bluuebunny/crossref_metadata_2025 huggingface dataset:
A176 DOUBLE-BALLOON ENDOSCOPIC ULTRASOUND-GUIDED GASTROENTEROSTOMY FOR A MALIGNANT GASTRIC OUTLET OBSTRUCTION: SIMPLIFYING A COMPLEX PROCEDURE
Authors: Singh K S , Chen Y , Bessissow A
Published: February 2020

Background

Endoscopic enteral stenting is the standard of care for gastric outlet obstruction (GOO) despite high risks for stent dysfunction and need for re-intervention. Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is a novel technique that has the potential to decrease the risk of stent dysfunction due to tumor tissue in-/over-growth. EUS-GE; however, is technically challenging thereby limiting its widespread use.

Aims

To describe the use of the EUS-GE technique in the management of a GOO using a widely available vascular balloon catheter in aims to demonstrate a modified, more accessible approach to EUS-GE.

Methods

A 76-year-old woman with a suspected distal common bile duct (CBD) cholangiocarcinoma presented with GOO due to extrinsic compression of the duodenum from the CBD mass. After discussion with the patient and family, a decision was undertaken to perform EUS-GE. An enteroscope was inserted to the level of the obstruction. An 0.035 inch x 450 cm guidewire was advanced across the obstruction and into the jejunal loops under fluoroscopy. Two vascular balloon catheters with a compliant balloon diameter reaching up to 46mm (Coda balloon; Cook Medical, Bloomington, Indiana, USA) were placed with the balloons set 10 cm apart. The device was advanced distal to the obstruction over the wire using fluoroscopic guidance. The balloons were then inflated, occluding the distal and proximal ends of the small bowel loop closest to the stomach. This segment was then dilated with infusion of saline and contrast and identified using EUS. An electrocautery-enhanced 15-mm LAMS was then inserted forming the GE.

Results

The patient’s post-procedure course was uncomplicated and she tolerated a stent diet within 24 hours of the procedure with no recurrent obstruction at 3 months follow-up.

Conclusions

EUS-GE is a promising modality for GOO. The described case demonstrates that a modified approach using widely available vascular balloon catheters can effectively facilitate the technical aspect of this procedure. Further studies are needed to validate this novel technique.

Funding Agencies

None
A177 AN UNUSUAL CULPRIT OF AN UPPER GASTROINTESTINAL BLEED IN A PAEDIATRIC PATIENT
Authors: Bortolin K , Chavhan G , Siddiqui I , Ling S C
Published: February 2020

Background

Leiomyomas are benign tumors originating from mesenchymal cells in the muscularis propria that present equally among the sexes usually as localized lesions after the fifth decade. Though rare, esophageal leiomyomas (EL) make up the majority of benign esophageal tumors and are typically located distally. Of all known cases, 2.6% are paediatric. In this population they are 1.71 times more common in females and are often diffuse. Most are slow growing and asymptomatic but when >5cm patients describe dysphagia, vomiting, pain, cough and anorexia. Gastric leiomyomas causing upper gastrointestinal bleeding (UGIB) in adults are reported.

Aims

To discuss a rare cause of UGIB in a child.

Methods

Case report.

Results

We present a 16-year-old Asian boy with no significant past medical history who was transferred to our institution for an UGIB following 3 days of dark black stools, 1 day of coffee ground emesis and pre-syncope. There was no history of non-steroidal anti-inflammatory use.

At presentation he was in shock and received fluid resuscitation and a pantoprazole infusion. His hemoglobin dropped to 81 from 150g/L and corrected with 2 units of packed red blood cells. He was pale, non-dysmorphic with no cutaneous lesions, abdomen was non-distended and non-tender with no masses or hepatosplenomegaly.

An abdominal ultrasound showed mild bowel wall thickening in the cecum and terminal ileum.

Emergent upper endoscopy identified an ulcerated sessile mass at the gastro-esophageal junction. Biopsies revealed polypoid inflamed gastric mucosa with a focal intestinal metaplasia, negative for malignancy.

Magnetic resonance scan characterized a 3.8x4.3x2.5cm lesion in the stomach cardia not extending beyond the serosa with suggested causes including EL and gastrointestinal stromal tumor (GIST).

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) demonstrated a 2.8x1.8cm well circumscribed homogenous hypoechoic mass in the muscularis propria of the distal esophagus. Histopathology showed bland tumor cells with eosinophilic cytoplasm and nuclei that did not demonstrate atypia. Immunohistochemistry (IHC) stains were positive for smooth muscle actin and desmin. CD117, S-100 and DOG1 were negative. Findings were therefore in keeping with a leiomyoma and not a GIST.

He was referred to the Cancer Genetics clinic for consideration of hereditary leiomyomatosis renal cell cancer and General Surgery for resection.

Conclusions

This case highlights a rare cause of UGIB in a child. EL are scarcely found in children and at present there are no reports of EL causing UGIB. They can be associated with Alport Syndrome or Familial Leiomyomatosis. IHC is an essential diagnostic tool, enabling differentiation of EL from GIST which is important as the latter has malignant potential. EL can be monitored with endoscopy if small but are surgically resected if symptomatic, ulcerated, or growing.

Funding Agencies

None
A189 NON-ALCOHOLIC FATTY LIVER DISEASE AND SEN-V INFECTION: AN INTERIM ANALYSIS
Authors: Rumbolt C B , Minuk G , Osiowy C , Grubert Van Iderstine M
Published: February 2020

Background

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease in which 10–20% of patients are at risk of progressing to cirrhosis. Several risk factors and genetic variants have been proposed to explain such progression but these fail to explain all cases.

