epithelium in EoE. However, the functional roles of LOX in the esophageal epithelium remains unknown.

View Article and Find Full Text PDF

Eosinophilic esophagitis (EoE) is an emerging form of food allergy that exerts a significant clinical and financial burden worldwide. EoE is clinically characterized by eosinophil-rich inflammatory infiltrates in esophageal mucosa and esophageal dysfunction. Remodeling events in esophageal epithelium and lamina propria also frequently occur in patients with EoE.

View Article and Find Full Text PDF

Introduction: There are limited data characterizing eating habits among pediatric patients with eosinophilic esophagitis (EoE). We compared eating behaviors in pediatric patients with EoE with healthy controls and assessed the degree of correlation with symptomatology, endoscopic and histologic findings, and esophageal distensibility.

Methods: We conducted a prospective, observational study where subjects consumed 4 food textures (puree, soft solid, chewable, and hard solid) and were scored for eating behaviors including number of chews per bite, sips of fluid per food, and consumption time.

View Article and Find Full Text PDF

Background: Eosinophilic esophagitis (EoE) is characterized by persistent or relapsing allergic inflammation, and both clinical and histologic features of esophageal inflammation persist over time in most individuals. Mechanisms contributing to EoE relapse are not understood, and chronic EoE-directed therapy is therefore required to prevent long-term sequelae.

Objective: We investigated whether EoE patients in histologic remission have persistent dysregulation of esophageal gene expression.

View Article and Find Full Text PDF

Although eosinophilic gastrointestinal diseases, including eosinophilic esophagitis, have been described over the past 2 to 3 decades, barriers to diagnosis and treatment are common and compounded by issues related to social determinants of health, race, ethnicity, and access to care. These barriers contribute to delays in diagnosis, resulting in persistent inflammation in the gastrointestinal tract, which can have significant consequences, including fibrostenotic complications in adults, failure to thrive in children, and decreased quality of life in all affected patients. In this commentary, we summarize gaps in knowledge regarding the epidemiology of eosinophilic gastrointestinal diseases, highlight barriers to diagnosis, discuss potential approaches based on best practices in other atopic and chronic gastrointestinal diseases, and provide recommendations for reducing barriers to timely diagnosis of eosinophilic gastrointestinal diseases in underserved populations.

View Article and Find Full Text PDF

Background & Aims: Autophagy has been demonstrated to play roles in esophageal pathologies both benign and malignant. Here, we aim to define the role of autophagy in esophageal epithelium under homeostatic conditions.

Methods: We generated tamoxifen-inducible, squamous epithelial-specific (autophagy related 7) conditional knockout mice to evaluate effects on esophageal homeostasis and response to the carcinogen 4-nitroquinoline 1-oxide (4NQO) using histological and biochemical analyses.

View Article and Find Full Text PDF

Background And Aims: A key histopathological feature of inflammatory bowel disease is damage to the mucosa, including breakdown of the epithelial barrier. Human enteroids and colonoids are a critical bench-to-bedside tool for studying the epithelium in inflammatory bowel disease. The goal of the current study was to define transcriptional differences in healthy versus diseased subjects that are sustained in enteroids and colonoids, including from disease-spared tissue.

View Article and Find Full Text PDF

The Consortium of Eosinophilic Gastrointestinal Diseases and The International Gastrointestinal Eosinophil Researchers organized a day-long symposium at the 2022 Annual Meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured a review of recent discoveries in the basic biology and pathogenesis of eosinophilic gastrointestinal diseases (EGIDs) in addition to advances in our understanding of the clinical features of EGIDs. Diagnostic and management approaches were reviewed and debated, and clinical trials of emerging therapies were highlighted.

View Article and Find Full Text PDF