Daniel J. Mulder

FGF9-induced proliferative response to eosinophilic inflammation in oesophagitis

Background: Oesophagitis is characterised by basal cell hyperplasia and activated eosinophils, which release mediators including major basic protein (MBP). MBP and its mimetic polyarginine activate the calcium sensing receptor (CaSR) on oesophageal epithelium. Fibroblast growth factor 9 (FGF9) is implicated in epithelial homeostasis and proliferative response to injury, but has not been characterised in the oesophagus. Objective: To characterise FGF9 in oesophageal epithelium and oesophagitis, as the result of MBP activation of the CaSR. Methods: Human oesophageal epithelial cells (HET-1A) were used to compare affects of calcium, polyarginine and MBP-peptide on FGF9. HET-1A were transfected with interfering RNA (siRNACaSR). FGF9, FGF receptors 2 and 3, bone morphogenetic protein (BMP)-2, BMP-4 and noggin mRNA expression were detected by reverse transcriptase polymerase chain reaction. FGF9 was measured from HET-1A and from normal, gastro-oesophageal reflux and eosinophilic oesophagitis (EoE) patient biopsies using ELISA and immunohistochemistry. HET-1A proliferation was studied using bromodeoxyuridine and MTT. Results: FGF9 was secreted by HET-1A cells treated with polyarginine and MBP-peptide, but not calcium. This effect was abrogated by siRNACaSR. FGF9 receptor mRNA was present. HET-1A cells proliferated following rhFGF9, but not MBP-peptide treatment, and rhFGF9 altered transcription of downstream proliferation-related genes (noggin, BMP-2 and BMP-4). FGF9 was increased in biopsies from patients with eosinophilic oesophagitis, which correlated with basal hyperplasia. Conclusion: Eosinophil-released MBP acts on the CaSR to increase FGF9 in oesophageal epithelial cells, leading to proliferation. Increased FGF9 is found in biopsies of EoE patients and may play a role in the pathogenesis of oesophagitis.

Antigen Presentation and MHC Class II Expression by Human Esophageal Epithelial Cells: Role in Eosinophilic Esophagitis

Professional antigen-presenting cells (APCs) play a crucial role in initiating immune responses. Under pathological conditions, epithelial cells at mucosal surfaces act as nonprofessional APCs, thereby regulating immune responses at the site of exposure. Epithelial cells in the esophagus may contribute to the pathogenesis of eosinophilic esophagitis (EoE) by presenting antigens on the major histocompatibility complex (MHC) class II. Our goal was to demonstrate the ability of esophageal epithelial cells to process and present antigens on the MHC class II system and to investigate the contribution of epithelial cell antigen presentation to EoE. Immunohistochemistry detected HLA-DR, CD80, and CD86 expression and enzyme-linked immunosorbent assay detected interferon-γ (IFNγ) in esophageal biopsies. Antigen presentation was studied using the human esophageal epithelial cell line HET-1A by reverse transcriptase-PCR, flow cytometry, and confocal microscopy. T helper cell lymphocyte proliferation was assessed by flow cytometry and IL-2 secretion. IFNγ and MHC class II were increased in mucosa of patients with EoE. IFNγ increased mRNA of HLA-DP, HLA-DQ, HLA-DR, and CIITA in HET-1A cells. HET-1A engulfed cell debris and processed ovalbumin. HET-1A cells expressed HLA-DR after IFNγ treatment. HET-1A stimulated T helper cell activation. In this study, we demonstrated the ability of esophageal epithelial cells to act as nonprofessional APCs in the presence of IFNγ. Esophageal epithelial cell antigen presentation may contribute to the pathophysiology of eosinophilic esophagitis.

Clinical features distinguish eosinophilic and reflux-induced esophagitis.