SEN-V is a hepatotropic ssDNA virus transmitted by both parenteral and non-parenteral routes. In a previous study we documented serologic evidence of SEN-V infection in 21% of 108 patients with chronic Hepatitis B (HBV), C (HCV) or PBC disease. In a recent Japanese study, HCV patients who were SEN-V positive had higher rates of disease progression than those who were SEN-V negative. Conversely, in an Iranian study, liver enzyme levels were lower in HBV patients co-infected with SEN-V. No study has yet documented the prevalence or impact of SEN-V infection in NAFLD.

Aims

To determine the prevalence and impact of SEN-V infection in NAFLD.

Methods

Thirty-three consecutive patients with NAFLD confirmed on liver biopsy had serologic testing for SEN-V DNA using short and long primer target sequences; sequencing was confirmed by BLAST and phylogenetic analysis. Patients with other causes of chronic liver disease were excluded. ALT levels, NAFLD activity scores (NAS), and fibrosis scores on biopsy were compared between the SEN-V positive and negative groups using Mann-Whitney, t-test, and chi squared as appropriate.

Results

SEN-V serologic testing was positive in 15/33 (45%) NAFLD patients, significantly higher than the 24/108 (21%) reported in non-NAFLD historical controls (p < 0.01). Mean serum ALT levels were similar in the two cohorts (SEN-V positive: 109 +/- 163 versus SEN-V negative: 62 +/- 54 IU/L, p= 0.27). The median NAS scores were identical in both groups (5/8) 95% CI [3,6]. Although the median fibrosis stage in SEN-V positive patients was lower (1.0 95% CI [0,3] vs. 2.5 95% CI [1,4] respectively), the difference did not reach statistical significance (p= 0.27).

Conclusions

Within the limits of this small interim analysis, serologic evidence of SEN-V infection was more common amongst NAFLD patients than historical controls with non-NAFLD chronic liver diseases. However, there were no significant differences in ALT levels, NAS scores or fibrosis stages between SEN-V positive versus negative NAFLD patients. These results suggest that if SEN-V infection has any impact on NAFLD, it may contribute to the development but not severity of the disease.

Funding Agencies

None
A192 DEPLETING ASCL2 IN ESOPHAGEAL ORGANOIDS TO INVESTIGATE ITS ROLE IN STEM CELLS MAINTENANCE
Authors: Hamilton M , Jean D , Giroux V
Published: February 2020

Background

Recently, the first population of stem cells in the esophageal epithelium was identified with the help of the Keratin 15(Krt15) marker. However, little is known about the mechanisms underlying the expansion and the function of stem cells in the esophagus. It was shown that ASCL2, a transcription factor, is upregulated in Krt15+cells compared with Krt15- cells. ASCL2 is a gene target of the Wnt/β-catenin pathway, which act as a regulator of proliferation and maintenance of the stemness state. The ultimate goal of my research project is to determine the role of ASCL2 in the maintenance of esophageal stem cells and to identify his binding partners.

Aims

To investigate the role of ASCL2 in esophageal epithelial biology, we aim at establishingAscl2knockout esophageal organoid lines.

Methods

Lentiviral infection and CRISPR/Cas9 knockout approach were optimized in mouse esophageal organoids. ASCL2was invalidated with CRISPR/Cas9 and/or inducible specific shRNAs in primary mouse esophageal cell line and organoids. Antibodies directed against ASCL2 were also tested to validate cell lines.

Results

First, to optimize lentiviral infection in mouse esophageal organoids, we produced GFP-expressing lentiviruses. Viruses were then concentrated and incubated with a single cell suspension of mouse organoid cells under gentle activation. Infected cells were embedded in Matrigel and grown in organoids. GFP+ cells were then selected using an antibiotic resistance strategy. Second, we used our optimized lentiviral infection protocol to express specific gRNAs in mouse esophageal organoids, which were previously screened in a primary mouse esophageal cell line. Knockout were validated using Western Blot. Invalidation of ASCL2 was performed using CRISPR/Cas9 and inducible shRNAs. We also validated three commercially available ASCL2 antibodies in WB and IF.

Conclusions

ASCL2 is expressed in the mouse esophagus tissue and organoids, and it can be invalidated in cell lines and organoids.

Funding Agencies

NSERC, CRC Tier2
A200 HUMANIZED CELIAC-PRONE EPITHELIUM IN VITRO EXPRESS MHC-II AND CO-STIMULATORY MOLECULES NECESSARY FOR GLUTEN PEPTIDE PRESENTATION
Authors: Rahmani S , Galipeau H J , Su H , Chirdo F G , Didar T F , Verdu E
Published: February 2020

Background

The role intestinal epithelial cells (IECs) play in the breakdown of tolerance to gluten at an early stage in celiac disease (CeD) is unclear. Epithelial stress is a feature of CeD, and although the triggers are largely unknown, it is accompanied by expression of several markers that could be involved in initiation of inflammatory responses. IECs have been shown to express MHC class II (MHC-II) molecules and participate in antigen presentation in several models. Whether IECs can participate in gluten peptide presentation, the major environmental trigger in celiac disease, is unknown. To study this, a model expressing human MHC-II, HLA DQ8 or HLA-DQ2, would be required.

Aims

To develop organoid monolayers from transgenic mice expressing human celiac risk genes: HLA-DQ8 and -DQ2. To investigate conditions leading to the induction of epithelial MHC-II and its main co-stimulatory molecules, CD80, CD86 and CD40, that could enable early gluten peptide presentation.

