Shauna Schroeder

The oesophageal string test: a novel, minimally invasive method measures mucosal inflammation in eosinophilic oesophagitis

Objective Eosinophil predominant inflammation characterises histological features of eosinophilic oesophagitis (EoE). Endoscopy with biopsy is currently the only method to assess oesophageal mucosal inflammation in EoE. We hypothesised that measurements of luminal eosinophil-derived proteins would correlate with oesophageal mucosal inflammation in children with EoE. Design The Enterotest diagnostic device was used to develop an oesophageal string test (EST) as a minimally invasive clinical device. EST samples and oesophageal mucosal biopsies were obtained from children undergoing upper endoscopy for clinically defined indications. Eosinophil-derived proteins including eosinophil secondary granule proteins (major basic protein-1, eosinophil-derived neurotoxin, eosinophil cationic protein, eosinophil peroxidase) and Charcot–Leyden crystal protein/galectin-10 were measured by ELISA in luminal effluents eluted from ESTs and extracts of mucosal biopsies. Results ESTs were performed in 41 children with active EoE (n=14), EoE in remission (n=8), gastro-oesophageal reflux disease (n=4) and controls with normal oesophagus (n=15). EST measurement of eosinophil-derived protein biomarkers significantly distinguished between children with active EoE, treated EoE in remission, gastro-oesophageal reflux disease and normal oesophagus. Levels of luminal eosinophil-derived proteins in EST samples significantly correlated with peak and mean oesophageal eosinophils/high power field (HPF), eosinophil peroxidase indices and levels of the same eosinophil-derived proteins in extracts of oesophageal biopsies. Conclusions The presence of eosinophil-derived proteins in luminal secretions is reflective of mucosal inflammation in children with EoE. The EST is a novel, minimally invasive device for measuring oesophageal eosinophilic inflammation in children with EoE.

Effect of proton pump inhibitor on esophageal eosinophilia.

Objective: Differentiation between the common etiologies of dense esophageal eosinophilia such as gastroesophageal reflux disease (GERD) and eosinophilic esophagitis can be difficult. We hypothesized that histologic features may provide diagnostic clues concerning the etiology of esophageal eosinophilia. Methods: We performed a retrospective chart review of 204 children with the diagnosis of esophagitis characterized by ≥15 eosinophils (eos) per high-power field (HPF) in at least 1 biopsy. We then restricted our analysis to subjects who had received at least 8 weeks of only proton pump inhibitors (PPIs) followed by endoscopy and who had a clinicopathologic response to this treatment. Symptoms, endoscopic findings, and pathologic descriptions were reviewed and an eosinophil peroxidase (EPX) index was determined to assess for degranulation/eosinophil activation. Results: Of the 204 identified charts, 7 subjects identified met the inclusion criteria. Five of these 7 patients showed a clinicopathologic response to PPIs after their follow-up endoscopy, (mean peak eosinophil count: 92 vs 5 eos/HPF, and EPX index: 39.2 vs 14.6, pre- and posttreatment, respectively). Two patients experienced initial resolution of symptoms and esophageal eosinophilia with PPI therapy; however, within 17–23 months they redeveloped symptoms and esophageal eosinophilia while receiving PPI therapy at the time of a third endoscopy (mean peak eosinophil count: 40 vs 11 vs 36 eos/HPF, and EPX index: 44 vs 21 vs 36.5, pre-, post- and posttreatment, respectively). No clinicopathologic features or degranulation patterns differentiated subjects with GERD/PPI responsive esophageal eosinophilia from those who had transient response to PPI treatment. Conclusions: No clinicopathologic features differentiated subjects who responded to PPI treatment. PPI treatment can be helpful to exclude GERD and PPI responsive esophageal eosinophilia but long-term follow-up is critical in the management of esophagitis.