Background and Objectives : Diagnosing eosinophilic esophagitis (EoE) depends on intraepithelial eosinophil count of ≥15 eosinophils per high-power field (HPF); however, differentiating EoE from gastroesophageal reflux disease (GERD) continues to be a challenge because no true “criterion standard” criteria exist. Identifying clinical and endoscopic characteristics that distinguish EoE could provide a more comprehensive diagnostic strategy than the present criteria. The aim of the study was to determine symptoms and signs that can be used to distinguish EoE from reflux esophagitis. Methods: Adult and pediatric patients with EoE were identified by present diagnostic guidelines including an esophageal biopsy finding of ≥15 eosinophils/HPF. Patients with GERD were age-matched one to one with patients with EoE. Clinical, endoscopic, and histologic information at the time of diagnosis was obtained from the medical record and compared between pairs by McNemar test. A conditional logistic regression model was created using 6 distinguishing disease characteristics. This model was used to create a nomogram to differentiate EoE from reflux-induced esophagitis. Results: Patients with EoE were 75% men and 68% had a history of atopy. Many aspects of EoE were statistically distinct from GERD when controlling for age. Male sex, dysphagia, history of food impaction, absence of pain/heartburn, linear furrowing, and white papules were the distinguishing variables used to create the logistic regression model and scoring system based on odds ratios. The area under the curve of the receiver-operator characteristic curve for this model was 0.858. Conclusions: EoE can be distinguished from GERD using a scoring system of clinical and endoscopic features. Prospective studies will be needed to validate this model.

Atopic and non-atopic eosinophilic oesophagitis are distinguished by immunoglobulin E-bearing intraepithelial mast cells

Mulder D J, Mak N, Hurlbut D J & Justinich C J 
(2012) Histopathology 61, 810–822

Recurrent abdominal pain and weight loss in an adolescent: Celiac artery compression syndrome

Celiac artery compression syndrome is a rare cause of abdominal pain and weight loss, likely caused by compression of the celiac artery or plexus by the median arcuate ligament. A case of celiac artery compression syndrome in a 17-year-old male patient with severe postprandial pain and weight loss is described. Imaging techniques such as computed tomography, angiography and Doppler ultrasound identified the abnormality, which was corrected by laparoscopic surgery.

Expression of Toll-Like Receptors 2 and 3 on Esophageal Epithelial Cell Lines and on Eosinophils During Esophagitis

BackgroundThe chronic disease eosinophilic esophagitis may be mediated by the innate immune system. Activation of toll-like receptors (TLRs) in other tissues is known to initiate eosinophil infiltration, thus TLRs may be a potential mediator of esophageal eosinophilia. Little is known about TLRs in the esophagus.AimsThe purpose of this study was to identify the presence and activation of TLR2 and TLR3 on esophageal epithelial cell lines, primary epithelial cells and mucosal esophageal biopsies.MethodsTLR2 and TLR3 were identified by immunocytochemistry and immunoblot. PCR assessed alterations to gene expression by activation of TLR2 and TLR3. Immunohistochemistry co-localized eosinophils and TLR2/TLR3 on esophageal biopsies.ResultsTLR2 and TLR3 were expressed on the esophageal adenocarcinoma cell lines TE-1 and TE-7, but only TLR3 was present on the esophageal epithelial cell line HET-1A. Thymic stromal lymphopoietin gene expression was altered in response to ligands zymosan and polyI:C, demonstrating activation. Primary esophageal epithelial cells did not express TLR2 or TLR3. In esophageal biopsies, TLR2 and TLR3 expression was limited to eosinophils and other immune cells during esophagitis.ConclusionsTLR2 and TLR3 expression on cultured esophageal epithelial cells differs from TLR2 and TLR3 expression in esophageal biopsies, which is limited to immune cells during esophagitis.

Multiple squamous hyperplastic-fibrous inflammatory polyps of the oesophagus: a new feature of eosinophilic oesophagitis?

This report describes the unusual case of a 12-year-old boy with multiple polyps in the oesophagus and concurrent eosinophilic oesophagitis (EoE). Polyps were of a fibrous-inflammatory composition featuring eosinophils, mast cells, hyperplastic epithelium and fibrosis, which are all features described with EoE. EoE is an increasingly recognised clinicopathological disorder characterised by large numbers of eosinophils infiltrating the oesophageal mucosa. Polyps in the oesophagus are rare, have not previously been associated with EoE, and may represent a new feature of the disease.