Methods

In order to show pathophysiological significance of the model, we used two approaches, either induction of inflammation in vivo through gluten sensitization, or direct stimulation of the monolayers using pro-inflammatory cytokines relevant in CeD, such as IFNγ. Mice were sensitized with Pepsin-Trypsin digested gliadin and cholera toxin (CT) once a week for 3 weeks, followed by a challenge phase in which they only received gliadin. Control mice received CT only. We then developed organoid monolayers from the duodenum followed by stimulation with 10 ng/ml IFNγ. Finally, markers necessary for gluten peptide presentation, the expression of MHC-II and its co-stimulatory molecules, were evaluated using flow cytometry.

Results

Both in vivo gluten sensitization and in vitro stimulation of the organoid derived monolayer with IFNγ induced a proinflammatory response, that independently primed the epithelium to express MHC-II molecules (p =0.02 and <0.0001, respectively). When in vivo sensitization and in vitro IFNγ stimulation were combined, epithelial MHC-II expression was further upregulated (p <0.0001). Lastly, only the combination of gluten sensitization and in vitro IFNγ induced expression of MHC-II co-stimulatory molecules, which are necessary for antigen presentation.

Conclusions

Our findings support that gluten induced-inflammation in vivo as well as independent stimuli that release IFNγ enhance the capacity of the IECs to express MHC-II molecules. However, co-stimulatory molecules are only expressed by the epithelium when both gluten tolerance is broken by in vivo sensitization and the organoid monolayers is further exposed to IFNγ. The results support the hypothesis that the epithelium participates in gluten peptide presentation and that this pathway is stimulated by both gluten-dependent and independent inflammation.

Funding Agencies

CIHRSupported by CIHR and a Farncombe Family Grant to EFV and TFD.
A207 RIPK2 AND AMPK AS EMERGING THERAPEUTIC TARGETS FOR INFLAMMATORY BOWEL DISEASE
Authors: Guo Y , Dieleman L A , Dooky H , Joshi H , Wine E , Baksh S
Published: February 2020

Background

Persistent inflammation can trigger altered epigenetic, inflammation and bioenergetics states. Inflammatory bowel disease (IBD) is a heterogeneous disease with an abnormal inflammatory state and subsequent metabolic syndrome disorder. Current IBD therapeutics are directed to inhibit inflammatory pathways, such as inflammation of the epithelial cells in the colonic crypts. We hypothesize that in order to achieve mucosal healing and to keep patients in remission we must (i) inhibit inflammatory mediators and (ii) resolve secondary effects of inflammation such a reset of metabolic dysfunction.

Aims

The aims of this study are to explore correlations between inflammation/metabolic markers and the severity of the disease to uncover emerging new therapeutic players.

Methods

More than one hundred patients were recruited and underwent colonoscopy. In order to explore how biomarkers change with disease and time, all patients had IBD for more than 10 years or less than 5 years. Those diagnosed with cancer, celiac sprue, or diabetes were excluded. The activity of key metabolic markers (such as AMPK) was tracked using phospho-specific antibodies. Immunohistochemistry and immunoblotting were carried out, as described by Gordon et al., PLOSone 2013. All patients were consented under our IBD ethics protocol (Pro00001523 and Pro00077868).

Results

Using intestinal biopsies from non-IBD, UC and CD patients, we explored the expression/activation levels of markers of inflammation (such as obligate NOD2 kinase RIPK2) and metabolism (AMPK) in order to gain insight into correlations with clinical severity of the disease. We confirm that the loss in the activity of AMPK occurs with a gain of activity of RIPK2 that drives the inflammatory phenotype of the gut in patients with long-standing IBD (>10 years). (If inflammation is inhibited in a mouse model of IBD, metabolic reset occurs to regain AMPK and promote mucosal healing). However, RIPK2 remains elevated in patients that are currently on IBD therapeutics.

Conclusions

Therapeutics inhibiting inflammation (RIPK2) and stimulating metabolic (AMPK) drivers of the disease may be a useful combination therapy to completely eliminate inflammation, reset abnormal metabolism and achieve full remission in IBD patients with longstanding disease.

Funding Agencies

None
A212 CHROMOFUNGIN PROTECTS AGAINST DSS-INDUCED COLITIS BY REGULATING P-53 APOPTITIC PATHWAY
Authors: Diarra A , Eissa N , Ghia J
Published: February 2020

Background

Development of ulcerative colitis is associated with epithelial apoptosis mediated by p53-apoptotic pathway through the activation B-cell lymphoma 2 (Bcl-2), Bcl-2 associated-X protein (BAX) and Bcl-2 antagonist/killer-1 (BAK1) proteins. Chromofungin (CHR), a chromogranin-A derived peptide expressing a cell penetrating peptide motif, decreased the severity of colitis via the suppression of mucosal and pro-inflammatory macrophages-related p53-dependent apoptosis.

Aims

We aimed to investigate a) whether the gene profile expression of apoptosis could be extended to other p53-associated genes; b) whether the gene expression of some of the p53-apoptosis marker could be confirmed by protein analysis; and c) whether due to the cell penetrating peptide motif, CHR could enter into peritoneal macrophages.

