Glenn T. Furuta

ACG clinical guideline: Evidenced based approach to the diagnosis and management of esophageal eosinophilia and eosinophilic esophagitis (EoE).

Esophageal eosinophilia and eosinophilic esophagitis (EoE) are increasingly recognized and prevalent conditions, which now represent common clinical problems encountered by gastroenterologists, pathologists, and allergists. The study of EoE has become a dynamic field with an evolving understanding of the pathogenesis, diagnosis, and treatment. Although there are limited data supporting management decisions, clinical parameters are needed to guide the care of patients with eosinophilic–esophageal disorders. In this evidence-based review, recommendations developed by adult and pediatric gastroenterologists are provided for the evaluation and management of these patients. New terminology is emphasized, particularly the concepts of esophageal eosinophilia and proton-pump inhibitor-responsive esophageal eosinophilia (PPI-REE) as entities distinct from EoE.

Coordinated adenine nucleotide phosphohydrolysis and nucleoside signaling in posthypoxic endothelium: role of ectonucleotidases and adenosine A2B receptors.

Limited oxygen delivery to tissues (hypoxia) is common in a variety of disease states. A number of parallels exist between hypoxia and acute inflammation, including the observation that both influence vascular permeability. As such, we compared the functional influence of activated polymorphonuclear leukocytes (PMN) on normoxic and posthypoxic endothelial cells. Initial studies indicated that activated PMN preferentially promote endothelial barrier function in posthypoxic endothelial cells (>60% increase over normoxia). Extension of these findings identified at least one soluble mediator as extracellular adenosine triphosphate (ATP). Subsequent studies revealed that ATP is coordinately hydrolyzed to adenosine at the endothelial cell surface by hypoxia-induced CD39 and CD73 (>20-and >12-fold increase in mRNA, respectively). Studies in vitro and in cd39-null mice identified these surface ecto-enzymes as critical control points for posthypoxia-associated protection of vascular permeability. Furthermore, insight gained through microarray analysis revealed that the adenosine A2B receptor (AdoRA2B) is selectively up-regulated by hypoxia (>5-fold increase in mRNA), and that AdoRA2B antagonists effectively neutralize ATP-mediated changes in posthypoxic endothelial permeability. Taken together, these results demonstrate transcription coordination of adenine nucleotide and nucleoside signaling at the vascular interface during hypoxia.

Evaluation, Diagnosis, and Treatment of Gastrointestinal Disorders in Individuals With ASDs: A Consensus Report

Autism spectrum disorders (ASDs) are common and clinically heterogeneous neurodevelopmental disorders. Gastrointestinal disorders and associated symptoms are commonly reported in individuals with ASDs, but key issues such as the prevalence and best treatment of these conditions are incompletely understood. A central difficulty in recognizing and characterizing gastrointestinal dysfunction with ASDs is the communication difficulties experienced by many affected individuals. A multidisciplinary panel reviewed the medical literature with the aim of generating evidence-based recommendations for diagnostic evaluation and management of gastrointestinal problems in this patient population. The panel concluded that evidence-based recommendations are not yet available. The consensus expert opinion of the panel was that individuals with ASDs deserve the same thoroughness and standard of care in the diagnostic workup and treatment of gastrointestinal concerns as should occur for patients without ASDs. Care providers should be aware that problem behavior in patients with ASDs may be the primary or sole symptom of the underlying medical condition, including some gastrointestinal disorders. For these patients, integration of behavioral and medical care may be most beneficial. Priorities for future research are identified to advance our understanding and management of gastrointestinal disorders in persons with ASDs.

Epithelial hypoxia-inducible factor-1 is protective in murine experimental colitis

Mucosal epithelial cells are uniquely equipped to maintain barrier function even under adverse conditions. Previous studies have implicated hypoxia in mucosal tissue damage resulting from both acute and chronic inflammation. Given the importance of the transcriptional regulator hypoxia-inducible factor-1 (HIF-1) for adaptive hypoxia responses, we hypothesized that HIF-1 may serve as a barrier-protective element during mucosal inflammation. Initial studies of hapten-based murine colitis revealed extensive mucosal hypoxia and concomitant HIF-1 activation during colitis. To study this in more detail, we generated 2 mouse lines with intestinal epithelium-targeted expression of either mutant Hif1a (inability to form HIF-1) or mutant von Hippel-Lindau gene (Vhlh; constitutively active HIF-1). Studies of colitis in these mice revealed that decreased HIF-1 expression correlated with more severe clinical symptoms (mortality, weight loss, colon length), while increased HIF levels were protective in these parameters. Furthermore, colons with constitutive activation of HIF displayed increased expression levels of HIF-1-regulated barrier-protective genes (multidrug resistance gene-1, intestinal trefoil factor, CD73), resulting in attenuated loss of barrier during colitis in vivo. Taken together, these studies provide insight into tissue microenvironmental changes during model inflammatory bowel disease and identify HIF-1 as a critical factor for barrier protection during mucosal insult.