Esophageal microbiome in eosinophilic esophagitis

Objective The microbiome has been implicated in the pathogenesis of a number of allergic and inflammatory diseases. The mucosa affected by eosinophilic esophagitis (EoE) is composed of a stratified squamous epithelia and contains intraepithelial eosinophils. To date, no studies have identified the esophageal microbiome in patients with EoE or the impact of treatment on these organisms. The aim of this study was to identify the esophageal microbiome in EoE and determine whether treatments change this profile. We hypothesized that clinically relevant alterations in bacterial populations are present in different forms of esophagitis. Design In this prospective study, secretions from the esophageal mucosa were collected from children and adults with EoE, Gastroesophageal Reflux Disease (GERD) and normal mucosa using the Esophageal String Test (EST). Bacterial load was determined using quantitative PCR. Bacterial communities, determined by 16S rRNA gene amplification and 454 pyrosequencing, were compared between health and disease. Results Samples from a total of 70 children and adult subjects were examined. Bacterial load was increased in both EoE and GERD relative to normal subjects. In subjects with EoE, load was increased regardless of treatment status or degree of mucosal eosinophilia compared with normal. Haemophilus was significantly increased in untreated EoE subjects as compared with normal subjects. Streptococcus was decreased in GERD subjects on proton pump inhibition as compared with normal subjects. Conclusions Diseases associated with mucosal eosinophilia are characterized by a different microbiome from that found in the normal mucosa. Microbiota may contribute to esophageal inflammation in EoE and GERD.

Novel Device to Sample the Esophageal Microbiome—The Esophageal String Test

A growing number of studies implicate the microbiome in the pathogenesis of intestinal inflammation. Previous work has shown that adults with esophagitis related to gastroesophageal reflux disease have altered esophageal microbiota compared to those who do not have esophagitis. In these studies, sampling of the esophageal microbiome was accomplished by isolating DNA from esophageal biopsies obtained at the time of upper endoscopy. The aim of the current study was to identify the esophageal microbiome in pediatric individuals with normal esophageal mucosa using a minimally invasive, capsule-based string technology, the Enterotest™. We used the proximal segment of the Enterotest string to sample the esophagus, and term this the “Esophageal String Test” (EST). We hypothesized that the less invasive EST would capture mucosal adherent bacteria present in the esophagus in a similar fashion as mucosal biopsy. EST samples and mucosal biopsies were collected from children with no esophageal inflammation (n = 15) and their microbiome composition determined by 16S rRNA gene sequencing. Microbiota from esophageal biopsies and ESTs produced nearly identical profiles of bacterial genera and were different from the bacterial contents of samples collected from the nasal and oral cavity. We conclude that the minimally invasive EST can serve as a useful device for study of the esophageal microbiome.

Esophageal human β-defensin expression in eosinophilic esophagitis

Background:Defensins are antimicrobial peptides expressed on mucosal surfaces that contribute to maintaining intestinal homeostasis by providing innate defense mechanisms for the epithelia. Defensin expression is altered in a number of diseases that affect mucosal surfaces, such as atopic dermatitis, allergic rhinitis, and inflammatory bowel disease. Similar to atopic dermatitis, eosinophilic esophagitis (EoE) is a chronic disease in which the squamous epithelial surface is affected by a similar TH2 microenvironment and eosinophil-predominant inflammation. Therefore, we hypothesized that defensin expression would be decreased in EoE.Methods:To address this, we measured defensin expression in vitro in cell lines derived from patients with EoE (EoE1-T) or gastroesophageal reflux disease (GERD) (NES-G4T cells) and ex vivo in esophageal mucosal biopsy samples from children with EoE or GERD and control children without esophageal disease.Results:Interleukin-5 induced a decrease in human β-defensin (hBD) -1 and hBD3 expression in EoE1-T but not in NES-G4T cells. Compared with esophageal biopsy specimens from GERD and control children, specimens from EoE pediatric patients revealed a significant decrease in mRNA and protein expression for hBD1 and hBD3.Conclusion:Diminished expression of hBD1 and hBD3 may make the esophageal epithelium more susceptible to the development and/or perpetuation of EoE.