Methods

UC-related colitis was induced in C57BL/6 mice (7 weeks) by administering dextran sulfate sodium (DSS) (5%, 5 days). Preventive CHR (2.5 mg/kg/day) or vehicle treatment started 1-day before colitis induction and lasted for 5-days. Profiler™ PCR Array was performed to screen a panel of 84 genes representative of the p53 signal pathway in colitic whole mucosa distal colonic samples treated or not with CHR. Western blot analysis was performed to confirm individual protein changes. Naïve macrophages were plated overnight and nonadherent cells were removed the next day. Cells were incubated with rhodamined CHR (4 ul) for 5, 10, 20, 30 min before washing and fixing them, detection was made via confocal microscopy.

Results

In colitic conditions, an up regulation of 26 genes associated to the p53-dependent apoptosis pathway were detected including Apaf1, Bax, Bbc3, Bcl2, Cradd, Fadd, Cul9, Pmaip1, Tnfrsf10b. In vivo CHR treatment decreased significantly the colitis and was associated with a significant downregulation of 19 genes including the 9 aforementioned when compared with biopsies from colitic groups. Compared to untreated groups, colitic mice treated with CHR demonstrated a significant decrease of BAX and BAK protein and the apoptotic ER stress inducer marker, X-Binding Protein 1. A large number of peritoneal macrophages displayed rhodamine within the all intracellular compartment. The presence of the peptide inside the cell can be visible as early as 5 min and the signal gradually increases.

Conclusions

CHR decreases the inflammatory process via the suppression of a large number of p53-related apoptotic proteins. CHR quickly enters the macrophage but the exact mechanism of entrance needs to be further defined. Targeting functional analysis of CHR may lead in the future to novel therapeutics for UC.

Funding Agencies

CCCNSERC
A221 CROHN’S DISEASE POLYGENIC RISK SCORE IS ASSOCIATED WITH FECAL CALPROTECTIN CONCENTRATION IN ASYMPTOMATIC FIRST-DEGREE RELATIVES OF CROHN’S DISEASE PATIENTS
Authors: Lee S , Shestopaloff K , Espin-Garcia O , Turpin W , Raygoza Garay J , Power N , Smith M , Silverberg M , Xu W , Paterson A D , Croitoru K
Published: February 2020

Background

Fecal calprotectin concentration (FC), a measure of gut inflammation is reported to be significantly higher in healthy first-degree relatives (FDR) of Crohn’s disease (CD) patients compared to healthy controls. In contrast, FC in spouses of CD patients was not significantly different from controls, suggesting that a genetic predisposition rather than a shared environmental factor affects FC.

Aims

We investigated the genetic association with FC in healthy FDRs of CD patients. Notably, these subjects are known to be enriched with CD risk alleles.

Methods

We investigated 1455 healthy Caucasian FDRs of CD patients from the GEM Project. Subjects were genotyped by HumanCoreEXOME chip and ImmunoChip platforms and then imputed by the Haplotype Reference Consortium v1.1 panel (Michigan Imputation Server). SNPs with a minor allele frequency<5% were removed. FC was measured using BUHLMANN ELISA kit. Heritability was estimated using a pedigree based SOLAR program and a SNP-based GCTA software. Genome wide association of FC was tested using the GEE framework that accounts for family clusters, age, sex, first 3 genetic principal components and multiplex family status (≥2 FDRs diagnosed with CD). In addition, CD-polygenic risk scores were derived based on summary statistics and imputed SNPs from a recent GWAS by pruning and thresholding (P+T) and LDPred algorithm (PMID:31002795).

Results

Among 1455 subjects, 45.2% were male, median age was 19 years (IQR 13–26), 8.8% were from multiplex families, and median FC was 52 mg/kg (IQR 31–87; 20.8% had FC>100). We estimated the heritability of FC to be 27% (27.1%, standard error=9%, p<0.001 by pedigree approach; 27.9%, SE=12%, p<0.001 by SNP approach). An untargeted GWAS failed to show any significant association with FC (i.e. p<5x10-8). The lowest p value was obtained for rs224631 (p=5x10-7). Strikingly, an increase in CD polygenic risk scores was significantly associated with an increase of FC (p=5.2x10-5 with P+T method).

Conclusions

We demonstrate that FC concentration is a heritable trait in unaffected FDRs of CD patients. Although the association between genetic variants with FC did not reach GWAS significance, CD-polygenic risk score, which incorporates small effect size CD-associated SNPs, was significantly associated with FC concentrationin this cohort. Our results suggest that FC concentration is influenced genetically with contributions from CD-associated SNPs in unaffected FDRs of CD probands. It remains to be determined if the genetic influence to FC concentration is dependent/independent with the future development of CD.

Submitted on behalf of The CCC-GEM Project research team

Funding Agencies

CCCHelmsley Charitable Trust/ Mount Sinai Hospital Fellowship Award
A230 GAPS IN IDENTIFYING FOOD-RELATED QUALITY OF LIFE AND HYPERVIGILANCE IN AT-RISK INDIVIDUALS WITH IBD: REVIEW OF VALIDATED SCREENING TOOLS
Authors: Sasson A N , Targownik L , Vagianos K , Bernstein C N
Published: February 2020

Background

Inflammatory bowel disease (IBD) has a profound impact on psychosocial aspects of food and nutrition, thereby affecting food-related quality of life (QoL). While there is literature on associated prevalence of increased anxiety in individuals with IBD, there is limited data on its contribution to hypervigilance and orthorexia with food intake. Many patients with IBD have strong beliefs about dietary symptom triggers, which can lead to avoidance behaviors and decreased nutrient intake. This can exacerbate malnutrition and disordered eating, as well as increase disease-related stress and negatively impact coping. While there are validated scales evaluating anxiety-related, QoL-related and food-related behaviors in IBD, a combined screening tool to assess this comorbid axis is not well described.