B cells, IgE and mechanisms of type I hypersensitivity in eosinophilic oesophagitis

The pathogenesis of eosinophilic oesophagitis (EO) is unknown. EO has recently been defined as significantly elevated intraepithelial eosinophils (⩾15 per high-power field) throughout the oesophageal mucosa, coupled with clinical and endoscopic signs of oesophagitis that cannot be attributed to gastro-oesophageal reflux disease (GORD) or other causes.1 2 This inflammatory condition is more likely to occur in atopic individuals and is limited to the oesophagus where Th2 cytokines and mast cells are also abnormally elevated.1 Removal of specific protein or all proteins from the diet may resolve the inflammatory response in some patients.3 Animal models point to antigen exposure in lung or nasal mucosa leading to local inflammation and oesophagitis.4 EO may indeed be the manifestation of an oesophageal hypersensitivity response to food or environmental antigens, but since a systemic response is not present, local mucosal immune events may be important in this disease. Patients with EO have increased numbers of cells required for local immunoglobulin E (IgE) antibody production. Lucendo et al used sensitive immunohistochemical evaluation to quantify B cells (CD20+);5 however, very few intraepithelial B cells were detected in oesophagitis (EO and GORD), and the numbers did not reach statistical significance. Mucosal mast cells are also increased in the oesophagus in EO, and these cells stain positively for IgE.5 6 7 …

Impact of Crohn Disease on Eosinophilic Esophagitis: Evidence for an Altered TH1-TH2 Immune Response

JPGN Volume 53, N E osinophilic esophagitis (EoE) is an emerging disease defined by symptoms, endoscopic findings, and 15 intraepithelial eosinophils per high-power field on esophageal biopsy (1). The cause of EoE is unknown; it is thought to be associated with the T helper lymphocyte (TH) type 2 response (2). Treatment strategies include restricting food allergens and topical corticosteroids to dampen the immune response (3). Withdrawal of therapy frequently leads to relapse of EoE, and sustained resolution of the disease is rare (4). A study of the natural history of EoE in 30 patients for an average of 7.2 years found that EoE persisted in all of the patients (5). Crohn disease (CD), a chronic inflammatory bowel disease, is associated with a TH1 and TH17 cytokine profile (6). CD may also affect the esophagus. A combination of genetic, environmental, and immune factors influence T helper lymphocyte differentiation and their unique cytokine expression profiles (7). The interplay between TH1 and TH2 immunity in the gastrointestinal tract in humans is complex and poorly understood; no distinct boundary exists between these 2 types of inflammatory response. Coexisting TH1 and TH2 diseases have been shown to have reciprocal or additive effects (8). The following case provides insight into the disease pathophysiology by demonstrating reciprocal influences of CD (TH1) and EoE (TH2 disease). An 11-year-old boy presented with dysphagia of 2 years’ duration. He denied symptoms of reflux disease. He had a history of asthma, allergic rhinitis, and multiple food and environmental allergies. Skin prick testing was positive for peanut, soybean, shrimp, walnut, celery, tomato, cat, ragweed, and tree pollen. The patient was avoiding all skin prick–positive foods. Asthma was managed with montelukast (5 mg daily, Singulair, Merck Frosst, Kirkland, Canada), a b2-receptor agonist, and fluticasone propionate (250 mg twice daily, Flovent, GlaxoSmithKline, Mississauga, Canada). Esophagogastroduodenoscopy revealed gross endoscopic

Image of the month. Gone fishin': a surprising finding while investigating possible eosinophilic esophagitis.

An upper endoscopy was undertaken. A plastic toy fish (2 1.5 0.5 cm) was vi sualized in the proximal esophagus, with the tail fin firmly embedded in the mucosa (Fig. 1). In retrospect, this foreign body could not be seen on the CT images. We attempted to cut the fin using a FS-5U-1 Loop Cutter (Olympus Canada, Markham, Ontario). This caused the object to be dislodged, leaving a 2-cm esophageal mucosal tear. The object was then secured with a polypectomy snare and withdrawn through the mouth. Two endoscopic clips (Resolution Boston Scientific, Natick, MA) were applied to close the tear. The patient admitted to having swallowed a plastic fish while bathing 6 months earlier. Three mucosal biopsies from the midesophagus and 3 from the distal esophagus revealed no other pathology. The patient was asymptomatic at a 6-month follow-up visit.