Recent advances in the treatment of eosinophilic esophagitis

First described nearly 20 years ago, eosinophilic esophagitis (EoE) is an inflammatory disease of the esophagus characterized by eosinophilic infiltration of the esophageal epithelium. Over 50% of the current literature on EoE has been published in the last 3 years, signaling both a rising incidence and increased recognition of this disorder. Treatment options available for patients with EoE include dietary management and/or pharmacologic therapy. An individualized approach to treatment is preferred, with an emphasis on patient–parental preference. The objective of this article is to discuss the current and future treatment options for EoE.

Infliximab-associated Immunomediated Hepatitis in Children With Inflammatory Bowel Disease

ABSTRACT Infliximab (IFX) is commonly used to induce and maintain remission in inflammatory bowel disease (IBD). We report the first 2 cases of children with ulcerative colitis who had normal liver transaminases before IFX and were diagnosed with immunomediated hepatitis after IFX induction. Both the cases had negative antibodies for antinuclear, smooth muscle, and liver kidney microsome, with 1 patient having positive autoimmune serology (dsDNA) and overlap primary sclerosing cholangitis. IFX was discontinued and transaminases normalized without steroid administration. Clinicians treating pediatric patients with IBD with IFX should be aware of IFX immunomediated hepatitis. This phenomenon is previously reported in adult patients with IBD. To our knowledge, these are the first cases reported in pediatric patients with IBD.

Eosinophils Modulate the Composition of Stool Microbiota: P-262

gies are now available (1). Compared to other next-generation platforms, Pacbio RS has the advantage of a much shorter sequencing time ( 1 hr) and long read lengths (up to 8kb). However, the embedded, relatively high random sequencing error rate is considered a limiting factor for applying this technology to 16Sbased taxonomy assignment and phylogenetic analysis. The aim of this study was to evaluate the performance of Pacbio RS on 16S sequencing of the fecal microbiome of Ashkenazi Jews (AJ, a genetically homogeneous high-risk population) with and without Crohn’s disease. METHODS: Stool from 7 AJ-CD patients (in remission) and 8 AJ healthy controls were analyzed. We established a protocol for multiple 16S rRNA sequencing using the Pacbio RS system and performed taxon-based and phylogenetic analysis. Total DNA was extracted from the fecal samples and PCR amplified with unique 16 bp bar-coded primer sets targeting the V3-to-V4 hypervariable regions. PCR amplicons were pooled in equal molar amounts and sent for library preparation and sequencing. Control E. coli BL21 strain was used to test the overall classification rates. RESULTS: A single run at the movie length of 2x45 minutes generated 55k reads with 33k reads being longer than 2kb (Figure1a). We used the QIIME pipeline (2) to assign the 16S rRNA CCS (circular consensus sequencing) reads to the taxonomy at phylum, class and family level (Figure1b). Repeated measurements of 2 subjects (P3; P5) showed high correlations at phylum, class and family taxa levels (r>0.99). The classification rates for the control E. coli were 99.5% at three taxa levels, respectively. We also used the QIIME pipeline to compare the bacterial composition in CD patients and unaffected controls. The microbiome diversity shown by alpha diversity rarefaction plots (Figure2a) was not significantly different between CD and controls. However, the unweighted unifrac PCoA analysis (Figure2b) clustered microbiota by the disease status. The two pairs of repeated measurements were closely clustered with each other, as expected. Comparing each taxon, Clostridia (class level), Ruminococcaceae (family level) and Verrucomicrobiaceae (family level) were significantly less abundant in CD than controls, consistent with previous studies (3, 4). CONCLUSION(S): Our data suggest that sequencing error introduced by the Pacbio platform is unlikely to affect the classification of common bacterial species in the gut. Using the 16S deep sequencing on the Pacbio RS platform, we reproduced previously observed differences in microbial composition between CD and controls, suggesting it as a promising method to conduct microbiome studies. Supported by a CCFA Career Development Award (JH) and grants from The Chemotherapy Foundation (SI), New York Crohn’s Foundation (IP), and the National Cancer Institute UH3CA140233, R01CA159036, and R03CA159414 (ZP).