Aims

To conduct a systematic review of existing literature in order to inform practice and facilitate development of an effective food-related hypervigilance and QoL evaluation in IBD patients

Methods

The literature was systematically searched through September 2019, using an electronic database querying Embase, PubMed, MEDLINE, Cochrane Library and PsycINFO. We searched original articles describing development, validation and measurement properties for screening tools on anxiety, QoL and food-related behaviors in IBD from 1975 to 2018. The primary outcome of interest was to evaluate the current measurements of the validated tools to identify whether a screening tool highlighting all above parameters exists for patients with IBD.

Results

Initial database search resulted in 5548 articles. After screening titles and abstracts, 168 were included. After full text review and deduplication, 23 validated scales were identified for use in IBD patients with respect to measuring anxiety, health-related QoL and food-related behaviors. There was substantial heterogeneity in IBD populations using the assessment tools (adult vs. pediatric, CD vs. UC, inpatient vs. outpatient). The breakdown of studies identified: 2 studies (8.6%) evaluated QoL and anxiety, 2 studies (8.6%) evaluated QoL and food-related behaviors. The remainder of studies individually assessed QoL, anxiety and food-related behaviors (47.8%, 26% and 8.6% respectively). None of the tools performed satisfactory to establish all three measurements in individuals with IBD.

Conclusions

Recent evidence suggests the presence of dietary hypervigilance in individuals with chronic GI conditions potentially leading to food restrictive behaviors impacting QoL. Screening models evaluating multivariable relations of anxiety in food-related behaviors and QoL in IBD is lacking. Efforts should be made to develop and validate a multi-assessment screening tool to aid in early identification of this prevalence in IBD patients to facilitate improved management outcomes.

Funding Agencies

None
A248 WHAT IS THE MINIMUM TRAINING STANDARD FOR POINT OF CARE INTESTINAL ULTRASOUND? A SINGLE CENTER, PROSPECTIVE, OBSERVATIONAL STUDY TO DEFINE TRAINING STANDARDS
Authors: Hansen T , Baraty B , Lu C , Tanyingoh D , Maaser C , Novak K L
Published: February 2020

Background

Higher demands for colonoscopy and magnetic resonance imaging (MRI) for long term disease monitoring can be expected as the prevalence of IBD continues to rise in Canada. As resources are perpetually constrained, timely access to effective monitoring strategies important to direct care are increasingly compromised. Intestinal ultrasound provides a cost-effective solution to these challenges. Intestinal ultrasound (IUS) is a patient-centered, accurate modality used during clinic by non-radiologists to enhance clinical decision making. Minimum IUS training standards have yet to be established.

Aims

The aim of this study is to report a single operator IUS performance characteristics after completion of 4 weeks of training with 100 completed supervised scans.

Methods

A single center, prospective, observational study over 4 years utilizing a convenience sample of patients presenting to the inflammatory bowel disease (IBD) clinic at the University of Calgary. A single operator compared IUS to gold standard (either colonoscopy, or alternative cross-sectional imaging) with sensitivity, specificity, positive and negative predictive value calculated for each year. Joinpoint regression was performed to analyze the trend for sensitivity and specificity over the study period.

Results

A total of 235 IUS were performed on 235 individuals diagnosed with IBD between 2013 and 2016. There were individuals with 26 ulcerative colitis and 209 persons diagnosed with Crohn’s disease. There was a non-significant increase in sensitivity and specificity point estimates over the 4 year period (Table 1). The sensitivity, specificity, positive predictive value, and accuracy of IUS in 2016 were 100% (95% CI: 81%-100%), 92% (95% CI: 62%-100%), 94% (95% CI: 72%-99%) and 97% (95% CI: 8%-100%) respectively.

Conclusions

IUS provision by a gastroenterologist having completed 100 supervised scans during training within an expert center is sufficient, resulting in high accuracy. Although there is some improvement over time, the trend towards improvement over time is not significant. This study provides evidence to inform IUS training programs with a minimum training standard benchmark, imperative with expanding demand and development of new expert centers.

Funding Agencies

None
A252 FUNCTIONAL ANALYSIS OF GENETIC AETIOLOGIES IN A DOWNSTREAM OF TYROSINE KINASE (DOK) PROTEIN IN THE PATHOGENESIS OF PEDIATRIC INFLAMMATORY BOWEL DISEASE (IBD)
Authors: Batura V , Guo C , Warner N , Leung G , Ricciuto A , Muise A
Published: February 2020

Background

IBD is a form of chronic inflammatory disorder of the gastrointestinal tract that arises due to genetic, environmental, immunological and microbial factors. The precise pathological mechanisms remain elusive. It is thought that the onset of pediatric IBD can largely be attributed to genetics. Muise lab, at SickKids, regularly screens children at the SickKids IBD clinic and through an international consortium to find possible genetic links to the disease. We report a patient at SickKids with biallelic mutations in DOK4 who has severe Crohn’s Disease along with other inflammatory conditions. Downstream of kinase (DOK) proteins are a family of adaptor molecules that serve as scaffolding proteins important in regulating cell signaling, especially in T cells. DOK4 has been shown to have negative regulatory effects on T cell activation but is also expressed across various other tissues where its function is yet to be determined. We predict that these mutations are causing immune cell dysregulation, which may be contributing to the patients IBD.

Aims

Through this study, we aim to enhance our understanding of the pathobiological mechanism of novel mutations in DOK4.