Association of eosinophilic inflammation with esophageal food impaction in adults

INTRODUCTION Esophageal food impaction is a common presentation of eosinophilic esophagitis. The prevalence of eosinophilic esophagitis among patients with food impaction is unknown. To address this, we evaluated clinicopathologic features of adults with food impaction. METHODS For a 3-year period, patients from a single, adult, community-based gastroenterology practice with esophageal food impaction were evaluated. Histories were assessed and esophageal biopsy specimens were evaluated by routine and immunohistochemical techniques. RESULTS Thirty-one patients with food impaction were evaluated. Seventeen of 31 patients had >20 eosinophils/high power field (HPF) without gender predilection. Thirteen of these 17 patients had been treated with proton pump inhibitors at the time biopsy specimens were obtained. Patients with >20 eosinophils/HPF were significantly younger (mean age 42 +/- 4 years) than patients with <20 eosinophils/HPF (mean age 70 + 3 years). Superficial white exudates and eosinophilic microabscesses in the squamous epithelium were features observed only in patients with >20 eosinophils/HPF. Immunopathologic analysis demonstrated increased CD8 lymphocytes and major basic protein deposition in their squamous epithelium. CONCLUSIONS More than half of patients with esophageal food impaction in a primary gastroenterology practice have >20 eosinophils/HPF. Based on clinicopathologic features, a significant number likely have eosinophilic esophagitis.

Mucosal Protection by Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibition

BACKGROUND & AIMS A number of recent studies have implicated tissue hypoxia in both acute and chronic inflammatory diseases, particularly as they relate to mucosal surfaces lined by epithelial cells. In this context, a protective role for the transcriptional regulator hypoxia-inducible factor (HIF) was shown through conditional deletion of epithelial HIF-1alpha in a murine model of colitis. Here, we hypothesized that pharmacologic activation of HIF would similarly provide a protective adaptation to murine colitic disease. METHODS For these purposes, we used a novel prolyl hydroxylase (PHD) inhibitor (FG-4497) that readily stabilizes HIF-1alpha and subsequently drives the expression downstream of HIF target genes (eg, erythropoietin). RESULTS Our results show that the FG-4497-mediated induction of HIF-1alpha provides an overall beneficial influence on clinical symptoms [weight loss, colon length, tissue tumor necrosis factor-alpha (TNFalpha)] in murine trinitrobenzene sulfonic acid (TNBS) colitis, most likely because of their barrier protective function and wound healing during severe tissue hypoxia at the site of inflammation. CONCLUSIONS Taken together these findings emphasize the role of epithelial HIF-1alpha during inflammatory diseases in the colon and may provide the basis for a therapeutic use of PHD inhibitors in inflammatory mucosal disease.

Eosinophils in the Esophagus—Peptic or Allergic Eosinophilic Esophagitis? Case Series of Three Patients with Esophageal Eosinophilia

OBJECTIVES:Scattered eosinophils in the distal esophagus traditionally provide the hallmark for peptic esophagitis, but the upper limit of eosinophils and the longitudinal extent of peptic inflammation along the esophagus are unknown. Recently, adults and children with upper intestinal symptoms and >20 eosinophils/high-power field (eos/HPF) have been given the diagnosis of allergic esophagitis. Standardized diagnostic criteria for allergic esophagitis are lacking and the isolated finding of large numbers of eosinophils in the squamous epithelium has been used as the defining feature. We cared for three patients with symptoms and endoscopic features of esophagitis with >20 eos/HPF in their esophageal mucosa. Symptoms, endoscopic features, and histologic findings resolved after 2 months of proton pump inhibitor (PPI) treatment. The aim of this case series is to demonstrate that features thought to be consistent with a diagnosis of allergic esophagitis are also observed in peptic esophagitis.METHODS:A retrospective chart review of three patients with esophagitis (>20 eos/HPF) whose symptoms and eosinophilia resolved with PPI treatment was performed. Esophageal biopsies were reviewed in a blinded manner by one pathologist.RESULTS:Patients (aged 14, 25, and 5 yr) presented with dysphagia, food impaction, and vomiting. Endoscopic features included white exudates and linear furrows. None of the patients received antiallergic treatments or dietary eliminations prior to endoscopy. Following treatment with PPIs alone, all patients became asymptomatic and endoscopic findings reverted to normal. In all three patients, pre- and post-PPI treatment eosinophil numbers/HPF decreased to normal/near normal (37 to 1, 21 to 3, and 52 to 0 eosinophils/HPF in patients 1, 2, and 3, respectively).CONCLUSION:Large numbers of eosinophils can be seen in peptic esophagitis. This histologic finding must be interpreted in the context of the clinical setting in which it is obtained.