Methods

We have established T cell lines, expressing wild type and mutated DOK4, which will be used to perform functional tests, such as localization analysis through immunofluorescence and cytokine profiling, to check for T cell function. We have patient derived organoids, which will be used to assess changes in gut morphology using imaging techniques. We will also generate mutant zebrafish model that will be used to determine the susceptibility to colitis related to this mutation, disease progression and gut peristalsis using live imaging technology.

Results

Preliminary data shows variation in expression of the protein within patient derived peripheral blood mononuclear cells (PBMCs) compared to a healthy donor.

Conclusions

With this study, we hope to identify new therapeutic targets for patients with DOK4 mutations.

Funding Agencies

CIHRThe Leona M. and Harry B. Helmsley Charitable Trust
A255 EMPHYSEMATOUS CYSTITIS: A MARKER OF SEVERE CROHN’S DISEASE?
Authors: Hasan S , Salh B
Published: February 2020

Background

Emphysematous cystitis (EC) is characterized by the presence of air within the bladder walls, a complication of infection by gas producing organisms within the urinary system. However, rare cases of EC in the setting of infectious gastroenteritis have been reported suggesting an alternate etiology. We report a case of EC in the setting of severe Crohn’s colitis with no clinical evidence of urinary tract infection.

Aims

This report outlines the rare case of a patient with active Crohn’s disease who presented with bloody diarrhea, anemia, hypoalbuminemia and initial radiological evidence of EC. We expand on the subsequent clinical investigations, diagnosis, treatment plan and hospital course of the patient.

Methods

Case report, review of literature.

Results

A 43-year old female presented with a 2-month history of bloody diarrhea consisting of 8–12 bowel movements a day, 10 kg of weight loss and peripheral edema. She also had multiple ulcerated lesions on her abdominal wall and in the perianal region. Initial CT scan was significant for pancolitis, anasarca and EC. The follow-up CT cystogram, flexible cystoscopy and pelvic MRI confirmed the diagnosis of EC and ruled out any fistulous tracts in the pelvis including enterovesical/colovesical fistula. The patient did not report any urinary symptoms and the urinalysis was within normal limits. Infectious workup including urine and blood cultures, stool ova and parasite, stool C. difficile PCR, TB IGRA, Hep A, Hep B, Hep C and HIV serologies were all negative. Despite the paucity of infectious findings, the EC was empirically treated with an intravenous third-generation cephalosporin. Colonoscopy was significant for multiple ulcerated and hyperemic areas with pseudopolyps all throughout the right, transverse and left colon. Biopsies confirmed Crohn’s colitis with no evidence of granulomata or dysplasia, and were also negative for CMV immunohistochemistry. The perianal and abdominal wall lesions were suspected to be pyoderma gangrenosum although biopsies were equivocal. The colitis was initially treated with intravenous steroids followed by biologic therapy with Infliximab. While there was some interval improvement of symptoms, the in-hospital course was further complicated by a rectal bleed requiring surgical obliteration of the rectal artery, then a colonic perforation requiring total colectomy.

Conclusions

This is a rare case of EC in a patient with severe Crohn’s colitis. There was no clinical evidence of urinary tract infection or fistulising disease. According to our review, this is the first reported incident of EC in a patient with inflammatory bowel disease without any prior intra-abdominal surgeries. While active Crohn’s disease alone is a critical illness, we conclude that concomitant EC is a poor prognostic factor.

Funding Agencies

None
A261 MICROBIOTA PROFILES OF PATIENTS WITH MENTAL DISODERS DIFFER FROM THOSE OF HEALTHY CONTROLS
Authors: Rabbia V , De Palma G , Lu J , Verdu E , Collins S M , Anglin R , Surette M , Bercik P
Published: February 2020

Background

Mental disorders are the leading cause of disabilities worldwide, with depression and anxiety among the most common ones, affecting up to 1/3 of the worldwide population at least once in their lifetime. In both preclinical models and clinical studies, gut microbiota has been associated with altered behavior and anxiety or depression, respectively.

Aims

To investigate 1) whether the microbial profiles of patients with generalized anxiety disorder (GAD) and major depression disorder (MDD) differ from those of healthy controls (HC), and 2) whether specific bacterial taxa associate with GAD or MDD.

Methods

118 patients with primary GAD (n=82, 83.3 % female) or MDD (n=36, 62.9 % female) and 99 matched HC (66.6 % female) were recruited through the Anxiety Treatment and Research Centre. Anxiety, depression and stress levels were assessed by DASS-21 questionnaire. Stool samples were collected anaerobically and analysed for 16S rRNA gene sequencing through Illumina technique. The data was divided in 4 groups: 1) mental health disorder (MHD) combining GAD and MDD, 2) GAD, 3) MDD, and 4) HC. The data was analyzed following the pipelines of dada2 and QIIME2. RandomForest plugin for QIIME2 was used to investigate predictive characteristics of MHD, GAD or MDD microbiota. SPSS software v.23 was used to perform Spearman correlations and logistic regressions between microbial taxa and clinical scores.

Results

The mean anxiety score was 16.2 (severe anxiety) for GAD patients and 9.8 (moderate anxiety) for MDD patients; the mean depression score was 19.2 (moderate depression) for MDD patients and 16.0 (moderate depression) for GAD patients, while healthy controls averaged only 1.5 (normal anxiety) and 1.7 (normal depression) for anxiety and depression, respectively. The microbiota profile of the MHD group was predictive of the patients’ disease state with an 83.3% accuracy. In particular, increased relative abundance of Bacteroides ovatus and Bacteroides spp. and decreased relative abundance of Dialister spp. (Veilonellaceae), Haemophilus parainfluenzae and Bifidobacterium adolescentis, were predictive of MHD. Neither the GAD or MDD group microbiota profiles alone were accurate in the prediction of the patients’ disease state. There was a positive correlation between the relative abundance of Bacteroides spp. and a negative correlation between the relative abundance of Clostridium sensu stricto spp. and Sutterella, and the clinical scores of combined MDH and HC groups.

Conclusions

Our data suggest that patients with mental health disorders have different microbiota profiles compared to healthy controls. We have identified specific bacterial signatures that will inform mechanistic studies in gnotobiotic mouse models to investigate further the role of microbiome in mental disorders.

Funding Agencies

NIH
A266 IS A MULTIVITAMIN SUFFICIENT TO MEET NUTRITIOAL REQUIREMENTS IN CANADIAN ADULTS FOLLOWING A GLUTEN-FREE DIET?
Authors: Chibbar R , Weiten D , Green K H , Rigaux L , Bernstein C N , Graff L A , Duerksen D , Silvester J
Published: February 2020

Background

Concerns exist regarding nutritional deficiencies and risk of metabolic syndrome in patients with celiac disease (CD) on a gluten-free diet (GFD).

Aims

This study assessed if patients with CD trying to follow a GFD meet Recommended Dietary Allowance (RDA) targets for macro- and micronutrients and the effect of supplement use in reaching RDA targets.

Methods

Adults (>16 years) with biopsy confirmed CD (Marsh 3) were recruited within 6 weeks of starting a GFD. Participants prospectively completed a 3-day food record, including dietary supplement use, at 6, 12, and 24 months after study entry. Macro- and micronutrient consumption was determined using the Nutrition Coordinating Center Food & Nutrient Database (NCCDB), USDA National Nutrient Database for Standard Reference (USDA SR28), and CRON-O-Meter Community Database (CCDB). RDA targets were analyzed using a paired t-test and logistic regression, adjusted for age and sex.

Results

Forty-nine participants (71% female; mean age 49 years) completed interpretable food records at all time points. Most (59%) used supplements and supplement use was highest at 6 months (51%). Considering macronutrients, ≥88% met the RDA for carbohydrates and protein at each time point; however, only 44% met the target for fibre. Participants who took a supplement plus a multivitamin were significantly more likely than those who took only a multivitamin to meet the RDA for vitamins B12 and D. Fewer than 20% of those who took neither a multivitamin nor an iron supplement met the RDA, whereas ≥70% of those taking a multivitamin had adequate iron intake. Participants were significantly more likely to meet RDA targets for calcium with a supplement than with a multivitamin only. Even with supplementation, ≤55% met the RDA for folate.

Conclusions

There is a need for ongoing monitoring and dietician support for GFD treatment in CD. Adults with celiac disease met RDA targets for protein and carbohydrate, but not fibre. While specific calcium supplementation was required to meet RDA targets for calcium, a multivitamin was generally sufficient to meet RDA targets for iron, Vitamin B12 and D. Folate was below target at all time points even with supplementation.

Funding Agencies

CAG, CIHRNIH
A267 ROLE OF INTESTINAL EPITHELIAL NUCLEAR RECEPTOR HNF4A DURING METABOLIC DISORDERS
Authors: Tremblay S , Girard R , Noll C , Carpentier A , Boudreau F
Published: February 2020

Background

HNF4α belongs to the hormone nuclear receptor family and is expressed in liver, intestinal epithelium and pancreas where it regulates genes involved in the control of metabolism. Inactivating mutations in the HNF4A gene cause several forms of maturity-onset diabetes of the young (MODY). However, the specific deletion of Hnf4a in mouse pancreatic beta cells does not lead to diabetes, suggesting the contribution of other tissues, such as the intestine, are necessary for the progression of the disease.

Aims

Our main hypothesis was that intestinal epithelial HNF4α regulates gene products that act through a paracrine mode of communication in the context of glucose metabolism. The aims of this study were to investigate the impact of deleting Hnf4a in the mouse intestinal epithelium during glucose homeostasis and to identify molecular mechanisms involved during glucose-induced obesity resistance.

Methods

The Villin-Cre recombinase transgenic mouse model was used to conditionally delete Hnf4a in the intestinal epithelium (Hnf4adeltaIEC). Hnf4adeltaIEC mice were put on a high sugar diet for 8 to 12 weeks, using a 30% sucrose supplemented ab lithium water. Blood glucose values in controls and mutants were measured from whole venous blood from fasted mice or during glucose and insulin tolerance tests. Mouse serum hormone levels (Ghrelin, Fibroblast-growth factor-15 (Fgf15), Insulin, Cholecystokinin (CCK), etc.) were measured using mouse ELISA kits. The Promethion High-Definition Room Calorimetry System was used for indirect calorimetry and metabolic studies.

Results

Both male and female Hnf4adeltaIEC mice displayed a metabolic resistance to develop obesity under sucrose supplementation when compared to control mice. While male mutant mice showed a resistance to obesity after only 2 weeks of treatment, female mutant mice took at least 6 weeks to display some resistance. The gut hormones ghrelin and Fgf15 were also found modified in fasted mutant mice. Female mutant mice presented a significant increase of 1.8 fold in circulating Fgf15 and an increase of 1.4 fold in circulating ghrelin. Similar changes were observed in male mutant mice. However, only male mutant mice presented an insulin resistance and an oral glucose tolerance after between 6 and 8 weeks. Brown adipose tissue (BAT) whitening was observed after 8 weeks of sucrose treatment in control obese animals, a condition that was prevented in Hnf4adeltaIEC mice.