Eosinophilic esophagitis: It's not just kid's stuff

Increasing evidence suggests that the esophagus serves as both a conduit for food and a participant in immune responses.1-6 This complex structure possesses innate elements of defense and orchestrates the migration of inflammatory cells, such as lymphocytes and eosinophils, into the squamous epithelium. In that regard, recent clinical experiences have identified an emerging entity termed eosinophilic esophagitis (EE). Although it is thought to occur primarily in children, a significant body of evidence suggests EE affects adults as well. Diagnostic clues are often detected in the gross appearance of the esophageal mucosa, thus emphasizing the important role of GI endoscopists in recognizing this disease. To complete this review of EE, the MEDLINE database was searched for articles containing the words “eosinophilic esophagitis,” “allergic esophagitis,” “ringed,” or “corrugated esophagus.” This search yielded 83 articles dating back to 1978. Review articles, articles lacking any details of the esophageal histology, and those reporting eosinophilic esophagitis in association with eosinophilic gastroenteritis were excluded. Twenty-nine articles and 3 abstracts detailing the experiences of gastroenterologists, pathologists, allergists, and radiologists with 186 patients with EE (35% adults) were examined and form the basis for the clinical details of this article.4,7-37 In addition, 5 investigations examined the immunopathology and pathogenesis of this condition.4,10,38-40 More than two thirds of the articles were published during the last 5 years.

Lipid mediator-induced expression of bactericidal/ permeability-increasing protein (BPI) in human mucosal epithelia

Epithelial cells which line mucosal surfaces are the first line of defense against bacterial invasion and infection. Recent studies have also indicated that epithelial cells contribute significantly to the orchestration of ongoing inflammatory processes. Here, we demonstrate that human epithelial cells express bactericidal/permeability-increasing protein (BPI), an antibacterial and endotoxin-neutralizing molecule previously associated with neutrophils. Moreover, we demonstrate that such BPI expression is transcriptionally regulated by analogs of endogenously occurring anti-inflammatory eicosanoids (aspirin-triggered lipoxins, ATLa). Initial studies to verify microarray analysis revealed that epithelial cells of wide origin (oral, pulmonary, and gastrointestinal mucosa) express BPI and each is similarly regulated by aspirin-triggered lipoxins. Studies aimed at localization of BPI revealed that such expression occurs on the cell surface of cultured epithelial cell lines and dominantly localizes to epithelia in human mucosal tissue. Functional studies employing a BPI-neutralizing anti-serum revealed that surface BPI blocks endotoxin-mediated signaling in epithelia and kills Salmonella typhimurium. These studies identify a previously unappreciated “molecular shield” for protection of mucosal surfaces against Gram-negative bacteria and their endotoxin.

Allergic esophagitis in children: a clinicopathological entity.

Infiltration of esophageal epithelium by eosinophils is seen in reflux esophagitis and allergic gastroenteritis. This study was performed to identify differences between patients with acid reflux esophagitis and those with non-acid reflux, possibly allergic, esophagitis. Intraepithelial eosinophils were demonstrated in posttherapy esophageal biopsy specimens in 28 children treated for gastroesophageal reflux disease (GERD). These patients were divided into three groups based on their response to treatment and the results of esophageal pH probe monitoring. Eleven patients (Group A) had incomplete clinical response and normal pH probe monitoring results. Ten patients (Group B) had incomplete response but did not have pH probe monitoring. These two groups formed the index population. Seven patients (Group C) had clinical improvement with GERD therapy and abnormal pH probe monitoring characteristic of GERD; they constituted the control population. Clinical, laboratory, and pathologic features were evaluated to detect differences between index and control populations. Dysphagia, food impaction, failure to thrive, peripheral eosinophilia, and abnormal allergen skin test results were detected only in Group A and B patients. Biopsy specimens of the distal 9 cm of the esophagus, after GERD therapy, contained larger numbers of eosinophils in Groups A and B than in Group C as shown on high-power fields (HPF) (A: 31/HPF +/- 19.5; B: 28/HPF +/-23.7; versus C: 5/HPF +/-6.7; p = 0.009). Eosinophil aggregates were identified only in Groups A and B (p = 0.07). Eosinophils located preferentially in the superficial layers of the squamous epithelium were noted only in Groups A and B (p = 0.02). Group A and B patients demonstrated clinical improvement when given antiallergic therapy. The authors identified a group of pediatric patients characterized by an allergic history, lack of adequate response to GERD therapy, normal esophageal pH probe monitoring results, and large numbers of eosinophils in esophageal biopsy specimens obtained after GERD treatment. On the basis of these features, the authors propose that these patients represent examples of allergic esophagitis.