Conclusions

The identification of paracrine intestinal targets for HNF4α in association with glucose metabolism will provide a better understanding of the molecular nature of tissues crosstalk in energy balance and in metabolism disorders including diabetes and obesity.

Funding Agencies

CIHR
A269 EUS-GUIDED ROSE FNA AND CNB FOR THE DIAGNOSIS OF PANCREATIC CANCER: A COMPARATIVE ANALYSIS
Authors: Almudaires A , Williams G , Gruchy S E , Morgenthau A
Published: February 2020

Background

Endoscopic ultrasound-guided fine-needle aspiration with Rapid On Site Evaluation (ROSE EUS-FNA) and endoscopic ultrasound-guided core-needle biopsy (EUS-CNB) are widely used for the diagnosis of pancreatic tumors. There is no known published randomized control trial that compares between the two modalities. Given the aggressive nature of pancreatic cancer, it is crucial to make a prompt diagnosis in order to initiate treatment in a timely fashion.

Aims

This study compares the diagnostic performance of ROSE EUS-FNA and EUS-CNB for diagnosis of pancreatic cancer.

Methods

A retrospective review was performed for patients who underwent ROSE EUS-FNA and/ or EUS-CNB for solid pancreatic lesion. Diagnostic yield (defined as percentage of diagnostic samples), diagnostic accuracy (defined as percentage of correct diagnosis), sensitivity and specificity for malignancy were compared between ROSE EUS- FNA and EUS- CNB. Baseline characteristics for both patients and lesions were also obtained.

Results

A total of 82 patients with solid pancreatic lesions were reviewed. 84 EUS with 61 FNA and 74 CNB were performed. The diagnostic yield was 42/61 (69%) and 59/74 (79.7%) for FNA and CNB respectively (P 0.166). The diagnostic accuracy was 33/61 (54%) and 53/74 (71%) for FNA and CNB respectively (P 0.0326).

50 patients underwent both FNA and CNB during the same EUS. The calculated diagnostic yield among this subgroup was 33/50 (66%) and 39/50 (78%) for FNA and CNB respectively (P 0.265); with diagnostic accuracy of 26/50 (52%) for FNA and 34/50 (68%) for CNB (P 0.152). The diagnostic accuracy after combining both techniques was 40/50 (80%).

The incremental increase in diagnostic yield by combining both methods was 12/50 (24%) and 6/50 (12%) relative to FNA and CNB respectively.

The sensitivity for the diagnosis of malignancy for FNA and CNB was 60.8% and 92.7%, respectively. The specificity was 100% for both methods.

Conclusions

EUS-guided CNB is a superior method of assessing solid pancreatic lesion and pancreatic malignancy with better diagnostic yield and accuracy and higher sensitivity than ROSE EUS-FNA.

Funding Agencies

None
A272 THE CANADIAN DIRECT OBSERVATION OF PROCEDURAL SKILLS (CANDOPS) TOOL FOR ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY: A MULTI-CENTRE PROSPECTIVE STUDY
Authors: Khan U , Barkun A N , Benchimol E I , Salim M , Telford J J , Enns R A , Mohamed R , Forbes N , Sandha G S , Mosko J , May G , Kortan P , Chatterjee A , James P
Published: February 2020

Background

Previous studies have demonstrated that many graduating trainees may not have all of the skills needed to independently practice endoscopic retrograde cholangiopancreatography (ERCP) safely and effectively. As a part of competency-based learning curriculum development, it is essential to provide formative feedback to trainees and ensure they acquire the knowledge and skills for independent practice.

Aims

To assess the performance of advanced endoscopy trainees across Canada using the Canadian Direct Observation of Procedural Skills (CanDOPS) ERCP assessment tool. Procedural items evaluated include both technical (cannulation, sphincterotomy, stone extraction, tissue sampling, and stent placement) and non-technical (leadership, communication and teamwork, judgment and decision making) skills.

Methods

We conducted a prospective national multi-centre prospective study. Advanced endoscopy trainees with at least two years of gastroenterology training or five years of general surgery in North America and minimal experience performing ERCPs (less than 100 ERCP procedures) were invited to participate. The CanDOPS tool was used to measure every fifth ERCP performed by trainees over a 12-month fellowship training period. ERCPs were evaluated by experienced staff endoscopists at each study site under standard clinical protocol. Cumulative sum (CUSUM) analyses were used to generate learning curves.

Results

The data from five Canadian sites and 11 trainees participated in the study. A total of 261ERCP evaluations were completed. Median number of evaluations by site and trainee was 49 (IQR 31–76) and 15 (IQR 11–45). Median number of cases trainees performed prior to their ERCP training was 50 (IQR 25–400). There was a significant improvement in almost all scores over time, including selective cannulation, sphincterotomy, biliary stenting and all non-technical skills (P<0.01). CUSUM analyses using acceptable and unacceptable failure rates of 20% and 50% demonstrated trainees achieved competency for most measures in their final month of their training. Competency in tissue sampling was not achieved within a one-year training period.

Conclusions

This is the first ERCP performance evaluation tool that examines multiple technical and non-technical aspects of the procedure. Although trainee ERCP skills do improve during their training period, there exists a notable variability in time to competency for the different skills measured using the CanDOPS tool. Large prospective research is required to determine if competency is achieved using more stringent definitions of ERCP competency and to determine factors associated with reaching competency.

Funding Agencies

None